Auditory ossicles in Scanning Electron Microscopy

Introduction: Knowledge about the physiology of a healthy middle ear is essential for understanding the activity and mechanics of the ear as well as the basics of ossiculoplasty. Trauma of the epithelial lining of the tympanic cavity as well as the ossicular chain may be the result of chronic inflammation and surgery. Depending on the observed changes of the middle ear lining, there are several types of distinguished chronic inflammatory changes: simple, with cholesteatoma, with the formation of inflammatory granulation tissue, in course of specific diseases. Purpose: The aim of the article is presentation of the microstructure and vasculature of the ossicular chain in the Scanning Electron Microscope. Particular attention is drawn to the anatomical aspects of the structure and connections of auditory ossicles as vital elements for reconstruction of the conduction system of the middle ear. Material and method: The analysis covered auditory ossicles standardly removed in accordance with the methodology of the investigated surgical procedures. The preparations were evaluated in a scanning electron microscope. Results: The exposure of bone surface promotes deep erosion. The advanced process of destruction of bone surface in the case of chronic otitis media correlates with a significant degree of damage to both the lining covering the auditory ossicles and that surrounding articular surfaces. Conclusions: (1) The ossicles in the image of the Scanning Electron Microscope are covered with lining. It passes from the surface of the ossicles to the vascular bundles, forming vascular sheaths; (2) Damage to lining continuity on the surface of the auditory ossicles promotes the rapid destruction of bone tissue in the inflammatory process; (3) The dimensions of the individual ossicles are respectively: malleus – 8.36 +/- 0.01, incus – 8.14 +/- 0.0, stapes – 3.23 +/- 0.01 mm. Behavior of the anatomical length of ossicular chain during tympanoplasty appears to be essential to maintaining adequate vibration amplitude of the conductive system of the middle ear.