Third molars may double the risk of an angle fracture of the mandible

Abstract

Data sources Medline, Embase and references of relevant articles. Study selection Reports were selected if they were cohort studies reporting mandibular angle fractures in people with and without third molars. Case–control studies and case series that provided information about the proportion of people who had a third molar among the total suffering angle fractures and those without angle fractures were included.Data extraction and synthesis Odds ratios and 95% confidence intervals were calculated from study data and results summarised using Mantel–Haenszel fixed-effects models and DerSimonian and Laird random-effects model. Formal heterogeneity tests were also carried out. Results Six studies, all case series and involving 3002 patients with mandibular fractures, met the inclusion criteria (see Table 1). Crude relative risk estimates for an angle fracture, comparing patients with a third molar with those without, ranged from 1.2 to 12.7. There was significant heterogeneity across the six studies (P=0.001), but when two less methodologically rigorous studies were excluded this was no longer the case (P=0.22). Conclusions The presence of a lower third molar may double the risk of an angle fracture of the mandible. This could have a bearing on any clinical decision on whether to extract the molar. © EBD 2004.