title: The utility of cephalometry with the Muller maneuver in evaluating the upper airway and its surrounding structures in Chinese patients with sleep-disordered breathing.
abstract: OBJECTIVE
  The objective was to simultaneously measure the size and collapsibility of the upper airway in Chinese patients with sleep-disordered breathing using cephalometry with the Muller maneuver.
  
  
  METHODS
  Prospective study of 100 consecutive Chinese patients evaluated for sleep-disordered breathing at a sleep center.
  
  
  METHODS
  Each patient received overnight polysomnography and two lateral cephalograms (at the end-expiration phase and the Muller maneuver, respectively) to evaluate the upper airway and its surrounding structures (soft palate, tongue, and hyoid bone). After excluding 15 subjects from this study because of unclear cephalograms, 85 patients with sleep-disordered breathing were enrolled, including 32 with snoring or mild obstructive sleep apnea and 53 with moderate to severe obstructive sleep apnea.
  
  
  RESULTS
  Patients with varying degrees of severity of sleep-disordered breathing significantly differed in terms of the structure and function of the upper airway and the surrounding structures. The Muller maneuver may result in dynamic changes in the retropalatal airway and pharyngeal length, and the levels of dynamic changes were related to the severity of sleep-disordered breathing. Pearson correlation analysis revealed that the decrease in the minimum retropalatal dimension during the Muller maneuver in patients with snoring or with mild obstructive sleep apnea was related to the thickening of the soft palate and posterior displacement of tongue. Meanwhile, the decrease in the minimum retropalatal dimension in patients with moderate to severe obstructive sleep apnea was related to lengthening of the soft palate, increased tongue height, and downward displacement of the tongue and hyoid bone.
  
  
  CONCLUSIONS
  Cephalometry with the Muller maneuver may provide further insight into the pathogenesis of various levels of severity of sleep-disordered breathing.
authors.affiliation: Sleep Center, Chang Gung Memorial Hospital, Taipei, Taiwan.
authors.forename: Yu-Fang
authors.initials: YF
authors.lastname: Liao
authors.forename: Chiung-Shing
authors.initials: CS
authors.lastname: Huang
authors.forename: Ming-Lung
authors.initials: ML
authors.lastname: Chuang
mesh_terms: D000293:Adolescent; D000328:Adult; D044466:Asian People; D002508:Cephalometry / Q000379:methods; D004562:Electrocardiography; D004576:Electromyography; D004585:Electrooculography; D006801:Humans; D008875:Middle Aged; D009068:Movement / Q000502:physiology; D010160:Palate, Soft / Q000503:physiopathology; D017286:Polysomnography / Q000295:instrumentation; D011446:Prospective Studies; D012720:Severity of Illness Index; D012886:Skull / Q000033:anatomy & histology*; D012891:Sleep Apnea Syndromes / Q000175:diagnosis* / Q000208:ethnology; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000208:ethnology / Q000503:physiopathology; D014059:Tongue / Q000503:physiopathology