Surgical and orthodontic management of impacted maxillary canines-Anila Charles, Sangeetha Duraiswamy1, Krishnaraj R1, Sanjay Jacob.(SRM Journal of Research in Dental Sciences | Vol. 3 | Issue 3 |

July-September 2012)Department of Orthodontia, Madha Dental College, M.G.R University, 1Department of Orthodontia, SRM

Dental College, SRM University, Chennai, Tamil Nadu, India

Presented by- Dr. parag s. deshmukh

Contents:

Introduction

Eruption

Incidence

Classification

Etiology

Diagnosis

Management

Case reports

Introduction

IMPACTUS (latin origin) = pushed against

Archer (1975) defines impacted tooth as one which is completely or partially unerupted and is positioned against another tooth or bone or soft tissue so that its further eruption is unlikely.

Archer William H. Oral and Maxillofacial Surgery, Vol. I,ed. 5, Philadelphia, WB Saunders Co. 1975

Impacted canine

◦ Impaction of maxillary and mandibular canines is a frequently encountered clinical problem.

◦ Third molars are the most commonly impacted teeth and canines stood second.

According to Broadbent, 1941-

Development of canine : • It develops at 4 – 5 months of age between the roots of

deciduous Ist molar.

Calcification of canine : • It begins to calcify around 12 months of age.

Eruption of canine :

• calcification is taking place far above the roots of deciduous molar , allowing development of the first premolar between the deciduous molar roots.

• At this stage the permanent canine is located immediately above both the erupting first premolar and the erupted first deciduous molar.

• As the deciduous teeth erupts towards the occlusal plane, the permanent incisor and canine crypts migrate forward in the jaws

• The positional changes between 8 and 10 years of age need careful observation for detection of potential impaction (Williams, 1981).

• During this stage of development the canine normally migrates buccally from a position lingual to the root apex of the deciduous precursor; however, some canines do not make the transition from the palatal to the buccal side of the dental arch and remain palatally unerupted.

• With sufficient increase in the size of the subnasal area, the maxillary canine normally moves downward, forward and laterally away from the root of the lateral incisor.

• Between 8 and 12 years of age, the 'ugly duckling' stage, there is insufficient space at the apical base to permit the axis of the lateral incisor to shift into the more erect alignment of young adulthood until the canine approaches its place in the dental arch.

• In the final phase of eruption, canines drive their way between the lateral incisors and first premolars, forcing these teeth to become more upright.

Incidence

Dachi and Howell reported that the

incidence of maxillary canine

impaction is 0.92%(Dachi SF, Howell FV. A survey of

3,874 routine full mouth radiographs. Oral Surg Oral Med

Oral Path 1961;14:1165-9.)

Thilander and Myrberg estimated

the cumulative prevalence of canine impaction in 7 to 13-year-old children to be 2.2%(Thilander B,

Myrberg N. The prevalence of malocclusion in Swedish school

children. Scand J Dent Res 1973;81:12-20.)

Ericson and Kurol estimated the

incidence at 1.7% Impactions are twice

as common in females (1.17%) as in males (0.51%).(Ericson S, Kurol J. Radiographic assessment of maxillary canine eruption in children with clinical signs of eruption disturbances. Eur J

Orthod 1986;8:133-40.)

Of all patients with maxillary

impacted canines, it is

estimated that 8% have bilateral

impactions

The incidence of permanent canine impactions was 20 times higher in the maxilla than in the mandible. (Johnston WD.

Treatment of palatally impacted canine teeth. Am J Orthod

1969;56:589‑96.)

Becker et al. reported that the palatally displaced canines occurred three times more frequently than those found buccally. (Becker A, Smith P, Behar R. Theincidence of anomalous maxillary lateral incisors in relation to palatally‑displaced cuspids. AngleOrthod 1981;51:24‑9.)

Johnston reported that the palatal impactions were

twice as common as the labial impactions.

CLASSIFICATION OF IMPACTED CANINE

Impacted canine

Maxillary canine Mandibular canine

Buccal Palatal LingualBuccal

Classification of palatally impacted canine

The classification is based on two variables:

(1) Transverse relationship of the crown of the tooth to the line of dental arch which may be

(a) Close

(b) Distant ( nearer the midline)

 

(2) Height of the crown of the teeth in relation to the occlusal plane which may be

(a) High

(b) Low

 

Group 1 - Proximity to the line of arch – close.

- Position in the maxilla – low.

Group 2 - Proximity to the line of arch – close.

