Prediction of recovery from neurosensory deficit after bilateral sagittal split osteotomy

Objective. To observe the suitability of different combinations of readily available tests to predict recovery from a neurosensory deficit after bilat eral sagittal split osteotomy (BSSO). Study design. Thirty patients scheduled for BSSO were examined before surge ry and 4 days, 3 weeks, 3 months, 6 months, and 1 year after surgery. At ea ch follow-up, the patients self-evaluated the subjective neurosensory defic it of the lower lip and chin of both sides. Neurosensory function was also measured by tests consisting of light touch, 2-point discrimination, pin ta ctile discrimination, thermal discrimination, and sensibility testing of th e mandibular molars. The positive predictive values (PPV) of each test for recovery from the neurosensory deficit were calculated, Furthermore, differ ent tests were combined, and the PPVs for recovery from the neurosensory de ficit of these combinations were analyzed. Results. A positive response to sensibility testing of the mandibular first and second molars 4 days and 3 weeks after surgery was related to a PPV of 100% and 87%, respectively, for full recovery from sensation loss at 1 yea r. However, none of the tests alone could reliably predict: recovery from t he neurosensory deficit after BSSO. When 3 different tests were combined, t he best results were achieved by the combinations of a light test or a 2-po int discrimination test and a pin tactile test with the sensibility testing of mandibular molars. Conclusions. Sensibility testing of mandibular molars can be used to predic t recovery from the neurosensory deficit after BSSO. The best positive pred ictive ability can be achieved by combining a mechanoceptive test, a nocice ptive test, and sensibility testing of mandibular molars.