B. Schickinger et al., VARIANT PETROTYMPANIC FISSURE AS POSSIBLE CAUSE OF AN OTOLOGIC COMPLICATION DURING TMJ ARTHROSCOPY - A CASE-REPORT, International journal of oral and maxillofacial surgery, 27(1), 1998, pp. 17-19
In this reported case, a variant petrotympanic fissure - opening at th
e height of the orifice of the Eustachian tube into the hypotympanon -
was identified by high resolution computed tomography (CT) as the pos
sible cause of a tympanic membrane perforation. Inner ear function was
preserved by an otosclerotic stapes which prevented destruction of th
e labyrinth. The perforation was closed by a myringoplasty and was to
be followed by a stapedectomy after six months to restore normal heari
ng. Surgeons performing temporomandibular joint arthroscopy should be
aware that in a small percentage of patients a variant anatomy of the
tympanic plate exists and, therefore, great care must be exercised in
the manipulation of instruments near this structure. A preoperative hi
gh resolution CT with thin slices of the temporal bone might allow ide
ntification of these high risk patients.