Corrosion casts of the temporal bone.

Area of Science:

• Anatomy
• Otolaryngology
• Developmental Biology

Background:

• The bony labyrinth is a complex structure within the temporal bone housing the organs of hearing and balance.
• Understanding the developmental trajectory of the bony labyrinth is crucial for diagnosing congenital conditions and interpreting imaging studies.

Purpose of the Study:

• To compare the size of the bony labyrinth in infant specimens with that of adult specimens.
• To determine if significant growth occurs in the bony labyrinth after birth.

Main Methods:

• Dried human temporal bones from infants and adults were utilized.
• Fusible metal was injected into the bony labyrinth.
• Surrounding bone was dissolved using weak acid to expose the labyrinthine structures.
• Measurements of the semicircular canals and cochlea were taken and compared between age groups.

Main Results:

• The bony labyrinth, encompassing the semicircular canals and cochlea, demonstrates adult-like dimensions in infants.
• No significant size difference was observed between the bony labyrinth of infants and adults.

Conclusions:

• The bony labyrinth reaches its full size early in development, likely before or at birth.
• Postnatal development does not significantly alter the overall dimensions of the bony labyrinth.