title: Identification of craniofacial risk factors for obstructive sleep apnoea using three-dimensional MRI.
abstract: The alteration of craniofacial structures has been associated with obstructive sleep apnoea (OSA). We hypothesised that: 1) a smaller mandible is a risk factor for OSA; and 2) the previously observed inferiorly positioned hyoid bone in apnoeics is associated with enlarged tongue volume. This is a case-control study using three-dimensional magnetic resonance imaging cephalometry. 55 apneics and 55 controls were matched for age, sex and race. The analysis was stratified by sex and controlled for age, race, height, neck visceral fat, skeletal type and tongue volume. We found that a 1-sd increase in mandibular length and depth were associated with decreased risk of sleep apnoea (OR 0.52, 95% CI 0.28-0.99 and OR 0.46, 95% CI 0.23-0.91, respectively) in males but not in females. Greater hyoid-to-nasion (OR 2.64, 95% CI 1.19-5.89 in males and OR 5.01, 95% CI 2.00-12.52 in females) and supramentale-to-hyoid (OR 2.39, 95% CI 1.12-5.14) in males and OR 3.38, 95% CI 1.49-7.68 in females) distances were associated with increased risk of OSA. The difference for hyoid position between apnoeics and controls was lost after controlling for tongue volume. Enlargement of tongue is likely to be the pathogenic factor for inferior-posterior positioning of hyoid. A small and shallow mandible is an independent risk factor for OSA in males but not in females.
authors.affiliation: Center for Sleep and Respiratory Neurobiology, University of Pennsylvania School of Medicine, 3624 Market Street, Suite 205, Philadelphia, PA 19104, USA. Luqi.Chi@uphs.upenn.edu
authors.forename: L
authors.initials: L
authors.lastname: Chi
authors.forename: F-L
authors.initials: FL
authors.lastname: Comyn
authors.forename: N
authors.initials: N
authors.lastname: Mitra
authors.forename: M P
authors.initials: MP
authors.lastname: Reilly
authors.forename: F
authors.initials: F
authors.lastname: Wan
authors.forename: G
authors.initials: G
authors.lastname: Maislin
authors.forename: L
authors.initials: L
authors.lastname: Chmiewski
authors.forename: M D
authors.initials: MD
authors.lastname: Thorne-FitzGerald
authors.forename: U N
authors.initials: UN
authors.lastname: Victor
authors.forename: A I
authors.initials: AI
authors.lastname: Pack
authors.forename: R J
authors.initials: RJ
authors.lastname: Schwab
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002508:Cephalometry / Q000379:methods; D019465:Craniofacial Abnormalities / Q000150:complications* / Q000503:physiopathology; D005260:Female; D006801:Humans; D006928:Hyoid Bone / Q000002:abnormalities / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008334:Mandible / Q000002:abnormalities / Q000503:physiopathology; D008875:Middle Aged; D009929:Organ Size; D010614:Pharynx / Q000002:abnormalities / Q000503:physiopathology; D012307:Risk Factors; D012737:Sex Factors; D020181:Sleep Apnea, Obstructive / Q000209:etiology* / Q000503:physiopathology; D014059:Tongue / Q000002:abnormalities / Q000503:physiopathology