Internal auditory canal: pre- and postnatal growth.
OBJECTIVE
The purpose of this study was to describe the size and shape of the internal auditory canal (IAC) during development.


METHODS
The study was conducted in 98 dried temporal bones from 7-month-old fetuses to adults. Silicone mould casts of the IAC were used.


METHODS
The length of the IAC was measured on the moulds corresponding four walls as the diameter on the fundus, middle portion, and porus.


RESULTS
Although size and shape vary considerably among individuals, the data showed no significant differences between the right and left sides of the same individual. The values of the wall length and porus diameter increase as a function of age, especially for the upper wall and horizontal diameter. Both middle portion diameters suffer variations at different ages, increasing and decreasing until reaching the final shape. The diameter of the fundus, near the inner ear, remains stable.


CONCLUSIONS
Our results showed that during development, the shape of the IAC adapts to cranial growth, with those of adults and fetuses having a similar shape but different dimensions, which was quite evident near the porus.
Bonaldi
Laís Vieira
LV
Departments of Morphology and Otolaryngology, Federal University of São Paulo (UNIFESP-EPM), São Paulo, Brazil.
do Lago
Aline
A
Crema
Luciana C
LC
Fukuda
Yotaka
Y
Smith
Ricardo Luiz
RL
D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D007758:Ear, Inner / Q000033:anatomy & histology* / Q000254:growth & development*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male