Mandibular molar impaction and related retrospective study finding incidence of impacted mandibular third molars in a population sample from Bosnia and Herzegovina

1. Tooth Impaction
Hiba Hamid

2. DEFINITION
IMPACTION:
It is the tooth that has failed to
erupt completely or partially to its
correct position in the dental arch
well beyond its eruption date and
its eruption potential is lost.

3. COMMONLY IMPACTED TEETH
• Mandibular third molar
• Maxillary third molar
• Maxillary canine
• Mandibular premolars
• Maxillary premolars
• Mandibular canine
• Maxillary central incisor
• Maxillary lateral incisor

4. CAUSES OF IMPACTION
LOCAL CAUSES:
• Obstruction for eruption
• Lack of space
• Ankylosis of primary or permanent
tooth
• Ectopic position of tooth bud
• Dilaceration of roots
• Soft tissue or bony lesions

5. CAUSES OF IMPACTION CONT’D
SYSTEMIC CAUSES:
• Pre-natal causes: hereditary
• Post-natal causes: tuberculosis, rickets,
malnutrition
• Endocrinal disorders of thyroid,
parathyroid, or pituitary gland
• Hereditary disorders: osteoporosis, cleft
palate

6. CLASSIFICATION OF IMPACTED TEETH
WINTER’S CLASSIFICATION
According to angulation:
oMesioangular
oHorizontal / transverse / inverted
oVertical
oDistoangular
oBuccoangular
oLinguoangular

8. CLASSIFICATION OF IMPACTED TEETH CONT’D
WINTER’S CLASSIFICATION
According to depth
o Position A: highest position of the tooth is on
a level with or above the occlusal line
o Position B: highest position is below the
occlusal plane, but above the cervical level
of the second molar
o Position C: highest position is below the
cervical level of the second molar

10. CLASSIFICATION OF IMPACTED TEETH CONT’D
PELL AND GREGORY’S CLASSIFICATION
Relation of impacted mandibular third molar to ramus of mandible and the second molar
• Class I: sufficient space available between the anterior border of ascending ramus and
distal side of the second molar for the eruption of the third molar
• Class II: space available between anterior border of ascending ramus and distal side of
second molar is less than the mesiodistal width of the crown of the third molar
• Class III: third molar is totally embedded in the bone from the ascending ramus
because of absolute lack of space

13. Incidence of impacted
mandibular third molars
in population of Bosnia
and Herzegovina: a
retrospective
radiographic study

14. Article Details
Published in Journal of Health Sciences
Corresponding Authors: Sadeta Šeèiæ, Samir Prohiæ,
Sanja Komšiæ, Amra Vukoviæ
Department of Oral Surgery, Faculty of Dentistry
University of Sarajevo
Bosnia and Herzegovina
Submitted on 14th March, 2013
Accepted on 3rd June, 2013

15. AIM OF THE STUDY
Evaluate the incidence and the pattern of impaction of
mandibular third molars in population of Bosnia and
Herzegovina using panoramic radiographs of patients
referred to Department of Oral Surgery, Faculty of
Dentistry, University of Sarajevo.

16. STUDY SAMPLE
• Retrospective analysis of OPG radiographs of pts. referred to Oral Surgery
Department, Uni. of Sarajevo, from January 2010 to February 2013.
• Pts. referred with indication of removal of impacted third molars.
• Signed consent was obtained from patients for the study.
• 2000 radiographs were viewed and related data selected from their dental
records.

17. INCLUSION / EXCLUSION CRITERIA
INCLUSION CRITERIA:
• Complete root formation of mandibular third molar
EXCLUSION CRITERIA:
• Pts. younger than 19 years
• Poor quality of OPG
• Incomplete medical and dental records
• Presence of dentoalveolar trauma or other pathological dentoalveolar condition
• Presence of any systemic or craniofacial anomaly or syndrome (e.g. Down syndrome,
Cleidocranial dysostosis)
• Absence of mandibular second molar

18. STATISTICAL ANALYSIS
Data recorded into specially designed forms containing following
information:
• age,
• gender,
• place of residence,
• region,
• impacted tooth,
• angulation of impaction (acc. to Winter’s classification),
• level of impaction (acc. to Pell and Gregory’s classification),
• pathology and complications associated with impacted and semi-impacted
third molars

19. RESULTS
• 2000 radiographs analyzed. 761 presented with at least 1 impacted third molar.
• 1034 impacted mandibular molars were present: 508 mand. left third molar, 526 mand. right
third molar
• 761 patients analyzed in study: 270 males, 491 females. Male to female ratio= 1:1.8
• Age range: 19 – 85 years with mean ± standard deviation: 27 ± 9
• Significant difference in incidence of impaction found between females and males (p<0.05)
• Vertical angulation most common pattern of impaction (65%), followed by mesioangular (20%),
horizontal (9%), distoangular (5%), and buccolingual (1%).

23. CONCLUSION
• 38% of pts. presented with at least one
impacted third molar
• Common age group: third decade
• Significant difference in incidence of
impaction found between males and females
• Vertical angulation most common pattern of
impaction
• Majority of pts. presented with class I of
level of impaction