Do the presence of mandibular third molar and the occlusal support affect the occurrencand the mode of mandibular condylar fractures?

To investigate the influence of occlusal support and the presence and position of mandibular third molars on the incidence of mandibular condylar fractures. Records of 222 patients who presented with mandibular fracture at the Department of Oral and Maxillofacial Surgery, Kagawa Prefectural Central Hospital, from 2006 to 2019 were retrospectively analyzed. The following variables were investigated: age, sex, cause of fracture, the presence and state (impaction and angula-tion) of mandibular third molars, the site of mandibular fracture, and the presence of occlusal support for molars. Various risk factors for mandibular condylar head and subcondylar fractures were investigated. The majority of fractures were caused by a fall. The risk of mandibular subcondylar fractures was significantly higher in patients with occlusal support and mandibular third molars. The risk of mandibular condylar head fractures was significantly higher in patients without occlusal support or mandibular third molars. The position and angulation of mandibular third molars did not show significant difference between occurrences of head or subcondylar fractures. This study demonstrated that occlusal support and the presence of mandibular third molars significantly increased the risk of subcondylar fractures. One the contrary, their absence increased the risk of condylar head fractures.