title: The interaction between changes in upright mandibular position and supine airway size in patients with obstructive sleep apnea.
abstract: BACKGROUND
  The purpose of this study was to investigate the interaction between upright mandibular position change and supine upper airway size in men with obstructive sleep apnea fitted with titratable oral appliances.
  
  
  METHODS
  Baseline supine cephalometry before placement of the oral appliance and after titration with the oral appliance in place were undertaken in 14 patients, and upright mandibular position change was evaluated with and without the titrated oral appliance in place with a DigiGraph workstation (Dolphin Imaging Systems, Valencia, Calif).
  
  
  RESULTS
  The apnea-hypopnea index was significantly reduced after titration of the oral appliance (P < .01). Upright mandibular position change was associated with significant vertical (P < .01) and horizontal (P < .01) mandibular repositioning. The size of the supine velopharynx (P < .05), but not the supine oropharynx, was significantly enlarged at the titrated mandibular position. The supine oropharyngeal size change was correlated with the upright horizontal repositioning of the mandible (r = 0.69, P < .01).
  
  
  CONCLUSIONS
  Evaluation of upright mandibular position changes with the DigiGraph workstation enables one to predict supine oropharyngeal enlargement with oral appliance therapy. Dose-dependent effects of the horizontal component of upright mandibular protrusion on supine oropharyngeal size in addition to velopharyngeal enlargement might contribute to oral appliance effectiveness in obstructive sleep apnea patients.
authors.affiliation: University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Satoru
authors.initials: S
authors.lastname: Tsuiki
authors.forename: Fernanda R
authors.initials: FR
authors.lastname: Almeida
authors.forename: Alan A
authors.initials: AA
authors.lastname: Lowe
authors.forename: Jiaping
authors.initials: J
authors.lastname: Su
authors.forename: John A
authors.initials: JA
authors.lastname: Fleetham
mesh_terms: D000328:Adult; D002508:Cephalometry; D006801:Humans; D007574:Jaw Relation Record; D008297:Male; D008334:Mandible / Q000033:anatomy & histology; D019186:Mandibular Advancement / Q000295:instrumentation*; D008875:Middle Aged; D017090:Occlusal Splints; D010614:Pharynx / Q000503:physiopathology*; D012016:Reference Values; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology / Q000628:therapy*; D016896:Treatment Outcome