title: Cochlear coiling pattern and orientation differences in cochlear implant candidates.
abstract: BACKGROUND
  Detailed studies of cochlear morphology can guide our approach to cochleostomy and electrode insertion to optimize neuronal and hair cell preservation and ultimate electrode location.
  
  
  METHODS
  Normal developed cochleae from 124 cochlear implant candidates were studied. We performed morphometric analysis of the right cochleae in all subjects based on computed tomographic data. The length and width of the cochlear base, the angle between the first and second turn of the cochlea, and the cochlear orientation within the cranial base were measured and compared across age groups. In cochlear implant candidates with underdeveloped cochleae (n = 7), we performed similar measurements and assessed the modiolar inlet area on 3D volume rendered images.
  
  
  RESULTS
  The birth to 1 year and 1- to 2-year age groups showed insignificant differences in the lengths and widths of the cochlear base, although variability was considerable, and a significantly wider angle (from the midsagittal line) than that of the older age groupings (p < 0.05). For underdeveloped cochleae, the length and width of the cochlear base were significantly smaller and angled between the first and second turn differed from the normal developed group. The modiolar inlet also was significantly smaller in the underdeveloped cochleae compared with normal cochleae.
  
  
  CONCLUSIONS
  We observed that perspective 3D-volume rendering of the cochlea enables the determination of key features of cochlear morphology and orientation that may escape detection with routine computed tomographic scanning. Infants and young toddler candidates demonstrate greater variability in the dimensions of the cochlear base and in the orientation of the cochlea within the cranium. As evolving surgical techniques and device design enhance the ability of the surgeon to avoid cochlear damage and optimize electrode location, refined morphometric information may assist the surgeon in tailoring strategies of scala tympani implantation.
authors.affiliation: Department of Otolaryngology & Head and Neck Surgery, The Johns Hopkins University, Baltimore, Maryland, USA. rmarti72@jhmi.edu
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Martinez-Monedero
authors.forename: John K
authors.initials: JK
authors.lastname: Niparko
authors.forename: Nafi
authors.initials: N
authors.lastname: Aygun
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D003051:Cochlea / Q000000981:diagnostic imaging* / Q000601:surgery; D019929:Cochlear Implantation; D003054:Cochlear Implants; D006319:Hearing Loss, Sensorineural / Q000000981:diagnostic imaging* / Q000601:surgery; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D008875:Middle Aged; D012533:Scala Tympani / Q000000981:diagnostic imaging* / Q000601:surgery; D014057:Tomography, X-Ray Computed