Fissula ante fenestram
Citation, DOI & article data
The fissula ante fenestram (plural: fissula ante fenestras) is a small connective tissue-filled cleft in the otic capsule of the temporal bone, not typically visible on CT. The area around the fissula ante fenestram is the usual origin of fenestral otosclerosis.
The fissula ante fenestram is situated in the region anterior to the oval window 1. The structure is an irregular projection from the junction of the vestibule and scala vestibuli that extends to the periosteum of the middle ear just beneath the cochleariform process, where the tendon of the tensor tympani muscle turns laterally toward the malleus 2.
The fissula ante fenestram was previously thought to be related to the cochlear cleft 3, but recent studies have shown the latter to be a separate structure 4.
A structure called the fossula post fenestram is also described in histological studies and refers to a completely different but anatomically-proximate structure.
- it is the only structure named fissula in the human body
- it has not been found in any other animal
History and etymology
It is derived from the classical Latin:
- fissula meaning a 'small cleft'
- ante meaning 'forwards of'
- fenestram (accusative form of fenestra) meaning 'window'.
Hence, it literally means 'the small cleft forwards of the window'.
The plural, although rarely seen, is fissula ante fenestras. It is not 'fissulae' as some might erroneously believe.
- 1. Lee TC, Aviv RI, Chen JM et-al. CT grading of otosclerosis. AJNR Am J Neuroradiol. 2009;30 (7): 1435-9. doi:10.3174/ajnr.A1558 [pubmed citation]
- 2. Bast TH. Development of the otic capsule: II. The origin, development and significant of the fissula ante fenestram and its relation to otosclerotic foci. (1933) Archives of Otolaryngology. 18 (1): 1. doi:10.1001/archotol.1933.03580060005001
- 3. Chadwell JB, Halsted MJ, Choo DI, Greinwald JH, Benton C. The cochlear cleft. (2004) AJNR. American journal of neuroradiology. 25 (1): 21-4. Pubmed
- 4. Pucetaite M, Quesnel AM, Juliano AF, Curtin HD, Reinshagen KL. The Cochlear Cleft: CT Correlation With Histopathology. (2020) Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology. doi:10.1097/MAO.0000000000002637 - Pubmed