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A study on modelling cochlear duct mid-scalar length based on high-resolution computed tomography, and its effect on peri-modiolar and mid-scalar implant selection

Published online by Cambridge University Press:  19 August 2019

G Pamuk ,
A E Pamuk ,
A Akgöz ,
E Öztürk ,
M D Bajin  and
L Sennaroğlu
G Pamuk
Affiliation:
Department of Otorhinolaryngology, Kırıkkale Yüksek İhtisas Hospital, Kırıkkale, Turkey
A E Pamuk*
Affiliation:
Department of Otorhinolaryngology, Kırıkkale Yüksek İhtisas Hospital, Kırıkkale, Turkey
A Akgöz
Affiliation:
Department of Radiology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
E Öztürk
Affiliation:
Department of Biostatistics, Faculty of Medicine, Hacettepe University, Ankara, Turkey
M D Bajin
Affiliation:
Department of Otorhinolaryngology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
L Sennaroğlu
Affiliation:
Department of Otorhinolaryngology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
*
Author for correspondence: Dr Ahmet Erim Pamuk, Department of Otorhinolaryngology, Kırıkkale Yüksek İhtisas Hospital, Kırıkkale 71400, Turkey E-mail: [email protected] Fax: +90 318 215 1195
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Abstract

Objective

To determine cochlear duct mid-scalar length in normal cochleae and its role in selecting the correct peri-modiolar and mid-scalar implant length.

Methods

The study included 40 patients with chronic otitis media who underwent high-resolution computed tomography of the temporal bone. The length and height of the basal turn, mid-modiolar height of the cochlea, mid-scalar and lateral wall length of the cochlear duct, and the ‘X’ line (the largest distance from mid-point of the round window to the mid-scalar point of the cochlear canal) were measured.

Results

Cochlear duct lateral wall length (28.88 mm) was higher than cochlear duct mid-scalar length (20.08 mm) (p < 0.001). The simple linear regression equation for estimating complete cochlear duct length was: cochlear duct length = 0.2 + 2.85 × X line.

Conclusion

Using the mid-scalar point as the reference point (rather than the lateral wall) for measuring cochlear duct mid-scalar length, when deciding on the length of mid-scalar or peri-modiolar electrode, increases measurement accuracy. Mean cochlear duct mid-scalar length was compatible with peri-modiolar and mid-scalar implant lengths. The measurement method described herein may be useful for pre-operative peri-modiolar or mid-scalar implant selection.

Keywords

Cochlear DuctCochlear ImplantationElectrodes, ImplantedRadiographic Image Interpretation, Computer-AssistedTomography, Spiral Computed
Type
Main Articles
Information
The Journal of Laryngology & Otology , Volume 133 , Issue 9 , September 2019 , pp. 764 - 769
Copyright
Copyright © JLO (1984) Limited, 2019 

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Footnotes

Dr A E Pamuk takes responsibility for the integrity of the content of the paper

References

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