Attic Antrum Ear

Upon reaching the posterolateral wall of the attic further expansion of the cholesteatoma is deflected superiorly toward the aditus ad antrum and mastoid antrum.

Attic antrum ear.

As the cholesteatoma fills the aditus ad antrum the adjacent lateral semicircular canal is at risk. The mastoid antrum tympanic antrum antrum mastoideum valsalva s antrum is an air space in the petrous portion of the temporal bone communicating posteriorly with the mastoid cells and anteriorly with the epitympanic recess of the middle ear via the aditus to mastoid antrum entrance to the mastoid antrum. The aditus to mastoid antrum otomastoid foramen or entrance or aperture to the mastoid antrum is a large irregular cavity that leads backward from the epitympanic recess into a considerable air space named the tympanic or mastoid antrum. It is a large air containing space in the upper part of mastoid and communicates with the attic through the aditus.

Effusions localized to the epitympanum attic mastoid antrum and or mastoid air cells sparing the middle ear cavity proper may be due to a selective decrease in intratympanic pressure in this area attic block that is obstruction to ventilation of the attic antrum and mastoid air cells due to compromise of the anterior and posterior tympanic isthmi see the anatomy and normal variations section. A slight constriction divides it into an upper and a lower chamber the tympanum tympanic cavity proper below and the epitympanum above. These chambers are also referred to as the atrium and the attic respectively. The lateral wall is formed largely by the tympanic membrane and to a lesser extent by the bony outer attic wall called the scutum.