Position in the maxilla – forward , low &

mesial to the lateral incisor root.

Group 3 - Proximity to the line of arch – close.

- Position in the maxilla – high.

Group 4 - Proximity to the line of arch – distant.

       - Position in the maxilla – high.

Group 5 - canine root apex mesial to that of lateral incisor or

distal to that of first premolar.

Group 6 - Erupting in the line of arch in place and resorbing the

roots of incisors.

 

Classification by ACKERMAN and FIELDS in 1935.

IMPACTED CANINE

Horizontally vertically

Palatal Above Labial

Mid- alveolar

Below

( With respect to the arch) (With respect to the apex)

(J CO 1979 DEC)

Etiology:Becker Concepts :

◦ Becker (1984) hypothesized two processes in the palatal impaction of the maxillary canine:

1. Absence of initial early guidance from an anomalous lateral incisor2. Failure of buccal movement of the canine at an unspecified age .

MC Bridge Concept

Canine formed at high level in the anterior wall of antrum, below the floor of orbit, having long tortous path of eruption.

Moyers Concept: Summarized by Bishara:

A)Primary cause: 1) Trauma to decidious tooth bud 2) Rate of Resorption of decidious tooth 3) Availability of space in the arch 4) Disturbance in tooth Eruption Sequence 5) Rotation of tooth buds 6) In Cleft area in Person with Cleft 7) Premature root Closure

B)Secondary cause:                 1) Abnormal muscle pressure                2) Febrile diseases                3) Endocrine disturbances 4) Vitamin D deficency.

AJO. 1992.Feb.Bishara

Berger Concept :{Systemic cause of impaction}

1)Malnutrition

2)     Tuberculosis

3)     Syphilis

4)     Rickets

5)     Anemia

6)     Progeria

7)     Syndromes:

a)      Cleidocranial dysplasia

b)      Achondraplasia

c) Down syndrome

Vonder Heydt Concept:

“The total arch length for the permanent teeth is primarily established very early in life, at the time of eruption of thefirst permanent molars, and because the canine is largeand late in erupting, it is often not found in the alignmentof the arch. As in musical chairs, the room for this tooth is all gone, and it must assume an awkward and embarrassingly

inappropriate position on the arch alignment.”

Guidance Theory - Miller -Normal Eruption: Canine usually have a more mesial development path, which is guided downwards apparently along the distal aspect of the lateral incisor roots.

1) First stage Impaction : If there is a loss of guidance's due to missing lateral incisors or late developing laterals, canine will have mesial and palatal path of eruption. In this event there is no vertical movement of canine into the alveolar process, results in more horizontal impaction.

2) First stage impaction and secondary correction : Once it reached the palatal alveolar process, canine is redirected to more favorable path of eruption.

Second stage Impaction :

Self correction is prevented by, late developing lateral incisors (peg laterals) which deflect the tooth further palatally

Second stage Impaction and secondary correction:

Extraction of deciduous canine or even extraction of lateral incisors leads to spontaneous eruption of the impacted tooth.

Genetic Theory

◦ This theory indicates multiple evidential categories for the genetic origin of palatally impacted canines, such as: Familial and bilateral occurrence, Sex differences, as well as an increased occurrence of other significant reciprocal dental associations such as ectopic eruption of first molars, infraocclusion of primary molars, aplasia of premolars and one third molar.

◦ Pirinen et al., showed that 106 patients with palatally displaced canines had first and second degree relatives with some dental anomalies.

Peck and peck:

Occurrence with other dental anomalies: Palatally impacted canine is an inherited trait occurs in combination with tooth agenesis, tooth size reduction, Supernumery tooth and other ectopically positioned tooth.

Peck et al., examined the specificity of tooth-agenesis sites associated with the occurrence of 58 palatally displaced canines. Palatally displaced canines associated significantly with third molar agenesis. (Peck S, Peck L, Kataja M. Concomitant occurrence of canine malposition and tooth agenesis: evidence of orofacial genetic fields. Am J Ortho Dentofacial orthop. 2002;122:657–60.)

SEQUELAE OF IMPACTED CANINE

Labial or lingual

malpositioning of impacted

tooth

Migration of neighbouring teeth and loss of arch length

Internal resorption or external root

resorption of impacted or

neighbouring tooth

Dentigerous cyst formation

Infection particularly with partial

eruption

Referred pain

Shafer et al.

