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CC BY-NC-ND 4.0 · Int Arch Otorhinolaryngol 2019; 23(02): 184-190
DOI: 10.1055/s-0038-1661360
Original Research
Thieme Revinter Publicações Ltda Rio de Janeiro, Brazil

Variations in Cochlear Size of Cochlear Implant Candidates

Devira Zahara
1   Department of Otorhinolaryngology - Head and Neck Surgery, Faculty of Medicine, Universitas Sumatera Utara, Medan, Sumatera Utara, Indonesia
,
Rima Diana Dewi
1   Department of Otorhinolaryngology - Head and Neck Surgery, Faculty of Medicine, Universitas Sumatera Utara, Medan, Sumatera Utara, Indonesia
,
Askaroellah Aboet
1   Department of Otorhinolaryngology - Head and Neck Surgery, Faculty of Medicine, Universitas Sumatera Utara, Medan, Sumatera Utara, Indonesia
,
Fikri Mirza Putranto
2   Department of Otorhinolaryngology - Head and Neck Surgery, Faculty of Medicine, and Health Sciences, Universitas Islam Negeri Syarif Hidayatullah Jakarta, Jakarta, Indonesia
,
Netty Delvrita Lubis
3   Department of Radiology, Faculty of Medicine, Universitas Sumatera Utara, Medan, Sumatera Utara, Indonesia
,
Taufik Ashar 
4   Department of Environmental Health, Faculty of Public Health, Universitas Sumatera Utara, Medan, Sumatera Utara, Indonesia
› Author Affiliations
Further Information

Publication History

11 February 2018

06 May 2018

Publication Date:
24 October 2018 (online)

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Abstract

Introduction The cochlear anatomy varies in each individual, and that has an impact on decisions regarding the insertion of electrodes. The measurement of the cochlear size is the routine examination required to choose the proper cochlear implant (CI) electrodes.

Objective To acquire normative data on the size of the cochlea (length, width, height, scala timpani [ST] height, cochlear duct length [CDL]) of CI candidates in Medan, Indonesia.

Methods This descriptive study was conducted based on high-resolution computed tomography (HRCT) temporal bone data and on HRCT temporal data manipulated to reconstruct three-dimensional (3D) multiplanar images with OsiriX MD DICOM Viewer version 9.5.1 (Pixmeo SARL, Bernex, Geneva, Switzerland) viewer of 18 patients (36 ears) who were CI candidates in Medan, Indonesia, in order to determine cochlear length (A), cochlear width, cochlear height, ST height and CDL, calculated through a simple mathematical function.

Results The average cochlear length (A) was 8.75 mm (standard deviation [SD] = 0.31 mm); the average cochlear width was 6.53 mm (SD = 0.35 mm); the average cochlear height was 3.26 mm (SD = 0.24 mm) and the average ST height at the basal cochlea was 1.00 mm (SD = 0.1 mm); and 0.71 mm (SD = 0.1 mm) at the half turn of cochlea. The average total CDL was 32.45 mm (SD = 1.31 mm; range: 30.01–34.83 mm).

Conclusion The cochlear size varies in each individual; therefore, the temporal bone measurement of CI candidates using HRCT is essential: for the selection of suitable implant electrodes; to minimize cochlear damages at the insertion of the electrode arrays; and to maximize the hearing improvements.

Keywords

cochlea - cochlear implant - computed tomography - temporal bone
 

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