Neurosensory deficit and functional impairment after sagittal ramus osteotomy: A long-term follow-up study

Purpose: This study evaluated persistent neurosensory deficit (NSD) and functional sensory deficit (FSD) after mandibular bilateral sagittal split osteotomies (BSSO) and their association with patient age at time of operation and eight additional variables. Patients and Methods: Eighty-five patients more than 2 years post-BSSO were identified and stratified 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 split," excessive intraoperative bleeding, nerve manipulation, removal of third molars, use of rigid fixation, simultaneous mandibular procedures, 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 was performed to determine differences between groups. Logistic regression was used to evaluate each variable and determine its association with 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 increasing persistence with increasing age was not significant (P = .248). However, persistent FSD with increasing age was highly significant (P = .003). The incidence of FSD in group 4 was statistically greater than in the other groups (P < .001; P < .001; P = .004, respectively). Logistic regression identified patient age and "bad splits" as associated with FSD (P = .003; P = .015, respectively). Conclusions: The incidence of persistent FSD more than 2 years post-BSSO increases with increasing age in a predictable and highly significant manner. Presurgical counseling should address this issue. FSD is also significantly associated with "bad splits." No other variables were found to be significant.