title: Petromastoid canal and cochlear aqueduct in cochlear implant candidates.
abstract: OBJECTIVE
  To present temporal bone fine channels in cochlear implantation candidates.
  
  
  METHODS
  Review of the axial sections of 108 temporal bone CTs. In type I, the petromastoid canal (PMC) was invisible but appeared as channels in type II and type III, <0.5 and 0.5-1 mm wide, respectively, and in type IV was >1 mm wide. The cochlear aqueduct (CA) was visualized up to the vestibule in type 1, the medial two thirds in type 2, the external aperture and/or the medial third in type 3, and was undetectable in type 4.
  
  
  RESULTS
  The PMC size and shape differed significantly between the young (aged <5 years) and older (aged 5-16 years) children and between the young children and adults. A wide PMC (>2 mm) was found in only children younger than 2 years. Children up to 2 years of age and those aged 2 to 5 years demonstrated similar findings. The CA types differed among the pediatric and adult CI candidates, with the main difference appearing after the age of 16 years. There was no correlation between CA and PMC types.
  
  
  CONCLUSIONS
  It is likely that the age-related changes in CA and PMC are attributable to the developmental or age-related changes in skull base growth.
authors.affiliation: Department of Otolaryngology and Head and Neck Surgery, Sheba Medical Center, affiliated with the Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. sabim@bezeqint.net
authors.forename: Lela
authors.initials: L
authors.lastname: Migirov
authors.forename: Jona
authors.initials: J
authors.lastname: Kronenberg
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D003051:Cochlea / Q000000981:diagnostic imaging* / Q000254:growth & development*; D003052:Cochlear Aqueduct / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000254:growth & development; D019929:Cochlear Implantation; D004424:Ear Canal / Q000033:anatomy & histology; D006801:Humans; D007223:Infant; D019291:Skull Base / Q000254:growth & development; D013701:Temporal Bone / Q000033:anatomy & histology; D014057:Tomography, X-Ray Computed