title: Mapping surgical coordinates of the sphenopalatine foramen: surgical navigation study.
abstract: OBJECTIVE
  To identify measurements that may help intra-operative localisation of the sphenopalatine foramen.
  
  
  METHODS
  The study used three-dimensional surgical navigation software to study radiological anatomy, in order to define the distances and angulations between identifiable bony landmarks and the sphenopalatine foramen.
  
  
  RESULTS
  The distance from the anterior nasal spine to the sphenopalatine foramen was 59 mm (+/-4 mm; inter-observer variation = 0.866; intra-observer variation = 0.822). The distance from the piriform aperture to the sphenopalatine foramen was 48 mm (+/-4 mm; inter-observer variation = 0.828; intra-observer variation = 0.779). The angle of elevation from the nasal floor to the sphenopalatine foramen was 22 degrees (+/-3 degrees; inter-observer variation = 0.441; intra-observer variation = 0.499).
  
  
  CONCLUSIONS
  The sphenopalatine foramen is consistently identifiable on three-dimensional, reconstructed computed tomography scans. Repeatable measurements were obtained. The centre point of the foramen lies 59 mm from the anterior nasal spine at 22 degrees elevation above the plane of the hard palate and 48 mm from the piriform aperture. We discuss how these data could be used to facilitate intra-operative location of the sphenopalatine foramen in difficult cases.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Glasgow Royal Infirmary, Glasgow, Scotland, UK. lubna0110@yahoo.com
authors.forename: L
authors.initials: L
authors.lastname: Hadoura
authors.forename: C
authors.initials: C
authors.lastname: Douglas
authors.forename: G W
authors.initials: GW
authors.lastname: McGarry
authors.forename: D
authors.initials: D
authors.lastname: Young
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D004844:Epistaxis / Q000000981:diagnostic imaging* / Q000601:surgery; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009295:Nasal Bone / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000601:surgery; D009297:Nasal Mucosa / Q000098:blood supply; D015588:Observer Variation; D021362:Palate, Hard; D013100:Sphenoid Bone / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000601:surgery; D014057:Tomography, X-Ray Computed / Q000379:methods; D055815:Young Adult