TREATMENT DETERMINANTS OF THE GINGIVAL SMILE

Jessica H. Cox, D.D.S.

An Abstract Presented to the Faculty of the Graduate School

of Saint Louis University in Partial Fulfillment

of the Requirements for the Degree of

Master of Science in Dentistry

2010

1

ABSTRACT

Objective: The purpose of this study is to determine

which dental, skeletal, and soft tissue characteristics

affect lip height and which characteristics affect lip

height changes during treatment. Materials and Methods:

Models for 200 randomly selected subjects were obtained and

used to calibrate the smiling photographs of each subject.

The photographs were then measured to determine the change

in gingival display that occurred during treatment. The

change in gingival display was used to create three groups:

those that obtained the greatest increase, greatest

decrease, and average change in gingival display. The

cephalometric radiographs were then traced for each subject

and digitized. The pre and post treatment cephalometric

radiographs of each subject were superimposed and a total

of 54 linear measures were made at each time point. The

measures were then compared using t-tests for intra-group

changes from T1 to T2 and an Analysis of Variance (ANOVA)

for inter-group comparisons at each time point.

Results: There were no significant differences between the

groups at the pretreatment time point. Paired t tests

revealed significant differences in 25 of the 27 vertical

measures within all groups from the pre treatment to post-

2

treatment time points. The horizontal measures indicated

more significant differences in the backward direction in

the greatest increase group than the other two groups. The

significant vertical difference between the groups at the

post-treatment time point was found between the average

change group and the greatest increase group at condylion.

The significant horizontal differences between the groups

were found between the greatest increase and greatest

decrease groups at the soft tissue lips. The lips moved

significantly backward in the greatest increase group while

they stayed relatively the same in the greatest decrease

group.

Conclusions: No pretreatment characteristic could be

identified to predict the tendency to experience an

increase or decrease in gingival display during orthodontic

treatment. The lips moved significantly backward in the

group that experienced an increase in gingival display

while they stayed relatively the same in the group that

experienced a decrease. Although not significant, other

general tendencies were apparent between the two extreme

groups. Further research is warranted.

TREATMENT DETERMINANTS OF THE GINGIVAL SMILE

Jessica H. Cox, D.D.S.

A Thesis Presented to the Faculty of the Graduate School

of Saint Louis University in Partial Fulfillment

of the Requirements for the Degree of

Master of Science in Dentistry

2010

i

COMMITTEE IN CHARGE OF CANDIDACY:

Professor Rolf G. Behrents,

Chairperson and Advisor

Professor Eustaquio Araujo

Assistant Professor Ki Boem Kim

ii

DEDICATION

To my loving husband, Wynne, who has made many

sacrifices to support me in my academic endeavors and whose

constant encouragement has enabled me to work through even

the most stressful times.

To my parents, who have encouraged me to strive for

excellence and have convinced me that, with work, I can

achieve any goal. Everything I have accomplished is due to

the confidence they have instilled and the encouragement

they continue to show.

To my family and friends, who have loved and supported

me throughout my education.

iii

ACKNOWLEDGEMENTS

! I would like to thank Dr. Behrents for giving me the

opportunity to continue my education in the specialty of

orthodontics and for his constant guidance and

encouragement during the past two and a half years.

I would like to thank Dr. Araujo for his encouragement

and guidance.

I would like to thank Dr. Kim for his support and

friendship.

Thanks to Dr. Heidi Israel for her assistance with the

statistical analysis.

!

!

iv

TABLE OF CONTENTS

List of Tables…………………………………………………………………………………………………………………vi

List of Figures…………………………………………………………………………………………………………………x

CHAPTER 1: INTRODUCTION…………………………………………………………………………………………1

CHAPTER 2: REVIEW OF THE LITERATURE…………………………………………………………4

Ideal Smile Esthetics…………………………………………………………………4

Definition of a Gummy Smile…………………………………………………5

Causes of a Gummy Smile Pre-Treatment………………………8

Sex Predilection………………………………………………………………………8

Musculature and Lip Incompetence……………………………8

Lip Length……………………………………………………………………………………10

Altered Passive Eruption………………………………………………10

Skeletal Disharmonies………………………………………………………13

Possible Causes of Gummy Smile Development

During Orthodontic Treatment……………………………………………18

Unexpressed Vertical Growth………………………………………18

Extrusive Forces……………………………………………………………………20

Anterior-Posterior Position of the Maxilla21

Treatments For Gingival Smiles………………………………………23

Treatments For Gingival Smiles Caused by

Altered Passive Eruption………………………………………………23

Treatments For Gingival Smiles Caused by

Incorrect Dental and Skeletal

Relationships……………………………………………………………………………25

Orthodontic Intrusion…………………………………………25

Implant Intrusion……………………………………………………26

Orthognathic Surgery……………………………………………28

v

Treatments For Gingival Smiles Caused by

Hyperfunction of the Lip Elevators……………………29

Muscle Resection………………………………………………………30

Botulinum Toxin…………………………………………………………31

Anterior Nasal Spine Implants……………………34

Summary and Statement of Thesis……………………………35

References……………………………………………………………………………………37

CHAPTER 3: JOURNAL ARTICLE

Abstract……………………………………………………………………………………………………………………41

Introduction…………………………………………………………………………………………………………43

Materials and Methods…………………………………………………………………………………46

Sample……………………………………………………………………………………………………………46

Sample Selection…………………………………………………………………………………46

Data Collection……………………………………………………………………………………51

Data Analysis…………………………………………………………………………………………57

Analysis of Error………………………………………………………………………………57

Results………………………………………………………………………………………………………………………58

Discussion………………………………………………………………………………………………………………77

Design……………………………………………………………………………………………………………77

Findings………………………………………………………………………………………………………78

Conclusions……………………………………………………………………………………………………………94

Appendix A………………………………………………………………………………………………………………96

Appendix B……………………………………………………………………………………………………………110

Literature Cited……………………………………………………………………………………………123

Vita Auctoris…………………………………………………………………………………………………………………124

vi

LIST OF TABLES

Table 3.1: Descriptive Statistics for the Change in

Gingival Display for the 200 subjects……………………49

Table 3.2: Description of Sample Groups……………………………………………50

Table 3.3: Landmark abbreviations and descriptions………………51

Table 3.4: Group 1 Pre-Treatment Vs. Post-Treatment

Landmark Measures…………………………………………………………………………61

Table 3.5: Group 2 Pre-Treatment Vs. Post-Treatment

Landmark Measures…………………………………………………………………………63

Table 3.6: Group 3 Pre-Treatment Vs. Post-Treatment

Landmark Measures…………………………………………………………………………65

Table 3.7: Descriptive Statistics for Significant

Horizontal Soft Tissue Landmarks at the Post-

Treatment Time Point…………………………………………………………………67

Table 3.8: ANOVA for Significant Horizontal Soft Tissue

Landmarks at the Post Treatment Time Point………67

Table 3.9: Tukey Post Hoc Multiple Comparisons Of

Significant Horizontal Soft Tissue Landmarks

at the Post Treatment Time Point…………………………………68

Table 3.10: Descriptive Statistics for the Significant

Vertical Landmark at the Post Treatment Time

Point…………………………………………………………………………………………………………69

Table 3.11: ANOVA for the Significant Vertical Measure at

the Post Treatment Time Point…………………………………………69

Table 3.12: Tukey’s Post Hoc Multiple Comparisons of the

Significant Vertical Landmark at the Post

Treatment Time Point…………………………………………………………………69

Table 3.13: Comparison of Mandibular Horizontal Measures

at T1 and T2…………………………………………………………………………………70

Table 3.14: Table 3.13 Comparison of Mandibular Vertical

Measures at T1 and T2………………………………………………………………71

vii

Table 3.15: Comparison of the Horizontal Maxillary

Landmarks at T1 and T2……………………………………………………………72

Table 3.16: Comparison of Vertical Maxillary Landmarks at

T1 and T2………………………………………………………………………………………………72

Table 3.17: Comparison of Horizontal Soft Tissue Landmarks

at T1 and T2………………………………………………………………………………………73

Table 3.18: Comparison of Vertical Soft Tissue Landmarks

at T1 and T2………………………………………………………………………………………74

Table 3.19: Comparison of Horizontal Dental Landmarks at

T1 and T2………………………………………………………………………………………………75

Table 3.20: Comparison of Vertical Dental Landmarks at T1

and T2………………………………………………………………………………………………………76

Table 3.21: Group Gender Percentages………………………………………………………88

Table 3.22: Mean Lip Length at T1………………………………………………………………89

Table 3.23: Mean Lip Length at T2………………………………………………………………89

Table 3.24: Change in Mean Lip Length from T1 to T2………………89

Table 3.25: Group Molar Classification…………………………………………………90

Table 3.26: Molar Classification Percentages…………………………………91

Table 3.27: Group Percentages of Class IIs………………………………………91

Table 3.28: Class II Division Percentages…………………………………………92

Table A.1: Pre-Treatment Horizontal Mandibular Measures

Descriptive Statistics……………………………………………………………96

Table A.2: ANOVA for Pre-Treatment Horizontal Mandibular

Measures……………………………………………………………………………………………………97

Table A.3: Pre-Treatment Vertical Mandibular Measures:

Descriptive Statistics………………………………………………………………98

Table A.4: ANOVA for Pre-Treatment Vertical Mandibular

Measures……………………………………………………………………………………………………99

viii

Table A.5: Pretreatment Horizontal Maxillary Measures:

Descriptive Statistics……………………………………………………………100

Table A.6: ANOVA for Pretreatment Horizontal Maxillary

Measures…………………………………………………………………………………………………100

Table A.7: Pretreatment Vertical Maxillary Measures:

Descriptive Statistics……………………………………………………………101

Table A.8: ANOVA for Pretreatment Vertical Maxillary

Measures…………………………………………………………………………………………………101

Table A.9: Pretreatment Horizontal Dental Measures:

Descriptive Statistics……………………………………………………………102

Table A.10: ANOVA for Pre-Treatment Horizontal Dental

Measures………………………………………………………………………………………………103

Table A.11: Pretreatment Vertical Dental Measures:

Descriptive Statistics…………………………………………………………104

Table A.12: ANOVA for Pretreatment Vertical Dental

Measures………………………………………………………………………………………………105

Table A.13: Pretreatment Measures for Non-significant

Horizontal Soft Tissue Landmarks:

Descriptive Statistics…………………………………………………………106

Table A.14: ANOVA for Non-significant Pretreatment

Horizontal Measures…………………………………………………………………107

Table A.15: Pretreatment Vertical Measures for Soft Tissue

Landmarks: Descriptive Statistics…………………………108

Table A.16: ANOVA for Pretreatment Vertical for Soft Tissue

Landmarks……………………………………………………………………………………………109

Table B.1: Post-Treatment Non-Significant Horizontal

Mandibular Measures: Descriptive Statistics.110

Table B.2: ANOVA for Post-Treatment Mandibular Horizontal

Measures………………………………………………………………………………………………111

Table B.3: Post-Treatment Non-Significant Vertical

Mandibular Measures: Descriptive Statistics…112

ix

Table B.4: ANOVA for Non-Significant Post-Treatment

Vertical Mandibular Measures……………………………………………113

Table B.5: Post-Treatment Horizontal Maxillary Measures:

Descriptive Statistics……………………………………………………………114

Table B.6: ANOVA for Post-Treatment Horizontal Maxillary

Measures…………………………………………………………………………………………………114

Table B.7: Post Treatment Vertical Maxillary Measures:

Descriptive Statistics……………………………………………………………115

Table B.8: ANOVA for Post-Treatment Vertical Maxillary

Measures…………………………………………………………………………………………………115

Table B.9: Non-Significant Post-Treatment Horizontal Soft

Tissue Measures………………………………………………………………………………116

Table B.10: ANOVA for Non-Significant Post Treatment

Horizontal Soft Tissue Measures…………………………………116

Table B.11: Post-Treatment Vertical Soft Tissue Measures:

Descriptive Statistics…………………………………………………………117

Table B.12: ANOVA for Post-treatment Vertical Measures for

Soft Tissue Landmarks……………………………………………………………118

Table B.13: Post-treatment Horizontal Dental Measures:

Descriptive Statistics…………………………………………………………119

Table B.14: ANOVA for Post-Treatment Horizontal Dental

Measures………………………………………………………………………………………………120

Table B.15: Post-Treatment Vertical Dental Measures:

Descriptive Statistics…………………………………………………………121

Table B.16: ANOVA for Post-Treatment Vertical Dental

Measures………………………………………………………………………………………………122

x

LIST OF FIGURES

Figure 3.1: Calculation of Gingival Display…………………………………47

Figure 3.2: Description of Measures of Gingival Display…48

Figure 3.3: Cephalometric Landmarks………………………………………………………53

Figure 3.4: Reference Planes…………………………………………………………………………55

Figure 3.5: Examples of Vertical and Horizontal Measures

from the Reference Planes…………………………………………………56

Figure 3.6: Graphical Representation of Changes from T1

to T2 for Group 1………………………………………………………………………81

Figure 3.7: Graphical Representation of Changes from T1

to T2 for Group 2…………………………………………………………………………82

Figure 3.8: Graphical Representation of Changes from T1

to T2 for Group 3…………………………………………………………………………83

1

CHAPTER 1: INTRODUCTION

!

!

As society becomes more esthetically conscious,

orthodontists are more challenged to produce not only

outstanding occlusions, but also outstanding esthetics.

Every minute detail is becoming more important in

separating the good from the great orthodontist. Recent

studies have indicated that the amount of gingival display

on smiling is very important to smile attractiveness.1 In

fact, Van der Geld et al. found that the amount of gingival

display was an important characteristic in a person’s own

satisfaction with their smile.2

When an excessive amount of gingiva is displayed upon

smiling, the term “gummy” is often used. While many

clinicians anecdotally point to the “lack of vertical

control” as the cause of orthodontically produced

“gumminess,” few studies that investigate the cause of post

treatment gummy smiles are present in the literature. Peck

et. al in 1992 found that the tendency of a person to

project a gummy smile was related to anterior vertical

maxillary excess, the muscular ability to raise the upper

lip higher than average when smiling, greater overjet,

greater interlabial gap at rest, and greater overbite.3 In

his study to determine the effectiveness of improving

2

patient smiles with orthodontic treatment and the

variability of improvement from orthodontist to

orthodontist, Mackley found that the orthodontist who was

most successful in producing greater post treatment smile

improvement scores decreased the stomion-incision

measurement while those that increased the stomion-incision

measure produced smiles with lower post treatment

improvement scores. He states, “This measurement is an

indication of the amount of gingival tissue that shows when

a person is smiling.” He also suggested that the most

successful orthodontist also increased the inclination of

the maxillary incisor to the NA line, while those that

produced less improvement decreased this measure. He

concludes that in order to “maximize our potential for

improving the smile, we must include in our treatment plan

an objective for moving the anterior teeth vertically to

improve their relationship to the smiling lip line.”4

While both of these studies indicate possible reasons

for an increase in gingival display, neither indicates any

pre-treatment skeletal or dental factors that might help a

clinician to predict the tendency to develop this

“gumminess” nor investigates post-treatment skeletal

factors that might be associated with this negative

condition. The purpose of this study is to determine which

3

dental, skeletal, and soft tissue characteristics effect

smiling lip height and which characteristics affect lip

height changes during treatment.

4

CHAPTER 2: REVIEW OF THE LITERATURE

Ideal Smile Esthetics

According to Hulsey, “A smile is one of the most

effective means by which people convey their emotions.”5

People with dental deformities often make every effort to

cover the displeasing portion with their lips. They rarely

smile or laugh, and thus might be viewed by others as

unfriendly.6 This might not only affect a person in their

personal life, but also professionally. According to Dale

Carnegie, one of the most important ways to win friends and

influence people is to smile.7 In fact, according to Van der

Geld et. al., studies have shown that higher intellectual

and social abilities have been attributed to individuals

with esthetic smiles.2 This is the reason that millions of

people seek orthodontic treatment each year, to produce a

smile they are pleased to view themselves and show to

others. As society becomes more esthetically conscious,

orthodontists are challenged to produce not only

outstanding occlusions, but also outstanding esthetics.

Every minute detail is becoming more important in

separating the good from the great treatment. However, in

order to create the best possible esthetics, orthodontists

must understand what the public at large views as beauty.

As Peck, Peck, and Kataja suggest, “We orthodontists tend

5

to forget that facial esthetics is a subject that interests

all people everywhere, and the ultimate source of esthetic

values should be the people and not just ourselves.”3 Within

recent years, many researchers have directed their studies

towards addressing this very question.

In their study to determine the average desirable

characteristics of an esthetic smile, Tjan et al. found

that the average esthetic smile has the following

characteristics: the full length of the maxillary anterior

teeth are displayed, the gingiva does not show, the incisal

curvature of the maxillary anterior teeth parallels the

inner curvature of the lower lip, the incisal curvature

either touches or almost touches the lower lip, the six

maxillary anterior teeth and the first or second premolars

are displayed, and the midline coincides with the philthrum

of the lip.8 Many other studies have confirmed these

findings.1,4,7

Definition of a Gummy Smile

Studies aimed at determining the characteristics of an

“ideal smile” have all stressed the importance of the

vertical placement of the maxillary incisors in relation to

both the upper and lower lips in the production of the most

esthetic smile. Van der Geld et al., found that the size of

the teeth, visibility of the teeth, and upper lip position

6

are critical factors in self perception of smile

attractiveness, as well as the color of the teeth and

gingival display. In their study, participants with 2 to 4

mm of gingival display were judged most favorable,2 however

the literature suggests varying threshold levels of

gingival display are tolerated before the amount of

gingival display negatively affects the perceived esthetics

of a smile.9 Kokich et al., first reported that 4.0

millimeters (mm) of gingival display represents the

threshold of acceptability, but more recently, using

smaller increments of measure, found 3 mm of gingival

display are considered unaesthetic by lay people.10 Chiche

and Pinault found that up to 3 mm of gingival tissue may be

displayed before esthetics is compromised.11 Geron and

Atalia found that gingival exposure is considered an

unaesthetic feature above 1 mm in the maxilla,12 and Hunt et

al. found the acceptable range for gingival exposure to lie

between 0 and 2 mm with an ideal of no gingival exposure.13

Ker et al. reported that while laypersons preferred 2.1 mm

of incisor coverage, +- 4 mm was within the range of

acceptiblity.1 In his study to determine whether the smiles

of orthodontically treated patients are as esthetically

pleasing as those of persons with “normal” occlusion,

7

Hulsey noted that the most attractive smiles were those in

which the upper lip rested at the height of the gingival

margin of the maxillary incisor.5 Perhaps the variation in

preference for the amount of gingival display is due in

part to a variation in the preference of gingival display

between male and female subjects. In their study, Gul-e-

Erum found the ideal gingival display to be 0 mm for males

and 2 mm for females.14

While the acceptable range of gingival exposure has been

debated, it is apparent that an excess of 4 mm of gingival

display on smiling is considered unaesthetic, and the

majority of the literature supports 0-1 mm of gingival

exposure as the ideal. For this reason, orthodontists

should pay special attention to the vertical placement of

the maxillary anterior teeth during treatment planning and

treatment. As Mackley asserts, “If we are going to maximize

our potential for improvement of the smile, we must include

in our treatment plan an objective that will improve the

relationship of maxillary incisors to the smiling lip line.

