The effect of mandibular third molar presence and position on the risk of an angle fracture

Purpose: This study assessed the relationship between the presence and position of mandibular third molars (M3) and angle fractures. Patients and Methods: A retrospective cohort study design and a sample composed of patients admitted for treatment of mandible fractures between January 1993 and April 1998 were used. Data sources were the patients' medical records and radiographs. The predictor variables were the presence and position of M3. M3 position was grouped into 9 categories based on the Pell and Gregory classification. The outcome variable was the presence of an angle fracture. Other study variables included age, sex, race, mechanism of injury, and fracture location. Results: The eligible sample was composed of 437 patients, of whom 367 had data available for analysis. Patients with M3 present had a 1.9 times (95% confidence interval = 1.2 to 2.9) greater chance of an angle fracture than patients without M3s (P = .003). There was a statistically significant variation in the risk for an angle fracture, depending on M3 position (P = .049). Conclusion: The study results confirm other reports that patients with M3 present have an increased risk for angle fractures. Furthermore, it also showed that the risk for an angle fracture varied depending on M3 position.