Contingent electrical stimulation inhibits jaw muscle activity during sleep but not pain intensity or masticatory muscle pressure pain threshold in self-reported bruxers: a pilot study

Abstract

This study investigated the effect of contingent electrical stimulation (CES) on present pain intensity (PI), pressure pain threshold (PPT), and electromyographic events per hour of sleep (EMG/h) on probable bruxers with masticatory myofascial pain. The study enrolled 15 probable bruxers with masticatory myofascial pain in 3 phases: (1) baseline EMG/h recording, (2) biofeedback treatment using a CES paradigm (active group, n = 7) or inactive device (control group, n = 8), and (3) posttreatment EMG/h recording. PI and PPT were assessed after each phase. Analysis of variance models were used to compare results at a 5% significance level. Patients in the active group had 35% lower EMG/h in P2 and 38.4% lower EMG/h in P3, when compared with baseline. There were no differences in PI or PPT levels at any phase. CES could reduce EMG activity associated with sleep bruxism in patients with masticatory myofascial pain but did not influence perceived pain.