Eustachian Tube: An Overview

As a complicated anatomical structure, the Eustachian tube (ET) (also called the pharyngotympanic or auditory tube) plays a critical role in maintaining homeostasis in the middle ear. It begins in the middle ear and continues medially before opening just behind the inferior turbinate; the bony lateral third passes through the squamous and petrous parts of the temporal bone. Two-thirds of the medial fibrocartilage forms the torus tubarius, a mucosal elevation that opens into the nasopharynx. When one yawns, sneezes, swallows, or performs the Valsalva maneuver—all of which apply positive pressure—the levator and tensor veli palatine muscles contract, opening the tube. When the ET is unable to perform any of the above three functions, the condition is called Eustachian tube dysfunction (ETD). It can be classified as acute if it occurs within 3 months or as chronic if it occurs after that time. Fullness or “popping” in the ear, decreased hearing, tinnitus, autophony, otalgia, and imbalance are symptoms of ETD, which affect 1% of the population. Dilatative ETD, patulous ETD, and barotrauma-induced ETD are the three main types.