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Updated: Jun 13, 2026
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Dissection of the Auditory Bulla in Postnatal Mice: Isolation of the Middle Ear Bones and Histological Analysis
Published on: January 4, 2017
Morphology of the human tympanic membrane annulus
Firas Kassem1, Dov Ophir, Joelle Bernheim
1Department of Otolaryngology-Head and Neck Surgery, Meir Medical Center, Kfar Saba, Israel. firas67@hotmail.com
Summary
The human tympanic annulus has a horseshoe shape and thins symmetrically towards its ends. This detailed morphology provides insights into middle ear function and surgical approaches.
Area of Science:
- Anatomy
- Otolaryngology
- Medical Imaging
Background:
- The tympanic annulus is a crucial component of the tympanic membrane.
- Understanding its precise morphology is essential for middle ear surgery and diagnostics.
Purpose of the Study:
- To comprehensively analyze the morphology and topography of the human tympanic annulus.
- To provide detailed measurements of the tympanic annulus's dimensions.
Main Methods:
- Analysis of postmortem human adult tympanic membranes (n=23).
- High-quality imaging and computer-aided measurements of annular caliber at nine reference points.
- Utilized formalin-fixed temporal bones from a university-affiliated hospital.
Main Results:
- The tympanic annulus exhibits a horseshoe-like shape, with a portion absent superiorly.
- Maximal mean caliber measured 748 ± 201 µm at the manubrial axis.
- The annulus thins symmetrically anteriorly and posteriorly to approximately 15% of its maximal caliber.
Conclusions:
- The tympanic annulus's horseshoe shape and symmetrical thinning are key morphological features.
- These findings can guide transcanal middle ear exploration and inform understanding of TM vibratory properties.
- Data may aid in understanding marginal perforations and retraction pockets.
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