DIAGNOSIS

CLINICAL EVALUATION

• Amount of space available in dental arch for impacted canine is assessed in model.Study model analysis

• Gives clue of position of impacted tooth.Morphology of adjacent tooth

• Canine bulge present buccally or palatally.Contours of adjacent alveolar bone

Mobility of adjacent tooth

• Root resorption.

Delayed eruption of deciduous canine

RADIOGRAPHIC METHOD FOR DIAGNOSIS

In Orthodontic treatment planning, the exact localization of the position of an impacted canine is necessary.

Periapical

Mandibular arch

Max. ant. occlusal True vertex/occlusal

OPG Lateral ceph

Extraoral

I. Qualitative radiographs

Maxillary arch Occlusal

PA view

Parallax method

Radiographic views at right angle

II. 3-D diagnosis of the position

C T scanning

Periapical Radiography-

•Are the simplest and the most informative X-ray films.

• As this view passes through minimum of surrounding

tissues, it gives accuracy & quality of resolution.

• It is aimed to be perpendicular to an imaginary plane

bisecting the angle between the long axis of an erupted

tooth and the film plane to produce minimum

distortion.

The periapical film gives the following information:

[1] Presence or absence of impacted tooth.

[2] Stage of development.

[3] Presence & size of follicle.

[4] Indicates crown or root resorption, resorption pattern

& integrity.

[5] Indicates presence or absence of supernumerary tooth.

[6] Indicates soft tissue lesions like cysts.

OCCLUSAL RADIOGRAPH

1.Maxillary anterior occlusal

• In the maxillary arch, the nose and forehead interfere with

the positioning of x-ray tube close to the area to be viewed.

• The best that can be achieved by positioning the tube

close to the face, so that it becomes high and steeply angled

view.

2. Ture vertex / occlusal

• A true vertex view is one which passes parallel to the long

axis of central incisors.This is possible if the cone is placed

over the vertex of the skull to produce vertex occlusal film.

• Since the beam has to travel a great distance there is loss of

clarity.

Extraoral Radiography:

• OPG has the advantage of simplicity & quickly

offering a good scan of the teeth & jaws from

Temporomandibular joint to Temporomandibular joint.

• True & oblique lateral extraoral views are also used for

localization of impacted teeth, however the results are

misleading.

• True P-A view defines the buccolingual relationship of

an object.

Parallax method:

- By Clark & Richards

• Principle:

• 2 periapical views of the same object are taken from

slightly different angles which can provide depth to

the flat 2-D picture depicted by each of the films

individually.

• Useful in distinguishing the buccal or lingual

displacement of the canine.

Procedure:

1. In the periapical film, the

X-ray is taken in the area of

interest with the X-ray beam

passing perpendicular to a

tangent to the line of arch at

this point & at an appropriate

angle to horizontal plane.

2. In the second film, the X-ray tube is shifted mesially or

distally round the arch but held at the same angle to the

horizontal plane. The X-ray tube should describe between

30-450 of an arc of circle whose centre is somewhere in

the middle of the palate.

Result:

• It is based on the SLOB principle.

• If the object has moved on the same side as that

of the X-ray tube it is lingually placed & if it has

moved on the opposite side it is on the buccal

side

Radiographic views at right angles:

1. A true lateral view {e.g. Lateral

cephalograph} gives information

regarding the antero-posterior &

ventral location of an object . However,

it gives no information regarding

bucco-lingual {transverse} plane of an

object.

2. A true occlusal view will provide information in the

transverse & antero-posterior direction of an object .

3. True postero-anterior view defines the

ventral plane & buccolingual

relationship of an object.

• These views provide complete information regarding

3 planes of space of any impacted teeth .

CT Scanning:

By Ericson & Kurol

• Used to diagnose the exact

position of an impacted

tooth.

• Clear serial radiographs

may be taken at graduated

depth in any part of

human body in this

method.

• This technique allows the

elimination of

superimposition of other

structures.

• It is however rarely used in

the diagnosis of impacted teeth

because of

(1) Large radiation

dosage.

(2) High cost.

DETERMINING THE PROGNOSIS◦FACTORS INFLUENCING THE TREATMENT

DECISION OF AN IMPACTED CANINE

Position of canine – Favorable or Unfavorable

Age of patient

Availability of space

Presence of adequate width of attached gingiva

VERTICAL RULE

OF THIRDS

HORIZONTAL RULE

OF THIRDS

LABIAL IMPACTION

Either due to ectopic migration of the canine crown over the root of the lateral incisor or insufficient space in the arch caused by a midline shift of dental origin.

