Neurosensory Disturbances and Recovery Patterns in Orthognathic Surgery: A Retrospective Analysis of 579 Cases From a Tertiary Referral Center

Background Le Fort I osteotomy and sagittal split ramus osteotomy (SSRO) are the most commonly performed procedures for correcting skeletal jaw deformities. Despite improved safety, neurosensory disturbances remain a significant postoperative complication. Comprehensive quantitative assessment of sensory recovery and identification of risk factors are essential for optimizing patient counseling and surgical planning. Methods A total of 579 cases with a complete six-month follow-up were analyzed from 642 consecutive orthognathic surgeries performed between 1 April 2020 and 31 March 2025 at the Tokyo Dental College Ichikawa General Hospital. Neurosensory function was assessed using Semmes-Weinstein (SW) monofilament testing at one week and at one, two, three, and six months postoperatively. Normal sensation was defined as the detection of SW 1.65 monofilament, and severe hypoesthesia as failure to detect SW 4.56 or higher. Statistical analyses included chi-square tests, Mann-Whitney U tests, and multivariate logistic regression. Results Intraoperative complication rates were 0.4% in the Le Fort I group (n=225) and 2.5% in the SSRO group (n=354). Postoperatively, infraorbital nerve paresthesia occurred in 36/225 cases (16.0%), while inferior alveolar nerve paresthesia occurred in 139/354 left sides (39.3%) and 112/354 right sides (31.6%). Six-month neurosensory recovery rates were 94.4% in the Le Fort I group and 92.9% in the SSRO group, with >85% of recoveries occurring within the first three months. Mandibular advancement of ≥5 mm was the most significant independent risk factor for bilateral inferior alveolar nerve disturbance (left: <i>p</i>=0.000292; right: <i>p</i>=0.00196). Other complications included maxillary sinus mucosal thickening (14.2%) and metal plate fracture (1.1%). Conclusion Orthognathic surgery at this tertiary center demonstrated low intraoperative risk and excellent neurosensory recovery. However, mandibular advancements of ≥5 mm significantly increased the risk of inferior alveolar nerve injury, underscoring the need for enhanced preoperative counseling and surgical planning.