title: Association between sleep bruxism, swallowing-related laryngeal movement, and sleep positions.
abstract: OBJECTIVE
  To describe the relationships of sleep bruxism to swallowing and sleep positions.
  
  
  METHODS
  Controlled descriptive study.
  
  
  METHODS
  Polysomnography and audio-video recordings were done in a hospital sleep laboratory.
  
  
  METHODS
  Nine patients with sleep bruxism and 7 normal subjects were matched for age and sex.
  
  
  METHODS
  n/a.
  
  
  RESULTS
  During sleep, patients with sleep bruxism showed a higher frequency of rhythmic masticatory muscle activity episodes (6.8 +/- 1.0 [SEM]/h) than did normals (0.5 +/- 0.1/h, p < 0.01). Swallowing-related laryngeal movements occurred more frequently in sleep of patients with sleep bruxism (6.8 +/- 0.8/h) than in normals (3.7 +/- 0.3/h, p < 0.01). In both groups, during sleep, close to 60% of rhythmic masticatory muscle activity episodes were associated with swallowing. In sleep bruxism patients, 68% of swallowing events occurred during rhythmic masticatory muscle activity episodes, while only 10% of swallowing events were associated with rhythmic masticatory muscle activity in normal subjects. Sleep bruxism patients and normals spent 95.5% and 87.3% of sleeping time in the supine and lateral decubitus positions, respectively. In both groups, up to 96% of rhythmic masticatory muscle activity and swallowing were observed in the supine and lateral decubitus position. In sleep bruxism patients, although sleeping time did not differ between the 2 sleeping body positions, 74% of rhythmic masticatory muscle activity and swallowing events were scored in the supine position compared to 23% in the lateral decubitus position.
  
  
  CONCLUSIONS
  During sleep, rhythmic masticatory muscle activity is often associated with swallowing. In sleep bruxism patients, most of these oromotor events are observed in the supine position. The physiologic link between rhythmic masticatory muscle activity and swallowing and the clinical relevance of sleep position in sleep bruxism management need to be investigated.
authors.affiliation: Facultés de médecine et de médecine dentaire, Université de Montréal, Québec, Canada.
authors.forename: Shouichi
authors.initials: S
authors.lastname: Miyawaki
authors.forename: Gilles J
authors.initials: GJ
authors.lastname: Lavigne
authors.forename: Mayer
authors.initials: M
authors.lastname: Pierre
authors.forename: F
authors.initials: F
authors.lastname: Guitard
authors.forename: Jacques Y
authors.initials: JY
authors.lastname: Montplaisir
authors.forename: Takafumi
authors.initials: T
authors.lastname: Kato
mesh_terms: D000328:Adult; D003679:Deglutition / Q000502:physiology*; D004562:Electrocardiography; D004569:Electroencephalography; D004576:Electromyography; D004585:Electrooculography; D005260:Female; D006801:Humans; D007830:Larynx / Q000502:physiology*; D008297:Male; D008410:Masticatory Muscles / Q000502:physiology; D011187:Posture; D012890:Sleep / Q000502:physiology*; D020186:Sleep Bruxism / Q000150:complications*; D012894:Sleep Stages / Q000502:physiology; D014743:Videotape Recording