To do less than this is to do our patients a disservice.”4

When an excess of gingiva superior to the maxillary

anterior teeth is displayed upon full smile, it is termed a

gingival smile.3 The gingival smile is known by a variety of

terms including “gummy smile, high lip line, short upper

8

lip, and full denture smile.”3 Perhaps this variety in terms

is indicative of the many different causes of a gummy

smile.

Causes of a Gummy Smile Pre-Treatment

Sex Predilection

The tendency to have a gingival smile, appears to have

a sex predilection. According to a study by Tjan, Miller,

and The, low smile lines are predominantly a male

characteristic by 2.5 to 1, and high smile lines are

predominantly a female characteristic by 2 to 1.8 Peck,

Peck, and Kataja quantified these findings. They found

that at maximum smile, the upper lip line relative to the

gingival margin of the maxillary central incisors is

positioned 1.5 mm more superiorly in females than in

males.15 Similarly, Vig and Brundo found that maxillary

anterior tooth display was found almost twice as often in

women as in men.16 A literature search by Van der Geld and

Van Waas, further supports this assertion, indicating that

on average, the smile line was situated higher among women

than among men.17

Musculature and Lip Incompetence

The musculature can also have an effect. Peck et al,

found that the upper lip in gingival smile subjects

9

elevates superiorly 1 mm more from rest to maximum smile

than did a reference group.3 They also found that the

interlabial gap at rest position was much higher on average

(6.2mm) for the gingival smile line sample, than the

reference sample (3.0 mm).3 This indicates that lip

incompetence can be associated with a gingival smile line.

Upon further investigation, they found that 93% of the

gingival smile line group were lip incompetent at rest,

while only 63% of the reference sample were lip incompetent

at rest. When the likelihood ratio was calculated, it was

determined that the gingival smile line subjects were 5.5

times more likely to exhibit lip incompetence at rest than

the reference population.3 In his descriptive essay,

Matthews proposes that a person exhibiting an interlabial

gap at rest will also have a gingival smile line,6 however

while Peck et al. found that 93% of his gingival smile line

subjects also exhibited an interlabial gap at rest, he also

found that the opposite was not true. Only 56% of their

subjects with interlabial gaps at rest presented a gingival

smile line. Therefore, while Peck et al.’s study supports

the assertion that an interlabial gap at rest is highly

associated with the tendency to have a gingival smile line,

it also indicates that an interlabial gap at rest cannot be

considered predictive of the gingival smile phenomenon.3

10

Interestingly, Schendel et al. cite a large

interlabial distance as a common characteristic of vertical

maxillary excess, and these VME subjects also displayed an

excessive amount of the maxillary teeth and gingiva upon

smiling.18 These findings suggest that orthodontic

techniques that cause lip incompetence, might also have a

tendency to cause a gingival smile.

Lip Length

While lip length has been suspect in producing a

gingival smile line, Peck et al. found no difference in

upper lip length between the gingival smile and reference

groups, with both samples having a mean value of 22.3 mm.3

This is consistent with Schendel et al.’s report that

surgical patients with vertical maxillary excess have

normal lip lengths.18 In fact, in a study of 70 gingival

smile females, Singer found that the gingival smile group

actually had a significantly longer lip length than the

non-gingival smile sample.19

Altered Passive Eruption

Short clinical crown heights have also been reported to

increase the tendency to produce a gingival smile. Short

clinical crown heights can be due to altered passive

11

eruption, inflammation, and gingival enlargement. Active

eruption is the movement of the tooth toward the occlusal

plane. Passive eruption is the apical migration of the

gingival margin. Therefore, altered passive eruption, is

the delay in the apical migration of the epithelial

attachment toward the root surface of at the CEJ. According

to Waldrop, altered passive eruption can cause excessive

gingival display.20 Garber and Salama agree stating, “if the

teeth appear to be somewhat short and squat-meaning that

the vertical dimension appears to be too short as compared

with the horizontal dimension, the gummy smile is probably

due to altered passive eruption.”21 However, in Peck’s

study, the clinical crown height of the two groups was not

significantly different.3 As Garber and Salama point out, in

many cases, a gummy smile may be due to a combination of

vertical maxillary excess and altered passive eruption.21

Altered passive eruption can be classified into two

distinct types. In Type I, there is an excessive amount of

gingiva from the free gingival margin to the mucogingival

junction. In Type II, there is a normal amount of gingiva

as measured from the free gingival margin to the

mucogingival junction. Type I is further subdivided into

sub-categories A and B depending on the relationship of the

osseous crest to the cemento-enamel junction of the tooth.

12

In subcategory A, the dimension between the osseous crest

and the CEJ is greater than 1 mm, and therefore adequate

for the insertion of the connective tissue attachment

component of the biologic width. In subcategory B, the

osseous crest is in close proximity to the cementoenamel

junction, therefore adequate space for the connective

tissue attachment component of the biologic width is not

present, and the connective tissue appears to attach at the

same level as the cementoenamel junction. This seems

contrary to the biologic width, as the connective tissue

attachment must be present, yet cannot attach to the

enamel. According to Garber and Salama, clinical and

histological observations suggest that an increased

buccolingual dimension of the osseous form allows for

apical angulation of the bone crest from the gingival

aspect of the periodontal ligament side.21 While periodontal

connective tissue fibers normally run horizontally across

the osseous crest extending from the cementum to the

gingival, in this form of altered passive eruption, the

fibers run apically, parallel to this angular crest,

allowing the connective tissue fibers to insert into the

cementum just apical to the cementoenamel junction.

The biologic width is approximately 2.7 mm in

dimension.19,20

and is made up of 1 mm of junctional

13

epithelium, 1 mm of connective tissue attachment, and 1 mm

of sulcus depth.21 This “biologic width” is necessary for

the health of the periodontium and should not be violated

with restorative procedures. Due to its association with

this biologic parameter, the type and subcategory of

altered passive eruption present will determine the

treatment modality.21

In a study of 1025 patients, Volchansky et al. found

altered passive eruption in 12% of the patients.22 However,

more recently, Konikoff et al. found that 65% of post

orthodontic patients had less than ideal length to width

ratios in their anterior incisors.23 Therefore, after

thorough oral hygiene instruction, scaling and root

planning as needed, and a period of inflammation control,

patients with excessive gingival display should be

evaluated for altered passive eruption and the need for a

periodontal procedure.20

Skeletal Disharmonies

Growth of the maxilla is also related to gingival

smiles. According to Wilmar, the gingival smile line is

often associated with maxillary alveolar overdevelopment or

vertical maxillary excess (VME).24 Peck et al.’s study

supports this. They found that the anterior maxillary

14

height (measured from the palatal plane to the upper

incisor edge) showed a significant difference between the

gingival smile group and the reference group with a

difference of +2.3 mm (p <.001).3 In their study of

individuals with vertical maxillary excess, Schendel et al.

found that all persons in their VME sample, both with open

bite and without, showed excessive exposure of the

maxillary anterior teeth and poor upper lip to tooth

relationships in comparison to the norm.18 According to

Schendel et al., “extreme clockwise rotation, high angle

type, adenoid faces, idiopathic long face, total maxillary

alveolar hyperplasia, and vertical maxillary excess all

have excessive vertical growth of the maxilla as their

common denominator.”18 While many children and adults with

long faces also have vertical maxillary excess, Fields et

al. found that long faced children did not have a

significantly greater anterior dental height than normal

children, and while the adults had a tendency for excessive

eruption of all teeth, it was not statistically

significant.25 However, patients with long faces do have

some characteristic traits, such as increased mandibular

plane angles, increased palatal plane to mandibular plane

angles, increased ANB angles (and thus retrognathia), and

increased lower anterior face heights. Therefore, one

15

might conclude that persons with these characteristics

might also have the tendency for excessive gingival

display, although not to a predictive level. In a study by

McNamara et al, neither the vertical display on smile, nor

the amount of upper lip drape was correlated with the

skeletal vertical dimension,26 therefore it appears that

vertical maxillary excess is only one contributing factor

to a “gummy” smile.

In Schendel et al.’s study, the differences between

long faced, open bite and non open bite subjects were

investigated.18 They found that the open bite group had a

steeper mandibular plane angle, although both the open bite

and non open bite groups’ mandibular plane angles were

significantly greater than the norm. The occlusal plane

angle followed the same trend. The SNA was normal in both

groups, suggesting a normal anteroposterior position of the

maxilla in relation to the cranial base. However the SNB

was significantly decreased in both groups suggesting a

retrodisplacement of the mandible. Due to this

displacement, the ANB angle was also significantly

increased in both groups. Both the posterior height of the

maxilla and the anterior dental height were significantly

greater than normal. The largest vertical distance between

the two groups was the posterior facial height. The open

16

bite group had a normal ramal length while the non open

bite group exhibited a long ramal length.18 This suggests

that there was greater vertical growth of the ascending

ramus in the non open bite group that prevented the

development of an open bite. While Schendel and colleagues

found both groups to exhibit an increased amount of

maxillary display, it seems evident that orthodontic

treatment aimed to close the open bite via anterior

extrusion with or without posterior intrusion, would

exacerbate this problem.

The influence of skeletal disharmonies on the

production of a gingival smile line has been debated in the

literature. Singer cites SN-MP and SN-Pal as having

characteristic values associated with a gingival smile

line,19 however in Peck et al.’s study, the SN-MP and SN-PP

angles were not significantly different between the

gingival smile and reference groups.3 The study by Schendel

et al. would refute this finding, as they described all of

the VME sample to possess both an excess of gingival

display on smiling, and high mandibular plane angle’s as

well as an increased posterior height of the maxilla.18

A study by Fields et al. compared the differences in

long faced children and adults as compared to normal and

short faced children and adults. They found that long

17

faced, short faced, and normal children all have a similar

relationship of the maxilla to the cranial base. The long

and short-faced children had a tendency for a smaller SNB

angles, and therefore more retrognathic profiles than

normal children. The long-faced children had steep

mandibular plane angles while the short-faced children

displayed low mandibular plane angles. Measures of the

total anterior facial height were significantly different

between the groups, however there were no differences

evident in posterior total facial height. The differences

in the anterior facial height were found to lie within the

anterior lower face height, as the measures of the anterior

upper facial height were similar among the groups. Upon

further examination to determine the cause of this

difference, they found no difference in the size of the

ramus, but the gonial angles were significantly larger in

long-faced children and smaller in short-faced children.

Long-faced children had significantly greater posterior

maxillary and mandibular dental heights than normal

children. However, surprisingly there was not a significant

difference in the anterior upper dental height, although

the mean height was larger in the long faced children. As

would be expected, short faced children had significantly

18

less anterior upper and lower dental height than normal

children.25

Similar results were found for the adult groups with a

few important differences. Like the children, all groups

had similar cranial base configurations with well-related

maxillas, the long faced adults tended to be more

retrognathic, and the mandibular plane angles indicated

significant differences. The posterior total facial

heights and the anterior upper face heights were similar

for the groups, and the long faced adults had significantly

increased lower anterior facial heights. Similar to the

children, the long faced adults had normal mandibular body

lengths and increased gonial angles, but unlike the

children they had a tendency toward short rami and

excessive eruption of all teeth.25

Possible Causes of Gummy Smile Development During

Orthodontic Treatment

Unexpressed Vertical Growth

As Fields and colleagues asserts, “it is possible that

ramus differences are not apparent in children, since rapid

skeletal growth, and therefore, significant ramus

lengthening had not yet occurred in the preadolescent

sample.”25 This might indicate a cause for the skeletal

19

tendency to become gummy during the course of orthodontic

treatment. Because orthodontic treatment is often commenced

during early adolescence, the growth that occurs in long

faced individuals during this time (between childhood and

adulthood) appears to convert children with normal ramus

lengths and normal anterior dental heights to adults with

short mandibular ramus lengths and a tendency toward long

anterior dental heights. This decreased amount of growth of

the ramus, appears to affect the mandibular rotation, and

therefore produces a steeper mandibular plane angle.27

Schendel et. al. found short ramus heights in long faced

individuals with open bites, but long ramus heights in long

faced patients without open bites compared to the norm.

Those with short ramus heights and open bites also had much

much higher mandibular plane angles (SN-MP) on average

(48.61 degrees) than the non-open bite, long-faced

individuals with long ramal lengths (39.78 degrees).

However, both long faced groups had much greater mandibular

plane angles than the norm (31.75 degrees).18 This finding

agrees with the finding of Isaacson et al. who found

shorter ramus heights to be characteristic of patients with

steep mandibular plane angles.27

This lengthening in anterior dental heights (or

vertical maxillary excess) that appears to occur as long-

20

faced children grow into adulthood, would likely increase

the gingival display in these patients during growth even

without orthodontic treatment (as previously discussed).

Extrusive Forces

The tendency to develop a gingival smile might be

improved with careful orthodontic manipulation, however it

could easily be exacerbated if not diligently monitored, as

many of the forces used in orthodontic treatment are

extrusive. As Fields et al. points out, “although these

facial patterns are established early, events may occur

during adolescence to magnify or maintain the

differences.”25 Because the full effect of this growth

pattern is not yet evident during childhood, the prudent

orthodontist will recognize this pattern during diagnosis

of young patients, and discuss its tendency to produce

excessive gingival display with the patient and parents.

He/she should also include in his/her treatment steps to

control and not exacerbate this tendency.

In Isaacson et al.’s study of the extreme variations

in vertical facial growth, they state that the vertical

growth of the anterior face must be equal in size and

timing of the growth increases in the posterior face, or

the mandible will rotate at its articulation.27 According

21

to Isaacson et al., “if the vertical increases at the

facial sutures and/or the alveolar process should exceed

the vertical increases at the mandibular condyle, the

mandible would rotate backward. Conversely, if vertical

growth at the condyle should exceed the sum of the vertical

growth components at the facial sutures and alveolar

processes, the mandible would rotate forward.”27 According

to this study, if extrusive orthodontic forces cause

vertical growth of the alveolus faster than the condyle is

growing vertically, then the mandible could rotate backward

even in a patient without previous vertical growth.

Anterior-Posterior Position of the Maxilla

In their study, Isaacson et al. also found that as

the mandibular plane angle (SN-MP)decreased, the mean

values for SNA and SNB increased.27 The mean ANB angle

remained relatively constant. The measurements of linear

distance from a perpendicular to SN to the maxillary first

molar indicated that not only the skeletal components

increased in the horizontal dimension as the mandibular

plane angle decreased, but the dental components also

became more anteriorly situated.27 Therefore, Isaacson

concluded that the horizontal position of the maxilla

effects the mandibular plane angle. For this reason, a

22

person with a forward positioned maxilla and some vertical

maxillary excess could have a low mandibular plane angle,

and therefore, unless specifically measured, the maxillary

excess could perhaps be unapparent upon initial

examination. Persons presenting with a forward positioned

maxilla whether high or low angle, often have a Class II

skeletal and dental pattern. Orthodontic treatment aimed

at distalizing the maxilla, or maxillary dentition, to

correct the Class II dentition, according to Isaacson’s

study, would cause downward rotation of the mandible and an

increase in the mandibular plane angle, and would therefore

allow room for further increase in the height of the

maxilla both posteriorly and anteriorly. According to

Schendel and Field’s studies, this could cause an increased

tendency for gingival display.18,25

However, the literature tends to refute this point.

In Peck’s study, the gingival smile line group had greater

values for both overbite and overjet, by 1.5 mm and 1.0 mm

respectively.3 Therefore, it would seem that correcting the

overjet, might decrease the gingival smile. Accordingly,

Vig and Brundo found that individuals with moderate to

severe Class II malocclusions demonstrated an exceptional

resistance to the normal pattern of decreased maxillary

incisor show with age.16 Peck et al. suggest that

23

orthodontic correction of overjet may then improve a

gingival smile line in a Class II condition.3

Treatments For Gingival Smiles

As with any other orthodontic problem, the appropriate

treatment for a gingival smile is determined by the cause.

A gingival smile caused by short clinical crowns should be

treated with the appropriate gingival procedure, while a

gingival smile due to incorrect dental and skeletal

relationships should be treated orthodontically, or with a

combination of orthodontics and surgery. Other less

invasive procedures are also emerging to camouflage a

skeletal problem such as botox injections to decrease the

mobility of the upper lip and even anterior nasal spine

implants.

Treatments for Gingival Smiles Caused by Altered Passive

Eruption

As previously discussed, altered passive eruption

ia classified into two types, and the appropriate treatment

is determined by the type present. In Type I, there is an

excessive amount of gingiva from the free gingival margin

to the mucogingival junction. In Type II, there is a

normal amount of gingiva as measured from the free gingival

24

margin to the mucogingival junction. Type I is further

subdivided into sub-categories A and B depending on the

relationship of the osseous crest to the cemento-enamel

junction of the tooth. In subcategory A, the dimension

between the osseous crest and the CEJ is greater than 1 mm,

and therefore adequate for the insertion of the connective

tissue attachment component of the biologic width. In

subcategory B, the osseous crest is in close proximity to

the cementoenamel junction, therefore adequate space for

the connective tissue attachment component of the biologic

width.

Because there is adequate room for the connective tissue

attachment in Type IA, a simple gingivectemy procedure can

be performed to remove the excess gingiva. However,

because there is not adequate space for the connective

tissue attachment in Type IB, the connective tissue is

attached to the enamel. Therefore, without moving the

crestal bone apical to the cementoenamel junction to allow

adequate space for the connective tissue attachment to form

in its proper location, the connective tissue attachment

will reform on the enamel, and the gingival margin will

rebound. For this reason, gingivectemy procedures will be

unsuccessful, and a crown lengthening procedure to move the

25

crestal bone apically will be necessary to provide stable

results.20,21

In Type II altered passive eruption, the zone of

masticatory mucosa is not excessive, despite the clinically

evident short teeth. Treatment requires apical reduction

of the entire dentogingival complex with or without osseous

reduction to provide more ideal esthetics.20

Treatments for Gingival Smiles Caused by Incorrect Dental

and Skeletal Relationships

According to Proffit et al. “There are now three possible

approaches to excessive gingival exposure due to incorrect

dental and skeletal relationships: orthodontic intrusion,

orthognathic surgery to move the maxilla up, and implant

anchorage to intrude the maxillary teeth.28 The appropriate

treatment is determined by the etiology of the problem and

the age of the patient.

