title: Contingent electrical lip stimulation for sleep bruxism: a pilot study.
abstract: BACKGROUND
  No effective method has been found to fully control sleep bruxism, although contingent feedback methods show some promise.
  
  
  OBJECTIVE
  This demonstration-of-concept study evaluated the effect of contingent electrical lip stimulation on sleep bruxism.
  
  
  METHODS
  Recordings of masseter muscle activity were performed over 5 nights in 7 subjects with acknowledged bruxism and dental attrition (5 men, 2 women). A small electrical switch, activated with light force clenching, was mounted between 2 occlusal orthotics. This switch triggered a stimulator, which delivered slightly noxious electrical pulses to the subject's lip. After a baseline first night recording session, stimulation was delivered in 1-hour blocks for half of each sleep period during nights 2 through 5. Paired t tests (alpha = 0.05) were conducted on 4 recorded bruxism parameters.
  
  
  RESULTS
  With stimulation, the number (+/-SD) of events/hour reduced from a baseline level of 3.9 +/- 2.0 to 2.4 +/- 0.8 and the mean amplitude (% maximum voluntary contraction) reduced from 28.7 +/- 20.0 to 17.6 +/- 4.1. There was a mean decrease in the duration (s/event) from 10.6 +/- 1.4 to 9.1 +/- 2.5 and the total event time (s/hour) was reduced from 41.7 +/- 22.4 to 23.2 +/- 11.0. Among these measures, bruxism events with and without stimulation were compared, and only the duration of individual bruxism events (s/event) showed a significant change (P=.038). Finally, no subject reported being awakened from sleep by the stimulation.
  
  
  CONCLUSIONS
  The reductions in bruxism events were noteworthy, especially considering that stimulation was delivered for only half of the sleeping period.
authors.affiliation: Department of Fixed Prosthodontics, School of Dentistry, Tokushima University, Tokushima, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Nishigawa
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kondo
authors.forename: Hisahiro
authors.initials: H
authors.lastname: Takeuchi
authors.forename: Glenn T
authors.initials: GT
authors.lastname: Clark
mesh_terms: D000328:Adult; D004599:Electric Stimulation Therapy / Q000295:instrumentation / Q000379:methods*; D004576:Electromyography; D004867:Equipment Design; D005260:Female; D006801:Humans; D008046:Lip; D008297:Male; D008406:Masseter Muscle / Q000503:physiopathology; D016555:Matched-Pair Analysis; D009119:Muscle Contraction / Q000502:physiology; D010865:Pilot Projects; D012815:Signal Processing, Computer-Assisted; D020186:Sleep Bruxism / Q000503:physiopathology / Q000517:prevention & control / Q000628:therapy*; D013997:Time Factors