Postnatal development of static volume of the eustachian tube lumen. A computer-aided three-dimensional reconstruction and measurement study.

Eleven human temporal bone-eustachian tube (ET) specimens obtained from 11 individuals (ages, 3 months to 88 years) were studied to investigate the static volume of the ET lumen. The volumes were measured by computer-aided 3-dimensional reconstruction and measurement methods. Four of the 11 individuals were children, and the remaining 7 were adults. The total volume of the ET lumen was significantly larger in the adults than in the children (p < .01). This difference was produced by significant growth of the volume of the cartilaginous and junctional portions (p < .01). The lumen of the bony portion, by contrast, did not change with age. Increased volume of the ET lumen, especially of the cartilaginous and junctional portions, would be expected to increase both ventilation and clearance. Therefore, the small volume of ET lumen of the cartilaginous and junctional portions in children may be a predisposing factor for otitis media.