title: Pharyngeal dimensions in healthy men and women.
abstract: BACKGROUND
  Epidemiological studies reveal a high male prevalence of obstructive sleep apnea syndrome. A possible explanation for this male predominance is the existence of anatomical differences in the upper airway between men and women.
  
  
  METHODS
  The upper airways of 10 male and 10 female healthy volunteers were prospectively evaluated by magnetic resonance imaging. Anatomical pharyngeal and column cross-sectional linear measurements were made in sagittal T1 and axial T1 and T2 weighted fast spin-echo images.
  
  
  RESULTS
  Men had significantly greater mean sagittal pharyngeal structural dimensions compared to women for all structures with the exception of the craniocaudal length of the soft palate and the thickness of the submentonian fat. In contrast, cross-sectional linear dimensions were similar in men and women with the exception of the laterolateral tongue length, which was greater in men. All mean linear measurements of the pharyngeal air column were similar in men and women at all studied levels.
  
  
  CONCLUSIONS
  Men and women present pharyngeal air columns with similar dimensions, but in women this column is surrounded by smaller structures, which might imply a smaller effort to keep its patency. Our data suggest the existence of an anatomical protective factor in women against the upper airway collapse.
authors.affiliation: Department of Radiology, Neuroradiology Division, São Paulo University Medical School, São Paulo, SP, Brazil. loredaniel@uol.com.br
authors.forename: Mauro Miguel
authors.initials: MM
authors.lastname: Daniel
authors.forename: Maria Cecília
authors.initials: MC
authors.lastname: Lorenzi
authors.forename: Claudia
authors.initials: C
authors.lastname: da Costa Leite
authors.forename: Geraldo
authors.initials: G
authors.lastname: Lorenzi-Filho
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010159:Palate / Q000033:anatomy & histology; D010614:Pharynx / Q000033:anatomy & histology*; D011446:Prospective Studies; D012737:Sex Factors; D020181:Sleep Apnea, Obstructive / Q000209:etiology*; D014059:Tongue / Q000033:anatomy & histology