Morphologic variations of clinically normal mallei and incudes

Area of Science:

• Anatomy
• Otology
• Anthropology

Background:

• The malleus and incus are crucial middle ear ossicles.
• Understanding their morphology aids in otogeny studies and implantable device design.
• Bilateral symmetry, otitis media correlation, and feature concordance remain underexplored.

Purpose of the Study:

• To investigate bilateral symmetry of malleus and incus features and shapes.
• To determine if malleus and incus morphology correlates with otitis media indicators.
• To assess feature and shape concordance between malleus and incus within the same ear.

Main Methods:

• Prevalence study of 41 adult crania.
• Postmortem analysis of malleus and incus morphology.
• Radiographic assessment of mastoid sizes as an otitis media indicator.

Main Results:

• Most mallei possessed lateral processes and inflected manubrium tips.
• Most incudes displayed specific features like concave superior borders and anteriorly curved anterior edges.
• Only the absence of the malleus lateral process showed a potential link to smaller mastoid size; no feature concordance was observed.

Conclusions:

• Malleus and incus bones in clinically normal ears exhibit significant feature and shape variations.
• These variations are predominantly bilaterally symmetric.
• No concordance was found between malleus and incus features or shapes within an ear.