Evaluation of recovery period in lower lip hypoesthesia after bilateral sagittal split osteotomy using trigeminal somatosensory evoked potential

ABSTRACT Background/Purpose Bilateral sagittal split osteotomy (BSSO) is one of the most frequently used treatments for jaw deformity worldwide. However, lower lip hypoesthesia is a postoperative complication of BSSO. Trigeminal somatosensory evoked potential (TSEP) can be used to evaluate neural pathway abnormalities by measuring latency. The purposes of this study were to measure latency before and after BSSO and to examine the relationship between latency and the duration of hypoesthesia recovery. Study design and methods This observational retrospective case-control study analyzed data recorded from 2013 to 2018. We divided the patient data into five groups according to recovery time. Using the latency obtained in TSEP as the main outcome, we examined the relationship between hypoesthesia recovery time and latency. Results The group with unresolved postoperative hypoesthesia 6 months after surgery had significantly greater latency values extension than that without postoperative hypoesthesia. Conclusion By measuring the degree of prolongation of latency before and after surgery, it can be possible not only to indicate the presence of hypoesthesia but also to predict the hypoesthesia recovery period.