Neurosensory differences after wire and rigid fixation in patients with mandibular advancement

Purpose: The purpose of this analysis was to compare the frequency and severity of nerve damage with rigid and wire fixation in patients participating in a prospective, randomized clinical trial. Patients and Methods: One hundred twenty-six patients who required a bilateral sagittal split osteotomy and mandibular advancement were randomly assigned to receive either rigid or wire fixation. Tactile sensation in the mental nerve region bilaterally was determined presurgically and throughout the subsequent 2 years by using monofilament detection and brush stroke direction. Neurosensory levels were compared between the types of fixation over time. Results: Evaluation with monofilament detection showed no significant difference between types of fixation throughout the 2-year follow-up. However, brush stroke determination showed significantly greater hypesthesia with rigid compared with wire fixation from 8 weeks through 2 years postoperatively. Conclusion: Rigid fixation resulted in more anesthesia in the mental nerve distribution than wire fixation when tested with brush stroke direction. However, increased anesthesia was not present when measured with monofilament determination. (C) 2000 American Association of Oral and Maxillofacial Surgeons.