The Effect of Mandibular Third Molar Eruptional Situation and Position on the Risk of Angle Fracture

Angle facture is one of the most common sites of mandibular fractures and presence of third molar in this area increases the risk of such fracture. The aim of this study was to assess the effect of eruption situation and position of third molar on the risk of angle fracture. This descriptive study comprised of 82 patients. The patients were treated in Ahwaz hospitals during four years (2001– 2005) and were suffering from angle fracture at the third molar. For every patient a questionnaire form wasc completed. The panoramic radiography of each patient scrutinized to determine other information such as position and impaction situation of third molars (according to Pell and Gregory classification). Favorability or unfavorability of fractures and the presence of fractures in other sites of the mandible were also considered. The results showed that the incidence of angle fractures to be higher in men and were caused mostly by motor accidents. Unfavorable angle fractures occurred more than favorable ones. Fractures of other areas often located in contralateral parasymphysis. The vertical class IA and secondary class IB were the most common eruptional situation and position of third molars. According to the results, erupted or semi-erupted third molars increased the risk of angle fracture. In addition since the upper border of mandible is under muscular tension zone so we hypothesis that presence of an intact band of bone in upper border of angle will decrease the risk of fracture, with the eruption of third molar, this integrity is lost and the probability of angle fracture increases.