Relationship between inferior alveolar nerve imaging and neurosensory impairment following bilateral sagittal split osteotomy in skeletal Class III cases with mandibular prognathism.

Postoperative inferior alveolar nerve (IAN) neurosensory impairment was prospectively evaluated in 20 consecutive patients with mandibular prognathism who underwent bilateral sagittal split osteotomy. Routine presurgical imaging was obtained for all patients in study and control groups (10 patients each). Cone beam CT of the mandibular ramus and body was performed in 10 randomly selected patients (study group) and the precise location of the IAN was determined preoperatively and intraoperatively. Nerve sensation was evaluated by subjectively monitoring the physical feeling of the lower lip and the chin skin preoperatively and at different times postoperatively. Exact nerve location was successfully determined in all 10 cases in the study group. There were almost no significant differences between patients' sensation scores at the chin skin and lip sites. No significant differences were found between the two sides of the 20 patients. A significant increase in the score trend along the timeframes, in both groups, could be clearly seen together with a statistically significant difference (P≤0.004) between the study and the control groups. In conclusion, precisely locating the IAN using CT is a significant means for efficiently minimizing nerve damage during sagittal split osteotomy.