Sensitivity of the Inferior Lip and Chin following Mandibular Bilateral Sagittal Split Osteotomy Using Piezosurgery

Abstract

Bimaxillary osteotomy, including bilateral sagittal split osteotomy, is the most commonly performed orthognathic surgical intervention in Europe and the United States. Neurosensory perturbation in the territory of the inferior alveolar nerve is a reported adverse effect of bilateral sagittal split osteotomy. Piezosurgery is a relatively new technique that allows bone to be cut while preserving soft tissues, including nerves. The purpose of this study was to assess inferior alveolar nerve function through clinical neurosensory testing after bilateral sagittal split osteotomy using Piezosurgery. Between February and September of 2004, 20 patients (40 sides) presenting with dentoskeletal deformities underwent bimaxillary osteotomy, including bilateral sagittal split osteotomy. The Mectron Piezosurgery device was used to perform all sagittal splits, with distraction being performed between the two bone valves. The inferior alveolar nerve was evaluated both objectively with clinical neurosensory testing, including pin-prick sensation, light touch sensation, and two-point discrimination tests, and subjectively at the following time points: preoperatively; at days 5, 7, and 10, postoperatively; and at the second month postoperatively. The anatomical integrity of the inferior alveolar nerve was respected in all cases. Observed normal results for the different tests at 10 days were 90, 82, and 70 percent, respectively, for pin-prick sensation, light touch sensation, and two-point discrimination. By computing scores for different clinical neurosensory tests, the authors observed between 75 and 80 percent complete neurosensory recuperation as early as the second postoperative month. Piezosurgery used for bilateral sagittal split osteotomy allows prompt recovery of inferior alveolar nerve neurosensory function within 2 months. No comparison is possible with the results using the standard technique for bilateral sagittal split osteotomy.