Clinical course study of postoperative recovery of neurosensory disturbance after inferioralveolar nerve transection during sagittal split osteotomy.

Purpose : Inferior alveolar nerve transection (IANT) is a severe complication of sagittal split osteotomy (SSO). This study aimed to retrospectively evaluate the long-term sensory recovery in patients who experienced intraoperative IANT compared to those who did not. Materials and methods : This retrospective cohort study reviewed patients who underwent SSO from 2016 to 2022. Patients were divided into Group A (with IANT, 11 sides) and Group B (without IANT, 151 sides). Sensory perception was assessed using the Semmes-Weinstein (SW) test, static two-point discrimination (s-2PD) test, and a Numerical Rating Scale (NRS) at preoperative baseline and at 1, 3, 6, and 12 months postoperatively. Mann-Whitney U and Dunnett's tests were used for statistical analysis (p < 0.05). Results : Group A demonstrated significantly worse sensory outcomes than Group B on all tests at all postoperative time points (p < 0.01). In Group B, SW and s-2PD values were significantly worse than baseline at 1 and 3 months but showed no significant difference at 6 and 12 months. In contrast, Group A outcomes remained significantly impaired compared to their own preoperative baseline throughout the 12-month follow-up. Conclusions : Complete IANT during SSO results in a profound and likely permanent neurosensory deficit. While patients without nerve transection typically recover baseline sensory perception by 6 months, those with IANT experience only minimal improvement and remain significantly impaired at a year post-surgery.