Do third molars weaken the mandibular angle?

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.