The effects of nocturnal electromyographic biofeedback on sleep quality and psychological stress

Abstract

Sleep bruxism (SB) causes many dental problems and complications with fixed partial dentures on implants. Although it is an important issue in clinical dentistry, no reliable treatment is available for SB. In the present study, we employed the electromyographic biofeedback device SleepGuardTM, which is attached to the forehead, detects SB, and alerts subjects with a gentle beeping sound to stop SB. The aim of the present study was to clarify the effects of biofeedback treatment on the incidence of masticatory muscle activity, sleep quality, and psychological stress levels. Ten subjects (five male and five female subjects) participated in the study, and a crossover design was used. Sleep measurements were taken on three consecutive nights to obtain data without SleepGuardTM (baseline group), with SleepGuardTM with the beeping sound (on group), and with SleepGuardTM without the beeping sound (off group). Data obtained on the final day were evaluated. STAI-JYZ scores were assessed and salivary chromogranin A (CgA) levels and cortisol concentrations were measured to compare psychological and physical stress after sleep. Friedman’s and Dunn’s tests were used to compare each parameter among the three groups. A marked decrease was observed in the incidence of SB events per hour in seven subjects in the on group. The beeping of SleepGuardTM did not affect the percentage of sleep stages, salivary CgA levels, cortisol concentrations, or STAI-JYZ scores. Our results suggest that biofeedback therapy with a beeping sound inhibited SB without negatively impacting sleep quality or psychological stress.