title: The effect of mandibular advancement appliances on awake upper airway and masticatory muscle activity in patients with obstructive sleep apnoea.
abstract: BACKGROUND
  There is little understanding of how dental appliances, designed to posture the mandible forwards, act on pharyngeal airway dilatory and masticatory muscles in patients with obstructive sleep apnoea (OSA). This study evaluates, in a prospective cohort design, the effect of mandibular advancement splints (MAS) on awake genioglossus (GG), geniohyoid (GH) and masseter (M) muscle activity.
  
  
  METHODS
  Fifty OSA patients received a custom-made removable Herbst MAS appliance, adjusted for maximum therapeutic benefit, as judged by subjective improvement. Awake electromyographic (EMG) activity was recorded at baseline and with the MAS in situ, by using bipolar surface electrodes in patients seated upright and in the natural head position. The lower splint was modified to facilitate the placement of the intra-oral bipolar surface electrodes used to record GG EMG activity.
  
  
  RESULTS
  Significant increases in GG (P = 0.041), GH (P<0.001) and M (P<0.001) muscle activity accompanied placement of the MAS.
  
  
  CONCLUSIONS
  These findings support the contention of a physiological role, which may act to augment the anatomical action of MAS.
authors.affiliation: Oral Growth and Development, Institute of Dentistry, Bart's and The London Queen Mary's School of Medicine and Dentistry, University of London, London, UK. a.s.johal@qmul.ac.uk
authors.forename: Ama
authors.initials: A
authors.lastname: Johal
authors.forename: Gulsharondip
authors.initials: G
authors.lastname: Gill
authors.forename: Anthony
authors.initials: A
authors.lastname: Ferman
authors.forename: Kieron
authors.initials: K
authors.lastname: McLaughlin
mesh_terms: D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D019186:Mandibular Advancement / Q000295:instrumentation* / Q000379:methods; D008410:Masticatory Muscles; D008875:Middle Aged; D009119:Muscle Contraction; D009968:Orthodontic Appliances, Removable; D012132:Respiratory Muscles; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology* / Q000517:prevention & control*; D016896:Treatment Outcome