Arch length tooth material discrepancy is the most common cause

Williams suggested that extraction of the maxillary deciduous canine at an early age of eight or nine years will enhance the eruption and self‑correction.

Olive suggested that opening space for the canine crown with routine orthodontic mechanics might allow for spontaneous eruption of an impacted canine.

Techniques for uncovering a labially impacted maxillary canine:

• Excisional uncovering

• Apically positioned flap &

• Closed eruption technique.

When referring a patient for surgical exposure of a labial or intra-alveolar impaction of a maxillary canine, the orthodontist should evaluate 4 criteria to determine the correct method for uncovering the tooth.

1. Assessement of labiolingual position of the canine crown. • If labially impacted- any of the technique can be used.

• If the tooth is impacted in the center of the alveolus, an excisional approach and an apically positioned flap are generally more difficult to perform, because extensive bone might need to be removed from the labial surface of the crown.

2. To evaluate is the vertical position of the tooth relative to the mucogingival junction.

• If most of the canine crown is positioned coronal to the mucogingival junction , any of the 3 techniques can be used to uncover the tooth.

• If placed apical to mucogingival junction-excisional technique & apically positioned flap will not be used; closed eruption technique should be used.

3. Criterion to evaluate is the amount of gingiva in the area of the impacted canine.

• If there were insufficient gingiva in the area of the canine , the only technique that predictably would produce more gingiva is an apically positioned flap.

• However, if there were sufficient gingiva to provide at least 2 to 3 mm of attached gingiva over the canine crown after it had been erupted, any of the 3 techniques could be used.

4. To evaluate is the mesiodistal position of the canine crown.

• If the crown were positioned mesially and over the root of the lateral incisor, it could be difficult to move the tooth through the alveolus unless it was completely exposed with an apically positioned flap.

Palatal impaction

The most common impaction

encountered by orthodontists is the palatal impaction of maxillary canines.

Ericson & Kurol stated that if

periapical radiographs showed

that the crown of the permanent

canine were positioned over the root of the maxillary lateral incisor, but not past the mesial surface of the root,

self-correction of the ectopic canine

occurred with high predictability if the deciduous canine were removed.

However, if the permanent canine

were positioned well beyond the mesial

surface of the lateral incisor root, self-

correction does not occur with

extraction of the deciduous canine.

For most orthodontists, uncovering a palatally impacted canine occurs after the first 6 to 9 months of orthodontic alignment of the maxillary dentition.

Space is created for the crown of the impacted tooth, and the patient is referred to a surgeon to uncover the crown.

Usually, soon after the surgery, the orthodontist begins dragging the crown toward the edentulous site.

However, the crown of a palatally impacted canine is often in intimate contact with the lingual surfaces of the roots of the ipsilateral central and lateral incisors.

The problem in these situations is insufficient bone removal over the crown of the impacted canine.

When a force is placed on the tooth and the enamel of the impacted crown comes into contact with the bone, there are no cells in the enamel to resorb the bone.

Resorption will eventually occur through pressure necrosis, but it will occur slowly.

Wololshyn et al studied bone levels adjacent to impacted canine after bringing it to the level.

He found that bone level distal to lateral & mesial to canine were more apical suggesting bone loss post orthodontics

Kokich and Mathews recommend an alternative technique with earlier timing for uncovering palatally impacted canines.

They time the uncovering of palatal canines before the start of orthodontic treatment.

In these situations, a full-thickness mucoperiosteal flap is elevated in the area of the impacted canine .

All bone over the crown is removed down to the cementoenamel junction.

The flap is repositioned, and a hole is made through the gingival flap .

Once the bone and tissue have been removed, these palatally displaced canines will erupt on their own .

In about 6 to 8 months, the canines generally have erupted to the level of the occlusal plane.

It seems appropriate to uncover palatally impacted canines early, during the mixed dentition, so that they can erupt autonomously, without orthodontic intervention, until the crown has erupted to the level of the occlusal plane.

At that time, it can be moved more efficiently into the dental arch.

By treating palatally impacted canines in this manner, the overall treatment time for the patient is reduced, and the periodontal and esthetic results are superior compared with previous methods for exposing palatally impacted

Surgical Exposure of impacted tooth: Circular incision or open approach :

This is done by removing mucosa over the crown to expose the

impacted tooth.

Advantages:

a) Easy to perform

  b) Suitable access can be provided for bonding of the

attachment

c) Reduction of impaction is rapid.

