title: [The relationship between upper airway curvature and obstructive sleep apnea and hypopnea syndrome].
abstract: OBJECTIVE
  The fluid flow through curved tubes has characteristics that an increase in the curvature induces pressure losses as well as higher resistance in the same region. The purpose of this study is to analyze the relationship between upper airway curvature and obstructive sleep apnea and hypopnea syndrome(OSAHS).
  
  
  METHODS
  18 male OSAHS patients were paired by age with 18 males with no snoring. The mean AHI was 58.8. The supine lateral cephalometric films were obtained from CT and analysed using curvature software. Data were presented as mean and paired t test was conducted using SPSS10.0 software package. Correlative analysis was performed to indicate the relationship between BMI and AHI, curvature and BMI, respectively.
  
  
  RESULTS
  The airway curvature was significantly different between the two groups(P<0.01). The curvature radius was significantly correlative with BMI (P<0.01), but not with AHI(P>0.05).
  
  
  CONCLUSIONS
  Upper airway curvature was related significantly to the pathogenesis of OSAHS. An increase of curvature on anterior wall of velopharynx in OSAHS patients can change the pressure and resistance distribution in upper airway.
authors.affiliation: Department of Oral Maxillofacial Surgery, College of Stomatology, Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200011, China. zminnie@yahoo.com
authors.forename: Min
authors.initials: M
authors.lastname: Zhu
authors.forename: Xiao-feng
authors.initials: XF
authors.lastname: Lu
authors.forename: Hui-min
authors.initials: HM
authors.lastname: Shi
mesh_terms: D006801:Humans; D008297:Male; D010614:Pharynx / Q000033:anatomy & histology*; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology*; D012913:Snoring