Analysis of clinical usefulness of the heat flux technique: predictability of the recovery from neurosensory disturbances in the chin undergoing mandibular sagittal split ramus osteotomy

Abstract

To examine the prognosis of the neurosensory disturbance (NSD) in the chin after bilateral sagittal split ramus osteotomy (BSSRO), using the heat flux technique. Twenty-nine patients (total 58 sides) undergoing BSSRO were examined. The warm sensory threshold (WHF) and cold sensory threshold (CHF) in the chins of these patients were measured by the heat flux technique. Touch sensory threshold (TS) was measured by an Semmes-Weinstein esthesiometer. Touch sensory disturbance was subjectively evaluated by visual analog scale. At all of the postoperative time points, there were no significant differences in the incidence rate among all tests (chi-squared test; P > .05). WHF, CHF, and TS were significantly correlated with the subjective evaluation. Recovery from NSD was delayed in cases that the postoperative variation of 2 weeks was >400 W/m(2) in WHF and CHF and the filament marking at 2 weeks after surgery was >3.5 in TS. The heat flux technique appears to be a useful method for the prediction of the recovery from NSD in the chin.