epitympanic

Epitympanic refers to the epitympanic recess, the attic-like upper part of the middle ear located above the tympanic cavity. This region is the superior portion of the tympanic cavity and is bounded superiorly by the tegmen tympani, the thin plate of bone that forms the roof, and it communicates with the mastoid air cell system through the aditus to the mastoid antrum.

The epitympanum lies just above the tympanic membrane and is part of the middle ear cavity that houses portions of the auditory ossicles. In this recess, the head of the malleus and the body of the incus are situated, making it a key area for the transmission of sound from the tympanic membrane to the inner ear. The region also provides space for the origins and paths of muscles that can affect ossicular motion, such as the stapedius and tensor tympani, and for nearby neural structures that traverse the middle ear, including the chorda tympani nerve.

Clinically, the epitympanic region is notable for attic or epitympanic disease. Attic cholesteatoma, a destructive keratinizing lesion, can arise in this recess and invades surrounding bones, potentially eroding the tegmen tympani and posing a risk of intracranial complications. Chronic inflammatory processes may also lead to retraction pockets or fluid accumulation within the epitympanum, contributing to conductive hearing loss if ossicular mobility is impaired.

In summary, epitympanic denotes the upper middle-ear space essential for ossicular function and connected to the mastoid via the aditus, with important implications in middle-ear pathology.