Disadvantages:

a) Tooth will be invested on labial side with thin oral mucosa rather than attached gingiva. b)Typical soft tissue contour aggravates Plaque acclumation which leads to gingivitis. Inflammation will prevent regeneration of the Periodontal ligament which leads to apical movement of the epithelial attachment

Apically Repositioned Flap:◦ This method was proposed by Vanarsdall and corn in 1977.

procedure:

◦ In cases without deciduous canine, Mucoperiosteal flap is elevated from the crest of the ridge that includes attached gingiva.

◦ In cases with deciduous canine, tooth was extracted and the flap was designed to include the entire area of buccal gingival that invest it.

◦ In either cases, Split thickness Flap is elevated by incision made vertically into the vestibule someway up into the sulcus,to expose the canine.

◦ 2/3rd of bone covering the crown was removed.

◦ Connective tissue follicle was curreted from periphery of the exposed portion of the crown.

◦ Flap is then sutured to the labial side of the crown of the permanent canine, to cover the denuded periosteum and overlying cervical portion of the crown; while remainder portion of the crown is exposed.

◦ Surgical dressing was placed on enamel to prevent overgrowth of adjacent tissue. Dressing was removed 1 week post operatively. After 2

weeks, orthodontic traction was started.

Advantages: a) Maintain the width of attached gingiva b) Easy access for bonding of the attachment c) Tooth can be visualized from the time of exposure still it come to occlusion

Disadvantages: Vermette , 1995 a) Uneven and unesthetic gingival margin b) Increased Clinical crown length c) Some degree of attachment and bone loss on the labial surface,which was considered as possibly related to an increased potential for plaque accumulation. d) Vertical orthodontic relapse : After apical repositioning the gingival tissue heals to the adjacent mucosa, producing soft tissue band of gingival scarring. As the tooth is pulled incisally this mucosa get stretched down with it,toward the alveolar crest.Thus it tend to relapse once the force is released .

Full Flap Exposure: ◦ This method was proposed by MCBride in 1979.This method is more

effective for buccal and palatally impacted tooth.

Procedure:

◦ A full buccal surgical flap is raised to expose the canine.An attachment is bonded to the tooth and the flap is sutured back to its former place itself.

◦ Then a Twisted thread is tied to the bonded tooth and then drawn inferiorly and through the sutured ends of the replaced flap, or through the crest of the ridge or through the socket vacated by the extracted deciduous canine.

Advantages:

a) Tooth can be erupted towards and through the attached gingiva which maintains the width of the attached gingiva

b) No gingival scarring and good periodontal attachment is established

c) No vertical relapse

d)  Conservative bone removal

e)   Immediate traction possible

f) Less discomfort and good post operative Haemostasis

Disadvantage: a) Placement of the bonding attachment is necessary at the time of exposure b)  If there is a bond failure it needs re-exposure c)  Difficulty in gaining dry field d) Buttonholing: This occurs because of the buccal prominence of the tooth, lack of buccal bone and relative tightness of the replaced flap. The damage to the mucogingival tissue is due to the bulk of wide and high profile conventional bracket, which may leads to a breakdown of the overlying tissue to cause a dehiscence.

Apically positioned flap:

American Journal of Orthodontics and Dentofacial OrthopedicsVolume 126, Number 3

Anchor unit:

• When dealing with a malocclusion that incorporates an

impacted tooth, modification must be made for anchor

unit.

• A fully multi-bracketed appliance should normally be

placed & the entire dentition treated through the stages

of leveling & opening of adequate space in the arch for

impacted tooth.

• A heavy & more rigid arch wire is then placed into

the brackets on all the teeth of aligned & complete

dental arch, the aim is to provide solid anchor base that

will not allow distortion of arch wire to occur as a

result of force that will be applied to the impacted

tooth after exposure.

Attachments: –

Lasso wires

Threaded pins

Orthodontic bands

Standard orthodontic bracket

A simple eyelet

Elastic ties and modules

Magnets

{a} Lasso wires: 

It is twisted lightly around the neck of the canine.

Disadvantages:

   This results in irritation of the gingiva

   Prevents reattachments of the healing tissues in area of CEJ (cemento-enamel junction).

   May produce areas of external resorption & ankylosis in areas of CEJ.

So, it is rarely used now.

(b) Threaded Pins:

Provide the attachment for

an impacted tooth.

Disadvantages:

- Dentally invasive.

- Requires a subsequent restoration.

