title: Anatomic predictors of retropalatal mechanical loads in patients with obstructive sleep apnea.
abstract: BACKGROUND
  The retropalatal airway is one of the most collapsible sites during sleep in patients with obstructive sleep apnea (OSA). The primary anatomical contributors to increased collapsibility in the retropalatal segment remain unclear.
  
  
  OBJECTIVE
  This study seeks to investigate how the balance between pharyngeal soft tissues and the bony enclosure influences retropalatal mechanical loads in patients with OSA.
  
  
  METHODS
  The segmental mechanical load of the retropalatal pharynx was determined by the region's critical closing pressure in 30 anesthetized, paralyzed and intubated subjects with OSA. The volumetric anatomical parameters of the retropalatal airway were evaluated using magnetic resonance imaging, and their associations with retropalatal closing pressures were analyzed.
  
  
  RESULTS
  Increased retropalatal closing pressure was associated with the increased proportion of volumetric pharyngeal soft tissues to the surrounding cervicomandibular bony frame (r = 0.791, p < 0.001), enlarged soft tissues of the lateral wall (r = 0.752, p < 0.001) and soft palate (r = 0.726, p < 0.001). The decreased volume of the nasopharynx (r = -0.650, p < 0.001) and pharyngeal cavity (r = -0.653, p < 0.001) indicated a relatively higher retropalatal closing pressure. The multivariate linear regression model demonstrated that the proportion of retropalatal soft tissues to the bony frame and volume of the soft palate predicted 69.4% of the variability in closing pressure (F = 30.674, p < 0.001).
  
  
  CONCLUSIONS
  The increased volumetric proportion of pharyngeal soft tissue to the bone enclosure may be an important contributor to increased retropalatal mechanical loads.
authors.affiliation: Department of Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, China.
authors.forename: Yanru
authors.initials: Y
authors.lastname: Li
authors.forename: Jingying
authors.initials: J
authors.lastname: Ye
authors.forename: Tianzuo
authors.initials: T
authors.lastname: Li
authors.forename: Na
authors.initials: N
authors.lastname: Lin
authors.forename: Zhenchang
authors.initials: Z
authors.lastname: Wang
authors.forename: Chenyang
authors.initials: C
authors.lastname: Liang
authors.forename: Al
authors.initials: A
authors.lastname: Sperry
authors.forename: Demin
authors.initials: D
authors.lastname: Han
mesh_terms: D000328:Adult; D044466:Asian People; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D009126:Muscle Relaxation; D010160:Palate, Soft / Q000473:pathology* / Q000503:physiopathology; D010609:Pharyngeal Muscles / Q000473:pathology / Q000503:physiopathology; D010614:Pharynx / Q000473:pathology* / Q000503:physiopathology; D011237:Predictive Value of Tests; D020181:Sleep Apnea, Obstructive / Q000473:pathology* / Q000503:physiopathology