Postnatal Development of Eustachian Tube: A Computer-aided 3-D Reconstruction and Measurement Study

The postnatal development of the Eustachian tube (ET) and its surrounding structures was investigated by means of computer-aided three-dimensional (3-D) reconstruction methods in 13 normal human temporal bones, obtained from individuals 3 months to 71 years old. The cross-sectional area, width and height of the lumen in most of the cartilaginous portion of the ET were significantly smaller in children than in adults. In particular, there was a marked, age-associated difference in the shape of the lumen in the cartilaginous portion of the ET. In adults, the cross-sectional area of the lumen declined monotonically between a large opening at the pharyngeal orifice and the narrowest portion of the ET (near the border of the cartilaginous and junctional regions). In children, by contrast, the ET lumen was uniformly smaller over the first 80% of its length from the pharyngeal orifice. It is suggested that this immature morphology of the ET lumen may confer increased risk of developing otitis media during childhood.