Uncovering the secreted signals and transcription factors regulating the development of mammalian middle ear ossicles

Fossil remains witness the relationship between the appearance of the middle ear and the expansion of the brain in early mammals. Nevertheless, the lack of detachment of ear ossicles in the mammaliaform Morganucodon, despite brain enlargement, points to other factors that triggered brain expansion in early mammals. Moreover, brain expansion in some early mammalian groups seems to have favored brain regions other than the cortex.

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Scanning Electron Microscopy in the Evaluation of Defects to the Ossicular Chain in the Course of Chronic Otitis Media

Ear Nose & Throat Journal ◽

10.1177/0145561319873913 ◽

2019 ◽

pp. 014556131987391

Author(s):

Agnieszka Wiatr ◽

Katarzyna Swiezy ◽

Jacek Skladzien ◽

Maciej Wiatr

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Chronic Inflammation ◽

Otitis Media ◽

Middle Ear ◽

Chronic Otitis Media ◽

Ossicular Chain ◽

Suppurative Otitis Media ◽

Ear Ossicles ◽

Scanning Electron

Objective: Chronic otitis media is a heterogeneous disorder. Chronic suppurative otitis media with cholesteatoma and, to a lesser extent, chronic otitis media with granulation lead to the destruction of bone structures within the middle ear. Bone loss may appear in the prominence of the horizontal semicircular canals and the bony canal of the facial nerve. The inflammatory process may spread to the bony labyrinth of the sigmoidal sinuses and the cranial cavities. Materials and Methods: The analysis comprised the examination of fragments of auditory ossicles removed during surgery in 21 patients with various types of chronic inflammation of the middle ear. The purpose of this study was to evaluate the usefulness of scanning electron microscopy in evaluating the erosion of middle ear ossicles in different types of chronic otitis media. Images captured at various magnifications were used for the best possible illustration of the observed lesions in bone tissue. Results: The observed lesions and the degree of bone surface damage were dependent on the type of chronic inflammation of the middle ear. The largest destructive changes in the ossicular chain were observed in chronic otitis media with cholesteatoma; smaller changes were observed in chronic otitis media with granulation. Conclusion: In the case of damage to the ossicles inflicted by inflammation, the use of a modeled bone block made of a temporal bone taken from outside the tympanic cavity or a biomaterial prosthesis is a good choice in ossiculoplasty.

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Scanning Laser Doppler Vibrometry of the Middle Ear Ossicles

Ear Nose & Throat Journal ◽

10.1177/014556139707600409 ◽

1997 ◽

Vol 76 (4) ◽

pp. 213-222 ◽

Cited By ~ 33

Author(s):

Geoffrey R. Ball ◽

Alex Huber ◽

Richard L. Goode

Keyword(s):

Middle Ear ◽

Single Point ◽

Three Dimensional ◽

Laser Doppler Vibrometer ◽

Ossicular Chain ◽

Laser Doppler ◽

Scanning Laser ◽

Scanning Laser Doppler Vibrometer ◽

Point Analysis ◽

Ear Ossicles

This paper describes measurements of the vibratory modes of the middle ear ossicles made with a scanning laser Doppler vibrometer. Previous studies of the middle ear ossicles with single-point laser Doppler measurements have raised questions regarding the vibrational modes of the ossicular chain. Single-point analysis methods do not have the ability to measure multiple points on the ossicles and, consequently, have limited ability to simultaneously record relative phase information at these points. Using a Polytec Model PSV-100, detailed measurements of the ossicular chain have been completed in the human temporal bone model. This model, when driven with a middle ear transducer, provides detailed three-dimensional data of the vibrational patterns of the middle ear ossicles. Implications for middle ear implantable devices are discussed.

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