title: Influence of functional appliances on masticatory muscle activity.
abstract: The purpose of the present study was to investigate the influence of an activator appliance and a spring active appliance on masticatory muscle activity by means of electromyography (EMG). Twelve adult males with good general health were recruited as subjects. Three functional appliances were used in each subject for long-period EMG recording during daytime and sleep and short-time EMG recording during voluntary biting. Following findings were obtained. (1) The activity of all muscles was greater during biting than during daytime and sleep, (2) the muscle activities tended to increase in the digastric muscle and to decrease in the temporal muscle with activators under all conditions, and (3) the temporalis-masseter ratios became lower with the biting use of appliances. Therefore, this study suggests that functional appliances should be used during sleep and during the day in combination with voluntary biting to achieve adaptation and development of the masticatory muscles.
authors.affiliation: Department of Orthodontics and Craniofacial Developmental Biology, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima, Japan. tabehi@hiroshima-u.ac.jp
authors.forename: Hideki
authors.initials: H
authors.lastname: Tabe
authors.forename: Hiroshi M
authors.initials: HM
authors.lastname: Ueda
authors.forename: Masaaki
authors.initials: M
authors.lastname: Kato
authors.forename: Keiko
authors.initials: K
authors.lastname: Nagaoka
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Nakashima
authors.forename: Eka
authors.initials: E
authors.lastname: Matsumoto
authors.forename: Noriko
authors.initials: N
authors.lastname: Shikata
authors.forename: Kazuo
authors.initials: K
authors.lastname: Tanne
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D001732:Bite Force; D003799:Dental Stress Analysis; D004576:Electromyography; D006801:Humans; D008297:Male; D008410:Masticatory Muscles / Q000502:physiology*; D009334:Neck Muscles / Q000502:physiology*; D017289:Orthodontic Appliances, Functional; D012890:Sleep / Q000502:physiology