title: Effects of a titratable oral appliance on supine airway size in awake non-apneic individuals.
abstract: OBJECTIVE
  To define morphological changes in the upper airway and its surrounding structures after the insertion of a titratable mandibular repositioner.
  
  
  METHODS
  Ten non-apneic adult males participated in this study. A set of supine lateral cephalograms was taken for each subject at the end of expiration with a titratable oral appliance in place in four mandibular positions: most retruded (RP), maximum protrusion (MAX), 33% of MAX (MAX33), and 67% of MAX (MAX67). Changes in the anteroposterior width of the upper airway, positions of the hyoid bone and the third cervical vertebra were compared between the four mandibular positions. An ANOVA was used to test for statistical significance.
  
  
  METHODS
  N/A.
  
  
  METHODS
  N/A.
  
  
  METHODS
  N/A.
  
  
  RESULTS
  The anteroposterior width of the velopharynx significantly increased when the mandible was advanced from RP to MAX67 and MAX. However, there were no significant changes in the anteroposterior width of the oropharynx. Significant forward displacement of the hyoid bone and third cervical vertebra together with the mandible was found in MAX67 and MAX compared to RP.
  
  
  CONCLUSIONS
  Especially in MAX67 and MAX, the titratable oral appliance significantly enlarges upper airway size in the velopharynx and results in a forward displacement of the hyoid bone and the third cervical vertebra.
authors.affiliation: Maxillofacial Orthognathics, Maxillofacial Reconstruction, Division of Maxillofacial/Neck Reconstruction, Graduate School, Tokyo Medical and Dental University, Japan. tsuiki@interchange.ubc.ca
authors.forename: S
authors.initials: S
authors.lastname: Tsuiki
authors.forename: S
authors.initials: S
authors.lastname: Hiyama
authors.forename: T
authors.initials: T
authors.lastname: Ono
authors.forename: N
authors.initials: N
authors.lastname: Imamura
authors.forename: Y
authors.initials: Y
authors.lastname: Ishiwata
authors.forename: T
authors.initials: T
authors.lastname: Kuroda
authors.forename: A A
authors.initials: AA
authors.lastname: Lowe
mesh_terms: D000328:Adult; D002508:Cephalometry / Q000379:methods; D002574:Cervical Vertebrae / Q000502:physiology; D006801:Humans; D008297:Male; D019186:Mandibular Advancement / Q000379:methods; D009968:Orthodontic Appliances, Removable; D010160:Palate, Soft / Q000502:physiology; D020181:Sleep Apnea, Obstructive / Q000517:prevention & control*; D016683:Supine Position; D014851:Wakefulness