OBJECTIVE To evaluate the influence of the anatomic position and intraoperative exposure of the inferior alveolar nerve on neurosensory disturbance (NSD) in sagittal split ramus osteotomy. STUDY DESIGN The anatomic factors of the nerve were measured on preoperative three-dimensional computed tomography in 98 patients. The intraoperative nerve exposure was assessed. NSD was evaluated for 1 year after surgery. The correlations between NSD and the factors were analyzed. RESULTS The NSD decreased as the lateral marrow space from the nerve increased (P < .01). The complete nerve exposure increased NSD by 7.6 times (P = .01). The nerve exposure increased as the buccal plate thickness increased (P = .01) and decreased as the vertical marrow space from the nerve increased (P = .01). CONCLUSIONS The nerve exposure and the lateral marrow space from the nerve affected NSD. The buccal plate thickness and the vertical marrow space indirectly affected NSD through nerve exposure.