The foreshortened malleus: Anatomic variant, not pathologic sign

Area of Science:

• Otolaryngology
• Anatomy
• Pathology

Background:

• The malleus is a small bone in the middle ear.
• Its appearance can be observed through the external ear canal.
• Previous assumptions suggested a link between malleus appearance and otitis media.

Purpose of the Study:

• To quantitatively assess the malleus' appearance via the external ear canal.
• To determine if a shortened malleus is associated with otitis media.
• To investigate the clinical relevance of malleus morphology.

Main Methods:

• Analysis of postmortem adult crania (41 specimens).
• Radiographic quantification of mastoid size as an indicator of childhood otitis media.
• Measurement of malleus dimensions and angles from digitized tympanic membrane photographs (64 ears).

Main Results:

• Two distinct metrics for malleus foreshortening showed no significant correlation with each other.
• Mastoid size did not correlate with either malleus foreshortening metric.
• While mastoid pneumatization showed good right-left symmetry, malleus measurements did not, with confidence intervals including zero.

Conclusions:

• The physical appearance of the malleus does not correlate with mastoid size, an indicator of otitis media.
• Right-left symmetry of malleus morphology was not strongly supported.
• A foreshortened malleus is considered an anatomical variant, lacking clinical relevance as a sign of pathology.