Unifocal versus multifocal mandibular fractures and injury location

Mandibular fractures are frequently encountered in the trauma setting and comprise a significant number of facial injuries. The purpose of this study was to evaluate the prevalence and injury patterns of unifocal and multifocal mandibular fractures using thin-section imaging. Following IRB approval, 220 patients with mandibular fractures identified on maxillofacial CT scans performed between October 2008 and February 2011 were retrospectively reviewed. Examinations were performed on 64-multidetector row CT scanners with axial images acquired at 1.25-mm slice thickness. The location and number of fractures as well as causative mechanisms were recorded. Fractures were unifocal in 108/220 (49 %) and multifocal in 112/220 (51 %) patients. The mandibular angle was the most common fracture site in both unifocal and multifocal mandible fractures. In cases with multifocal mandibular fractures, bilateral fractures were more common (83 %) than unilateral multifocal mandibular fractures (17 %). Fractures involving the parasymphysis, the mandibular body, or ramus were significantly associated with the presence of additional mandibular fractures (p < 0.0001). While multifocal and unifocal fractures occurred in near equal frequency, bilateral multifocal fractures were much more common than unilateral multifocal mandibular fractures. Alveolar ridge fractures were exclusively seen in unifocal mandibular fractures.