Effect of Lower Third Molars on the Incidence of Mandibular Angle and Condylar Fractures

Purpose: Numerous previous studies already have proven that mandibles with a third molar are significantly more susceptible to angle fracture by external force. Similarly, other data suggest that the absence of a third molar increases the risk of condylar fracture, while concurrently decreasing the risk of angular fracture. We attempt to characterize the effect of a third molar on the incidence of mandibular angle and condylar fractures. Methods: This retrospective study reviews data from 385 patients, all of whom were seen in our clinics between February 2006 and November 2009. All data were collected from clinical examination notes and panoramic radiographs, with third-molar state evaluated by the Pell and Gregory classification system. Results: Our results mirror those of previous studies. The incidence of mandibular angle fracture was significantly greater on sides with a third molar, whereas the condylar fracture rate significantly increased in mandibles lacking a third molar or without a fully erupted third molar. The rate of symphysis and mandibular angle fracture was also high in cases of multiple comorbid fractures. Conclusions: Both the presence and the state of the lower third molar affect the risk of future mandibular angle and condylar fracture.