Perioperative neurosensory changes associated with treatment of mandibular fractures

Purpose: The purpose of this study was to document perioperative neurosensory changes in the inferior alveolar nerve (IAN) after mandibular fracture treatment and to identify risk factors associated with these changes. Materials and Methods: This was a prospective cohort study composed of patients treated for mandibular fractures. The primary study variable was the change between the postinjury/pretreatment IAN neurosensory examination score and the score after fracture reduction. Risk factors were categorized as demographic, anatomic, and treatment. Appropriate descriptive, bivariate, and multivariate statistics were computed. Results: The cohort was composed of 61 patients with 97 fractured sides. Forty-seven fractures (49%) were located between the lingula and mental foramen, and 50 fractures (51%) were located distal to the mental foramen. Thirty-nine fractures (41%) were displaced by 5 nun or more. Abnormal preoperative UN neurosensory examinations were documented in 81% of the fractured sides. Fifty-three fractures (54%) were treated by closed reduction and 44 (46%) by open reduction and internal fixation. In 82 fractures (85%), the IAN neurosensory score was unchanged or improved after treatment. In a multivariate model, preoperative neurosensory score, displacement, and treatment were associated with a statistically significant risk (P less than or equal to .05) for postoperative deterioration of IAN sensation. Conclusion: Open reduction and internal fixation, fracture displacement of 5 mm or more, and a normal preoperative IAN neurosensory examination were associated with an increased risk for deterioration of the UN neurosensory score after treatment of mandibular fractures. Additional studies are indicated to determine long-term IAN neurosensory function after mandibular fracture treatment and the factors that affect prognosis. (C) 2004 American Association of Oral and Maxillofacial Surgeons.