To assess the incidence of neurosensory disturbances (NSD) of the inferior alveolar nerve (IAN) after Intraoral verticosagittal ramus osteotomy (IVSRO).

The sensibility of the chin and lower lip of ten consecutive patients undergoing IVSRO was assessed. Evaluations were performed at 7 days preoperatively, 7 days, one month and six months postoperatively. The chin was divided into four quadrants, which were tested separately. The tests used were: two-point discrimination (2-P), brush stroke direction discrimination (BSD) and thermal stimuli (TH). Postoperatively, patients also answered a questionnaire.

The values for 2-P showed statistically significant difference when compared to preoperative measurements (P>0.05) in all quadrants, with exception to quadrant D. There was no statistically significant difference among preoperative values and 7 days, 1 month and 6 months postoperative values. For BSD and TH tests, no differences were found among time points. None of the 10 patients reported complete numbness after 1 week. After 6 months, complete recovery of the chin sensibility was reported in all 10 cases.

This study showed, objectively and subjectively, a low incidence of NSD after IVSRO. Further studies with larger samples are necessary to confirm these results.