Orthodontic Intrusion

If the maxillary anterior teeth are excessively extruded

in relation to the posterior teeth and the bite is deep,

then the anterior teeth can be orthodontically intruded.

According to Garber and Salama, the entire attachment

apparatus, incorporating the bone, periodontal ligaments,

and the soft tissue moves together with the tooth,21 and

26

therefore intrusion should improve a gingival smile.

However, according to Waldrop, the ability of the

orthodontist to change gingival margin locations with tooth

movement may be affected by the facial-lingual thickness of

the attached gingival and bone.20

If the gingival smile is due to a true skeletal

Vertical Maxillary Excess (VME), then the posterior portion

of the maxilla will also be vertically overexpressed,

causing the mandible to rotate downward and backward. In

children, this growth pattern could possibly be modified

with careful attention to prevent all subsequent posterior

vertical growth of the maxilla, thus allowing the mandible

to rotate upward and forward if there is adequate vertical

ramus growth.29 This can be achieved with various approaches

including high-pull headgear to the maxillary molars, high-

pull headgear to a maxillary splint, a functional appliance

with bite blocks, and even a high-pull headgear to a

functional appliance with bite blocks for the the most

severe cases.29

Implant Intrusion

Until recently, intrusion of the maxillary anterior teeth

without the side effects of posterior extrusion was very

difficult. Extraoral force applications using the head as

anchorage (i.e., headgear) was the method of choice to

27

either directly intrude the anterior teeth (i.e., J-Hook

headgear), or to prevent the side effects of an anterior

intrusion arch (i.e. high pull headgear). However, the

unesthetic appearance of headgear decreased patient

compliance with full time wear and therefore decreased its

effectiveness. With the advent of orthodontic implants,

also known as temporary anchorage devices, effective

intrusion of anterior teeth has become possible. In a

recent study by Deguchi et. al., the effects of intrusion

of the maxillary incisors via implants was compared to the

effects produced with a J-Hook headgear. They found that

while both groups experienced significant reductions in

overjet, overbite, and maxillary incisor to upper lip,

there were significantly greater reductions in overbite,

maxillary incisor to palatal plane, and maxillary incisor

to upper lip in the implant group. A force analysis

indicated that the implant intrusion produced a

significantly greater force in the vertical direction and

less in the horizontal direction than the J-hook headgear

group.30 This study indicates that implant intrusion might

achieve more true intrusion without the undesired tipping

of the maxillary incisors that often occurs with

traditional intrusion mechanics. In a recent study by

Polat-Ozsoy et.al., similar findings were reported. They

28

found a mean intrusion of 2.25 mm with only small and

insignificant changes in the U1 to NA and U1 to Palatal

plane angles, 1.22 and 1.81 mm respectively.31 Not only do

orthodontic implants appear to achieve more true intrusion

without the undesired side effects, but according to a

study by Scheffler at the University of North Carolina in

2005 (cited by Proffit et. al.) patients prefer implants to

headgear and reported minimal pain from implant placement.28

Other recent case reports have also demonstrated successful

treatment of patients with deep overbites and “gummy”

smiles with the use of orthodontic implants for maxillary

incisor intrusion.32,33

Orthognathic Surgery

In adults, growth modification is no longer an option.

Therefore, intrusion of the anterior teeth in the absence

of a deep bite would, at the very least, create a reverse

smile arc, and possibly result in an anterior open bite.

Therefore, orthognathic surgery to impact the maxilla is

the only true corrective treatment option. However, as

Garber et. al. points out, proper diagnosis of the severity

of the vertical maxillary excess present involves ruling

out the superimposition of altered passive eruption in

combination with maxillary hyperplasia. They state, if

altered passive eruption is present, it should be treated

29

first to develop a normal tooth form before a final

treatment plan is determined.21 Only then can the true

severity of the hyperplasia be assessed. In some cases, the

translation of the upper lip from rest to maximum smile is

greater the normal length of a tooth crown. In such a

case, the patient must determine if some gingival display

will be tolerated, or if a increased length of the crowns

of the maxillary incisors is preferred. This will prevent

overimpaction of the maxilla, which results in burying of

the incisal edge beyond the vermillion border of the lip

resulting in a dramatically aged appearance. For this

reason, it is critical to treat to the position of the lip

at rest. A minimum of 2 mm of the incisal edge of the

maxillary incisors should be displayed at rest.21 Peck

points to surgical repositioning of the maxilla to reduce

vertical maxillary excess as the most effective treatment

modality. However, he notes that this procedure has

limitations due to the lip shortening that occurs with

skeletal intrusion (50% of the skeletal intrusion).3

Treatments for Gingival Smiles Caused by Hyperfunction of

the Lip Elevator Muscles

Due to the invasiveness and cost of maxillary

osteotomy surgery, other methods of correcting a “gummy”

30

smile have emerged. In Peck et al.’s study, the gingival

smile group raised the upper lip higher than average during

smiling.3 This hyperfunction of the lip elevator muscles is

thought to contribute to the production of a gummy smile.

Therefore, several soft tissue surgical procedures have

been reported to correct a gummy smile caused by

hyperfunction. These methods include severing the muscular

attachments, botulinum toxin, and even an anterior nasal

spine implant.

Muscle Resection

Polo, Rubinstein and Kostianovsky describe a procedure

in which a portion of the gingival and buccal mucosa is

resected and the borders approximated and sutured.34 Litton

and Fournier describe a procedure to detach the elevator

muscles from the maxilla,35 while Miskinyar describes a

technique in which he performs a myectomy and partial

amputation of the levator labii superioris muscles.36

However, Ellenbogen reports that resection of the levator

labii superioris is short lived, and the gummy smile

returns within six months.37 He suggests placing either a

nasal cartilage or prosthetic material as a spacer to

prevent this reunion of the muscle fibers and reoccurrence

of the gummy smile.37 Miskinyar reported good results with

this technique at 8 year follow ups, but points out

31

possible disadvantages including migration of the spacer to

a foreign site, foreign body reaction if a prosthetic

implant is used, and the need for a second surgical

procedure if nasal cartilage is used.38 Rees and LaTrenta

describe a camouflage procedure for long faced syndrome

patients in which subperiosteal dissection of the lip

elevators is performed,39 and Ezquerra et al. describe a

multidisciplinary approach that incorporates lefort

osteotomies, with gingival remodeling, and the procedure

described by Rees and LaTrenta.40

Botulinum Toxin

Although less invasive than an osteotomy, surgical

procedures to resect the lip elevator muscles require

incisions with the possibility of scarring and variable

long-term results. Therefore, botulinum toxin has been

investigated as a non-surgical alternative for reducing

gingival display caused by muscular hyperfunction. In a

recent study by Mario Polo,41 twelve women with excessive

gingival display were injected at two sites with 1.25 U of

botulinum toxin in the right and left levator labii

superioris alaeque nasi muscles, and the overlap areas of

the levator labii superioris and zygomaticus minor muscles.

These injection were repeated in a second phase of the

study one month later and followed by a 2.5 U injection in

32

a third phase. Those that had the greatest amount of

elevation near the philthrum also received injections at

the origin of the depressor septi nasi muscle at the

orbicularis oris muscle at each phase of the study. He

found that all patients demonstrated improvement 10 days

post-injection, while the maximum effect was observed 14

days post-injection with a mean decrease in gingival

display of 4.2 mm. This effect was reversible, lasting for

3 to 6 months. He reports that all patients were pleased

with the results and no side effects were reported or

observed.41 In a letter to the editor in response to Polo’s

article, Niamtu, relates experiences of unesthetic perioral

animation in his patients treated with botulium toxin

injections. He states, “they looked dysfunctional,”

described a “range from slight change in smile, pucker, and

word pronunciation to a “stroke like” expression in some

phases of animation.” He suggests that the photos in

Polo’s study cannot truly display the appearance of the

patients in animation. While he relates years of

experience with botox, he warns that dramatic undesirable

results can be produced by inexperienced practitioners

including severe drooling, inability to pucker, grossly

asymmetric smiles, inability to annunciate words, and a

stroke like appearance.42

33

In a follow up study by Polo to determine whether the

dose and injection sites used in the pilot study produce

consistent, esthetically pleasing results, Polo injected 30

patients with 2.5 U at the same sites as discussed in his

pilot study and followed them at 2,4,8,12,16,20 and 24

weeks post-injection with changes documented by photographs

and videos. Again the maximum effect was observed at 2

weeks post-injection with a mean decrease in gingival

display of 5.1 mm. The gingival display increased

gradually, although the gingival display had not yet

returned to baseline by week 24. It was estimated with a

polynomial equation that the pre-treatment gingival display

would not be reached until 30 to 32 weeks post-injection.

At week 2, patients and a panel of specialty evaluators

rated the effects of the botox injections via pre and post

treatment photographs and videos on a 1 to 5 point scale

with 1 representing poor and 5 representing excellent.

Both patients and specialists rated the results between

very good and excellent with a mean of 4.66 and 4.65

respectively.43 In a recent study by Hwang et. al., the

distribution, morphology, and direction of muscles fibers

of the levator labi superioris (LLS), the levator labii

superioris alaeque nasi (LLSAN), and the zygomaticus minor

(ZMi)and major(ZMj) muscles were investigated on 25 adult

34

cadavers with the aim of proposing a safe and reproducible

injection point for botulinum toxin type A. They found

that the three lip elevator muscles converged on the area

lateral to the ala of the nose with no significant

differences in the angular projection of the muscle fibers

from origin to insertion between males and females or left

side to right side. This area of convergence was prosposed

as a safe and reproducible injection site for the botulinum

toxin. Injection at this site was demonstrated to be

clinically effective in the reduction of a gingival smile

due to muscular hyperfunction in two cases. In summary,

while still in its early stages, research indicates that

botulium toxin type A might be an effective, yet transient

treatment for excessive gingival display.

Anterior Nasal Spine Implants

In addition to surgical resection of the elevator muscles

and botulinium toxin to reduce the activity of the muscles,

the use of an anterior nasal spine implant has been

reported to mechanically obstruct the lip from raising and

thus reduce the amount of gingiva displayed upon smiling.

Austin describes a technique in which a pouch is created by

elevating the periosteum from the anterior nasal spine and

adjacent maxilla for 10 mm on each side. It is then filled

with a silicone implant material, which is allowed to

35

harden and conform to shape of the area. It is then

removed, trimmed to prevent protuberant edges and then

reimplanted into the pouch and the pocket is sutured. He

reports excellent results and pleased patients with a mean

follow up of three years. He reports only one infection

requiring removal of the implant and suggests both IV and

local antibiotics to prevent this complication.44

Summary and Statement of Thesis

The literature indicates that the “ideal” smile as

determined by the general public displays very little

gingiva upon smiling, and due to the increasing esthetic

demands of the public, orthodontists are taxed to produce

the “ideal.” Therefore, not only is the knowledge to treat

patients that present with “gummy” smiles necessary, but

more important is the knowledge to recognize those that

have a tendency to become “gummy,” and to prevent the

development of a “gummy” smile during orthodontic

treatment.

The purpose of this study is to compare the pre and

post treatment cephalometric radiographs of patients who

obtain a great increase in gingival display during

treatment to those that obtain a great decrease, as well as

those that obtain the average change in gingival display.

36

It is our hope that this comparison will identify the pre-

treatment skeletal, dental, and soft tissue characteristics

that indicate a tendency to obtain an increase or decrease

in gingival display during treatment and/or the skeletal,

dental, and soft tissue changes that occur to produce this

change in lip drape.

37

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36. Miskinyar SA. A new method for correcting a gummy

smile. Plast. Reconstr. Surg. 1983;72(3):397-400.

37. Ellenbogen R. Correspondence and brief communications.

Plast. Reconstr. Surg. (73):697-98.

38. Miskinyar S. Correspondence and brief communications.

Plast. Reconstr. Surg. (73):697.

39. Rees T, LaTrenta G. The long face syndrome and

rhinoplasty. Persp Plast Surg. (3):116.

40. Ezquerra F, Berrazueta MJ, Ruiz-Capillas A, Arregui JS.

New approach to the gummy smile. Plast. Reconstr. Surg.

1999;104(4):1143-1150; discussion 1151-1152.

41. Polo M. Botulinum toxin type A in the treatment of

excessive gingival display. Am J Orthod Dentofacial

Orthop. 2005;127(2):214-218; quiz 261.

42. Niamtu III J. Letters to the editor: Botox injections

for gummy smiles. Am J Orthod Dentofacial Orthop.

2008;133:782-3.

43. Polo M. Botulinum toxin type A (Botox) for the

neuromuscular correction of excessive gingival display

on smiling (gummy smile). Am J Orthod Dentofacial

Orthop. 2008;133(2):195-203.

44. Austin HW. Correction of the gummy smile--a plastic

surgeon's view. Dent Today. 1990;9(2):28.

41

CHAPTER 3: JOURNAL ARTICLE

Abstract

Objective: The purpose of this study is to determine

which dental, skeletal, and soft tissue characteristics

affect lip height and which characteristics affect lip

height changes during treatment. Materials and Methods:

Models for 200 randomly selected subjects were obtained and

used to calibrate the smiling photographs of each subject.

The photographs were then measured to determine the change

in gingival display that occurred during treatment. The

change in gingival display was used to create three groups:

those that obtained the greatest increase, greatest

decrease, and average change in gingival display. The

cephalometric radiographs were then traced for each subject

and digitized. The pre and post treatment cephalometric

radiographs of each subject were superimposed and a total

of 54 linear measures were made at each time point. The

measures were then compared using t-tests for intra-group

changes from T1 to T2 and an Analysis of Variance (ANOVA)

for inter-group comparisons at each time point.

Results: There were no significant differences between the

groups at the pretreatment time point. Paired t tests

revealed significant differences in 25 of the 27 vertical

42

measures within all groups from the pre treatment to post-

treatment time points. The horizontal measures indicated

more significant differences in the backward direction in

the greatest increase group than the other two groups. The

significant vertical difference between the groups at the

post-treatment time point was found between the average

change group and the greatest increase group at condylion.

The significant horizontal differences between the groups

were found between the greatest increase and greatest

decrease groups at the soft tissue lips. The lips moved

significantly backward in the greatest increase group while

they stayed relatively the same in the greatest decrease

group.

Conclusions: No pretreatment characteristic could be

identified to predict the tendency to experience an

increase or decrease in gingival display during orthodontic

treatment. The lips moved significantly backward in the

group that experienced an increase in gingival display

while they stayed relatively the same in the group that

experienced a decrease. Although not significant, other

general tendencies were apparent between the two extreme

groups. Further research is warranted.

43

Introduction

!

!

As society becomes more esthetically conscious,

orthodontists are becoming challenged to produce not only

outstanding occlusions, but also outstanding esthetics.

Every minute detail is becoming more important in

separating the good from the great treatment result.

Recent studies have indicated that the public at large

believes that the amount of gingival display on smiling is

very important to attractiveness.1 In fact, Van der Geld et

al. found that the amount of gingival display is an

important characteristic in a person’s own satisfaction

with their smile.2

When an excessive amount of gingiva is displayed upon

smiling, the term “gummy” is often used. While many

clinicians anecdotally point to the “lack of vertical

control” as the cause of orthodontically produced

“gumminess,” few studies that investigate the cause of post

treatment gummy smiles are present in the literature. Peck

et al. found that the tendency of a person to project a

gummy smile was related to anterior vertical maxillary

excess, the muscular ability to raise the upper lip higher

than average when smiling, greater overjet, greater

interlabial gap at rest, and greater overbite.3 This study,

44

as well as many others, have found that females have a

predilection to display more gingiva while smiling than

their male counterparts.3456

Lip length has also been suspect to affect gingival

display, however, the literature refutes this assertion.3,7

In fact, Singer reported that his gingival smile group had

a significantly longer lip length than his non-gingival

display group.8 Altered passive eruption has also been

suggested to produce short clinical crown heights and

therefore increase the tendency to produce a gingival

smile. However, in Peck et al.’s study, the clinical crown

height of the gingival display group was not significantly

different.3

In Mackley’s study to determine the effectiveness of

improving patient smiles with orthodontic treatment and the

variability of improvement from orthodontist to

orthodontist, he found that the orthodontist who was most

successful in producing greater post treatment smile

improvement scores decreased the stomion-incision

measurement, while those that increased the stomion-

incision measure produced smiles with lower post treatment

improvement scores. He states, “This measurement is an

indication of the amount of gingival tissue that shows when

a person is smiling.” He also suggested that the most

45

successful orthodontist also increased the inclination of

the maxillary incisor to the Nasion-A Point line, while

those that produced less improvement decreased this

measure. He concludes that in order to “maximize our

potential for improving the smile, we must include in our

treatment plan an objective for moving the anterior teeth

vertically to improve their relationship to the smiling lip

line.”9

While these studies indicate possible reasons for an

increase in gingival display, none indicate any pre-

treatment skeletal or dental factors that might help a

clinician to predict the development of this “gumminess”

during orthodontic treatment nor investigates post-

treatment skeletal and soft tissue factors that might

produce this negative condition. The purpose of this study

is to determine which dental, skeletal, and soft tissue

characteristics affect smiling lip height and which

characteristics affect lip height changes during

orthodontic treatment.

46

Materials and Methods

Sample

A sample of 200 subjects (114 Females and 86 Males)

was randomly selected from the archives of records at Saint

Louis University Center for Advanced Dental Education.

Only patients who began treatment between the ages of 10

and 14 years of age, and had pre and post treatment

photographs, models, and lateral cephalometric radiographs

were included. A consistent head position and extent of

smile in the pre and post-treatment photos were also

required in order to be included in the study.

Sample Selection

The database of records at the Center for Advanced

Dental Education at Saint Louis University was reviewed

beginning with the first letter of the alphabet. The first

200 patients that met the inclusion criteria were included

in the study. Once the records were obtained, the width of

the maxillary left central incisor was measured to the

nearest tenth of a millimeter using a digital caliper on

the stone model and recorded. This measure was then used

to calibrate the smiling photograph of the patient using

the Dolphin Imaging photo calibration tool. Once photo

calibration was completed, the length of the maxillary left

47

central incisor was measured on the stone model and

recorded. For this purpose, the length of the maxillary

left central incisor was defined as the distance between

the incisal edge and the most superior point on the

gingival margin. The distance between the incisal edge of

the maxillary left central incisor and the most incisal

portion of the upper lip was then recorded. The amount of

gingival display was recorded as the difference between the

length of the maxillary left central incisor and the

distance between the maxillary left central incisal edge

and the most inferior portion of the upper lip (Figure

3.1). Therefore, patients with visible gingival exposure

upon smiling would have a positive number of gingival

display and patients with lip coverage of their maxillary

incisors upon smiling would have a negative number recorded

(Figure 3.2).

Figure 3.1 Calculation of Gingival Display. The gingival exposure was calculated as the

difference between 1 and 2 minus the difference between 1 and 3. i.e. (1-2)-(1-3).

