DOES THE LOW AND SHORT MEDIAL CUT AFFECT LINGUAL NERVE RECOVERY AFTER SAGITTAL SPLIT OSTEOTOMY?

PURPOSE: To evaluate the recovery of lingual nerve (LN) neurosensory function in patients undergoing sagittal split osteotomy (SSO) with a low and short medial horizontal cut.

MATERIALS AND METHODS: This was a prospective study of patients with mandibular deformities undergoing SSO with a low and short medial horizontal cut over a 4-year period. The outcomes of interest were neurosensory recovery of the LN, as assessed objectively using functional sensory recovery (FSR) and subjectively by patient report.

RESULTS: The sample included 123 SSOs in 62 subjects with a mean age of 19.3 ± 3.1 years. Thirty-seven (61.7%) subjects were female. Mandibular advancements were performed in 52 SSOs (42.3%); mandibular setbacks were performed in 71 SSOs (57.7%). One subject underwent revision BSSO. FSR was achieved at 122 LNs (99.1%) within 6-weeks post-operatively, with 120 sites (97.5%) having S4 sensation at 6-weeks. Decreased LN sensation was reported at 10 (8.3%) sites at 1-week post-operatively. At 6-weeks post-operatively, 118 sites (97.5%) had reported normal sensation. By 12-weeks post-operatively, all LN sites had S4 sensation and there were no subjective complaints. Revision sagittal split osteotomy was associated with prolonged (≥6 weeks) time to S4 sensation (p = 0.02) and subjective complaint of decreased sensation (p = 0.02).

CONCLUSION: LN sensory recovery occurs rapidly following the low and short SSO, with 99% of sites achieving FSR and subjectively normal sensation within 6-weeks of surgery and all patients achieving FSR with S4 sensation by 12-weeks post-operatively. LN sensory recovery may be prolonged in patients undergoing revision SSO.