title: [Defect of the bony roof in the superior semicircular canal and its clinical implications].
abstract: OBJECTIVE
  The aetiology of the superior semicircular canal dehiscence is currently unknown. Our objective was to analyse and discuss different hypotheses about the origin of this pathology.
  
  
  METHODS
  In this study performed on 295 temporal bones, one case of partial alteration of the bony roof in the right superior semicircular canal was described from the anatomical and radiological points of view, and compared with the temporal bone on the other side.
  
  
  RESULTS
  Macroscopically, the superior semicircular canal shows deterioration in the bony roof, which consists exclusively of the inner or endosteal layer that separates the canal from the superior semicircular conduct. The Pöschl plane reconstruction showed a whole bony roof, but its thickness decreased from the canal curvature to the defect (from 0.6 to 0.3mm).
  
  
  CONCLUSIONS
  The presence of partial defects in the bony roof of the superior semicircular canal with absence of the external and middle layers, besides its lesser thickness, makes the canal susceptible to suffering a second event. This could produce its fracture and a dehiscence.
authors.affiliation: Departamento de Anatomía e Histología Humanas, Facultad de Medicina, Universidad de Zaragoza, España. jwhyte@unizar.es
authors.forename: Jaime
authors.initials: J
authors.lastname: Whyte Orozco
authors.forename: Claudio
authors.initials: C
authors.lastname: Martínez
authors.forename: Ana
authors.initials: A
authors.lastname: Cisneros
authors.forename: Jesús
authors.initials: J
authors.lastname: Obón
authors.forename: Borja
authors.initials: B
authors.lastname: Gracia-Tello
authors.forename: Miguel
authors.initials: M
authors.lastname: Angel Crovetto
mesh_terms: D002508:Cephalometry; D002648:Child; D034381:Hearing Loss / Q000209:etiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D004856:Postural Balance; D012665:Semicircular Canals / Q000002:abnormalities* / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000196:embryology / Q000293:injuries; D012678:Sensation Disorders / Q000209:etiology; D013701:Temporal Bone / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000196:embryology / Q000293:injuries; D036542:Tomography, Spiral Computed