Postnatal growth of the human temporal bone. Implications for cochlear implants in children

Area of Science:

• Otolaryngology
• Pediatric audiology
• Craniofacial development

Background:

• Cochlear implantation is increasingly common in children.
• Understanding pediatric ear anatomy and growth is crucial for device success.
• Postnatal development of the temporal bone influences surgical considerations.

Purpose of the Study:

• To quantify the three-dimensional postnatal growth of the pediatric labyrinth, middle ear, and mastoid.
• To compare pediatric ear dimensions with adult anatomy.
• To assess the implications of ear growth on cochlear implant device fitting and performance in children.

Main Methods:

• Histologic analysis of 48 pediatric temporal bones compared to adult specimens.
• Radiographic measurements of 253 pediatric skull series compared to adult series.
• Three-dimensional mensuration of the labyrinth, middle ear space, and mastoid region.

Main Results:

• The labyrinth demonstrated no significant postnatal growth and minimal inter-individual size variation.
• The middle ear showed growth primarily in the stapes footplate to tympanic membrane distance, with considerable variation.
• The mastoid exhibited growth in length, width, and depth, with distinct growth patterns (double logistic for length/width, single exponential for depth) and sexual dimorphism.

Conclusions:

• Pediatric inner ear dimensions are largely established postnatally, suggesting limited anatomical change relevant to cochlear implant placement.
• Middle ear and mastoid growth, particularly in the mastoid, are significant and follow predictable patterns, requiring consideration for pediatric cochlear implantation.
• These findings provide essential anatomical data for optimizing cochlear implant selection, surgical technique, and device programming in pediatric populations.