title: Facial axis angle as a risk factor for obstructive sleep apnea.
abstract: OBJECTIVE
  Many Japanese patients with obstructive sleep apnea (OSA) are less obese than Caucasian OSA patients despite their similar severity of OSA, suggesting that their etiology of OSA may differ. The purpose of this study was to identify bony factors associated with OSA in the Japanese population.
  
  
  METHODS
  The clinical records of study subjects were retrospectively reviewed, and cephalometric measurements based on Sella-Nasion references and the Ricketts method were statistically compared.
  
  
  METHODS
  Two hundred and six consecutive Japanese men complaining of habitual snoring and daytime sleepiness were enrolled in the study. All subsequently underwent an overnight polysomnographic examination.
  
  
  RESULTS
  Multiple regression analysis showed that the body mass index (p<0.0001) and facial axis angle (p=0.007) were the dominant overall determinants for the apnea hypopnea index. The sella to nasion to subspinale angle (SNA) and sella to nasion to supramentale angle (SNB) were lower in the non-obese, severe group than for non-obese, mild and moderate patients with OSA (p=0.0047 and 0.0016, respectively).
  
  
  CONCLUSIONS
  The risk factors for OSA in Japanese men may be obesity and the dolico facial pattern seen by the Ricketts method. In addition, a smaller SNA and SNB seem to be associated with the severity of OSA in non-obese patients.
authors.affiliation: Division of Respiratory Medicine, Niigata University Graduate School of Medical and Dental Sciences, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Kubota
authors.forename: Hideaki
authors.initials: H
authors.lastname: Nakayama
authors.forename: Toshinori
authors.initials: T
authors.lastname: Takada
authors.forename: Naho
authors.initials: N
authors.lastname: Matsuyama
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Sakai
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Yoshizawa
authors.forename: Masami
authors.initials: M
authors.lastname: Nakamata
authors.forename: Makoto
authors.initials: M
authors.lastname: Satoh
authors.forename: Kohei
authors.initials: K
authors.lastname: Akazawa
authors.forename: Eiichi
authors.initials: E
authors.lastname: Suzuki
authors.forename: Fumitake
authors.initials: F
authors.lastname: Gejyo
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D002508:Cephalometry; D005147:Facial Bones / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000473:pathology; D012189:Retrospective Studies; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000209:etiology* / Q000473:pathology