(Modified from Van der Geld et. al.)2

48

Figure 3.2 Description of Measures of Gingival

Display. A positive measure was given for any gingiva

visible above the maxillary left central incisor while any

incisor coverage was given a negative measure (Modified

from Peck and Peck)3

After the amount of gingiva displayed upon smiling was

determined for the pre and post treatment time points (T1

and T2) for each patient, the change from T1 to T2 was

determined and recorded to the nearest tenth of a

millimeter. The change in gingival exposure for the 200

patients was analyzed using the SPSS program and the mean

and median values were determined. The mean change in

gingival exposure for the 200 patients was 0.7349 mm while

the median change was 0.660 mm suggesting that a homogenous

sample of normally distributed patients was obtained (see

table 3.1).

49

Mean Change 0.7349 mm

Median Change 0.660 mm

Standard

Deviation

1.96581 mm

Range 13.87 mm

Minimum -6.92 mm

Maximum 6.95 mm

The sample was then divided into three groups: Group

1. those that obtained the greatest decrease in gingival

exposure during treatment; Group 2. those that had the

average amount of change during treatment; Group 3. those

that obtained the greatest increase in gingival exposure;

The groups were developed by taking one standard deviation

from the median. Those that obtained a minimum of one

standard deviation less than the median change during

orthodontic treatment were included in the “greatest

decrease” group or Group 1. The 15 patients on each side of

the median made up the “average change” group or Group 2.

Those that obtained a minimum of one standard deviation

greater than the median change during treatment were

included into the “greatest increase” group or Group 3.

Table 3.1 Descriptive Statistics for the change in

gingival display of the 200 subjects

50

Group 1 contained 21 subjects (8 females and 13 males)

and had a mean change of -2.55 mm. Group 2 contained 29

subjects (17 Females and 12 Males) (one was thrown out due

to a magnification differential) and had a mean change of

0.65 mm, and group 3 contained 33 subjects (20 females and

13 males) and had a mean change of 3.75 mm (see table 3.2).

Table 3.2: Description of Sample Groups

Group Number

of

Subjects

Mean Change

in Gingival

Display (mm)

Gender

Differences

Molar

Classifications

1

(Greatest

Decrease

in

Gingival

Display)

21 -2.55 8 Females

13 Males

8 Class I

9 Class II

4 Class III

2

(Average

Change in

Gingival

Display)

29 0.65 17 Females

12 Males

21 Class I

5 Class II

3 Class III

3

(Greatest

Increase

in

Gingival

Display)

33 3.75 20 Females

13 Males

19 Class I

11 Class II

3 Class III

51

Data Collection

The pre and post treatment cephalometric radiographs

of the three groups (83 subjects) were hand traced and 28

soft and hard tissue landmarks were identified(See table

3.3 and figure 3.3).

Table 3.3 Landmark abbreviations and descriptions

Landmark Abbreviation Description

Sella S Midpoint of the cavity of the

pituitary fossa of the sphenoid

bone

Nasion N Junction of the frontonasal

suture at the most posterior

point on the curve at the bridge

of the nose

Anterior Nasal

Spine

ANS Tip of the median, sharp bony

process of the maxilla at the

lower margin of the anterior

nasal opening

Posterior Nasal

Spine

PNS The most posterior point at the

sagittal plane on the bony hard

palate

Point A or

Subspinale

A pt The most posterior point on the

curve of the maxilla between the

anterior nasal spine and

supradentale

Point B or

Supramentale

B pt The point most posterior to a

line from infradentale to

pogonion on the anterior surface

of the symphyseal outline of the

mandible

Pogonion Pog Most anterior point on the

contour of the bony chin

Gnathion Gn Most inferior and anterior point

on the contour of the bony chin

Menton Me Most inferior point on the

symphyseal outline

Gonion

Go

Midpoint of the angle of the

mandible

Condylion Co Most posterior superior point on

the curvature of the average of

the right and left outlines of

the condylar head

Pronasale Prn Most anterior point on the tip

of the nose

Subnasale Sn The point at which the nasal

septum mergest, in the

midsagittal plane, with the

upper lip

52

Table 3.3 (Continued)

Landmark Abbreviation Description

Labrale Superius Ls Most anterior point of the upper

lip

Stomion Superius Ss Most inferior point of the upper

lip

Stomion Inferius Si Most superior point of the lower

lip

Labrale Inferius Li Most anterior point of the lower

lip

Soft Tissue

Pogonion

Pg’ Most anterior point of the soft

tissue chin

Maxillary Incisor

Apex

U1a

The root tip of the maxillary

central incisor

Maxillary Incisor

Incisal Edge

U1i

The incisal tip of the maxillary

central incisor

Mandibular Incisor

Apex

L1a The root tip of the mandibular

central incisor

Mandibular Incisor

Incisal Edge

L1i The incisal tip of the

mandibular central incisor

Maxillary First

Molar Apex

U6a The root tip of the most

anterior root of the maxillary

first molar

Maxillary First

Molar Mesial Cusp

Tip

U6c The anterior cusp tip of the

maxillary first molar

Mandibular First

Molar Apex

L6a The root tip of the most

anterior root of the mandibular

first molar

Mandibular First

Molar Mesial Cusp

Tip

L6c The anterior cusp tip of the

mandibular first molar

Posterior

Functional Occlusal

Plane

PFOP The plane that intersects the

biting surfaces of the posterior

teeth; measured from the distal

cusp of the maxillary first

molar

Anterior Functional

Occlusal Plane

AFOP A point formed by a

perpendicular from the tip of

the maxillary central incisor to

the plane that intersects the

biting surfaces of the posterior

teeth

53

Figure 3.3 Cephalometric Landmarks

!

54

After the cephalometric radiographs were traced, they

were digitized, using a Numonic Digitizing Table (model #

IPS/BL.E-A30BL.H). Dentofacial Planner 7.0 software was

used to translate each landmark into x-y coordinates. The

pre and post treatment cephalometric radiographs of each

subject were superimposed on the anterior cranial base

(best fit on the planum sphenoid, cribiform plate, greater

wings of sphenoid) and registered on sella.

Two reference planes were then generated to assist

with the cephalometric analysis. A horizontal reference

plane was drawn at the level of the sella-nasion line minus

7 degrees (SN-7°). A vertical reference plane (SN-7°-

perpendicular) was then drawn through sella, perpendicular

to the SN-7° line (see Figure 3.4).!

!

!

!

!

!

!

!

!

!

!

55

!

!

!

!

!

!

!

!

!

!

!

!

!

Figure 3.4 Reference Planes

A total of 54 linear measures were made on each

cephalometric radiograph at each time point (27 vertical

and 27 horizontal) by dropping lines perpendicular to the

SN-7 reference plane or SN-7 perpendicular respectively.

See Figures 3.5 and 3.6.

56

Figure 3.5 Examples of and vertical measures from the SN-7 the

reference plane

Figure 3.6 Examples of Horizontal Measures from the SN-7 Perpendicular

reference plane

57

Data Analysis

Due to the lack of literature available, all 27

variables were studied to determine which variables are

important in gingival display. In order to maintain the

power of the analysis, the variables were divided into four

groups: soft tissue, maxilla, mandible, and dental.

Paired t tests were used to compare the horizontal and

vertical measures within each group at the T1 and T2 time

points. An Analysis of Variance was (ANOVA) then used to

compare both the horizontal and vertical measures between

each analysis group at each time point (T1 and T2).

Because the sample sizes were not equal, the significant

measures were compared using Tukey’s Post Hoc and a mean

sample size of 26 was used.

All statistical computations were calculated by means

of standard computer software (SPSS for Windows, release

15.0.0, Inc., Chicago, IL). Statistical significance was

set at P<.05.

Analysis of Error

Due to the potential for human error inherent to the

process of landmark identification and tracing

cephalometric radiographs, as well as the process of

measuring gingival display using a digital caliper on

58

models and photo calibration, 10% of each of the samples

was randomly selected for measurement duplication. Twenty

subjects were re-measured for reliability of the gingival

measures (200 in initial sample), and 9 subjects were

remeasured for cephalometric analysis (83 subjects in

cephalometric study). All measures were repeated for the

cephalometric radiographs, models, and photos.

A reliability analysis (intercorrelation coefficient)

was performed comparing the initial to the repeated

measures. The reliability coefficient was found to range

from 0.995 to 0.999 for the gingival measures and to range

from 0.994 to 1.000 for the cephalometric measures.!

!

Results

The first set of inferential statistics tested for

significant differences between each of the groups at the

pre-treatment time point. The Analysis of Variance revealed

no significant differences between any of the groups for

any of the 27 landmarks in either the horizontal or the

vertical dimensions at the pretreatment time point (see

appendix A Tables A.1–A.16). Therefore, all significant

differences found at the post treatment time point can be

attributed to change that occurred during treatment.

59

Paired t tests were used to investigate significant

differences between the T1 and T2 time points within each

of the groups. They revealed significant differences in 25

of the 27 vertical measures for all three groups from the

pre treatment to post-treatment time points, as would be

expected in a growing sample. The non-significant variables

included nasion, which was included in the reference plane,

and condylion. The horizontal measures showed more

variability. The following horizontal measures were found

to be significant between the T1 and T2 time points for

group 1: pronasale, subnasale, menton, and gonion (Table

3.4). Significant horizontal measures from T1 to T2 for

group 2 include: pronasale, A point, B point, Gnathion,

menton, gonion, and L-6 Apex (Table 3.5). All horizontal

measures were significant between the T1 and T2 time points

for group 3 with the exception of nasion, pronasale,

subnasale, Posterior functional occlusal plane, Lower 6

tip, and Lower 6 apex (Table 3.6)

The following horizontal measures were found to be

significantly different at the post-treatment time point

between group 1 and group 3: Labrale superius, Stomion

superius, Stomion inferius, and Labrale inferius (tables

3.7-3.9). The non-significant measures at the post-

treatment time point appear in Appendix B (tables B.1-

60

B.16). No significant differences were found in the

horizontal measures between any of the groups (see Appendix

B Tables B.1,B.2, B.5, B.6, B.9, B.10, B.13, B.14), however

some tendencies are apparent when the groups are compared

at each time point (see Tables: 3.13-3.20). The only

significant vertical measure at the post treatment time

point was found between group 2 and group 3 at the

condylion measure (tables 3.10-3.12). No other significant

differences were found in the vertical measures at the post

treatment time point (see Appendix B Tables B.3, B.4, B.7,

B.8, B.11, B.12, B.15, B.16), however as with the

horizontal, some tendencies are easily seen when the groups

are compared (see Tables 3.13 -3.20).

61

Table 3.4 Group 1 Pre-treatment Vs. Post-treatment

Variable T1 T2 !T2-T1 Sig

V Nasion -8.9381 -8.9571 -0.019 0.162

H Nasion 72.8571 72.9571 0.1 0.241

V Pronasale 37.4381 44.1048 6.6667 ***0

H Pronasale 99.1286 102.481 3.3524

**

0.001

V Subnasale 50.5952 56.0238 5.4286 ***0

H Subnasale 85.7286 87.0762 1.3476

*0.031

V Labrale

Superius 64.6952 70.619 5.9238 ***0

H Labrale

Superius 90.4857 90.8762 0.3905 0.601

V Stomion

Superius 73.4619 79.6762 6.2143 ***0

H Stomion

Superius 82.919 82.5524 -0.3666 0.731

V Stomion

Inferius 74.6619 80.6 5.9381 ***0

H Stomion

Inferius 82.2238 82.3143 0.0905 0.94

V Labrale

Inferius 82.6143 89.6571 7.0428 ***0

H Labrale

Inferius 86.3 86.7619 0.4619 0.686

V Pogion' 106.2333 114.019 7.7857 ***0

H Pogion' 75.0667 75.3333 0.2666 0.823

V ANS 46.5048 50.6619 4.1571 ***0

H ANS 70.7095 69.8714 -0.8381 0.26

V PNS 44.3952 47.6619 3.2667 ***0

H PNS 18.2857 16.9762 -1.3095 0.118

V A Point 49.4667 54.3952 4.9285 ***0

H A Point 68.5048 67.5667 -0.9381 0.139

V B Point 94.6571 101.0381 6.381 ***0

H B Point 61.9048 61.3286 -0.5762 0.498

V Pogonion 107.0714 116.8333 9.7619 ***0

H Pogonion 61.3857 59.881 -1.5047 0.211

V Gnathion 111.2476 120.581 9.3334 ***0

H Gnathion 58.6762 56.4238 -2.2524 0.092

V Menton 112.3762 121.3429 8.9667 ***0

H Menton 54.7905 51.8095 -2.981 *0.046

V Gonion 74.1714 78.6714 4.5 **0.001

62

Table 3.4 (Continued)

Variable T1 T2 !T2-T1 Sig

H Gonion -11.419 -15.119 -3.7 **0.002

V Condylion 23.4714 22.781 -0.6904 0.534

H Condylion -19.6095 -20.8905 -1.281 0.078

V Post FOP 66.1714 71.7381 5.5667 ***0

H Post FOP 31.9143 32.1667 0.2524 0.775

V Ant FOP 76.819 82.1524 5.3334 ***0

H Ant FOP 74.5857 73.319 -1.2667 0.253

V U6 Apex 48.119 53.5 5.381 ***0

H U6 Apex 45.1 44.9905 -0.1095 0.896

V L6 Apex 89.0095 95.4857 6.4762 ***0

H L6 Apex 33.2524 34.0571 0.8047 0.389

V L6 Tip 68.2619 74.9143 6.6524 ***0

H L6 Tip 41.8 43.3143 1.5143 0.089

V U1 Tip 76.5048 81.8476 5.3428 ***0

H U1 Tip 74.6905 73.2381 -1.4524 0.203

V U1 Apex 49.2714 55.3381 6.0667 ***0

H U1 Apex 62.5905 62.4286 -0.1619 0.806

V L1 Tip 72.8619 79.9762 7.1143 ***0

H L1 Tip 70.9714 70.8286 -0.1428 0.878

V L1 Apex 92.7238 99.6381 6.9143 ***0

H L1 Apex 57.0857 56.3619 -0.7238 0.431

*p<.05

** p<.005

*** p<.001

(H = Horizontal Measure; V = Vertical Measure)

63

Table 3.5 Group 2 Pre-Treatment Vs. Post-Treatment

Variable T1 T2 !T2-T1 Sig

V Nasion -9.1966 -9.2000 -0.0034 0.745

H Nasion 74.8724 74.9000 0.0276 0.637

V Pronasale 40.1310 44.7621 4.6311 ***0

H Pronasale 101.4414 103.0793 1.6379 **0.01

V Subnasale 53.1069 57.2828 4.1759 ***0

H Subnasale 86.7207 87.0207 0.3000 0.556

V Labrale Superius 67.1586 71.669 4.5104 ***0

H Labrale Superius 88.3931 87.7759 -0.6172 0.326

V Stomion Superius 74.8207 78.6172 3.7965 ***0

H Stomion Superius 80.2414 79.9138 -0.3276 0.656

V Stomion Inferius 75.8034 79.4103 3.6069 ***0

H Stomion Inferius 79.9517 79.7724 -0.1793 0.81

V Labrale Inferius 83.3828 87.5207 4.1379 ***0

H Labrale Inferius 83.8586 83.8621 0.0035 0.996

V Pogion’ 108.1103 113.4828 5.3725 ***0

H Pogion’ 73.7966 72.8483 -0.9483 0.289

V ANS 47.7379 50.9931 3.2552 ***0

H ANS 72.0586 71.1207 -0.9379 0.088

V PNS 45.3379 46.5276 1.1897 *0.024

H PNS 16.4276 15.3586 -1.0690 0.146

V A Point 51.5655 55.1517 3.5862 ***0

H A Point 68.9414 67.6759 -1.2655 *0.04

V B Point 94.6897 100.4276 5.7379 ***0

H B Point 61.2414 59.7207 -1.5207 *0.042

V Pogonion 106.2793 112.2241 5.9448 ***0

H Pogonion 60.8172 59.3759 -1.4413 0.076

V Gnathion 106.2793 112.2241 5.9448 ***0

H Gnathion 60.8172 59.3759 -1.4413 *0.044

V Menton 113.5724 120.2 6.6276 ***0

H Menton 53.1345 51.2828 -1.8517 *0.026

V Gonion 74.2448 78.1759 3.9311 ***0

H Gonion -11.6310 -14.4897 -2.8587 ***0

V Condylion 22.0069 23.131 1.1241 0.202

H Condylion -20.4931 -21.0069 -0.5138 0.294

V Post FOP 67.5276000 71.5069 3.9793 ***0

64

Table 3.5 (Continued)

Variable T1 T2 !T2-T1 Sig

H Post FOP 31.1517 31.7414 0.5897 0.325

V Ant FOP 77.4966 80.5793 3.0827 ***0

H Ant FOP 72.6034 71.4517 -1.1517 0.063

V U6 Apex 49.3586 53.1345 3.7759 ***0

H U6 Apex 44.1552 43.7379 -0.4173 0.604

V L6 Apex 89.3000 93.7966 4.4966 ***0

H L6 Apex 31.9862 33.3828 1.3966 *0.031

V L6 Tip 69.9448 74.0828 4.1380 ***0

H L6 Tip 41.8207 42.2414 0.4207 0.518

V U1 Tip 77.5345 81.2172 3.6827 ***0

H U1 Tip 72.3552 71.169 -1.1862 0.063

V U1 Apex 51.6310 55.5517 3.9207 ***0

H U1 Apex 63.2724 62.1276 -1.1448 0.065

V L1 Tip 74.2448 79.769 5.5242 ***0

H L1 Tip 69.3517 69.0966 -0.2551 0.683

V L1 Apex 93.6241 98.3862 4.7621 ***0

H L1 Apex 55.6103 54.4276 -1.1827 0.148

* p<.05

** p<.005

*** p<.001

( H = Horizontal Measure; V = Vertical Measure)

65

Table 3.6 Group 3 Pre-Treatment Vs. Post-Treatment

Variable T1 T2 !T2-T1 Sig

V Nasion -8.9879 -8.997 -0.0091 0.374

H Nasion 73.2333 73.2909 0.0576 0.275

V Pronasale 40.703 46.4364 5.7334 ***0

H Pronasale 98.8152 99.3212 0.506 0.32

V Subnasale 52.4242 57.6182 5.194 ***0

H Subnasale 84.3636 83.5636 -0.8 0.116

V Labrale Superius 66.9152 72.0061 5.0909 ***0

H Labrale Superius 86.1273 84.8576 -1.2697 *0.022

V Stomion Superius 74.0848 78.7636 4.6788 ***0

H Stomion Superius 78.3091 76.1333 -2.1758 ***0

V Stomion Inferius 75.6121 79.7818 4.1697 ***0

H Stomion Inferius 77.9273 75.8939 -2.0334 **0.001

V labrale Inferius 83.0394 88.7909 5.7515 ***0

H Labrale Inferius 81.6061 80.1939 -1.4122 *0.018

V Pogion' 104.997 112.0848 7.0878 ***0

H Pogion' 72.4697 69.3909 -3.0788 **0.001

V ANS 47.0939 50.8697 3.7758 ***0

H ANS 71.5424 69.803 -1.7394 **0.019

V PNS 45.5242 46.9121 1.3879 ***0

H PNS 16.7061 14.6212 -2.0849 **0.001

V A Point 51.0606 55.0667 4.0061 ***0

H A Point 67.9273 65.9576 -1.9697 *0.005

V B Point 93.7909 99.8061 6.0152 ***0

H B Point 58.9879 55.5909 -3.397 ***0

V Pogonion 107.3212 114.1424 6.8212 ***0

H Pogonion 58.6848 55.3364 -3.3484 ***0

V Gnathion 112.5182 119.3152 6.797 ***0

H Gnathion 55.8091 51.9364 -3.8727 ***0

V Menton 113.6394 120.1485 6.5091 ***0

H Menton 50.9333 46.8788 -4.0545 ***0

V Gonion 76.9364 78.4152 1.4788 *0.005

H Gonion -11.303 -16.403 -5.1 ***0

V Condylion 21.4606 19.7818 -1.6788 *0.021

H Condylion -19.5061 -20.6545 -1.1484 *0.006

V Post FOP 67.8091 71.0909 3.2818 ***0

H Post FOP 30.4242 29.6455 -0.7787 0.171

V Ant FOP 77.7667 82.2818 4.5151 ***0

H Ant FOP 71.4303 68.5333 -2.897 ***0

V U6 Apex 49.7667 53.6485 3.8818 ***0

66

Table 3.6 (Continued)

!

