Related Experiment Video
Updated: Jun 8, 2025
06:42
Extracting the Cochlea from a Human Temporal Bone: A Cadaveric Protocol
Published on: August 18, 2023
671
Morphometric Measurements of the Incomplete Partition Type II (IP-II) Cochlea and Implications on Cochlear
Adam Y Xiao1, Miryam Saad1, Rance J T Fujiwara2
1Department of Head and Neck Surgery, University of California Los Angeles, Los Angeles, California, U.S.A.
Summary
This study provides key morphometric measurements of the incomplete partition type II (IP-II) cochlea, crucial for selecting cochlear implant electrodes. Findings reveal specific dimensions impacting electrode insertion in this common malformation.
Area of Science:
- Otolaryngology
- Neurosurgery
- Medical Imaging
Background:
- Incomplete partition type II (IP-II) is the most common congenital bony malformation of the inner ear.
- IP-II frequently necessitates cochlear implantation, yet electrode selection remains controversial due to limited anatomical data.
Purpose of the Study:
- To precisely measure the morphometry of the IP-II cochlea.
- To inform optimal cochlear implant electrode selection and insertion techniques.
Main Methods:
- 3D reconstructions were created from human temporal bones of IP-II patients and fetuses.
- Detailed measurements of spiral ganglion neurons, cochlear duct, and scala tympani dimensions were performed at 90-degree intervals.
Main Results:
- Spiral ganglion neurons terminated around 540 degrees, coinciding with the interscalar septal defect.
- Scala tympani height was significantly reduced at specific locations compared to normal cochleae, with a drastic decrease at 540 degrees (0.4 mm).
- These dimensions are smaller than the apical size of many current cochlear electrodes.
Conclusions:
- This study presents the first detailed morphometric data for the IP-II cochlea, including spiral ganglion neuron and scala tympani dimensions.
- The findings provide critical anatomical insights directly applicable to cochlear implant electrode choice in IP-II malformations.
Related Concept Videos
01:13The Cochlea
44.5K
The cochlea is a coiled structure in the inner ear that contains hair cells—the sensory receptors of the auditory system. Sound waves are transmitted to the cochlea by small bones attached to the eardrum called the ossicles, which vibrate the oval window that leads to the inner ear. This causes fluid in the chambers of the cochlea to move, vibrating the basilar membrane.
44.5K
01:16Anatomy of the Ear
7.2K
Auditory sensation, commonly called hearing, involves the transformation of sonic waves into neural impulses facilitated by the structures of the auditory organ. The prominent, flesh-like structure on the side of the head, called the auricle, directs sound waves towards the auditory canal. The auricle is often mislabeled as the pinna, a term more aligned with mobile structures like a feline's external ear. The auditory canal penetrates the cranium via the external auditory meatus of the...
7.2K