LABIAL SENSORY FUNCTION FOLLOWING SAGITTAL SPLIT OSTEOTOMY

A retrospective assessment of labial sensory function following sagitt al split osteotomy was undertaken by a combination of record analysis, postal questionnaire and objective sensory testing. Case records for 90 sides operated upon by a single consultant surgeon between 1979 and 1992 identified a prevalence of persisting sensory change at 2 years of 6.7%. A higher incidence of sensory change was seen in patients tre ated with intermaxillary fixation/upper border wires than those manage d with buccal monocortical miniplates. Postal questionnaire returns fo r 67 consultant operated sides identified a higher incidence of sensor y change than recorded in the notes. 5.9% had long term persisting ana esthesia. Another 28% had more variable subtle sensory impairment. A s imilar relation to method of fixation was seen. An association between duration of temporary sensory change and magnitude of forward mandibu lar advance was noted. Objective sensory testing validated the subject ively reported sensory status but also identified many patients self-a ssessed as normal had some undetected sensory impairment. Possible mec hanisms for the above findings and implications for clinical practice are presented.