Variable T1 T2 !T2-T1 Sig

H U6 Apex 43.2333 41.8515 -1.3818 *0.015

V L6 Apex 89.6576 93.6636 4.006 ***0

H L6 Apex 30.1545 30.6091 0.4546 0.622

V L6 Tip 70.0606 74.3121 4.2515 ***0

H L6 Tip 39.7182 39.9727 0.2545 0.723

V U1 Tip 77.3576 82.0909 4.7333 ***0

H U1 Tip 71.5818 68.4182 -3.1636 ***0

V U1 Apex 51.4848 57.5879 6.1031 ***0

H U1 Apex 61.7727 60.0848 -1.6879 **0.003

V L1 Tip 74.003 80.1758 6.1728 ***0

H L1 Tip 67.203 65.8545 -1.3485 *0.018

V L1 Apex 92.8667 97.5273 4.6606 ***0

H L1 Apex 54.3545 51.0303 -3.3242 ***0

* p<.05

** p<.005

*** p<.001

( H= Horizontal measures; V = Vertical Measures)

67

Table 3.7 Descriptive Statistics for Significant Horizontal Landmarks

at the Post Treatment Time Point

Landmark Group N Mean

Std.

Deviation

Std.

Error

H Labrale Superius 1.00 21 90.8762 8.18113 1.78527

2.00< 29 87.7759 6.50805 1.20852

3.00 33 84.8576 7.90668 1.37638

Total 83 87.4000 7.80574 .85679

H Stomion Superius 1.00 21 82.5524 8.29244 1.80956

2.00< 29 79.9138 7.23714 1.34390

3.00 33 76.1333 8.17724 1.42348

Total 83 79.0783 8.22065 .90233

H Stomion Inferius 1.00 21 82.3143 8.30170 1.81158

2.00< 29 79.7724 7.24731 1.34579

3.00 33 75.8939 8.24541 1.43534

Total 83 78.8735 8.25628 .90624

H Labrale Inferius 1.00 21 86.7619 9.05635 1.97626

2.00< 29 83.8621 7.71674 1.43296

3.00 33 80.1939 8.75171 1.52348

Total 83 83.1373 8.79001 .96483

< denotes Group 2 landmarks that show no significant differences at the

post treatment time point; data given for comparison purposes

Table 3.8 ANOVA for Significant Horizontal Landmarks at the Post

Treatment Time Point

Sum of

Squares df

Mean

Square F Sig.

Between

Groups 471.168 2 235.584 4.165 *0.019

Within Groups 4525.052 80 56.563

H Labrale

Superius

Total 4996.220 82

Between

Groups 559.901 2 279.950 4.496 *0.014

Within Groups 4981.580 80 62.270

H Stomion

Superius

Total 5541.481 82

Between

Groups 565.019 2 282.510 4.498 *0.014

Within Groups 5024.602 80 62.808

H Stomion

Inferius

Total 5589.622 82

Between

Groups 577.018 2 288.509 4.008 *0.022

Within Groups 5758.657 80 71.983

H Labrale

Inferius

Total 6335.674 82

* p<.05

** p<.005

*** p<.001

68

Table 3.9 Tukey Post Hoc Multiple Comparisons Of Significant

Horizontal Landmarks at the Post Treatment Time Point

Dependent Variable

(I)

GROUP (J) GROUP

Mean

Difference

(I-J)

Std.

Error Sig.

H Labrale Superius 1.00 2.00 3.10033 2.15498 0.326

3.00 6.01861(*) 2.09941 *0.014

2.00< 1.00 -3.10033 2.15498 0.326

3.00 2.91829 1.91429 0.285

3.00 1.00 -6.01861(*) 2.09941 *0.014

2.00 -2.91829 1.91429 0.285

H Stomion Superius 1.00 2.00 2.63859 2.26107 0.476

3.00 6.41905(*) 2.20277 *0.013

2.00< 1.00 -2.63859 2.26107 0.476

3.00 3.78046 2.00853 0.150

3.00 1.00 -6.41905(*) 2.20277 *0.013

2.00 -3.78046 2.00853 0.150

H Stomion Superius 1.00 2.00 2.54187 2.27082 0.505

3.00 6.42035(*) 2.21226 *0.013

2.00< 1.00 -2.54187 2.27082 0.505

3.00 3.87847 2.01719 0.139

3.00 1.00 -6.42035(*) 2.21226 *0.013

2.00 -3.87847 2.01719 0.139

H Labrale Superius 1.00 2.00 2.89984 2.43104 0.461

3.00 6.56797(*) 2.36835 *0.019

2.00< 1.00 -2.89984 2.43104 0.461

3.00 3.66813 2.15951 0.212

3.00 1.00 -6.56797(*) 2.36835 *0.019

2.00 -3.66813 2.15951 0.212

* p<.05

** p<.005

*** p<.001

< denotes group 2 landmarks that show no significant differences

at the post treatment time point; data given for comparison

purposes

69

Table 3.10 Descriptive Statistics for the Significant

Vertical Landmark at the Post Treatment Time Point

Landmark Group N Mean

Std.

Deviation

Std.

Error

V Condylion 1.00< 21 22.7810 5.82019 1.27007

2.00 29 23.1310 5.20763 .96703

3.00 33 19.7818 4.78621 .83317

Total 83 21.7108 5.38202 .59075

< denotes group 1 landmarks that show no significant differences

at the post treatment time point; data given for comparison

purposes

Table 3.11 ANOVA for the Significant Vertical Measure at the Post

Treatment Time Point

Sum of

Squares df

Mean

Square F Sig.

V Condylion Between

Groups 205.337 2 102.668 3.785 *.027

Within

Groups 2169.884 80 27.124

Total 2375.220 82

* p<.05

** p<.005***

*** p<.001

Table 3.12 Tukey’s Post Hoc Multiple Comparisons of the Significant

Vertical Landmark at the Post Treatment Time Point

Dependent

Variable

(I)

GROUP

(J)

GROUP

Mean

Difference

(I-J)

Std.

Error Sig.

V Condylion 1.00< 2.00 -.35008 1.49228 0.970

3.00 2.99913 1.45380 0.104

2.00 1.00< .35008 1.49228 0.970

3.00 3.34922(*) 1.32560 *0.036

3.00 1.00< -2.99913 1.45380 0.104

2.00 -3.34922(*) 1.32560 *0.036 * p<.05

** p<.005

*** p<.001

< denotes group 1 landmarks that show no significant differences

at the post treatment time point; data given for comparison

purposes

70

Table 3.13 Comparison of Mandibular Horizontal Measures at the T1 and

T2 Time Points

Landmark Group N T1 T2 change

H BPt 1 21 61.9048 60.935 -0.9698

2 29 61.2414 59.7207 -1.5207

3 33 58.9879 55.5909 -3.397

Total 83 60.5133 58.3549 -2.1584

H Pog 1 21 61.3857 59.881 -1.5047

2 29 60.8172 59.3759 -1.4413

3 33 58.6848 55.3364 -3.3484

Total 83 60.1133 57.8976 -2.2157

H Gn 1 21 58.6762 56.4238 -2.2524

2 29 58.1448 56.4414 -1.7034

3 33 55.8091 51.9364 -3.8727

Total 83 57.3506 54.6458 -2.7048

H Me 1 21 54.7905 51.8095 -2.981

2 29 53.1345 51.2828 -1.8517

3 33 50.9333 46.8788 -4.0545

Total 83 52.6783 49.6651 -3.0132

H Go 1 21 -11.419 -15.119 -3.7

2 29 -11.631 -14.4897 -2.8587

3 33 -11.303 -16.403 -5.1

Total 83 -11.447 -15.4096 -3.9626

H Co 1 21 -19.6095 -20.8905 -1.281

2 29 -20.4931 -21.0069 -0.5138

3 33 -19.5061 -20.6545 -1.1484

Total 83 -19.8771 -20.8373 -0.9602

71

Table 3.14 Comparison of Mandibular Vertical Measures at T1 and T2

Landmark Group N T1 Mean T2 Mean Change

V BPt 1 21 94.6571 101.0381 6.381

2 29 94.6897 100.4276 5.7379

3 33 93.7909 99.8061 6.0152

Total 83 94.3241 100.3349 6.0108

V Pog 1 21 107.0714 116.8333 9.7619

2 29 106.2793 112.2241 5.9448

3 33 107.3212 114.1424 6.8212

Total 83 106.894 114.153 7.259

V Gn 1 21 111.2476 120.581 9.3334

2 29 111.7655 118.469 6.7035

3 33 112.5182 119.3152 6.797

Total 83 111.9337 119.3398 7.4061

V Me 1 21 112.3762 121.3429 8.9667

2 29 113.5724 120.2 6.6276

3 33 113.6394 120.1485 6.5091

Total 83 113.2964 120.4687 7.1723

V Go 1 21 74.1714 78.6714 4.5

2 29 74.2448 78.1759 3.9311

3 33 76.9364 78.4152 1.4788

Total 83 75.2964 78.3964 3.1

V Co 1 21 23.4714 22.781 -0.6904

2 29 22.0069 23.131 1.1241

3 33 21.4606 19.7818 -1.6788

Total 83 22.1602 21.7108 -0.4494

72

Table 3.15 Comparison of the Horizontal Maxillary Landmarks at T1 and

T2

Landmark Group N T1 Mean T2 Mean Change

H ANS 1 21 70.7095 69.8714 -0.8381

2 29 72.0586 71.1207 -0.9379

3 33 71.5424 69.803 -1.7394

Total 83 71.512 70.2807 -1.2313

H PNS 1 21 18.2857 16.9762 -1.3095

2 29 16.4276 15.3586 -1.069

3 33 16.7061 14.6212 -2.0849

Total 83 17.0084 15.4747 -1.5337

H APt 1 21 68.5048 67.5667 -0.9381

2 29 68.9414 67.6759 -1.2655

3 33 67.9273 65.9576 -1.9697

Total 83 68.4277 66.9651 -1.4626

Table 3.16 Comparison of Vertical Maxillary Landmarks at T1 and T2

Landmark Group N T1 Mean T2 Mean Change

V ANS 1 21 46.5048 50.6619 4.1571

2 29 47.7379 50.9931 3.2552

3 33 47.0939 50.8697 3.7758

Total 83 47.1699 50.8602 3.6903

V PNS 1 21 44.3952 47.6619 3.2667

2 29 45.3379 46.5276 1.1897

3 33 45.5242 46.9121 1.3879

Total 83 45.1735 46.9675 1.794

V APt 1 21 49.4667 54.3952 4.9285

2 29 51.5655 55.1517 3.5862

3 33 51.0606 55.0667 4.0061

Total 83 50.8337 54.9265 4.0928

73

Table 3.17 Comparison of Horizontal Soft Tissue Landmarks at T1 and T2

Landmark Group N T1 Mean T2 Mean Change

1 21 99.1286 102.481 3.3524

2 29 101.4414 103.0793 1.6379

3 33 98.8152 99.3212 0.506

H PRN

Total 83 99.812 101.4337 1.6217

1 21 85.7286 87.0762 1.3476

2 29 86.7207 87.0207 0.3

3 33 84.3636 83.5636 -0.8

H SBN

Total 83 85.5325 85.6602 0.1277

1 21 90.4857 90.8762 0.3905

2 29 88.3931 87.7759 -0.6172

3 33 86.1273 84.8576 -1.2697

H LS

Total 83 88.0217 87.4 -0.6217

1 21 82.919 82.5524 -0.3666

2 29 80.2414 79.9138 -0.3276

3 33 78.3091 76.1333 -2.1758

H SS

Total 83 80.1506 79.0783 -1.0723

1 21 82.2238 82.3143 0.0905

2 29 79.9517 79.7724 -0.1793

3 33 77.9273 75.8939 -2.0334

H SI

Total 83 79.7217 78.8735 -0.8482

1 21 86.3 86.7619 0.4619

2 29 83.8586 83.8621 0.0035

3 33 81.6061 80.1939 -1.4122

H LI

Total 83 83.5807 83.1373 -0.4434

1 21 75.0667 75.3333 0.2666

2 29 73.7966 72.8483 -0.9483

3 33 72.4697 69.3909 -3.0788

H POG’

Total 83 73.5904 72.1024 -1.488

74

Table 3.18 Comparison of Vertical Soft Tissue Landmarks at T1 and T2

Landmark Group N T1 Mean T2 Mean Change

1 21 37.4381 44.1048 6.6667

2 29 40.131 44.7621 4.6311

3 33 40.703 46.4364 5.7334

V PRN

Total 83 39.6771 45.2614 5.5843

1 21 50.5952 56.0238 5.4286

2 29 53.1069 57.2828 4.1759

3 33 52.4242 57.6182 5.194

V SBN

Total 83 52.2 57.0976 4.8976

1 21 64.6952 70.619 5.9238

2 29 67.1586 71.669 4.5104

3 33 66.9152 72.0061 5.0909

V LS

Total 83 66.4386 71.5373 5.0987

1 21 73.4619 79.6762 6.2143

2 29 74.8207 78.6172 3.7965

3 33 74.0848 78.7636 4.6788

V SS

Total 83 74.1843 78.9434 4.7591

1 21 74.6619 80.6 5.9381

2 29 75.8034 79.4103 3.6069

3 33 75.6121 79.7818 4.1697

V SI

Total 83 75.4386 79.859 4.4204

1 21 82.6143 89.6571 7.0428

2 29 83.3828 87.5207 4.1379

3 33 83.0394 88.7909 5.7515

V LI

Total 83 83.0518 88.5663 5.5145

1 21 106.2333 114.019 7.7857

2 29 108.1103 113.4828 5.3725

3 33 104.997 112.0848 7.0878

V POG’

Total 83 106.3976 113.0627 6.6651

75

Table 3.19 Comparison of Horizontal Dental Landmarks at T1 and T2

Landmark Group N T1 Mean T2 Mean Change

1 21 31.9143 32.1667 0.2524

2 29 31.1517 31.7414 0.5897

3 33 30.4242 29.6455 -0.7787

H PFOP

Total 83 31.0554 31.0157 -0.0397

1 21 74.5857 73.319 -1.2667

2 29 72.6034 71.4517 -1.1517

3 33 71.4303 68.5333 -2.897

H AFOP

Total 83 72.6386 70.7639 -1.8747

1 21 45.1 44.9905 -0.1095

2 29 44.1552 43.7379 -0.4173

3 33 43.2333 41.8515 -1.3818

H U6A

Total 83 44.0277 43.3048 -0.7229

1 21 33.2524 34.0571 0.8047

2 29 31.9862 33.3828 1.3966

3 33 30.1545 30.6091 0.4546

H L6A

Total 83 31.5783 32.4506 0.8723

1 21 41.8 43.3143 1.5143

2 29 41.8207 42.2414 0.4207

3 33 39.7182 39.9727 0.2545

H L6C

Total 83 40.9795 41.6108 0.6313

1 21 74.6905 73.2381 -1.4524

2 29 72.3552 71.169 -1.1862

3 33 71.5818 68.4182 -3.1636

H U1C

Total 83 72.6386 70.5988 -2.0398

1 21 62.5905 62.4286 -0.1619

2 29 63.2724 62.1276 -1.1448

3 33 61.7727 60.0848 -1.6879

H U1A

Total 83 62.5036 61.3916 -1.112

1 21 70.9714 70.8286 -0.1428

2 29 69.3517 69.0966 -0.2551

3 33 67.203 65.8545 -1.3485

H L1I

Total 83 68.9072 68.2458 -0.6614

1 21 57.0857 56.3619 -0.7238

2 29 55.6103 54.4276 -1.1827

3 33 54.3545 51.0303 -3.3242

H L1A

Total 83 55.4843 53.5663 -1.918

76

Table 3.20 Comparison of Vertical Dental Landmarks at T1 and T2

Landmark Group N T1 Mean T2 Mean Change

1 21 66.1714 71.7381 5.5667

2 29 67.5276 71.5069 3.9793

3 33 67.8091 71.0909 3.2818

V PFOP

Total 83 67.2964 71.4 4.1036

1 21 76.819 82.1524 5.3334

2 29 77.4966 80.5793 3.0827

3 33 77.7667 82.2818 4.5151

V AFOP

Total 83 77.4325 81.6542 4.2217

1 21 48.119 53.5 5.381

2 29 49.3586 53.1345 3.7759

3 33 49.7667 53.6485 3.8818

V U6A

Total 83 49.2072 53.4313 4.2241

1 21 89.0095 95.4857 6.4762

2 29 89.3 93.7966 4.4966

3 33 89.6576 93.6636 4.006

V L6A

Total 83 89.3687 94.1711 4.8024

1 21 68.081 74.3286 6.2476

2 29 69.5828 73.669 4.0862

3 33 69.8697 73.5909 3.7212

V U6C

Total 83 69.3169 73.8048 4.4879

1 21 68.2619 74.9143 6.6524

2 29 69.9448 74.0828 4.138

3 33 70.0606 74.3121 4.2515

V L6C

Total 83 69.5651 74.3843 4.8192

1 21 76.5048 81.8476 5.3428

2 29 77.5345 81.2172 3.6827

3 33 77.3576 82.0909 4.7333

V U1I

Total 83 77.2036 81.7241 4.5205

1 21 49.2714 55.3381 6.0667

2 29 51.631 55.5517 3.9207

3 33 51.4848 57.5879 6.1031

V U1A

Total 83 50.9759 56.3072 5.3313

1 21 72.8619 79.9762 7.1143

2 29 74.2448 79.769 5.5242

3 33 74.003 80.1758 6.1728

V L1I

Total 83 73.7988 79.9831 6.1843

1 21 92.7238 99.6381 6.9143

2 29 93.6241 98.3862 4.7621

3 33 92.8667 97.5273 4.6606

V L1A

Total 83 93.0952 98.3614 5.2662

77

Discussion

Design

The design of this retrospective study was aimed to

produce a truly randomized sample without selection bias.

