Efficacy of biofeedback therapy on sleep bruxism: A systematic review and meta-analysis

This study updates the review published by Wang et al in 2014 (Sleep Breath 2014;18(2):235-242). The review focuses on the most recent literature on management of sleep bruxism (SB) with biofeedback. An electronic search was conducted in five databases searching for articles published later than the date of Wang et al's search, viz., October 2012. Six articles of 2320 identified citations involving 86 adult participants were included in the qualitative synthesis. Of them, 4 were randomised controlled trials (RCTs) and 2 were uncontrolled before-after studies. Different feedback modalities (electrical, auditory and vibratory stimulus) were investigated. The overall quality of the selected studies was assessed using the GRADE criteria. Due to heterogeneity between studies, the quantitative synthesis was performed out of three RCTs, of which two were retrieved from the previous review. The meta-analysis indicated a non-significant difference in electromyographic-measured SB episodes per hour after one night of contingent electrical stimulation (CES) compared with placebo control, yet a significant difference was shown after five nights of CES. The quality of evidence identified through GRADEpro was from low to moderate, due to imprecision and inconsistency between studies. Qualitative synthesis did not present a reliable reduction in clinical pain levels; however, no substantial sleep disturbances were indicated following the intervention. In conclusion, one of the biofeedback modalities, CES, is effective in reducing SB-related motor activities after a short-term treatment period. However, evidence of long-term effects is lacking. Further longitudinal studies with larger samples are necessary to acknowledge the clinical application of biofeedback.