title: Three-dimensional reconstruction of the human semicircular canals and measurement of each membranous canal plane defined by Reid's stereotactic coordinates.
abstract: OBJECTIVE
  Equations for estimating the planar relationships of the human semicircular canals were devised by Blanks et al from a dissected bony labyrinth in a human skull. However, a similar study on the membranous semicircular canal planes has never been published.
  
  
  METHODS
  In this study, the angle between each membranous canal plane and Reid's stereotactic horizontal plane was measured on serial histologic sections of 7 temporal bones from Japanese adults. We reconstructed the 3 semicircular canals by computer-aided 3-dimensional analysis. The angles between each pair of both bony and membranous canal planes were measured.
  
  
  RESULTS
  In the bony labyrinth, the angles between the 2 canal planes of the lateral-anterior, anterior-posterior, and lateral-posterior pairs were 90.51 degrees +/- 2.98 degrees (mean +/- SD), 91.70 degrees +/- 1.85 degrees, and 94.52 degrees +/- 3.32 degrees, respectively. The angles between the 2 membranous canal planes of the lateral-anterior, anterior-posterior, and lateral-posterior pairs were 90.05 degrees +/- 4.74 degrees, 91.03 degrees +/- 2.93 degrees, and 91.92 degrees +/- 5.22 degrees, respectively.
  
  
  CONCLUSIONS
  The data from our study of the membranous labyrinth showed that the angles between each canal plane and the others were much closer to 90 degrees than was found by Blanks et al for the bony labyrinth.
authors.affiliation: Department of Otolaryngology, Kitasato University School of Medicine, Kanagawa, Japan.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Hashimoto
authors.forename: Hideaki
authors.initials: H
authors.lastname: Naganuma
authors.forename: Koji
authors.initials: K
authors.lastname: Tokumasu
authors.forename: Akihiko
authors.initials: A
authors.lastname: Itoh
authors.forename: Makito
authors.initials: M
authors.lastname: Okamoto
mesh_terms: D000328:Adult; D000368:Aged; D005133:Eye Movements / Q000502:physiology; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D019651:Plastic Surgery Procedures / Q000379:methods*; D012665:Semicircular Canals / Q000033:anatomy & histology* / Q000601:surgery*