To this end, all of the initial 200 patients were included

in the study despite the resulting occlusion or amount of

gingival display produced or eliminated during orthodontic

treatment. Because the change in gingival display obtained

during orthodontic treatment was the sole factor used to

create the groups, without respect to the initial gingival

display presented, the subjects in the “greatest increase

in gingival display” group could or could not have obtained

a “gummy” smile during orthodontic treatment, just as those

in the “greatest decrease in gingival display” group could

or could not have obtained a certain result. This study

investigated the change in gingival display or relation of

the upper lip to the maxillary teeth during treatment and

attempted to determine what, if any, cephalometric landmark

changes occurred to produce this change in lip drape

without introducing the selection bias that would be

produced by selecting only those that had excessive

gingival display after orthodontic treatment as has been

done in the past.

78

Findings

This study evaluated the pre-treatment and post-

treatment cephalometric radiographs of three groups of

subjects that experienced different changes in gingival

display during orthodontic treatment. The purpose of this

study was to determine if there are any pre-treatment

cephalometric characteristics that are associated with the

tendency to develop a gingival smile during orthodontic

treatment and what cephalometric changes occur to produce

changes in gingival display.

The ANOVA found no significant differences between the

three groups at the pre-treatment time point for any of the

variables. However, group 1 appears to have the tendency

to have more protrusive lips, a more forward dentition, a

more forward positioned mandible, and shorter ramus than

the average group. On the contrary, group 3 had the

tendency to have the lips, dentition, and mandible

positioned posteriorly and a longer ramus relative to the

average group.

The paired T tests revealed many significant vertical

changes between the T1 and T2 time points, as would be

expected in subjects beginning treatment between the age of

10 and 14; this effect is due to growth. All vertical

measures were significant within each group between the T1

79

and T2 time points except for Nasion and Condylion. This

indicates that all groups changed significantly vertically

during the treatment period. However, further

investigation suggests that group 1 had the tendency to

obtain the greatest vertical changes, followed by group 3,

and finally group 2. In fact, group 1 obtained the

greatest vertical changes in all variables except condylion

and the maxillary incisor apex.

The horizontal measures demonstrated more variability.

While all groups had some significant horizontal

differences within the group from the T1 to T2 time period,

Group 3 (the greatest increase group) had more variables

change significantly in the horizontal direction from the

T1 to T2 time period that the other groups.

The significant horizontal changes in Group 1, the

greatest decrease group, occurred at pronasale, subnasale,

menton, and gonion suggesting that only the nasal soft

tissue and the lower border of the mandible changed

significantly in the horizontal direction. The data

reveals that the soft tissue moved forward as would be

expected, and the lower border of the mandible moved

backward. The other tendencies, although not significant,

were for the soft tissue and mandibular first molar to move

forward, the teeth to move relatively little horizontally,

80

although slightly back, and the maxilla and other

mandibular points to move backward.

In group 2, only pronasale, A point, B point,

Gnathion, menton, gonion, and L-6 Apex changed

significantly in the horizontal direction from T1 to T2.

The data suggests that the maxilla and mandible moved

significantly in the backward direction, while pronasale

and the mandibular first molar apex moved forward. The

other tendencies, although not significant, include the

soft tissue remaining relatively the same, the teeth moving

forward, and the other maxillary and mandibular points

moving backward.

In Group 3, all horizontal measures were significant

with the exception of Nasion, Pronasale, subnasale,

Posterior Functional Occlusal Plane, and the mandibular

first molar tip and apex. Further examination reveals that

all significant horizontal changes in Group 3 occurred in

the backward direction. In fact, all horizontal changes in

the soft tissue, maxilla, mandible, and teeth were in the

backward direction with the exception of nasion, pronasale,

and the mandibular first molar.

The mean horizontal and vertical measures of each of

the landmarks were plotted on an X-Y axis and used to

produce a graphical representation of the changes from T1

81

to T2 for each of the groups.(See Figures 3.6, 3.7, and

3.8)

Figure 3.6

Group 1

82

Figure 3.7

Group 2

83

Figure 3.8

Group 3

84

From these figures it is apparent that all three

groups experienced significant downward change during

treatment, probably due to both growth and the extrusive

effects of treatment. However, group 1 experienced the most

vertical change, followed by group 3, and finally by group

2. While the maxilla and mandible move slightly in the

backward direction in groups 1 and 2, the soft tissue,

teeth,and overall growth vector tend to be in a downward

and forward direction, although more downward in the group

1. In group 3, all variables have a downward and backward

vector with the exception of the tip of the nose and the

mandibular molar.

Although the ANOVA did not detect any significant

differences in the horizontal position of the maxilla,

mandible, or teeth between the groups at the post treatment

time point, it appears that the cumulative effects of the

individual components affected the soft tissue of the lips

(labrale superius, stomion superius, stomion inferius, and

labrale inferius) to a significant degree between the two

extreme groups (groups 1 and 3). The soft tissue lips were

significantly further back in the greatest increase group,

group 3, than the greatest decrease group, group 1, at the

post treatment time point. This is not surprising as the

average lips moved backward during treatment in group 3,

85

while the lips stayed relatively the same, or moved

slightly forward in group 1. Because the ANOVA found no

significant differences in these or any other variable at

the pretreatment time point, these differences can be

attributed to a change that occurred during treatment.

The only significant vertical measure was Condylion

between groups 2 and 3. It appears that the condyle moved

significantly more in an upward direction in the greatest

increase group (group 3) than the average group (group 2),

which stayed relatively the same. Group 1 had a tendency to

have a vertical vector of growth as well, although not to a

significant degree. The other mandibular measures showed

similar amounts of downward change, with group 1 having a

slight tendency to obtain more downward change at the

pogonion and gnathion measures, followed by group 3, and

finally group 2. This trend for group 1 to obtain the

greatest vertical change was apparent in the maxillary and

dental vertical measures as well. However, the trend for

group 3 to obtain greater vertical changes than group 2 was

not as clear in these measures.

The soft tissues demonstrated some interesting post

treatment tendencies. There appears to be a tendency for

pronasale, subnasale, and labrale superius, stomion

superius, stomion inferius, and labrale inferius to start

86

treatment higher vertically in the greatest decrease group

than the greatest increase group. However, at the post

treatment time point, while pronasale, subnasale, and

labrale superius, remain more superior vertically in the

greatest decrease group, stomion superius, stomion

inferius, and labrale inferius are positioned inferior to

the same landmarks in group 3. It appears that although

the nose and superior most point on the upper lip retain

their pattern, the point where the upper lip meets the

lower lip moves more inferiorly during treatment in group 1

than group 3.

This suggests that a lip response to treatment could

be an important factor in gingival display. The data

suggests that the lips responded to the vertical component

of growth (or change) in group 1, but did not respond in a

similar fashion in group 3. Perhaps this lack of downward

movement of the point where the lips meet in group 3 could

be a function of the significant movement of the lips

horizontally backward during treatment.

In summary, the soft tissue lips and skeletal vertical

condylion were the only significant differences found

between the groups. However, further examination and

plotting of the mean X-Y location of each of the points and

the pre and post treatment time points reveal a generalized

87

tendency for the greatest decrease group, or group 1 to

have a large vertical component, as well as a forward

component. The average group, or group 2, has the tendency

to change in the typical downward and forward pattern, and

the greatest increase group, or group 3, has the tendency

to change in a slightly increased downward and backward

direction. Further examination of the lips suggests that

the lips of subjects in group 1 responded vertically to the

inferior vector of change during treatment, while the lips

of subjects in group 3 did respond in a similar fashion.

This suggests that the significant horizontal (backward)

movement of the lips during treatment affected the downward

response.

Aside from dental and skeletal components, other

considerations in gingival display suggested by the

literature are sex, molar classification, and lip length.

In this study, 61% of the greatest increase group, group 3,

were female (39% male). Accordingly, 62% of the greatest

decrease group, group 1, were male (38% female. Although

weak, this tendency is in agreement with the literature,

which suggests that the tendency to have a gingival smile

is predominantly a female characteristic, while a low smile

line is predominantly a male characteristic.4,3,5,6 The middle

group was

88

59% female and 41% male, which closely resembles the

original sample which was 57% female and 43% male (see

Table 3.21.)

Table 3.21 Group Gender Percentages

Group Number of

Subjects

Mean Change

in Gingival

Display

Gender

Differences

Percentages

1

21 -2.55 8 Females

13 Males

38% Female

62% Male

2

29 0.65 17 Females

12 Males

59% Female

41% Male

3

33 3.75 20 Females

13 Males

61% Female

39% Male

When lip length of the sample is investigated, it

appears that although insignificant, group 3, who obtained

the greatest increase in gingival display, tends to have a

slightly shorter lip length at T1, while group 1, the

greatest decrease group, tends to have the longest lip

length at T1 (see Table 3.22). For this purpose, lip

length was defined as the vertical length from subnasale to

stomion superius as defined by Peck et al.3 This finding is

consistent with the findings of Peck et al. who found no

significant difference in upper lip length between his

gingival smile group and reference group3 and Schendel et

al. who reported that surgical vertical maxillary excess

patients have normal lip lengths.7 The mean lip lengths

found were also in accordance with the reported “normal”

89

lip lengths at approximately 22 mm. However, the tendency

found is contrary to the findings of Singer who found that

his group of gingival smile subjects had significantly

longer lip lengths than his non-gingival display sample.8

Table 3.22 Mean Lip Length at T1

Group N VSBN1 VSTMSU1 Lip Length

1 21 50.5952 73.4619 22.8667

2 29 53.1069 74.8207 21.7138

3 33 52.4242 74.0848 21.6606

When the lip length at the T2 time point is examined,

this same trend continues (see table 3.23). However, when

the change in lip length from T1 to T2 is examined, it

appears that the greatest decrease in gingival display

group, group 1, had an increase in lip length between the

T1 and T2 time points, while the average group and the

greatest increase groups experienced a decrease in lip

length during treatment (see table 3.24)

Table 3.23 Mean Lip Length at T2

Group N VSBN2 VSTMSU2 Lip Length

1 21 56.0238 79.6762 23.6524

2 29 57.2828 78.6172 21.3344

3 33 57.6182 78.7636 21.1454

Table 3.24 Change in Mean Lip Length from T1 to T2

Group N

T1 Lip

Length

T2 Lip

Length Change

1 21 22.8667 23.6524 0.7857

2 29 21.7138 21.3344 -0.3794

3 33 21.6606 21.1454 -0.5152

90

When the molar classification of the three groups is

considered it appears that groups 2 and 3 have a larger

number of subjects with a class I molar classification,

groups 1 and 3 have a large number of class II subjects,

and all groups have approximately the same number of class

III subjects (see Table 3.25).

Table 3.25 Group Molar Classification

Molar Classification Group 1 Group 2 Group 3

Class I 8 21 19

Crowding 2 4 4

Division 1 2 1 7

Division 2 5 0 0

Class II

Total 9 5 11

Class III 4 3 3

Upon further examination, 75% of group 2, the average

group, was Class I molar. While groups 1 and 3 have large

percentages of Class I’s as well, 38% and 58% respectively,

Class II’s also demonstrate a strong presence in these

groups (43% and 33%). The Class III subjects, although

small in number, make up almost 20% of the greatest

decrease group, group 1 (see Table 3.26).

91

Table 3.26 Molar Classification Percentages

Group Class I Class II Class III

1 (N=21) 38 % (8) 43 % (9) 19 % (4)

2 (N=29) 73 % (21) 17 % (5) 10 % (3)

3 (N=33) 58 % (19) 33 % (11) 9 % (3)

When the Class II subjects are examined, of the 25

Class II subjects in the sample, 36% of them are in group

1, the greatest decrease group, and it appears that the

majority of the Class II subjects in group 1 are Division 2

(56%). In fact, the only Class II Division 2 subjects in

the sample, are in the greatest decrease group. 20% of the

class II subjects were in group 2, the average group. The

majority of the Class II subjects in group 2 are Class II

crowding subjects (80%). 44% of the class II subjects are

in group 3, and the majority of the Class II subjects in

group 3, the greatest increase group, are division 1

(64%)(see Tables 3.27 and 3.28).

Table 3.27 Group Percentages of Class II’s

Group Number of Class II’s Percentage of Class

II Subjects in Group

1 9 36%

2 5 20%

3 11 44%

92

Table 3.28 Class II Division Percentages

Group Crowding Division 1 Division 2 Total

1 2 (22%) 2 (22%) 5 (56%) 9

2 4 (80%) 1 (20%) 0 5

3 4 (36%) 7 (64%) 0 11

Although no clear conclusions can be drawn from the

Class I group, it appears that the Class II division groups

tend to experience either a great decrease or a great

increase in gingival display during treatment. This study

suggests that Class II division 1 subjects tend to

experience a great increase in gingival display, and Class

II division 2 subjects experience a great decrease. It

also suggests a slight tendency for Class III subjects to

experience a great decrease.

In conclusion, while no significant differences were

found at the pre-treatment time point to suggest one

specific pretreatment characteristic to identify patients

with the predisposition to experience an increase or

decrease in gingival display during treatment, the tendency

was for the greatest decrease group, group 1, to be male,

to be Class I, Class II division 2, or Class III, to have

slightly protrusive lips, teeth and mandibles, and short

93

rami in comparison to the average group. The greatest

increase group, group 3, tended to be female, to be Class I

or Class II crowding or division 1, and to have posteriorly

positioned maxillary, mandibular, and dental landmarks in

comparison to the average group with the exception of

gonion, which suggests a high mandibular plane angle. They

also had longer rami than the average group. Therefore,

careful study of cephalometric measures in the pre-

treatment radiograph for a pattern of anteriorly or

posteriorly positioned landmarks while considering the sex

of the patient and molar classification, might help a

clinician to recognize those that will have the tendency to

lose or gain gingival display during treatment.

While no specific maxillary, mandibular, or dental

movements can be identified to determine which movements

during treatment caused these patterns of change, it

appears that a strong downward vector of growth (or change)

during treatment can cause a decrease in gingival display,

while a downward and backward vector can produce a great

increase. Therefore, mechanics aimed toward preventing a

backward horizontal vector of change and instead promoting

a forward horizontal vector, could help to prevent an

excessive increase in gingival display during treatment,

94

while controlling the vertical in forward growers appears

to be important in preventing an excessive decrease.

Conclusions

1. No significant differences were found at the pre-

treatment time point, therefore no specific dental,

skeletal, or soft tissue characteristic can be

identified to predict an increase or decrease in

gingival display during orthodontic treatment.

2. The only vertical significant difference was found at

the post-treatment time point between the average

change group and the greatest increase group at

condylion; this significance is possibly due to the

large envelope of error at the condylion landmark.

3. The significant horizontal differences were found

between the greatest increase and greatest decrease

groups at labrale superius, stomion superius, stomion

inferius, and labrale inferius (the lips). The lips

moved significantly backward in the greatest increase

group while they stayed relatively the same in the

greatest decrease group.

4. Although not significant, the greatest decrease group

had a tendency to be male, have slightly protrusive

lips, forward positioned teeth and mandibles, and

95

shorter rami in comparison to the average group at

the pre-treatment time point. They experienced a

large vertical vector in change from T1 to T2. The

greatest increase group had a tendency to be female,

have posteriorly positioned maxillary, mandibular,

and dental landmarks, and longer rami in comparison

to the average group at the pre-treatment time point.

They tend to have a downward and backward vector in

change from T1 to T2.

5. The change in gingival display during orthodontic

treatment is a very complex phenomenon that is a

culmination of the affects of changes that occur in

the dental, skeletal, and soft tissue components.

Further research is warranted.

96

Appendix A: Nonsignificant Pre-treatment Data

Table A.1 Pre-Treatment Horizontal Mandibular Measures Descriptive

Statistics

Landmark Group N Mean

Std.

Deviation Std. Error

APBPT1 1.00 21 61.9048 7.77628 1.69692

2.00 29 61.2414 7.13930 1.32574

3.00 33 58.9879 8.31147 1.44684

Total 83 60.5133 7.79302 .85540

APPOG1 1.00 21 61.3857 8.89260 1.94052

2.00 29 60.8172 7.62239 1.41544

3.00 33 58.6848 9.21158 1.60353

Total 83 60.1133 8.58203 .94200

APGN1 1.00 21 58.6762 9.54950 2.08387

2.00 29 58.1448 8.12604 1.50897

3.00 33 55.8091 9.53272 1.65943

Total 83 57.3506 9.04886 .99324

APME1 1.00 21 54.7905 10.33073 2.25435

2.00 29 53.1345 8.46502 1.57192

3.00 33 50.9333 9.67954 1.68499

Total 83 52.6783 9.46061 1.03844

APGO1 1.00 21 -11.4190 5.28182 1.15259

2.00 29 -11.6310 5.56431 1.03327

3.00 33 -11.3030 6.03057 1.04979

Total 83 -11.4470 5.62044 .61692

APCO1 1.00 21 19.6095 3.84459 .83896

2.00 29 20.4931 3.30270 .61330

3.00 33 19.5061 3.44329 .59940

97

Table A.2 ANOVA for Pre-Treatment Horizontal Mandibular Measures

Landmark

Sum of

Squares df Mean Square F Sig.

Between Groups 132.820 2 66.410 1.096 .339

Within Groups 4847.135 80 60.589

APBPT1

Total 4979.955 82

Between Groups 115.706 2 57.853 .781 .461

Within Groups 5923.690 80 74.046

APPOG1

Total 6039.395 82

Between Groups 133.610 2 66.805 .812 .448

Within Groups 6580.697 80 82.259

APGN1

Total 6714.307 82

Between Groups 200.204 2 100.102 1.122 .331

Within Groups 7139.057 80 89.238

APME1

Total 7339.261 82

Between Groups 1.683 2 .841 .026 .974

Within Groups 2588.644 80 32.358

APGO1

Total 2590.327 82

Between Groups 17.051 2 8.526 .696 .502

Within Groups 980.436 80 12.255

APCO1

Total 997.487 82

98

Table A.3 Pre-Treatment Vertical Mandibular Measures: Descriptive

Statistics

Group N Mean

Std.

