COMPARATIVE-STUDY OF INFERIOR ALVEOLAR DISTURBANCE RESTORATION AFTER SAGITTAL SPLIT OSTEOTOMY BY MEANS OF BICORTICAL VERSUS MONOCORTICAL OSTEOSYNTHESIS

The comparative study of neurosensory disturbance of the inferior alve olar nerve after bilateral sagittal split osteotomies was carried out. The 112 patients who underwent bilateral sagittal split osteotomies w ere divided into two groups: one group consisted of 62 patients (124 o steotomy sites) who received bicortical osteosynthesis using the lag s crew principle (bicortical fixation group), and the other group consis ted of 52 patients (104 osteotomy sites) who underwent monocortical os teosynthesis using miniplates (monocortical fixation group). The incid ence of neurosensory disturbance of the inferior alveolar nerve as wel l as its recovery course was compared by patients' interview and Semme s-Weinstein pressure esthesiometer. Mean follow-up period was 12 month s (minimum 3 months, maximum 36 months). The incidences of sensory dis turbance of both groups were not significantly different at 2 weeks po stoperatively. During the period 6 to 12 months postoperatively, the n umber of patients having light touch sensory disturbance was significa ntly less in the monocortical fixation group than in the bicortical fi xation group. Moreover, the number of patients complaining of numbness during 6 to 18 months postoperatively was significantly less in the m onocortical fixation group. These findings suggested that the monocort ical osteosynthesis had less damage on the inferior alveolar nerve, le ading to the better restoration of neurosensory disturbance in patient s in whom the nerve damage was moderate.