Effect of contingent vibratory stimulus via an oral appliance on sleep bruxism after the splint adaptation period.

BACKGROUND Contingent vibratory feedback stimuli applied by a specially designed oral appliance (OA) have been reported to be effective in reducing sleep bruxism (SB). However, the inhibitory effects of the OA, which occur immediately after OA delivery, may have confounded this finding. OBJECTIVE This study sought to shed light on the effects of vibratory stimuli on SB after the OA adaptation period, when its inhibitory effects are diminished. METHODS Fourteen "definite" SB patients were enrolled. A force-based bruxism detection system was utilized to trigger a vibrator attached to the OA. Masseter electromyographic activity during sleep was recorded at home using portable polysomnography. After using the OA without vibratory stimulus for 16 nights (adaptation period), intermittent vibratory stimuli were applied every other half-hour for four nights (intervention period). Electromyographic activity over 10% of the maximum voluntary contraction was regarded as a SB episode. The number and the total duration of SB episodes per hour of sleep were calculated for the sessions with and without stimuli separately and averaged for four intervention nights. The effects of stimuli on these two variables were evaluated. RESULTS The number and the total duration of the sessions without stimuli were 5.2 episodes/h and 35.3 s/h, respectively. These values significantly decreased to 3.9 episodes/h and 15.1 s/h (p<0.05) for the sessions with vibratory stimuli. CONCLUSION Contingent vibratory stimulus via an OA may be effective for the management of SB even after adaptation to OA. (jRCTs: 032180032).