On the connection between the tympanic membrane and the malleus

Daniel De Greef; Jana Goyens; Isabel Pintelon; John-Paul Bogers; Vincent Van Rompaey; Evert Hamans; Paul Van de Heyning; Joris J J Dirckx

doi:10.1016/j.heares.2015.12.002

On the connection between the tympanic membrane and the malleus

Hear Res. 2016 Oct:340:50-59. doi: 10.1016/j.heares.2015.12.002. Epub 2015 Dec 15.

Authors

Daniel De Greef¹, Jana Goyens², Isabel Pintelon³, John-Paul Bogers³, Vincent Van Rompaey⁴, Evert Hamans⁴, Paul Van de Heyning⁴, Joris J J Dirckx⁵

Affiliations

¹ Laboratory of Biomedical Physics, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium. Electronic address: daniel.degreef@uantwerpen.be.
² Laboratory of Biomedical Physics, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium; Laboratory of Functional Morphology, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium.
³ Laboratory of Cell Biology and Histology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
⁴ Department of Otorhinolaryngology - Head and Neck Surgery, Wilrijkstraat 10, Antwerp University Hospital, 2650 Edegem, Belgium.
⁵ Laboratory of Biomedical Physics, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.

PMID: 26701786
DOI: 10.1016/j.heares.2015.12.002

Abstract

Background: The tympano-mallear connection (TMC) is the soft-tissue connection between the tympanic membrane (TM) and the manubrium of the malleus. Some studies suggest that its mechanical properties may have a substantial influence on the mechanics and transfer function of the middle ear. However, relatively little is known about the dimensions of the TMC and its variability among individuals.

Method: Thirteen samples were collected from human temporal bones, consisting of only the malleus and the TM. They were imaged using μCT without contrast enhancing agent. From the μCT images, the TMC dimensions were measured in both anterior-posterior direction (TMC width) and medial-lateral direction (TMC thickness). Three selected samples were examined using histological microscopy.

Results: Both TMC width and thickness featured a large variability among individuals. The minimal TMC width along the manubrium for different individuals covered a range between 83 and 840 μm. The minimal thickness ranged from 48 to 249 μm and the maximal thickness from 236 to 691 μm. Histological sections showed that the TMC consists of a narrow core of dense regular connective tissue, surrounded by loose connective tissue. In some samples, either of these two components was absent in the TMC at some manubrium locations. The configuration of these components varied among the samples as well.

Conclusion: Our data confirm that a large inter-individual variability exists in the properties of the TM-malleus connection in humans in terms of its dimensions, tissue composition and configuration. Average data and their variability margins will be useful input for testing the importance of the TMC in finite element models.

Keywords: Collagen fibers; Connective tissue; Eardrum; Manubrial fold; Manubrium; Middle ear; Plica mallearis; Stria mallearis.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Algorithms
Ear, Middle / anatomy & histology
Ear, Middle / physiology
Humans
Malleus / anatomy & histology
Malleus / physiology*
Pressure
Reproducibility of Results
Temporal Bone / physiology*
Tympanic Membrane / anatomy & histology
Tympanic Membrane / physiology*
X-Ray Microtomography