title: The relationships between cephalometric parameters and severity of obstructive sleep apnea.
abstract: OBJECTIVE
  To verify the relationships between cephalometric parameters and apnea hypopnea index (AHI) in snoring patients in Chiang Mai University Hospital.
  
  
  METHODS
  Fifty patients who attend ENT snoring clinic, Faculty of Medicine, Chiang Mai University Hospital during 1 October, 2007 to 31 October, 2008 were enrolled. All subsequently underwent overnight polysomnography by SOMNOCHECK(®) V2.04 and lateral cephalometric radiographs.
  
  
  RESULTS
  Of the 50 patients, 78% were men (n=39) and 22% were women (n=11). Ages ranged from 31 to 65 years. Average apnea hypopnea index (AHI)=18.4 ± 18.2 events/h. Body mass index (BMI)=27.2 ± 3.3 kg/m². The mean sella-nasion-subspinale (SNA)=84.1 ± 4.3°. Sella-nasion-supramental (SNB)=81.8 ± 3.4°. Posterior airway space (PAS)=14.9 ± 4.3mm. Distance between mandibular plane and hyoid (MP-H)=27.7 ± 5.6 mm. Distance between posterior nasal spine and tip of soft palate (PNS-P)=42.5 ± 5.4mm. Using Pearson's correlation analysis of BMI, the cephalometric parameters from all subjects with AHI revealed BMI, PAS and MP-H had significant correlation with AHI; p=0.009, p=0.003, and p=0.005, respectively. BMI, MP-H, and PAS were correlated with AHI. The multiple regression model for the effects of BMI, PAS, and MP-H on AHI is AHI=2.090(BMI)-1.953(PAS)+1.1333(MP-H)-40.54.
  
  
  CONCLUSIONS
  The model seems to be useful as a screening tool to assess the severity of obstructive sleep apnea in snoring patients.
authors.affiliation: Department of Otolaryngology, Chiang Mai University, Thailand. nsonsuwa@mail.med.cmu.ac.th
authors.forename: Nuntigar
authors.initials: N
authors.lastname: Sonsuwan
authors.forename: Sirithorn
authors.initials: S
authors.lastname: Suchachaisri
authors.forename: Ladda
authors.initials: L
authors.lastname: Chaloeykitti
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D002508:Cephalometry; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D011859:Radiography; D012886:Skull / Q000000981:diagnostic imaging; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology*