fissula ante fenestram

fissula ante fenestram

minute, slitlike passage in the otic labyrinthine wall anterior to the oval window to the vestibule. The bone around it often contains fibrous tissue and immature cartilage. It is a site with a predilection for otosclerosis and for some perilymphatic fistulae.

fis·su·la an·te fe·nes·tram

(fis'yū-lă an'tē fen-es'tram)
Minute, slitlike passage in the labyrinthine wall of the tympanic cavity, extending obliquely from the region of the cochleaform process to the vestibule of the bony labyrinth, anterior to the oval window; it is considered to be an extension of the perilymphatic space, but is occupied by a small band of connective tissue that is continuous with the mucosa of the tympanic cavity.
References in periodicals archive ?
The otosclerotic focus extended from the labyrinthine capsule through the fissula ante fenestram and into the round window niche (figure).
On the left side, the otosclerotic focus extended from the labyrinthine capsule, through the fissula ante fenestram, and into the round window niche.
Fenestral otoscierosis is the more common type, and it is thought to begin in the fissula ante fenestram (anterior oval window margin).
Potential sites of gas entry include the oval and round window niche, microfissures between the posterior semicircular canal and the round window, and the fissula ante fenestram.