title: Oropharyngeal collapse predicts treatment response with oral appliance therapy in obstructive sleep apnea.
abstract: OBJECTIVE
  To examine whether primary oropharyngeal collapse of the upper airway during sleep predicts treatment success with oral appliance therapy in patients with obstructive sleep apnea.
  
  
  METHODS
  Prospective physiologic study.
  
  
  METHODS
  Multidisciplinary sleep disorders clinic in a university teaching hospital.
  
  
  METHODS
  Twelve treatment-naïve adult patients with obstructive sleep apnea (apnea-hypopnea index > or = 10/h and at least 2 of the following symptoms: snoring, fragmented sleep, witnessed apneas, or daytime sleepiness).
  
  
  METHODS
  Custom-made mandibular advancement splint (MAS).
  
  
  RESULTS
  A baseline diagnostic polysomnogram confirmed AHI > or = 10 per hour. During the following acclimatization period, a custom-made adjustable MAS was incrementally advanced until maximum comfortable mandibular protrusion was reached. A second polysomnogram with MAS in situ determined efficacy. Following a 1-week washout period, a final sleep study was performed using multisensor catheters (with and without MAS, in random order during the same night) to determine upper-airway closing pressures and the site or sites of upper-airway collapse. MAS resulted in significant improvements, mean +/- SEM, in AHI (22.0 +/- 2.6 vs 9.2 +/- 1.9/h, p < .01) and upper-airway closing pressures during stage 2 non-rapid eye movement sleep (-1.1 +/- 0.3 vs -2.8 +/- 0.5 cm H2O, p < .01). All 4 patients with primary oropharyngeal collapse achieved an AHI < 5 per hour. Only 1 of the 8 patients with primary velopharyngeal collapse achieved an AHI < 5 per hour. Oropharyngeal collapse, compared with velopharyngeal collapse, predicted treatment success with MAS (p < .02).
  
  
  CONCLUSIONS
  These preliminary data suggest that primary oropharyngeal collapse of the upper airway during sleep is an important predictor of treatment outcome with MAS therapy.
authors.affiliation: Department of Respiratory & Sleep Medicine, St George Hospital, University of New South Wales, Sydney, Australia. Andrew.ng@sesiahs.health.nsw.gov.au
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Ng
authors.forename: Jin
authors.initials: J
authors.lastname: Qian
authors.forename: Peter A
authors.initials: PA
authors.lastname: Cistulli
mesh_terms: D000328:Adult; D045422:Continuous Positive Airway Pressure / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D019186:Mandibular Advancement / Q000295:instrumentation*; D008875:Middle Aged; D009960:Oropharynx / Q000503:physiopathology*; D009968:Orthodontic Appliances, Removable; D017286:Polysomnography; D011446:Prospective Studies; D011474:Prosthesis Design; D012890:Sleep / Q000502:physiology; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology* / Q000628:therapy*; D012894:Sleep Stages / Q000502:physiology