title: Morphological study of the human maxillofacial venous vasculature: examination of venous valves using the corrosion resin cast technique.
abstract: BACKGROUND
  The venous drainage in the human head and neck, structures located superior to the heart, generally does not counter the force of gravity. Accordingly, venous valves in the human head have been reported to be few or nonexistent, and therefore the direction of venous drainage is variable and obscure.
  
  
  METHODS
  We investigated whether venous valves were present in 13 heads of human adult cadavers using scanning electron microscopic observation of corrosive resin casts in the human maxillofacial region. This technique afforded the observation of the venous valves.
  
  
  RESULTS
  Venous valves were found throughout the facial region. In particular, there were many valves distributed in the lingual, upper and lower labial, facial and pharyngeal veins. The venous valves were particularly well formed at motile parts of the maxillofacial region.
  
  
  CONCLUSIONS
  It is suggested that these valves may aid the venous blood return and permit the blood drainage in one direction.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Kagawa Medical School, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Miyake
authors.forename: M
authors.initials: M
authors.lastname: Ito
authors.forename: S
authors.initials: S
authors.lastname: Nagahata
authors.forename: Y
authors.initials: Y
authors.lastname: Takeuchi
authors.forename: Y
authors.initials: Y
authors.lastname: Fukui
mesh_terms: D000368:Aged; D002102:Cadaver; D016319:Corrosion Casting; D005147:Facial Bones / Q000033:anatomy & histology / Q000098:blood supply*; D005260:Female; D006801:Humans; D008297:Male; D008437:Maxilla / Q000033:anatomy & histology / Q000098:blood supply*; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D008954:Models, Biological; D014680:Veins / Q000033:anatomy & histology*