title: Effect of a prosthetic appliance for treatment of sleep apnea syndrome on masticatory and tongue muscle activity.
abstract: BACKGROUND
  The efficiency of an appliance for treatment of sleep apnea shows inordinate interindividual difference. The mechanism of its therapeutic effects remains unresolved.
  
  
  OBJECTIVE
  This study examined the effect of the device on sleep apnea, and masticatory and tongue muscles.
  
  
  METHODS
  Fifteen patients with sleep apnea syndrome were evaluated polysomnographically, with and without the appliance. Electromyograms (EMG) of genioglossal, masseter, and lateral pterygoid muscles were recorded and EMG amplitudes measured before, during, and after the apneas. Apneas were classified into three types: obstructive, central, and mixed.
  
  
  RESULTS
  During obstructive apneas, muscles showed significantly lower EMG amplitudes; whereas during central apneas, no decrease in the mean EMG amplitude was observed. EMG amplitudes increased after insertion of the device. EMG amplitudes during obstructive apneas were significantly increased in the genioglossal (p < 0.03, t test) and lateral pterygoid muscles (p < 0.03) by the device. Obstructive and mixed apneas per hour were significantly reduced by the appliance; however, in contrast, central apneas showed slightly increased. The apnea index decreased significantly (p < 0.002) by the device owing to the paucity of central apneas.
  
  
  CONCLUSIONS
  The apnea appliance activated masticatory and tongue muscles during sleep and prevented the upper airway from collapsing. The prosthetic appliance was useful in the treatment of sleep apnea syndrome.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Faculty of Medicine, Kyoto University, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Yoshida
mesh_terms: D000368:Aged; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008406:Masseter Muscle / Q000503:physiopathology*; D008875:Middle Aged; D009334:Neck Muscles / Q000503:physiopathology*; D017090:Occlusal Splints; D010043:Outcome and Process Assessment, Health Care; D017286:Polysomnography; D011626:Pterygoid Muscles / Q000503:physiopathology*; D012891:Sleep Apnea Syndromes / Q000145:classification / Q000503:physiopathology* / Q000628:therapy*; D014059:Tongue / Q000503:physiopathology