Tags: Anatomical Structure.
The aditus to mastoid antrum (otomastoid foramen or entrance or aperture to the mastoid antrum) is a large irregular aperture that leads backward from the epitympanic recess into a considerable air space named the tympanic or mastoid antrum.The antrum communicates behind and below with the mastoid air cells which vary considerably in number size and form; the antrum and mastoid air cells are lined by mucous membrane continuous with that lining the tympanic cavity.On the medial wall of the entrance to the antrum is a rounded eminence situated above and behind the prominence of the facial canal; it corresponds with the position of the ampullated ends of the superior and lateral semicircular canals.
