Mandibular third molars and angle fractures.

PURPOSE: The study purpose was to measure associations between mandibular third molar (M3) status/position and risk for angle fracture.

MATERIALS AND

METHODS

We designed a multicenter retrospective cohort study composed of patients who presented for operative management of mandible fractures. The primary predictor variable was M3 (present/absent). The secondary predictor variable was M3 position classified using the Pell and Gregory system. The outcome variable was angle fracture (present/absent). Appropriate univariate, bivariate, and multivariate logistic regression analyses were computed. The level of statistical significance was set at P </=.05.

RESULTS

The study sample was composed of 1,450 subjects with a mean age of 30.6 +/- 10.4 years (range, 2 to 87 years). The risk of an angle fracture with and without M3s was 30.1% and 13.7%, respectively (adjusted odds ratio, 2.8; 95% confidence interval, 2.3 to 3.4; P <.001). Based on the Pell and Gregory classification, varying M3 position was associated with varying risks of angle fracture (P <.001).

CONCLUSION

The presence of M3s was associated with a 2.8-fold increased risk for angle fractures. M3 position was associated with a variable risk for angle fracture. Notably, the deep impactions were not associated with an increased risk for fracture.