Developmental changes in folding of the human eustachian tube

Histologic sections of human temporal bone with Eustachian tube attached were examined to investigate the changes that occur in folding of the Eustachian tube (ET) as it develops postnatally. Study of 45 specimens from individuals aged 3 months to 88 years of death, including 5 cases with chronic otitis media (OM) with perforation and 5 with OM with effusion, showed that the folds in the tube decreased significantly as age increased up to 20 years, after which no significant change with age was found. These results suggest that folding in the ET is important to its function in infants and children. Folding provides a relatively greater surface area for the tube, allowing for a greater abundance of ciliated cells, which would promote clearance of the middle ear through the ET. Greater folding might also support the tube's protective function by keeping the lumen narrow.