Micro-CT of the human ossicular chain: Statistical shape modeling and implications for otologic surgery

Area of Science:

• Anatomy
• Biomedical Engineering
• Otology

Background:

• The ossicular chain (incus, malleus, stapes) transmits sound vibrations but exhibits high morphological variability.
• Few studies have quantitatively analyzed ossicle morphology using advanced modeling techniques.

Purpose of the Study:

• To create high-quality 3D statistical shape models (SSMs) of human ossicles from a large cadaveric sample.
• To statistically analyze the variance in ossicle morphology and its impact on the ossicular chain.

Main Methods:

• Micro-computed tomography (μCT) scanning of 33 cadaveric temporal bone samples.
• Segmentation and creation of 3D SSMs for individual ossicles (malleus, incus, stapes).
• Analysis of ossicular chain dynamics to determine positional variance.

Main Results:

• Ossicles showed significant variation primarily in overall size.
• Specific morphological variability was identified in the malleus manubrium, incus long/lenticular processes, and stapes crura/footplate.
• Analysis of the entire ossicular chain revealed diverse stapes positions resulting from malleus fixation.

Conclusions:

• This study presents the first 3D SSMs of human ossicles, quantifying their morphological variance.
• Findings can guide otological surgical training, prosthesis development, and improve automated segmentation algorithms.
• All 3D models are publicly available for research and application.