   - Difficult to place along the long axis of the tooth because of smaller surgical exposure.

      - The drilled hole may inadvertently enter the pulp(unerupted teeth may have large pulp chambers).

So it is rarely used.

{c} Orthodontic bands:

They largely replace the

Lasso wires & threaded pins.

Advantage:

They are compatible with the health of periodontal tissues.

Disadvantage:

- Large surgical field required.

    -     Inadequate moisture control may hamper with the cement-band bond.     

{d}Standard orthodontic brackets:

• Any edge-wise , Begg’s , PAE brackets can be used.

• They are routinely used as direct attachments along

with the composites.       

Disadvantages:

        - As the bracket base is wide, it is difficult to adapt to

any other tooth surface except for the buccal surface.

        - The bracket’s shear bulk creates irritation as the tooth

is drawn the soft tissues.

- Ligature wire or elastic thread tied to bring the

impacted tooth into arch.

{e} A simple eyelet:

Advantages:

- An eyelet welded to band material with a mesh backing is soft

& easy to contour making its adaptation to bonding surface more

accurate which makes for superior retentive properties.

- Because of small size they can be placed in more awkwardly

placed teeth.

      -   It is less irritating to the surrounding tissues.     

(f) Elastic ties and modules

Advantages

- Application of light forces

- Good range of action

- Easier to tie

Disadvantages

- Tends to loosen

- High degree of force decay

{f} Magnets:

   It is made up of rare earth lanthanide alloys .

•   It is rarely used.

Disadvantage:

- corrosion.

Ballista Spring (Jacoby 1979)

◦ A ballista loop is a simple, convenient, unobtrusive method of applying a vertical vector of force to a palatally impacted tooth to erupt the crown into the center of the alveolus.

◦When the canine crown is displaced mesially and lies over the root of the permanent lateral incisor, an apically positioned flap is the appropriate surgical uncovering technique.

◦ Exposure of the crown facilitates attachment of an elastomeric chain directed toward the center of the edentulous alveolar ridge to gradually guide the canine crown into the dental arch.

• It is made of rectangular wires.• It proceeds forward until it is opposite to canine space and bent

vertically downwards and terminate into a small loop.• With slight finger pressure ,spring is tied to pigtail ligature, by this it

provide an extrusive force for the canine to erupt.• If the impacted tooth is resistant to movement or if the distance for

the tooth to move is more it will leads to lingual molar root torque leads to loss of anchorage. To overcome this feature TPA is used.      

Magnetic forces

CRESCINI approached a method called as TUNNEL TRACTION.

Procedure:

     a) Extract deciduous canine b) Full thickness mucoperiosteal flap is elevated to expose the cortical plate. c) Drill with bur until exposing crown of canine d) Tooth was bonded and ligature wire tied e) Traction force given after 1week of surgery

Advantage:

a) No buccal or palatal access b) No loss of supporting tissue

Disadvantage:

a) Post operative discomfort will be more.

Guiding tooth to oral enviroment :

      I) Active palatal arch (Becker1978)

• It consist of fine 0.020 inch removable palatal arch wire carrying an omega loop on each side.

• End of the wire is doubled for Frictionless fit in lingual sheath.• It is activated by elevating downward activated palatal arch wire and

hooking the pigtail ligature around it

3) Light Auxiliary Labial Arch (Kornhauser1996)

It is made up of 0.014 inch round SS wire with vertical loops in the

• This loop has a small helix.• Wire is tied with the basal arch wire in piggyback fashion.• If basal arch wire is not used it will leads to extrusion of adjacent tooth

and cause alteration of occlusal plane . 

Kilroy spring:• The Kilroy Spring is a constant force

module that is slid onto a rectangular archwire over the site of an impacted tooth.

• In the passive state, the vertical loop of the Kilroy Spring extends perpendicularly

from the occlusal plane (Fig. 2).

• To activate the spring, a stainless steel ligature is guided through the helix at the apex of the vertical loop, and the loop is directed toward the impacted tooth. The ligature is then tied to an attachment that has been direct-bonded to the surgically exposed tooth. (Fig. 3)

Kilroy II Spring

• The Kilroy II Spring was designed to produce more vertical than lateral eruptive forces for eruption of buccally impacted teeth.

• Its multiple helices increase its flexibility, but also increase the likelihood of impingement on the adjacent soft tissue.

• Consequently, more frequent progress checks are recommended with the Kilroy II.

