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 posi tion of mandibular third molars (M3) and angle fractures. Patients and Methods: A retrospective cohort study design and a sample comp osed of patients admitted for treatment of mandible fractures between Janua ry 1993 and April 1998 were used. Data sources were the patients' medical r ecords and radiographs. The predictor variables were the presence and posit ion 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 f racture. 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 vari ation in the risk for an angle fracture, depending on M3 position (P = .049 ). Conclusion: The study results confirm other reports that patients with M3 p resent have an increased risk for angle fractures. Furthermore, it also sho wed that the risk for an angle fracture varied depending on M3 position.