Third molar impaction in different facial types and mandibular length: A cross-sectional study

BACKGROUND: The etiology of mandibular third molar impaction is proposed to be mainly due to inadequate space between the distal of the second mandibular molar and the anterior border of the ramus of the mandible. This study was aimed to assess whether an association exists between different facial types and mandibular length to impaction of mandibular third molars. MATERIALS AND METHODS: The study consisted of 170 patients who were assessed for facial type clinically based on facial index and mandibular length radiographically on lateral cephalogram. The impaction status was determined clinically and radiographically on orthopantomogram. The facial type was categorized as euryprosopic (broad face), mesoprosopic (normal facial type), leptoprosopic (long face), hypereuryprosopic (extra broad face), and hyperleptoprosopic (extra long face). RESULTS: Of 170 patients, 18.8% of cases were with hypereuryprosopic profile, 33.5% of cases with euryprosopic profile, 24.7% with mesoprosopic profile, 21.8% with leptoprosopic, and 1.2% with hyperleptoprosopic profile were found. Nearly 42.2% of cases with hypereuryprosopic profile, 52.6% of cases with euryprosopic profile, 53.6% cases of mesoprosopic profile, and 60.3% cases of hyperleptoprosopic and leptoprosopic profile had impacted mandibular third molars. As for mandibular length assessment, 66% cases of short mandibular length, 64.5% cases of normal mandibular length, and 27.9% cases of long mandibular length had impaction. CONCLUSION: Within the limitations of the study, it was concluded that, though a higher incidence of impacted third molar was noted in patients with long facial pattern, no significant difference could be established among facial types and their association with impacted mandibular third molars. A significant association was noted between mandibular length and impaction.