title: A radiologic and anatomic study of the superior semicircular canal.
abstract: OBJECTIVE
  The present study sought to determine whether there is a correlation between the prevalence of superior semicircular canal (SSC) dehiscence (SSCD) on temporal CT and population age. The secondary objective was to identify anatomic factors for SSCD by studying SSC diameter and its protrusion into the middle cranial fossa. The aim was to determine the acquired or congenital origin of SSCD (Minor's syndrome).
  
  
  METHODS
  A single-center retrospective radiological and anatomic study included 180 CT scans of 354 petrous parts of the temporal bone taken between January and December 2011 in a university hospital center. Bone thickness above the SSC was measured and classified in 4 grades: grade 1, >2.5mm; grade 2, <2.5mm: grade 3, predehiscent; grade 4, dehiscent. SSC diameter was also measured, as was the height of SSC protrusion into the middle cranial fossa.
  
  
  RESULTS
  SSCD was found in 0.8% of cases and predehiscence in 12%. Patients with dehiscence were older; patients with grade 3 or 4 were significantly older than those free of dehiscence (P<0.05). There was no significant difference in SSC diameter according to grade. In grade 1, protrusion was greater than in other subjects, with a significant correlation between age and reduced protrusion (P<0.05).
  
  
  CONCLUSIONS
  The study demonstrated a correlation between aging and SSCD prevalence. Reduced SSC roof height with age suggests that SSCD may be an acquired phenomenon, related in some way to aging of the base of the skull.
authors.affiliation: Service d'ORL et de chirurgie de la face et du cou, hôpital Nord, CHU, place Victor-Pauchet, 80054 Amiens cedex, France.
authors.forename: N
authors.initials: N
authors.lastname: Klopp-Dutote
authors.affiliation: Service d'ORL et de chirurgie de la face et du cou, hôpital Nord, CHU, place Victor-Pauchet, 80054 Amiens cedex, France.
authors.forename: C
authors.initials: C
authors.lastname: Kolski
authors.affiliation: Service d'ORL et de chirurgie de la face et du cou, hôpital Nord, CHU, place Victor-Pauchet, 80054 Amiens cedex, France.
authors.forename: A
authors.initials: A
authors.lastname: Biet
authors.affiliation: Service d'ORL et de chirurgie de la face et du cou, hôpital Nord, CHU, place Victor-Pauchet, 80054 Amiens cedex, France.
authors.forename: V
authors.initials: V
authors.lastname: Strunski
authors.affiliation: Service d'ORL et de chirurgie de la face et du cou, hôpital Nord, CHU, place Victor-Pauchet, 80054 Amiens cedex, France. Electronic address: cyril_page@yahoo.fr.
authors.forename: C
authors.initials: C
authors.lastname: Page
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D005260:Female; D006801:Humans; D007759:Labyrinth Diseases / Q000000981:diagnostic imaging* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D012665:Semicircular Canals / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D013577:Syndrome; D055815:Young Adult
keywords: Anatomy; Minor's syndrome; Superior semicircular canal; Temporal bone CT