The Role of the Eustachian Tube in Middle Ear Disease.

The Eustachian tube is a complex structure connecting the middle ear to the nasopharynx that contributes to the normal function of the middle ear. Eustachian tube dysfunction (ETD) is thought to contribute to the majority of middle ear pathology, although the mechanisms and the degree to which it contributes to middle ear disease is poorly understood. We describe the anatomy and physiology of the Eustachian tube, define ETD, discuss the methods for measuring ETD and describe recent advances in treatment.