PURPOSE: The objective of the present systematic review was to test the hypothesis of no difference in neurosensory disturbances (NSDs) after bilateral sagittal split osteotomy (BSSO) with piezoelectric surgery compared with conventional techniques.
MATERIALS AND METHODS: A PubMed (Medline), Embase Library, and Cochrane Library search in combination with a manual search of relevant journals was conducted from January 2000 to November 2017. Randomized controlled trials and controlled trials in humans were considered. Primary outcome measures (assessment of neuro-sensitivity by subjective and objective evaluations) and secondary outcome measures (NSD risk factors, patient-reported outcome measures, complications, operating time, and intraoperative bleeding) were considered.
RESULTS: The search provided 241 studies of which 5 eligible studies were included. Meta-analysis was not possible because of considerable heterogeneity. Two studies were characterized by a moderate risk of bias and 3 were characterized by a high risk of bias. Piezoelectric surgery substantially decreased NSDs as evaluated by subjective tests. NSD after BSSO varied from 1.8 to 23.0% with piezoelectric surgery and from 7.3 to 52.0% with conventional techniques after 2 to 12 months. Furthermore, piezoelectric surgery seemed to considerably decrease the frequency of intraoperative bleeding in bimaxillary procedures and decrease the risk of an unfavorable split of the mandible and macroscopic damage of the inferior alveolar nerve.
CONCLUSIONS: The hypothesis of no difference in NSD after BSSO with piezoelectric surgery compared with conventional techniques could be neither confirmed nor rejected owing to insufficient knowledge. However, piezoelectric surgery seems to decrease the risk of NSDs after BSSO compared with conventional techniques. Long-term randomized controlled trials comparing the 2 treatment modalities by standardized subjective and objective electrophysiologic tests are needed before one treatment modality can be considered superior to another.