THE K- 9 SPRING

•Varun Kalra (2000)

• Made in 0.017”X 0.025”TMA wire

Advantages:

• Simple in design

• Low cost

• No patient compliance

• Light continuous eruptive and distalizing forces

JCO Oct 2000

JCO Oct 2000

CANTILEVER SPRING

Lindauer and Isaacson

(1995)

• TMA .017 X .025 wire used

• Force generated was measured

by dontrix guage.

• It should not exceed 70gms.JCO Feb 1999

TMA BOX LOOP

• TMA .017 X .025 wire

used.

• Produce sagittal and

horizontal corrections while

continuing vertical eruption.

Surendra Patel J C O 1999

NICKEL TITANIUM CLOSED-COIL SPRING

Loring L.Ross (1999)

• 0.009”X 0.041” spring

• Provides 80 gm of force when stretched to twice

its resting length

JCO Feb 1999

Procedure

THE MONKEY HOOK

S.Jay Bowman (2002)

• It is a simple auxiliary with an open loop on each

end for the attachment of intra oral elastic or

elastomeric chain or for connecting to a bondable

loop button.JCO July 2002

A combination of monkey hooks and bondable loop-

buttons allows the production of a variety of different

direction force such as:

I. Vertical intermaxillay eruptive forces

JCO July 2002

MANDIBULAR ACHORAGE

• Pramod K.Sinha (1999)

• Lingual arch is fabricated with 0.036 inch SS wire

• Vertical hooks (5-6mm in length)

• Elastic force should not exceed 40-60 gmAJO March 1999

Advantages

• Simplicity in appliance

design and application

• Reduced overall treatment

time

AUSTRALIAN HELICAL ARCHWIRE

• Christine Hauser (2000)

• Made in special plus .016”

arch wire

• Force should not exceed

200 gm

• Activation by twisting the

steel ligature wire every

two weeks

The amount of force can varied by using different arch wire designs

RETENTION CONSIDERATIONS

Evaluation of post treatment alignment by Becker et al

• Incidence of rotations and spacings

1. Impacted side- 17.4%

2. Control side 8.7%

• Ideal alignment on control side is twice as often as the impacted side.

To minimize rotational relapse, options available are

1. Fiberotomy

2. Bonded fixed retainer

This can be done during or after the treatment.

Clark’s suggestion for palatally impacted canine: Lingual

drifting can be prevented by removal of halfmoon- shaped

wedge of tissue from lingual aspect of canine.

Case report

◦ ERUPTION OF AN IMPACTED CANINE WITH A SEMI-FIXED APPLIANCE: - Dr. K. Neelima, Dr. K. Nagaraj , Dr. Roopa Jatti (The Orthodontic

CYBER journal, February 2010)

• A 19 1/2 year old female patient presented with an impacted upper left canine and an over-retained primary upper left canine.. She had a permanent dentition, with a Class I molar relationship and a proclined maxillary left lateral incisor. The overjet was 3mm and the overbite was close to normal. A palpable bulge was present on the buccal side of the impacted canine region on intraoral examination.

• Intraoral periapical radiographs taken with the slob technique and occlusal films confirmed that the impacted canine was on the labial side, with its crown mesially angulated and the tooth almost horizontally impacted. The crown of the impacted tooth was in close proximity to the root of the permanent lateral incisor

APPLIANCE DESIGN:

A semi-fixed appliance was used in the initial phases to achieve a favorable path of eruption. The appliance, comprised of wires extending from the maxillary first molar bands palatally into the Nance button to reinforce the proposed anchorage. Circumferential Clasps extending from the distal of the lateral incisor and the mesial of the first premolar were inserted into the Nance button to maintain space for alignment of the impacted canine.

SURGICAL TECHNIQUE:

◦ A labial flap was raised in the maxillary left canine region under local anesthesia. The crown of the impacted canine was exposed and a bracket was bonded to an accessible site on the tooth, using a light-cured adhesive for

◦ maximum strength. A 0.010” stainless steel ligature wire was passed through the bracket and brought out of the flap.

◦ A tunnel was created through the bone following extraction of the deciduous canine and the flap was then closed with silk sutures, which were to be removed one week later. The semi-fixed appliance was cemented an hour after the surgical procedure. The ligature wire was loosely ligated to the clasps of the semi-fixed appliance.

CASE PROGRESS: ◦ A distally directed force was initially applied to the tooth because of its

angulation. Once a favorable angulation was achieved, in approximately 90 days, an incisal eruptive force was applied, in addition to the distalizing force. Periodic intraoral periapical and occlusal radiographs were taken to assess the angulation and case progress. Once the tooth was almost upright, a full 0.022” x 0.028” Roth fixed appliance was bonded.

