Relationship between fractures of the mandibular angle and the presence and state of eruption of the lower third molar.

OBJECTIVES

This study attempted to relate the incidence of fractures at the mandibular angle with the presence and state of eruption of lower third molars.

STUDY DESIGN

The records and radiographs of 200 patients with mandibular fractures were examined. The presence and degree of impaction of lower third molars were assessed for each patient and related to the occurrence of fractures of the mandibular angle. Data were analyzed by chi-square statistic and the Student's t test.

RESULTS

The incidence of angle fractures was found to be significantly greater when unerupted lower third molars were present (p < 0.001). Bilateral unerupted third molar teeth predisposed to a fracture at the angle significantly more than unilateral unerupted third molars (p < 0.01). Furthermore, the amount of bony space occupied by an unerupted third molar tooth directly related to the weakness of that area of bone (p < 0.001).

CONCLUSIONS

This study provides clinical evidence to suggest that unerupted third molar teeth weaken the mandibular angle both quantitatively and qualitatively.