title: An investigation of upper airway changes associated with mandibular advancement device using sleep videofluoroscopy in patients with obstructive sleep apnea.
abstract: OBJECTIVE
  To quantitatively evaluate the effects of the mandibular advancement device (MAD) on changes in the upper respiratory tract during sleep using sleep videofluoroscopy (SVF) in patients with obstructive sleep apnea (OSA).
  
  
  METHODS
  Retrospective analysis.
  
  
  METHODS
  Academic tertiary referral center.
  
  
  METHODS
  Seventy-six patients (68 men and 8 women) who were treated with the MAD for OSA were included from September 1, 2005, through August 31, 2008.
  
  
  METHODS
  All patients underwent nocturnal polysomnography and SVF before and at least 3 months after receipt of the custom-made MAD. Sleep videofluoroscopy was performed before and after sleep induction and was analyzed during 3 states of awakeness, normoxygenation sleep, and desaturation sleep.
  
  
  METHODS
  Changes in the length of the soft palate, retropalatal space, retrolingual space, and angle of mouth opening were evaluated during sleep events with or without the MAD.
  
  
  RESULTS
  Without the MAD, the length of the soft palate and the angle of mouth opening increased during sleep events, especially in desaturation sleep, compared with the awake state. The retropalatal space and retrolingual space became much narrower during sleep compared with the awake state. The MAD had marked effects on the length of the soft palate, retropalatal space, retrolingual space, and angle of mouth opening. The retropalatal space and retrolingual space were widened, and the length of the soft palate was decreased. The MAD kept the mouth closed.
  
  
  CONCLUSIONS
  Sleep videofluoroscopy showed dynamic upper airway changes in patients with OSA, and the MAD exerted multiple effects on the size and configuration of the airway. Sleep videofluoroscopy demonstrated the mechanism of action of the MAD in patients with OSA. The MAD increased the retropalatal and retrolingual spaces and decreased the length of the soft palate and the angle of mouth opening, resulting in improvement of OSA.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Bundang-Gu, Seongnam, Korea.
authors.forename: Chul Hee
authors.initials: CH
authors.lastname: Lee
authors.forename: Jeong-Whun
authors.initials: JW
authors.lastname: Kim
authors.forename: Hyun Jong
authors.initials: HJ
authors.lastname: Lee
authors.forename: Pil-Young
authors.initials: PY
authors.lastname: Yun
authors.forename: Dong-Young
authors.initials: DY
authors.lastname: Kim
authors.forename: Beom Seok
authors.initials: BS
authors.lastname: Seo
authors.forename: In-Young
authors.initials: IY
authors.lastname: Yoon
authors.forename: Ji-Hun
authors.initials: JH
authors.lastname: Mo
mesh_terms: D000328:Adult; D000368:Aged; D000402:Airway Obstruction / Q000517:prevention & control; D015331:Cohort Studies; D005260:Female; D005471:Fluoroscopy / Q000379:methods*; D006801:Humans; D007830:Larynx / Q000502:physiology; D008297:Male; D008334:Mandible / Q000502:physiology; D008875:Middle Aged; D017090:Occlusal Splints; D010160:Palate, Soft / Q000502:physiology; D017286:Polysomnography / Q000295:instrumentation*; D011336:Probability; D015656:Respiratory Mechanics / Q000502:physiology*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D012890:Sleep / Q000502:physiology; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis* / Q000628:therapy*; D014741:Video Recording; D014851:Wakefulness; D055815:Young Adult