Deviation Std. Error

VBPT1 1.00 21 94.6571 9.30589 2.03071

2.00 29 94.6897 8.75905 1.62651

3.00 33 93.7909 5.73663 .99862

Total 83 94.3241 7.76865 .85272

VPOG1 1.00 21 107.0714 10.14934 2.21477

2.00 29 106.2793 9.05891 1.68220

3.00 33 107.3212 6.77227 1.17890

Total 83 106.8940 8.44151 .92658

VGN1 1.00 21 111.2476 9.99828 2.18180

2.00 29 111.7655 8.81473 1.63685

3.00 33 112.5182 6.81425 1.18621

Total 83 111.9337 8.32478 .91376

VME1 1.00 21 112.3762 9.73539 2.12444

2.00 29 113.5724 8.50466 1.57928

3.00 33 113.6394 6.79333 1.18257

Total 83 113.2964 8.13111 .89251

VGO1 1.00 21 74.1714 6.67661 1.45696

2.00 29 74.2448 6.33283 1.17598

3.00 33 76.9364 7.24939 1.26196

Total 83 75.2964 6.84639 .75149

VCO1 1.00 21 23.4714 4.14562 .90465

2.00 29 22.0069 3.86993 .71863

3.00 33 21.4606 4.30319 .74909

Total 83 22.1602 4.14458 .45493

99

Table A.4 ANOVA for Pre-Treatment Vertical Mandibular Measures

Sum of

Squares df Mean Square F Sig.

Between Groups 15.586 2 7.793 .126 .881

Within Groups 4933.266 80 61.666

VBPT1

Total 4948.852 82

Between Groups 17.641 2 8.821 .121 .886

Within Groups 5825.606 80 72.820

VPOG1

Total 5843.247 82

Between Groups 21.979 2 10.989 .155 .856

Within Groups 5660.787 80 70.760

VGN1

Total 5682.766 82

Between Groups 23.874 2 11.937 .177 .838

Within Groups 5397.555 80 67.469

VME1

Total 5421.429 82

Between Groups 147.398 2 73.699 1.595 .209

Within Groups 3696.191 80 46.202

VGO1

Total 3843.589 82

Between Groups 52.939 2 26.469 1.562 .216

Within Groups 1355.620 80 16.945

VCO1

Total 1408.559 82

100

Table A.5 Pretreatment Horizontal Maxillary Measures: Descriptive

Statistics

Landmark

Group N Mean

Std.

Deviation

Std.

Error

APANS1 1.00 21 70.7095 4.26555 .93082

2.00 29 72.0586 5.39931 1.00263

3.00 33 71.5424 5.85657 1.01950

Total 83 71.5120 5.29607 .58132

APPNS1 1.00 21 18.2857 3.76713 .82206

2.00 29 16.4276 4.57469 .84950

3.00 33 16.7061 4.52299 .78735

Total 83 17.0084 4.37775 .48052

APAPT1 1.00 21 68.5048 4.35367 .95005

2.00 29 68.9414 5.52323 1.02564

3.00 33 67.9273 6.11455 1.06441

Total 83 68.4277 5.46129 .59945

Table A.6 ANOVA for Pretreatment Horizontal Maxillary Measures

Landmark

Sum of

Squares df Mean Square F Sig.

APANS1 Between Groups 22.219 2 11.109 .390 .678

Within Groups 2277.749 80 28.472

Total 2299.968 82

APPNS1 Between Groups 47.062 2 23.531 1.235 .296

Within Groups 1524.442 80 19.056

Total 1571.504 82

APAPT1 Between Groups 16.041 2 8.020 .264 .769

Within Groups 2429.665 80 30.371

Total 2445.706 82

101

Table A.7 Pretreatment Vertical Maxillary Measures: Descriptive

Statistics

Landmark

Group N Mean

Std.

Deviation

Std.

Error

VANS1 1.00 21 46.5048 4.36411 .95233

2.00 29 47.7379 3.92368 .72861

3.00 33 47.0939 4.10449 .71450

Total 83 47.1699 4.08733 .44864

VPNS1 1.00 21 44.3952 4.04419 .88251

2.00 29 45.3379 3.71785 .69039

3.00 33 45.5242 3.06982 .53439

Total 83 45.1735 3.54975 .38964

VAPT1 1.00 21 49.4667 4.08978 .89246

2.00 29 51.5655 3.94609 .73277

3.00 33 51.0606 3.88514 .67632

Total 83 50.8337 3.99699 .43873

Table A.8 ANOVA for Pretreatment Vertical Maxillary Measures

Sum of

Squares df

Mean

Square F Sig.

APANS1 Between

Groups 22.219 2 11.109 .390 .678

Within

Groups 2277.749 80 28.472

Total 2299.968 82

APPNS1 Between

Groups 47.062 2 23.531 1.235 .296

Within

Groups 1524.442 80 19.056

Total 1571.504 82

APAPT1 Between

Groups 16.041 2 8.020 .264 .769

Within

Groups 2429.665 80 30.371

Total 2445.706 82

102

Table A.9 – Pretreatment Horizontal Dental Measures: Descriptive

Statistics

N Mean

Std.

Deviation

Std.

Error

1.00 21 31.9143 5.63784 1.23028

2.00 29 31.1517 5.92119 1.09954

3.00 33 30.4242 5.60820 .97626

APU6DCUSP1

Total 83 31.0554 5.68778 .62431

1.00 21 74.5857 8.65981 1.88973

2.00 29 72.6034 6.57634 1.22120

3.00 33 71.4303 7.24027 1.26037

APANTFOP1

Total 83 72.6386 7.42123 .81459

1.00 21 45.1000 5.03329 1.09835

2.00 29 44.1552 5.46956 1.01567

3.00 33 43.2333 5.24289 .91267

APU6APEX1

Total 83 44.0277 5.26075 .57744

1.00 21 33.2524 7.25869 1.58398

2.00 29 31.9862 7.16986 1.33141

3.00 33 30.1545 7.05120 1.22746

APL6APEX1

Total 83 31.5783 7.16935 .78694

1.00 21 41.8000 6.78454 1.48051

2.00 29 41.8207 5.76878 1.07124

3.00 33 39.7182 6.47150 1.12654

APL6TIP1

Total 83 40.9795 6.32430 .69418

1.00 21 74.6905 8.70028 1.89856

2.00 29 72.3552 6.54209 1.21484

3.00 33 71.5818 7.40107 1.28836

APU1TIP1

Total 83 72.6386 7.48388 .82146

1.00 21 62.5905 4.69978 1.02558

2.00 29 63.2724 5.28711 .98179

3.00 33 61.7727 5.30190 .92294

APU1APEX1

Total 83 62.5036 5.13110 .56321

1.00 21 70.9714 8.42117 1.83765

2.00 29 69.3517 6.41737 1.19167

3.00 33 67.2030 7.68820 1.33834

APL1TIP1

Total 83 68.9072 7.53363 .82692

1.00 21 57.0857 8.77863 1.91565

2.00 29 55.6103 7.00349 1.30051

3.00 33 54.3545 7.72812 1.34529

APL1APEX1

Total 83 55.4843 7.74774 .85042

103

Table A.10 ANOVA for Pre-Treatment Horizontal Dental Measures

Sum of

Squares df Mean Square F Sig.

Between Groups 28.906 2 14.453 .441 .645

Within Groups 2623.859 80 32.798

APU6DCUSP1

Total 2652.765 82

Between Groups 127.832 2 63.916 1.165 .317

Within Groups 4388.285 80 54.854

APANTFOP1

Total 4516.117 82

Between Groups 45.441 2 22.721 .817 .445

Within Groups 2223.945 80 27.799

APU6APEX1

Total 2269.386 82

Between Groups 130.572 2 65.286 1.279 .284

Within Groups 4084.189 80 51.052

APL6APEX1

Total 4214.761 82

Between Groups 87.159 2 43.579 1.092 .340

Within Groups 3192.577 80 39.907

APL6TIP1

Total 3279.735 82

Between Groups 127.598 2 63.799 1.143 .324

Within Groups 4465.099 80 55.814

APU1TIP1

Total 4592.697 82

104

Table A.11 Pretreatment Vertical Dental Measures:

Descriptive Statistics

Landmark Group N Mean

Std.

Deviation Std. Error

VU6DCUSP1 1.00 21 66.1714 5.75935 1.25679

2.00 29 67.5276 5.98301 1.11102

3.00 33 67.8091 4.53296 .78909

Total 83 67.2964 5.36478 .58886

VANTFOP1 1.00 21 76.8190 6.02400 1.31455

2.00 29 77.4966 5.92353 1.09997

3.00 33 77.7667 5.07202 .88293

Total 83 77.4325 5.56904 .61128

VU6APEX1 1.00 21 48.1190 5.06178 1.10457

2.00 29 49.3586 4.94264 .91782

3.00 33 49.7667 3.40070 .59199

Total 83 49.2072 4.42057 .48522

VL6APEX1 1.00 21 89.0095 6.72398 1.46729

2.00 29 89.3000 6.35756 1.18057

3.00 33 89.6576 5.58570 .97235

Total 83 89.3687 6.08873 .66833

VU6TIP1 1.00 21 68.0810 5.74279 1.25318

2.00 29 69.5828 5.53954 1.02867

3.00 33 69.8697 4.56505 .79467

Total 83 69.3169 5.21477 .57240

VL6TIP1 1.00 21 68.2619 5.90995 1.28966

2.00 29 69.9448 5.70993 1.06031

3.00 33 70.0606 4.52569 .78782

Total 83 69.5651 5.31313 .58319

VU1TIP1 1.00 21 76.5048 5.93628 1.29540

2.00 29 77.5345 5.81392 1.07962

3.00 33 77.3576 4.75434 .82762

Total 83 77.2036 5.39734 .59244

VU1APEX1 1.00 21 49.2714 5.49819 1.19980

2.00 29 51.6310 5.37202 .99756

3.00 33 51.4848 4.61892 .80405

Total 83 50.9759 5.15297 .56561

VL1TIP1 1.00 21 72.8619 6.54358 1.42793

2.00 29 74.2448 6.64189 1.23337

3.00 33 74.0030 4.94580 .86095

Total 83 73.7988 5.94683 .65275

VL1APEX1 1.00 21 92.7238 7.09767 1.54884

2.00 29 93.6241 6.82331 1.26706

3.00 33 92.8667 5.51048 .95925

Total 83 93.0952 6.33956 .69586

105

Table A.11 (Continued)

Landmark Group N Mean

Std.

Deviation Std. Error

APU6DCUSP1 1.00 21 31.9143 5.63784 1.23028

2.00 29 31.1517 5.92119 1.09954

3.00 33 30.4242 5.60820 .97626

Total 83 31.0554 5.68778 .62431

Table A.12 ANOVA for Pretreatment Vertical Dental Measures

Sum of

Squares df Mean Square F Sig.

Between Groups 36.801 2 18.400 .634 .533

Within Groups 2323.228 80 29.040

VU6DCUSP1

Total 2360.029 82

Between Groups 11.707 2 5.853 .185 .831

Within Groups 2531.455 80 31.643

VANTFOP1

Total 2543.162 82

Between Groups 35.860 2 17.930 .916 .404

Within Groups 1566.536 80 19.582

VU6APEX1

Total 1602.396 82

Between Groups 5.600 2 2.800 .074 .929

Within Groups 3034.359 80 37.929

VL6APEX1

Total 3039.959 82

Between Groups 44.213 2 22.106 .809 .449

Within Groups 2185.683 80 27.321

VU6TIP1

Total 2229.896 82

Between Groups 47.949 2 23.974 .846 .433

Within Groups 2266.860 80 28.336

VL6TIP1

Total 2314.809 82

Between Groups 14.213 2 7.107 .239 .788

Within Groups 2374.556 80 29.682

VU1TIP1

Total 2388.769 82

Between Groups 82.004 2 41.002 1.565 .215

Within Groups 2095.347 80 26.192

VU1APEX1

Total 2177.352 82

Between Groups 25.579 2 12.789 .356 .702

Within Groups 2874.331 80 35.929

VL1TIP1

Total 2899.910 82

Between Groups 12.734 2 6.367 .155 .857

Within Groups 3282.845 80 41.036

VL1APEX1

Total 3295.578 82

Between Groups 28.906 2 14.453 .441 .645

Within Groups 2623.859 80 32.798

APU6DCUSP1

Total 2652.765 82

106

Table A.13 Pretreatment Measures for Non-significant Horizontal Soft

Tissue Landmarks:

Descriptive Statistics

N Mean

Std.

Deviation Std. Error

APPRN1 1.00 21 99.1286 4.72400 1.03086

2.00 29 101.4414 5.45832 1.01358

3.00 33 98.8152 6.11331 1.06419

Total 83 99.8120 5.62664 .61760

APSBN1 1.00 21 85.7286 5.00591 1.09238

2.00 29 86.7207 4.95280 .91971

3.00 33 84.3636 5.73971 .99916

Total 83 85.5325 5.32949 .58499

APLABSU1 1.00 21 90.4857 8.64010 1.88542

2.00 29 88.3931 6.62403 1.23005

3.00 33 86.1273 7.14568 1.24390

Total 83 88.0217 7.49429 .82261

APSTMSU1 1.00 21 82.9190 8.88328 1.93849

2.00 29 80.2414 7.02569 1.30464

3.00 33 78.3091 6.94007 1.20811

Total 83 80.1506 7.63074 .83758

APSTINF1 1.00 21 82.2238 9.53566 2.08085

2.00 29 79.9517 7.13516 1.32497

3.00 33 77.9273 7.01228 1.22068

Total 83 79.7217 7.85295 .86197

APLABIN1 1.00 21 86.3000 10.49486 2.29017

2.00 29 83.8586 7.98411 1.48261

3.00 33 81.6061 7.71889 1.34369

Total 83 83.5807 8.68172 .95294

APPOG1 1.00 21 75.0667 9.85507 2.15055

2.00 29 73.7966 8.41879 1.56333

3.00 33 72.4697 9.60753 1.67246

Total 83 73.5904 9.21900 1.01192

107

Table A.14 ANOVA for Non-significant Pretreatment Horizontal Measures

Sum of

Squares df Mean Square F Sig.

APPRN1 Between Groups 119.592 2 59.796 1.932 .152

Within Groups 2476.456 80 30.956

Total 2596.048 82

APSBN1 Between Groups 86.835 2 43.418 1.549 .219

Within Groups 2242.247 80 28.028

Total 2329.082 82

APLABSU1 Between Groups 249.931 2 124.966 2.295 .107

Within Groups 4355.550 80 54.444

Total 4605.481 82

APSTMSU1 Between Groups 273.097 2 136.549 2.427 .095

Within Groups 4501.610 80 56.270

Total 4774.707 82

APSTINF1 Between Groups 239.265 2 119.633 1.987 .144

Within Groups 4817.576 80 60.220

Total 5056.841 82

APLABIN1 Between Groups 286.200 2 143.100 1.942 .150

Within Groups 5894.329 80 73.679

Total 6180.529 82

APPOG1 Between Groups 88.446 2 44.223 .514 .600

Within Groups 6880.726 80 86.009

Total 6969.172 82

108

Table A.15 Pretreatment Vertical Measures for Soft Tissue Landmarks:

Descriptive Statistics

N Mean

Std.

Deviation

Std.

Error

VPRN1 1.00 21 37.4381 4.44032 .96896

2.00 29 40.1310 5.91488 1.09837

3.00 33 40.7030 5.08604 .88537

Total 83 39.6771 5.35073 .58732

VSBN1 1.00 21 50.5952 4.08295 .89097

2.00 29 53.1069 4.81426 .89399

3.00 33 52.4242 4.90510 .85387

Total 83 52.2000 4.72652 .51880

VLABSU1 1.00 21 64.6952 5.44495 1.18819

2.00 29 67.1586 6.56166 1.21847

3.00 33 66.9152 4.84033 .84259

Total 83 66.4386 5.66824 .62217

VSTMSU1 1.00 21 73.4619 6.72588 1.46771

2.00 29 74.8207 6.05837 1.12501

3.00 33 74.0848 5.00132 .87062

Total 83 74.1843 5.79730 .63634

VSTINF1 1.00 21 74.6619 6.62982 1.44674

2.00 29 75.8034 5.66969 1.05283

3.00 33 75.6121 5.23311 .91097

Total 83 75.4386 5.70945 .62669

VLABIN1 1.00 21 82.6143 9.11210 1.98842

2.00 29 83.3828 6.53917 1.21429

3.00 33 83.0394 6.40561 1.11507

Total 83 83.0518 7.13812 .78351

VPOG1 1.00 21 106.2333 8.96874 1.95714

2.00 29 108.1103 9.40351 1.74619

3.00 33 104.9970 7.09976 1.23591

Total 83 106.3976 8.44500 .92696

109

Table A.16 ANOVA for Pretreatment Vertical for Soft Tissue Landmarks

Sum of

Squares df Mean Square F Sig.

VPRN1 Between Groups 145.985 2 72.993 2.652 .077

Within Groups 2201.701 80 27.521

Total 2347.687 82

VSBN1 Between Groups 79.591 2 39.796 1.817 .169

Within Groups 1752.289 80 21.904

Total 1831.880 82

VLABSU1 Between Groups 86.354 2 43.177 1.356 .264

Within Groups 2548.222 80 31.853

Total 2634.577 82

VSTMSU1 Between Groups 23.030 2 11.515 .337 .715

Within Groups 2732.880 80 34.161

Total 2755.910 82

VSTINF1 Between Groups 17.522 2 8.761 .264 .769

Within Groups 2655.494 80 33.194

Total 2673.017 82

VLABIN1 Between Groups 7.201 2 3.601 .069 .933

Within Groups 4170.926 80 52.137

Total 4178.127 82

VPOG1 Between Groups 150.376 2 75.188 1.056 .353

Within Groups 5697.703 80 71.221

Total 5848.080 82

110

Appendix B: Non-significant Post Treatment Data

Table B.1 Post-Treatment Non-Significant Horizontal Mandibular

Measures: Descriptive Statistics

N Mean

Std.

Deviation

Std.

