5196 mandible fractures among 4381 active duty army soldiers, 1980 to 1998

Objective. We present the frequencies of various types of mandibular fractu res along with associated mechanisms and injuries. Methods: Retrospective a nalysis of 5196 mandible fractures in 4381 patients extracted from the Tota l Army Injury and Health Outcomes Database (TAIHOD), a comprehensive databa se developed by the U.S. Army Research Institute of Environmental Medicine (USARIEM) that links population data to all hospitalizations among active d uty army soldiers. The database is based on the ICD-9 CM coding system. Res ults: We found the following frequencies for specific mandible fracture loc ations: angle 35.6%, symphysis 20.1%, subcondylar 14.2%, body 12.7%, condyl ar process 9.1%, ramus 4.5%, alveolar border 2.7%, and coronoid process 1%. The mechanisms of injury were separated into seven categories. Fighting ac counts for 36.2%, automobile accidents for 18.6%, athletics for 13.6%, fall s for 9.7%, motorcycle accidents for 3.1%, other land transport accidents f or 3%, and miscellaneous causes for 15.8%. A few fracture locations appear to be associated with specific mechanisms. Of 82 alveolar border fractures with known mechanisms, 37% resulted from automobile accidents. Of 1094 angl e fractures with known mechanisms, 48.6% resulted from fighting. Our data s how that the majority of fractures were isolated to one location. Only one fracture was recorded for 70.6%, 29.2% have two fractures recorded, 0.2% ha ve three or more fractures recorded. Associated injuries were common and in clude facial lacerations 1236 (28.2%), non-mandible facial bone fractures 7 33 (16.7%), intracranial injury 403(9.2%), internal injuries 229 (5.2%), fr actures of the upper limb 295 (6.7%), fractures of the lower extremity 302 (6.9%), and cervical fractures 34 (0.8%). Conclusions: The mechanism of inj ury is important in determining the most likely resultant mandible fracture in the case of angle of mandible and alveolar ridge fractures. The clinici an should maintain a high level of suspicion for associated injuries that o ccur more than one fourth of the time and even more frequently in motor veh icle accident victims. Associated intracranial injury is particularly impor tant to rule out. Associated facial fractures, intracranial injury, interna l injuries, and extremity injuries are all more common than cervical fractu res.