title: Could transient hypoxia be associated with rhythmic masticatory muscle activity in sleep bruxism in the absence of sleep-disordered breathing? A preliminary report.
abstract: Sleep bruxism (SB) is a repetitive jaw-muscle activity characterised by clenching or grinding of the teeth during sleep. Sleep bruxism activity is characterised by rhythmic masticatory muscle activity (RMMA). Many but not all RMMA episodes are associated with sleep arousal. The aim of this study was to evaluate whether transient oxygen saturation level change can be temporally associated with genesis of RMMA/SB. Sleep laboratory or home recordings data from 22 SB (tooth grinding history in the absence of reported sleep-disordered breathing) and healthy subjects were analysed. A total of 143 RMMA/SB episodes were classified in four categories: (i) no arousal + no body movement; (ii) arousal + no body movement; (iii) no arousal + body movement; (iv) arousal + body movement. Blood oxygen levels (SaO2 ) were assessed from finger oximetry signal at the baseline (before RMMA), and during RMMA. Significant variation in SaO2 over time (P = 0·001) was found after RMMA onset (+7 to +9 s). No difference between categories (P = 0·91) and no interaction between categories and SaO2 variation over time (P = 0·10) were observed. SaO2 of six of 22 subjects (27%) remained equal or slight increase after the RMMA/SB onset (+8 s) compared to baseline; 10 subjects (45%) slightly decreased (drop 0·01-1%) and the remaining (27%) decreased between 1% and 2%. These preliminary findings suggest that a subgroup of SB subjects had (i) a minor transient hypoxia potentially associated with the onset of RMMA episodes, and this (ii) independently of concomitant sleep arousal or body movements.
authors.affiliation: Faculté de médecine dentaire, Université de Montréal, Montréal, QC, Canada.
authors.forename: I E
authors.initials: IE
authors.lastname: Dumais
authors.affiliation: Faculté de médecine dentaire, Université de Montréal, Montréal, QC, Canada.|Centre de recherche, Hôpital du Sacré-Cœur de Montréal, Montréal, QC, Canada.
authors.forename: G J
authors.initials: GJ
authors.lastname: Lavigne
authors.affiliation: Faculté de médecine dentaire, Université de Montréal, Montréal, QC, Canada.
authors.forename: M C
authors.initials: MC
authors.lastname: Carra
authors.affiliation: Faculté de médecine dentaire, Université de Montréal, Montréal, QC, Canada.
authors.forename: P H
authors.initials: PH
authors.lastname: Rompré
authors.affiliation: Faculté de médecine dentaire, Université de Montréal, Montréal, QC, Canada.
authors.forename: N T
authors.initials: NT
authors.lastname: Huynh
mesh_terms: D000293:Adolescent; D000328:Adult; D001143:Arousal / Q000502:physiology; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000150:complications*; D008297:Male; D008410:Masticatory Muscles / Q000502:physiology*; D009068:Movement / Q000502:physiology; D010092:Oximetry; D010100:Oxygen / Q000097:blood*; D010507:Periodicity; D017286:Polysomnography / Q000379:methods; D012189:Retrospective Studies; D020186:Sleep Bruxism / Q000150:complications*; D012894:Sleep Stages / Q000502:physiology; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: desaturation; hypoxia; oximetry; rhythmic masticatory muscle activity; sleep arousal; sleep bruxism