Biofeedback treatment for sleep bruxism: a systematic review

The aim of this systematic review was to evaluate the efficacy of any biofeedback treatment on sleep bruxism. We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, ISI Web of Science, System for Information on Grey Literature in Europe, Chinese Biomedical Literature Database, and PsycINFO up to October 2012 for randomized controlled trials and controlled clinical trials involving biofeedback treatment for sleep bruxism. Reference lists of relevant studies were hand searched. Quality assessment and data extraction were performed by two reviewers independently. Seven eligible studies involving 240 participants were finally included. Three of them had moderate risk of bias, and four had high risk of bias. In an electromyographic-measured sleep bruxism episode, meta-analysis showed no significant difference between contingent electrical stimulation and blank control (95 % confidence interval = -12.33, 3.38, P = 0.26). Moreover, five studies reported electromyographic activity index. Due to the diversity of biofeedback modalities (auditory, electrical, and visual stimulus) and controls (splint, occlusal adjustment, etc.), these data were unable to be pooled, so only qualitative description was provided. In the current stage, there is no powerful evidence to support the use of biofeedback technology on sleep bruxism treatment. Contingent electrical stimulation which is defined as a kind of biofeedback modality shows no effect on reducing sleep bruxism episode compared with the no-treatment group. Although many studies support the efficacy of biofeedback treatment, more large sample-sized randomized controlled trials which adopt uniform outcome index are necessitated to verify its application.