title: Weak association between sleep bruxism and obstructive sleep apnea. A sleep laboratory study.
abstract: OBJECTIVE
  No definitive associations or causal relationships have been determined between obstructive sleep apnea-hypopnea (OSAH) and sleep bruxism (SB). The purpose of this study was to investigate, in a population reporting awareness of both OSAH and SB, the associations between each specific breathing and jaw muscle event.
  
  
  METHODS
  Polysomnography and audio-video data of 59 patients reporting concomitant OSAH and SB history were analyzed. Masseteric bursts after sleep onset were scored and classified into three categories: (1) sleep rhythmic masticatory muscle activity with SB (RMMA/SB), (2) sleep oromotor activity other than RMMA/SB (Sleep-OMA), and (3) wake oromotor activity after sleep onset (Wake-OMA). Spearman's rank correlation coefficient analyses were performed. Dependent variables were the number of RMMA/SB episodes, RMMA/SB bursts, Sleep-OMA, and Wake-OMA; independent variables were apnea-hypopnea index (AHI), arousal index(AI), body mass index(BMI), gender, and age.
  
  
  RESULTS
  Although all subjects had a history of both SB and OSAH, sleep laboratory results confirmed that these conditions were concomitant in only 50.8 % of subjects. Moderate correlations were found in the following combinations (p < 0.05); RMMA/SB episode with AI, RMMA/SB burst with AI and age, Sleep-OMA burst with AHI, and Wake-OMA burst with BMI.
  
  
  CONCLUSIONS
  The results suggest that (1) sleep arousals in patients with concomitant SB and OSAH are not strongly associated with onset of RMMA/SB and (2) apnea-hypopnea events appear to be related to higher occurrence of other types of sleep oromotor activity, and not SB activity. SB genesis and OSAH activity during sleep are probably influenced by different mechanisms.
authors.affiliation: Department of Crown and Bridge Prosthodontics, Graduate School of Dental Medicine, Hokkaido University, Kita 13 Nishi 7, Kita-ku, Sapporo, 060-8586, Japan.
authors.forename: Miku
authors.initials: M
authors.lastname: Saito
authors.affiliation: Department of Crown and Bridge Prosthodontics, Graduate School of Dental Medicine, Hokkaido University, Kita 13 Nishi 7, Kita-ku, Sapporo, 060-8586, Japan. taihiko@den.hokudai.ac.jp.
authors.forename: Taihiko
authors.initials: T
authors.lastname: Yamaguchi
authors.affiliation: Department of Temporomandibular Disorders, Center for Advanced Oral Medicine, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Saki
authors.initials: S
authors.lastname: Mikami
authors.affiliation: Department of Temporomandibular Disorders, Center for Advanced Oral Medicine, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: Department of Temporomandibular Disorders, Center for Advanced Oral Medicine, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Akihito
authors.initials: A
authors.lastname: Gotouda
authors.affiliation: Department of Temporomandibular Disorders, Center for Advanced Oral Medicine, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Okada
authors.affiliation: Department of Dental Radiology, Hokkaido University Hospital, Sapporo, Japan.
authors.forename: Ryuki
authors.initials: R
authors.lastname: Hishikawa
authors.affiliation: Erumunomori Medical Clinic, Sapporo, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Shibuya
authors.affiliation: Erumunomori Medical Clinic, Sapporo, Japan.
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Shibuya
authors.affiliation: Centre for Advanced Research in Sleep Medicine, Hôpital du Sacré-Coeur de Montréal, Montréal, QC, Canada.
authors.forename: Gilles
authors.initials: G
authors.lastname: Lavigne
mesh_terms: D000328:Adult; D000368:Aged; D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis* / Q000453:epidemiology; D020186:Sleep Bruxism / Q000175:diagnosis* / Q000453:epidemiology; D013223:Statistics as Topic
keywords: Arousal; Electromyography; Obstructive sleep apnea-hypopnea; Rhythmic masticatory muscle activity; Sleep bruxism; Tooth grinding