Do third molars weaken the mandibular angle?

Abstract

Objective: The purpose of this study is to estimate how is the magnitude of the impact of a mandibular third molar on the mandibular angle stiffness. Study Design: It was performed a literature search on whole MEDLINE and LILACS data base to find articles that match the following inclusion criteria: cohort studies presenting data on patients with mandibular fractures and third molars; that had a similar angle fracture definition; and that present data available to be cross-classified in a statistic analysis. Results: The sample was composed by 4 studies, involving 2533 patients from USA, Nigeria, Germany and Jordan, evaluated between 1976 and 2001. The analysis of the sample shows a relative risk for a mandibula to fracture, comparing patients with and without third molars, ranging from 1,18 to 2,25. The data of the sample was grouped because of the homogeneity of the articles methods. The estimated relative risk across the 4 studies was 1,94 (95% CI 1,6 -2,35). Conclusions: The presence of a third molar may double the risk of an angle fracture of the mandible to occur. Even with this data, the present study cannot support conditions related to the third molar that may affect this impact. Further studies are necessary to discuss the true indication of removal of these teeth as a prophylactic measure in population groups more predisposed to fracture.

Concomitant dental injuries in maxillofacial fractures - a retrospective analysis of 1219 patients

“…As punches often hit the mandible, this may well be the reason for the high number of wisdom teeth involved; wisdom teeth play an important role as a weak point in the mandible, making it prone for fractures of the mandibular angle (26)(27)(28).Motor vehicle accidents in our study totaled only 13%. Given that this group plays the main role for dental or maxillofacial traumatization in studies (15,18,29) from other countries, this number might be an argument for the high security standard, including the obligation to buckle up or wear protective headgear as a motorcyclist.…”

Do erupted third molars weaken the mandibular angle after trauma to the chin region? A 3D finite element study

“…Retrospective studies, case series and literature reviews have shown that the presence of third molars is linked to the increased prevalence of mandibular angle fracture. 6 There are not enough studies from the perspective of biomechanics, which show the true impact of third molar presence and the occurrence of fractures, because reproducing a real model of the mandible is difficult.…”

“…4 An experimental study with monkeys has shown that mandibles containing unerupted third molars fractured at approximately 60% of the force required to fracture mandibles with erupted third molars. 5 Bezerra et al 6 reported a 1.94fold higher risk of mandibular angle fractures when the third molar is present.…”

Impact of the lower third molar and injury mechanism on the risk of mandibular angle and condylar fractures

“…There are various studies suggesting that mandibular third molar (M3) contributes to the weakness of the angle region of the mandible and increase the risk of its fracture for even two to fourfolds . Bezerra et al . noticed that traumatic impacts of lower intensity (such as assaults and sport injuries) resulted in energy transmission along the lesioned body and were more frequently associated with mandibular angle fractures, especially in cases with third molar.…”