title: Dentofacial characteristics of Chinese obstructive sleep apnea patients in relation to obesity and severity.
abstract: OBJECTIVE
  To evaluate dentofacial characteristics in relation to obesity and degree of severity of obstructive sleep apnea (OSA) in male Chinese patients and to elucidate the relationship between demographic parameters (age, body weight, height, and body mass index [BMI]) cephalometric parameters and OSA in these subjects.
  
  
  METHODS
  Lateral cephalograms of 121 Chinese male patients in natural head posture were obtained. Based on BMI value, the patients were divided into three groups. Based on apnea-hypopnea index (AHI) value, the patients were divided into a mild-to-moderate and a severe group.
  
  
  RESULTS
  The hyoid position and soft palate length were significantly different among the three obesity groups. Soft palate length was significantly longer (P < .01) in the severe OSA group than in the mild-to-moderate OSA group. Tongue base was significantly more inferiorly placed (P < .05) in the severe OSA group than in the mild-to-moderate OSA group. Craniocervical extension was significantly increased (P < .05) in the severe OSA group. Statistically significant differences were found among the three obesity groups in mandibular length, mandibular body length, maxillary length, anterior cranial base length, and overbite. The multiple stepwise linear regression analysis identified body weight, lower posterior facial height, mandibular body length, craniocervical extension, and sella-hyoid distance as the significant predictive variables for AHI.
  
  
  CONCLUSIONS
  This study revealed the existence of craniofacial and upper airway soft tissue differences in relation to obesity and severity of OSA among male Chinese OSA patients. Body weight and certain cephalometric parameters were significant predictors of OSA in Chinese male subjects.
authors.affiliation: Orthodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong, SAR, People's Republic of China.
authors.forename: Huie Ming
authors.initials: HM
authors.lastname: Hou
authors.forename: Urban
authors.initials: U
authors.lastname: Hägg
authors.forename: Kim
authors.initials: K
authors.lastname: Sam
authors.forename: A B M
authors.initials: AB
authors.lastname: Rabie
authors.forename: Ricky W K
authors.initials: RW
authors.lastname: Wong
authors.forename: B
authors.initials: B
authors.lastname: Lam
authors.forename: Mary S
authors.initials: MS
authors.lastname: Ip
mesh_terms: D000328:Adult; D000367:Age Factors; D000704:Analysis of Variance; D044466:Asian People; D001827:Body Height; D015992:Body Mass Index; D001835:Body Weight; D002508:Cephalometry; D006723:Hong Kong; D006801:Humans; D006928:Hyoid Bone / Q000503:physiopathology; D016014:Linear Models; D008297:Male; D008334:Mandible / Q000473:pathology; D008437:Maxilla / Q000473:pathology; D009765:Obesity / Q000150:complications; D010160:Palate, Soft / Q000473:pathology; D019291:Skull Base / Q000473:pathology; D020181:Sleep Apnea, Obstructive / Q000150:complications / Q000473:pathology* / Q000503:physiopathology*; D014059:Tongue / Q000473:pathology