NEUROSENSORY DEFICIT AND FUNCTIONAL IMPAIRMENT AFTER SAGITTAL RAMUS OSTEOTOMY - A LONG-TERM FOLLOW-UP-STUDY

Purpose: This study evaluated persistent neurosensory deficit (NSD) an d functional sensory deficit (FSD) after mandibular bilateral sagittal split osteotomies (BSSO) and their association with patient age at ti me of operation and eight additional variables. Patients and Methods: Eighty-five patients more than 2 years post-BSSO were identified and s tratified by age: group 1, 10 to 19 years (n = 16); group 2, 20 to 29 years (n = 24); group 3, 30 to 39 years (n = 30); group 4, older than 40 years (n = 15). Mean mandibular advancement, incidence of ''bad spl it,'' excessive intraoperative bleeding, nerve manipulation, removal o f third molars, use of rigid fixation, simultaneous mandibular procedu res, and associated systemic disease were documented for each group. A questionnaire modified from Zuniga was used to document the presence of persistent (2 years or longer) NSD and FSD. Statistical analysis wa s performed to determine differences between groups. Logistic regressi on was used to evaluate each variable and determine its association wi th persistent NSD and FSD. Results: Persistent NSD by age was: group 1 , 81%; group 2, 46%; group 3, 73%; group 4, 87%. The trend of increasi ng persistence with increasing age was not significant (P = .248). How ever, persistent FSD with increasing age was highly significant (P = . 003). The incidence of FSD in group 4 was statistically greater than i n the other groups (P < .001; P < .001; P = .004, respectively). Logis tic regression identified patient age and ''bad splits'' as associated with FSD (P = .003; P = .015, respectively). Conclusions: The inciden ce of persistent FSD more than 2 years post-BSSO increases with increa sing age in a predictable and highly significant manner. Presurgical c ounseling should address this issue. FSD is also significantly associa ted with ''bad splits.'' No other variables were found to be significa nt.