Error

APBPT2 1.00 20 60.9350 8.89673 1.98937

2.00 29 59.7207 8.00211 1.48596

3.00 33 55.5909 9.41041 1.63814

Total 82 58.3549 9.00615 .99456

APPOG2 1.00 21 59.8810 10.18571 2.22270

2.00 29 59.3759 8.57441 1.59223

3.00 33 55.3364 10.14254 1.76559

Total 83 57.8976 9.74547 1.06970

APGN2 1.00 21 56.4238 10.38335 2.26583

2.00 29 56.4414 9.05793 1.68202

3.00 33 51.9364 10.79363 1.87893

Total 83 54.6458 10.23134 1.12304

APME2 1.00 21 51.8095 10.35750 2.26019

2.00 29 51.2828 9.92033 1.84216

3.00 33 46.8788 11.27691 1.96306

Total 83 49.6651 10.70626 1.17516

APGO2 1.00 21 -15.1190 7.43442 1.62232

2.00 29 -14.4897 5.36119 .99555

3.00 33 -16.4030 5.84826 1.01805

Total 83 -15.4096 6.11231 .67091

APCO2 1.00 21 -20.8905 3.74725 .81772

2.00 29 -21.0069 3.63789 .67554

3.00 33 -20.6545 2.97291 .51752

Total 83 -20.8373 3.37894 .37089

111

Table B.2 ANOVA for Post-Treatment Mandibular Horizontal Measures

Sum of

Squares df Mean Square F Sig.

APBPT2 Between Groups 439.343 2 219.671 2.831 .065

Within Groups 6130.620 79 77.603

Total 6569.963 81

APPOG2 Between Groups 362.458 2 181.229 1.953 .149

Within Groups 7425.422 80 92.818

Total 7787.880 82

APGN2 Between Groups 402.141 2 201.071 1.966 .147

Within Groups 8181.645 80 102.271

Total 8583.786 82

APME2 Between Groups 428.654 2 214.327 1.911 .155

Within Groups 8970.515 80 112.131

Total 9399.169 82

APGO2 Between Groups 58.883 2 29.442 .784 .460

Within Groups 3004.669 80 37.558

Total 3063.552 82

APCO2 Between Groups 1.996 2 .998 .085 .918

Within Groups 934.219 80 11.678

Total 936.214 82

112

Table B.3 Post-Treatment Non-Significant Vertical Mandibular Measures:

Descriptive Statistics

N Mean

Std.

Deviation

Std.

Error

VBPT2 1.00 21 101.0381 10.46535 2.28373

2.00 29 100.4276 8.00548 1.48658

3.00 33 99.8061 6.65277 1.15810

Total 83 100.3349 8.13086 .89248

VPOG2 1.00 21 116.8333 11.22891 2.45035

2.00 29 112.2241 8.10871 1.50575

3.00 33 114.1424 7.22176 1.25715

Total 83 114.1530 8.75861 .96138

VGN2 1.00 21 120.5810 11.04272 2.40972

2.00 29 118.4690 8.21671 1.52581

3.00 33 119.3152 6.98946 1.21671

Total 83 119.3398 8.51604 .93476

VME2 1.00 21 121.3429 10.50155 2.29163

2.00 29 120.2000 7.98199 1.48222

3.00 33 120.1485 6.70854 1.16781

Total 83 120.4687 8.15345 .89496

VGO2 1.00 21 78.6714 8.89203 1.94040

2.00 29 78.1759 6.42360 1.19283

3.00 33 78.4152 7.06864 1.23049

Total 83 78.3964 7.27393 .79842

113

Table B.4 ANOVA for Non-Significant Post-Treatment Vertical Mandibular

Measures

Sum of

Squares df Mean Square F Sig.

VBPT2 Between Groups 19.862 2 9.931 .147 .863

Within Groups 5401.226 80 67.515

Total 5421.089 82

VPOG2 Between Groups 258.766 2 129.383 1.716 .186

Within Groups 6031.720 80 75.397

Total 6290.487 82

VGN2 Between Groups 54.362 2 27.181 .369 .693

Within Groups 5892.517 80 73.656

Total 5946.879 82

VME2 Between Groups 21.525 2 10.762 .159 .854

Within Groups 5429.734 80 67.872

Total 5451.259 82

VGO2 Between Groups 3.011 2 1.505 .028 .973

Within Groups 4335.618 80 54.195

Total 4338.629 82

114

Table B.5 Post-Treatment Horizontal Maxillary Measures: Descriptive

Statistics

N Mean

Std.

Deviation

Std.

Error

APANS2 1.00 21 69.8714 5.53698 1.20827

2.00 29 71.1207 5.68321 1.05535

3.00 33 69.8030 6.23987 1.08622

Total 83 70.2807 5.83826 .64083

APPNS2 1.00 21 16.9762 3.69282 .80584

2.00 29 15.3586 5.07779 .94292

3.00 33 14.6212 4.79269 .83430

Total 83 15.4747 4.68716 .51448

APAPT2 1.00 21 67.5667 5.84092 1.27459

2.00 29 67.6759 5.89053 1.09384

3.00 33 65.9576 6.03961 1.05136

Total 83 66.9651 5.92318 .65015

Table B.6 ANOVA for Post-Treatment Horizontal Maxillary Measures

N Mean

Std.

Deviation

Std.

Error

APANS2 1.00 21 69.8714 5.53698 1.20827

2.00 29 71.1207 5.68321 1.05535

3.00 33 69.8030 6.23987 1.08622

Total 83 70.2807 5.83826 .64083

APPNS2 1.00 21 16.9762 3.69282 .80584

2.00 29 15.3586 5.07779 .94292

3.00 33 14.6212 4.79269 .83430

Total 83 15.4747 4.68716 .51448

APAPT2 1.00 21 67.5667 5.84092 1.27459

2.00 29 67.6759 5.89053 1.09384

3.00 33 65.9576 6.03961 1.05136

Total 83 66.9651 5.92318 .65015

115

Table B.7 Post Treatment Vertical Maxillary Measures: Descriptive

Statistics

N Mean

Std.

Deviation

Std.

Error

VANS2 1.00 21 50.6619 4.08821 .89212

2.00 29 50.9931 3.50916 .65164

3.00 33 50.8697 4.16792 .72554

Total 83 50.8602 3.88289 .42620

VPNS2 1.00 21 47.6619 4.59124 1.00189

2.00 29 46.5276 3.27642 .60842

3.00 33 46.9121 3.82865 .66648

Total 83 46.9675 3.83673 .42114

VAPT2 1.00 21 54.3952 4.36182 .95183

2.00 29 55.1517 3.68856 .68495

3.00 33 55.0667 4.08631 .71133

Total 83 54.9265 3.98754 .43769

Table B.8 ANOVA for Post-Treatment Vertical Maxillary Measures

Sum of

Squares df Mean Square F Sig.

VANS2 Between Groups 1.341 2 .670 .043 .958

Within Groups 1234.958 80 15.437

Total 1236.299 82

VPNS2 Between Groups 15.840 2 7.920 .532 .590

Within Groups 1191.243 80 14.891

Total 1207.082 82

VAPT2 Between Groups 8.046 2 4.023 .248 .781

Within Groups 1295.795 80 16.197

Total 1303.842 82

116

Table B.9 Non-Significant Post-Treatment Horizontal Soft Tissue

Measures

N Mean

Std.

Deviation

Std.

Error

APPRN2 1.00 21 102.4810 6.33653 1.38274

2.00 29 103.0793 6.75470 1.25432

3.00 33 99.3212 6.74939 1.17492

Total 83 101.4337 6.79591 .74595

APSBN2 1.00 21 87.0762 5.70578 1.24510

2.00 29 87.0207 5.91574 1.09853

3.00 33 83.5636 6.99526 1.21772

Total 83 85.6602 6.47483 .71070

APPOG2 1.00 21 75.3333 9.51212 2.07571

2.00 29 72.8483 9.25398 1.71842

3.00 33 69.3909 10.77284 1.87531

Total 83 72.1024 10.12069 1.11089

Table B.10 ANOVA for Non-Significant Post Treatment Horizontal Soft

Tissue Measures

Sum of

Squares df Mean Square F Sig.

APPRN2 Between Groups 248.830 2 124.415 2.813 .066

Within Groups 3538.295 80 44.229

Total 3787.126 82

APSBN2 Between Groups 240.837 2 120.418 3.013 .055

Within Groups 3196.882 80 39.961

Total 3437.719 82

APPOG2 Between Groups 477.973 2 238.987 2.414 .096

Within Groups 7921.146 80 99.014

Total 8399.120 82

117

Table B.11 Post-Treatment Vertical Soft Tissue Measures: Descriptive

Statistics

N Mean

Std.

Deviation

Std.

Error

VPRN1 1.00 21 37.4381 4.44032 .96896

2.00 29 40.1310 5.91488 1.09837

3.00 33 40.7030 5.08604 .88537

Total 83 39.6771 5.35073 .58732

VSBN1 1.00 21 50.5952 4.08295 .89097

2.00 29 53.1069 4.81426 .89399

3.00 33 52.4242 4.90510 .85387

Total 83 52.2000 4.72652 .51880

VLABSU1 1.00 21 64.6952 5.44495 1.18819

2.00 29 67.1586 6.56166 1.21847

3.00 33 66.9152 4.84033 .84259

Total 83 66.4386 5.66824 .62217

VSTMSU1 1.00 21 73.4619 6.72588 1.46771

2.00 29 74.8207 6.05837 1.12501

3.00 33 74.0848 5.00132 .87062

Total 83 74.1843 5.79730 .63634

VSTINF1 1.00 21 74.6619 6.62982 1.44674

2.00 29 75.8034 5.66969 1.05283

3.00 33 75.6121 5.23311 .91097

Total 83 75.4386 5.70945 .62669

VLABIN1 1.00 21 82.6143 9.11210 1.98842

2.00 29 83.3828 6.53917 1.21429

3.00 33 83.0394 6.40561 1.11507

Total 83 83.0518 7.13812 .78351

VPOG1 1.00 21 106.2333 8.96874 1.95714

2.00 29 108.1103 9.40351 1.74619

3.00 33 104.9970 7.09976 1.23591

Total 83 106.3976 8.44500 .92696

118

Table B.12 ANOVA for Post-treatment Vertical Measures for Soft Tissue

Landmarks

Sum of

Squares df Mean Square F Sig.

VPRN1 Between Groups 145.985 2 72.993 2.652 .077

Within Groups 2201.701 80 27.521

Total 2347.687 82

VSBN1 Between Groups 79.591 2 39.796 1.817 .169

Within Groups 1752.289 80 21.904

Total 1831.880 82

VLABSU1 Between Groups 86.354 2 43.177 1.356 .264

Within Groups 2548.222 80 31.853

Total 2634.577 82

VSTMSU1 Between Groups 23.030 2 11.515 .337 .715

Within Groups 2732.880 80 34.161

Total 2755.910 82

VSTINF1 Between Groups 17.522 2 8.761 .264 .769

Within Groups 2655.494 80 33.194

Total 2673.017 82

VLABIN1 Between Groups 7.201 2 3.601 .069 .933

Within Groups 4170.926 80 52.137

Total 4178.127 82

VPOG1 Between Groups 150.376 2 75.188 1.056 .353

Within Groups 5697.703 80 71.221

Total 5848.080 82

119

Table B.13 Post-treatment Horizontal Dental Measures: Descriptive

Statistics

N Mean

Std.

Deviation

Std.

Error

APU6DCUSP2 1.00 21 32.1667 6.27275 1.36883

2.00 29 31.7414 6.04380 1.12231

3.00 33 29.6455 5.80108 1.00984

Total 83 31.0157 6.04016 .66299

APANTFOP2 1.00 21 73.3190 8.07172 1.76139

2.00 29 71.4517 6.46720 1.20093

3.00 33 68.5333 8.27023 1.43966

Total 83 70.7639 7.79137 .85521

APU6APEX2 1.00 21 44.9905 5.20537 1.13591

2.00 29 43.7379 6.10248 1.13320

3.00 33 41.8515 5.40758 .94134

Total 83 43.3048 5.69038 .62460

APL6APEX2 1.00 21 34.0571 7.70302 1.68094

2.00 29 33.3828 7.57265 1.40621

3.00 33 30.6091 7.69766 1.33999

Total 83 32.4506 7.71428 .84675

APL6TIP2 1.00 21 43.3143 6.33208 1.38177

2.00 29 42.2414 6.02213 1.11828

3.00 33 39.9727 6.66681 1.16054

Total 83 41.6108 6.43983 .70686

APU1TIP2 1.00 21 73.2381 8.05341 1.75740

2.00 29 71.1690 6.79170 1.26119

3.00 33 68.4182 8.09955 1.40995

Total 83 70.5988 7.80918 .85717

APU1APEX2 1.00 21 62.4286 5.82024 1.27008

2.00 29 62.1276 5.53172 1.02721

3.00 33 60.0848 5.81711 1.01263

Total 83 61.3916 5.75070 .63122

APL1TIP2 1.00 21 70.8286 8.21238 1.79209

2.00 29 69.0966 6.53313 1.21317

3.00 33 65.8545 7.85136 1.36675

Total 83 68.2458 7.70360 .84558

APL1APEX2 1.00 21 56.3619 9.29481 2.02829

2.00 29 54.4276 7.33007 1.36116

3.00 33 51.0303 9.13809 1.59074

Total 83 53.5663 8.76685 .96229

120

Table B.14 ANOVA for Post-Treatment Horizontal Dental Measures

Sum of

Squares df Mean Square F Sig.

APU6DCUSP2 Between Groups 105.051 2 52.525 1.456 .239

Within Groups 2886.599 80 36.082

Total 2991.650 82

APANTFOP2 Between Groups 315.013 2 157.507 2.702 .073

Within Groups 4662.838 80 58.285

Total 4977.852 82

APU6APEX2 Between Groups 134.809 2 67.405 2.139 .124

Within Groups 2520.389 80 31.505

Total 2655.198 82

APL6APEX2 Between Groups 191.307 2 95.654 1.632 .202

Within Groups 4688.520 80 58.607

Total 4879.827 82

APL6TIP2 Between Groups 161.019 2 80.509 1.988 .144

Within Groups 3239.642 80 40.496

Total 3400.660 82

APU1TIP2 Between Groups 312.629 2 156.315 2.667 .076

Within Groups 4688.001 80 58.600

Total 5000.630 82

APU1APEX2 Between Groups 94.641 2 47.320 1.446 .241

Within Groups 2617.143 80 32.714

Total 2711.784 82

APL1TIP2 Between Groups 349.772 2 174.886 3.098 .051

Within Groups 4516.554 80 56.457

Total 4866.326 82

APL1APEX2 Between Groups 397.868 2 198.934 2.695 .074

Within Groups 5904.457 80 73.806

Total 6302.326 82

121

Table B.15 Post-Treatment Vertical Dental Measures: Descriptive

Statistics

N Mean

Std.

Deviation

Std.

Error

VU6DCUSP2 1.00 21 71.7381 6.82975 1.49037

2.00 29 71.5069 5.29305 .98289

3.00 33 71.0909 4.49481 .78245

Total 83 71.4000 5.37583 .59007

VANTFOP2 1.00 21 82.1524 6.11953 1.33539

2.00 29 80.5793 5.73127 1.06427

3.00 33 82.2818 5.14177 .89507

Total 83 81.6542 5.59445 .61407

VU6APEX2 1.00 21 53.5000 6.21651 1.35655

2.00 29 53.1345 5.82803 1.08224

3.00 33 53.6485 4.38906 .76404

Total 83 53.4313 5.34721 .58693

VL6APEX2 1.00 21 95.4857 7.60752 1.66010

2.00 29 93.7966 5.86092 1.08834

3.00 33 93.6636 5.61103 .97675

Total 83 94.1711 6.22312 .68308

VU6TIP2 1.00 21 74.3286 6.51591 1.42189

2.00 29 73.6690 5.37096 .99736

3.00 33 73.5909 4.51362 .78572

Total 83 73.8048 5.31519 .58342

VL6TIP2 1.00 21 74.9143 6.61901 1.44439

2.00 29 74.0828 5.48433 1.01842

3.00 33 74.3121 4.53299 .78909

Total 83 74.3843 5.39269 .59192

VU1TIP2 1.00 21 81.8476 6.46256 1.41025

2.00 29 81.2172 5.20364 .96629

3.00 33 82.0909 5.01955 .87379

Total 83 81.7241 5.42347 .59530

VU1APEX2 1.00 21 55.3381 5.54125 1.20920

2.00 29 55.5517 4.35313 .80836

3.00 33 57.5879 4.85391 .84496

Total 83 56.3072 4.92509 .54060

VL1TIP2 1.00 21 79.9762 6.43358 1.40392

2.00 29 79.7690 5.17060 .96016

3.00 33 80.1758 4.57705 .79676

Total 83 79.9831 5.23745 .57489

VL1APEX2 1.00 21 99.6381 7.82461 1.70747

2.00 29 98.3862 6.54658 1.21567

3.00 33 97.5273 5.54258 .96484

Total 83 98.3614 6.50024 .71349

122

Table B.16 ANOVA for Post-Treatment Vertical Dental Measures

Sum of

Squares df Mean Square F Sig.

VU6DCUSP2 Between Groups 5.885 2 2.942 .100 .905

Within Groups 2363.875 80 29.548

Total 2369.760 82

VANTFOP2 Between Groups 51.717 2 25.858 .823 .443

Within Groups 2514.709 80 31.434

Total 2566.426 82

VU6APEX2 Between Groups 4.211 2 2.105 .072 .931

Within Groups 2340.388 80 29.255

Total 2344.599 82

VL6APEX2 Between Groups 48.859 2 24.429 .625 .538

Within Groups 3126.772 80 39.085

Total 3175.631 82

VU6TIP2 Between Groups 7.806 2 3.903 .135 .874

Within Groups 2308.792 80 28.860

Total 2316.598 82

VL6TIP2 Between Groups 8.707 2 4.354 .147 .864

Within Groups 2375.942 80 29.699

Total 2384.650 82

VU1TIP2 Between Groups 12.211 2 6.105 .204 .816

Within Groups 2399.741 80 29.997

Total 2411.952 82

VU1APEX2 Between Groups 90.399 2 45.199 1.904 .156

Within Groups 1898.637 80 23.733

Total 1989.036 82

VL1TIP2 Between Groups 2.556 2 1.278 .045 .956

Within Groups 2246.781 80 28.085

Total 2249.336 82

VL1APEX2 Between Groups 57.207 2 28.604 .672 .514

Within Groups 3407.549 80 42.594

Total 3464.757 82

123

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124

VITA AUCTORIS

Jessica H. Cox was born in Pocahontas, Arkansas on

October 24, 1981 to Danny B. Holt, M.D. and Sandra F. Holt.

She is the second of four children.

She grew up in Pocahontas, Arkansas and graduated from

Pocahontas High School in May of 2000. She attended the

University of Mississippi in Oxford, Mississippi where she

obtained a Bachelor of Science degree in 2004. She obtained

her Doctor of Dental Surgery degree from the University of

Tennessee in May of 2007. In June of that same year, she

began her postgraduate orthodontic residency at Saint Louis

University, Center for Advanced Dental Education, where she

expects to receive a Master’s of Science in Dentistry in

Orthodontics in January 2010.

Jessica met her husband, Wynne, while attending the

University of Mississippi. They were married on June 17,

2006. Upon graduation, they plan to move to Hernando,

Mississippi where Jessica will start a private orthodontic

practice.