ROOT EXTERNAL MORPHOLOGY OF IMPACTED MANDIBULAR THIRD MOLARS:

A CROSS-SECTIONAL STUDY IN HAI PHONG MEDICAL UNIVERSITY HOSPITAL

Student: Pham Minh Thao

Instructor: Prof. Pham Van Lieu, PhD

Dr. PhamThanh Hai, DDS

OUTLINE

1. Background

2. Material and method

3. Research results - Discussion

4. Conclusion

5. Recommendations

• The latest teeth erupt between the ages of 18 and 25 • They often cause many problems therefore need to be extracted• There’re a lot of complications before, during and after 3rd molar

extraction one of the reasons was the variant of roots causing confused diagnosis.

BACKGROUND

How was the variants of the roots of mandibular third

molars?

Could their variations be predicted by Panoramic X- ray to

help the tooth removing, or not?

BACKGROUND

Reseach question

BACKGROUND

The variants of wisdom teeth

NormalVariants

48

BACKGROUND

The roots of mandibular wisdom tooth are often similar to the root of the 2nd molar.

Conformity panorama

BACKGROUND

2-D image ( Panorama X-ray)

3-D image ( CT X-ray)

Nonco

nfor

mity

pan

oram

a

Le Duc Lanh (2009): Panoramic X- ray reflected the 2D space, CT scanner showed the others anatomical structures

BACKGROUND

Number of root

Research 1 2 ≥ 3

Jun-Beom Park(2013)37,9% 56,5% 1,9%

Heinz-Theo Lübbers(2013) 86,7% 13,3 %

Maryam Kuzekanani (year)11.5% 73%

5,5%

Reviews of the recent related studies

1. Characterize the root external morphology of

impacted mandibular 3rd molar.

2. Compare the concordance of root morphology

between anatomical and panorama analysis.

OBJECTIVES

Materials :

- Mandibular impacted wisdom teeth was extracted, intact roots.

- Panoramic radiograph (before extracting)

n = 57 wisdom teeth

Design of the study: cross sectional study

MATERIAL AND METHOD

Sampling method:

- Convenient sample, all patients satisfying study criteria were enrolled in the study.

Selection criteria:

- The patients have impacted wisdom teeth, were extracted in Hai Phong Medical University Hospital, the roots were intact, or could be rearranged intactly.

MATERIAL AND METHOD

Exclusion criteria:

- The lower wisdom teeth were extracted, had

not Panorama X- ray before extracting.

Time of the study:

- From December, 2014 to April, 2015.

Statistic: Used SPSS software for statisting

and data processing.

MATERIAL AND METHOD

STEPS OF RESEARCH

Step 1: Interview the patient before extracting

Step 2: Collect Panoramic X- ray (before

extracting)

Step 3: Extract wisdom tooth

Step 4: Collect the wisdom tooth after extracting

Step 5: Observe

MATERIAL AND METHOD

The variables Identified index Data collection

1. General variable Age (calendar year) Interviewed

Gender (Male/Female)

Name of tooth (International

regulations)2. Similar to the roots of 2nd molar 2 separate roots, the roots

curved distally

Observed

3.Variations by quantity 1 root (single root) Observed

More than 3 roots

4. Variations by morphology Equal length roots Observed

Fused roots

Apical fused roots

Straight roots

Mesio-angular roots

5. Compare with Panoramic X- ray Conformity Observed

Nonconformity

Research sheet

MATERIAL AND METHOD

AgeTotal 11-20 21-30 31-40 41-50 51-60

57 5 31 16 4 1

100% 8.8 54.4 28.1 7.0 1.8

Consistent with the formation and evolution of wisdom tooth

Table 1: Ratio distribution of patients by age

RESULTS

1. Status distribution of patients by age

Figure 1: Rate of variants in mandibular wisdom teeth

14%

86%

Similar to the root shape of 2nd mo-larVariants

RESULTS

The variant had a high ratio, consistent with the reviews of Hoang Tu Hung and the other scientists

2. The appreance of the variant lower wisdom teeth

Figure 2: Rate of variations by quantity1 root 2 roots 3 roots 4 roots

0%

20%

40%

60%

80%

100%

12.30%

77.20%

8.80%1.80%

RESULTS

3. Variations by quantity

The tendency of result is similar to the results of M. Kuzekanani (73% two roots) , J. Park (56.5% two roots), Sarasswati F.K (67% two roots) with highest rate is 77.2% in 2 roots group

Equa

l len

gth

r...

Fuse

d ro

ots

Apica

l fus

ed r.

..

Stra

ight

root

s

Mes

ioan

gular r

...

Norm

al ro

ots

Other

s0%

25%

50%

75%

100%

10.50%

31.60%

3.50%10.50%15.80%

19.30%8.80 %

Fused roots had the highest proportion of 31.6%, similar to the reviews of Hoang Tu Hung

RESULTS

4. Variations by morphology

Figure 3: Proportion of variations by morphology

Variations by quantity

Variations by morphology

Combination0%

20%

40%

60%

80%

100%

22.80%

80.70%

23.00%

Figure 4: Combination of variations by quantity and by morphology

RESULTS

5. Combination of the variations by quantity and morphology

The combination were 23 %. when the variations by quantity appeared, the one by morphology appeared too. This result was consistent with Hoang Tu Hung

P<0.05

Figure 5: Concordance of Panoramic X-ray

77%

23%

ConformityNoncon-formity

RESULTS

6. Investigation of the concordance of Panoramic X-ray

Sarasswati F.K: the ratio of true positives of Panoramic X-ray in supporting diagnosis was notable high (66.6 %- 83.3 %),

1. Most of roots of morphology of impacted lower 3rd

molar was variant (86%). The ratio of the normal

wisdom teeth was very low (14%).

2. Most of the studied real roots were consistent with

their images on Panorama (77%).

CONCLUSIONS

1. Before extracting the impacted mandibular

wisdom tooth, it is necessary to take Panoramic

X- ray, because most of their roots was variant.

2. Need to take the CT scanner, or CT conebeam

in doubting cases, that can not be determined

on Panorama.

RECOMMENDATIONS

SOME GRAPHICS RESEARCH

Variations by quantity of third molars root

1 root 2roots 3 roots

Variations by morphology

SOME GRAPHICS RESEARCH

Thank you very much for your

attention