title: Upper airway changes in severe obstructive sleep apnea: upper airway length and volumetric analyses using 3D MDCT.
abstract: CONCLUSIONS
  Three-dimensional multi-detector computed tomography (3D MDCT) analysis of the upper airway suggested that the lengthening of the upper airway in the absence of volumetric change may independently contribute to the severity of obstructive sleep apnea syndrome (OSAS) in adults.
  
  
  OBJECTIVE
  We sought to investigate the relationships among the length and volume of the upper airway to the severity of OSAS.
  
  
  METHODS
  A total of 73 subjects underwent 3D MDCT scanning and standard polysomnography. We measured the upper airway length (UAL), which was defined as the vertical distance from the hard palate to the hyoid in the mid-sagittal plane. We also used the height-adjusted UAL for analyses. Upper airway volume was measured using a 3D reconstruction of the cross-sectional area from the hard palate to the hyoid.
  
  
  RESULTS
  The adjusted UAL showed a significant positive correlation with the apnea hypopnea index (AHI, r = 0.523, p < 0.000) and was a significant variable for predicting the AHI of OSAS patients in multiple stepwise regression analysis. Although the severe OSAS group had a greater adjusted UAL compared with that of other groups (p = 0.001), the volume of the upper airway did not show differences among groups.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Korea University College of Medicine, 516 Gojan-dong, Danwon-gu, Ansan-si, Gyeonggi-do, Korea.
authors.forename: Eun Joong
authors.initials: EJ
authors.lastname: Kim
authors.forename: Ji Ho
authors.initials: JH
authors.lastname: Choi
authors.forename: Yeon Soo
authors.initials: YS
authors.lastname: Kim
authors.forename: Tae Hoon
authors.initials: TH
authors.lastname: Kim
authors.forename: Sang Hag
authors.initials: SH
authors.lastname: Lee
authors.forename: Heung Man
authors.initials: HM
authors.lastname: Lee
authors.forename: Chol
authors.initials: C
authors.lastname: Shin
authors.forename: Seung Hoon
authors.initials: SH
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010614:Pharynx / Q000000981:diagnostic imaging*; D017286:Polysomnography; D020181:Sleep Apnea, Obstructive / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed; D014132:Trachea / Q000000981:diagnostic imaging*; D055815:Young Adult