title: Relationships among nocturnal jaw muscle activities, decreased esophageal pH, and sleep positions.
abstract: The purpose of this study was to examine the relationships among nocturnal jaw muscle activities, decreased esophageal pH, and sleep positions. Twelve adult volunteers, including 4 bruxism patients, participated in this study. Portable pH monitoring, electromyography of the temporal muscle, and audio-video recordings were conducted during the night in the subjects' homes. Rhythmic masticatory muscle activity (RMMA) episodes were observed most frequently, with single short-burst episodes the second most frequent. The frequencies of RMMA, single short-burst, and clenching episodes were significantly higher during decreased esophageal pH episodes than those during other times. Both the electromyography and the decreased esophageal pH episodes were most frequently observed in the supine position. These results suggest that most jaw muscle activities, ie, RMMA, single short-burst, and clenching episodes, occur in relation to gastroesophageal reflux mainly in the supine position.
authors.affiliation: Department of Orthodontics and Dentofacial Orthopedics, Okayama University Graduate School of Medicine and Dentistry, Okayama, Japan.
authors.forename: Shouichi
authors.initials: S
authors.lastname: Miyawaki
authors.forename: Yuko
authors.initials: Y
authors.lastname: Tanimoto
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Araki
authors.forename: Akira
authors.initials: A
authors.lastname: Katayama
authors.forename: Mikako
authors.initials: M
authors.lastname: Imai
authors.forename: Teruko
authors.initials: T
authors.lastname: Takano-Yamamoto
mesh_terms: D000328:Adult; D002012:Bruxism / Q000503:physiopathology; D004576:Electromyography; D049630:Esophageal Sphincter, Lower / Q000502:physiology; D004947:Esophagus / Q000502:physiology*; D005260:Female; D005764:Gastroesophageal Reflux / Q000503:physiopathology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008365:Manometry; D018670:Monitoring, Ambulatory; D009119:Muscle Contraction / Q000502:physiology; D011187:Posture / Q000502:physiology*; D016684:Prone Position / Q000502:physiology; D012890:Sleep / Q000502:physiology*; D016683:Supine Position / Q000502:physiology; D013703:Temporal Muscle / Q000502:physiology*; D013997:Time Factors; D014743:Videotape Recording