• Once the proper accomplished, the semi-fixed appliance was removed by cutting the wires extending from the molar bands into the Nance palatal button.

• Molar bands with buccal tubes were retained for further fixed appliance therapy.

• A 0.016” Nickel Titanium archwire was then placed for initial leveling and alignment followed by 0.017” x 0.025” and 0.019 x 0.025” Nickel Titanium aligning wires.

• A passive open coil spring was threaded over 0.019” x 0.025” stainless steel base arch wire for space maintenance in the canine region after which a 0.022” x 0.028” bracket was bonded to the now erupting upper left canine for its alignment into the arch.

• A 0.016” NiTi auxiliary overlay wire was placed on stainless steel base arch wire for further alignment of canine

RESULT:

◦ Total treatment time was about 14 months, which included an initial 7-8 months of treatment with a semi-fixed appliance, followed by full bonded fixed mechanotherapy.

◦ A minor amount of gingival recession was observed on the canine along with a slight amount of apical root resorption with regard to the adjacent lateral incisor.

◦ Both of these findings were, however, insignificant considering the amount of tooth movement required in this case and, most importantly, preserving the vitality of the associated teeth.

Case report:

◦ Labially Impacted Maxillary Canines Causing Severe Root Resorption of Maxillary Central Incisors. - Diane J. Milberga (Angle Orthod 2006;76:173–176.)

This 10-year-old African-American girl presented with a: Class II skeletal pattern due to mandibular retrusion; end to end molar relationships, retroclined maxillary incisors; labially impacted maxillary canines; and mandibular canines in labial Crossbite with the maxillary lateral incisors.

• The maxillary canines could not be palpated clinically. A panoramic radiograph revealed that the maxillary canines were erupting into the middle third of the apices of the maxillary central incisors.

Treatment plan:

◦ To reduce orthodontic treatment time and prevent further damage to the maxillary central incisor roots, the impacted maxillary canines and mandibular first premolars were extracted. Because of the proximity of maxillary canines and central incisor roots, alternative extraction sequences were not considered.

◦ The patient was referred to an endodontist to check the health of the asymptomatic maxillary central incisors and to monitor potential changes in the root length during orthodontic treatment.

◦ Orthodontic treatment plan included full upper and lower edgewise appliances, headgear wear at home, and full-time bite plate wear for crossbite. Maxillary first premolars would be substituted for the impacted maxillary canines.

◦ Maxillary first premolar and mandibular canine guidance would be the final occlusal treatment goal.

• Alignment of the dental arches was achieved with a 0.022 X 0.025 edgewise appliance.

• The wire sequence was:1. 0.01750 wildcat twist, three strand;2. 0.0160 round stainless steel;3. 0.0180 round stainless steel;4. 0.019 3 0.0250 rectangular stainless steel.

• The maxillary incisors were moved slowly, and achievement of ideal root torque was not attempted because of the apical end root resorption.

• Active treatment time was 22 months. During orthodontic treatment, the patient did not have any clinical symptoms of pulpal sensitivity of the maxillary central incisors.

• The final frontal facial photographs show a pleasing smile. Substitution of the shorter maxillary first premolar for the impacted and extracted canines was not an esthetic problem because of the patient’s long upper lip, which covered the gingival contours of her maxillary anterior teeth.

• Profile photographs show an improvement in maxillomandibular relationship because of favorable mandibular growth.

• At the present time, six years after treatment, the occlusion remains stable. The maxillary central incisors, which suffered external root resorption due to theimpacted maxillary canines, remain symptom free and have normal mobility. With removal of the maxillary canines and the source of pressure resorption, long-term prognosis for the maxillary central incisors is excellent.

• Six years later, the compromised orthodontic treatment result has proven to be stable and satisfactory, and the maxillary central incisors remain asymptomatic, have normal mobility, and continue to function well.

CONCLUSION:

◦ Various surgical and orthodontics techniques may be used to recover impacted maxillary canines.

◦ Proper management of these teeth requires appropriate surgical techniques to apply forces in a favourable direction and to have complete control for efficient correction, thereby avoiding damage to the adjacent teeth.

◦ The management of impacted canine is a complex procedure requiring a multidisciplinary approach.

◦ The clinician should communicate with each other to provide the patient with an optimal treatment plan based on scientific rationale.