VARIANT PETROTYMPANIC FISSURE AS POSSIBLE CAUSE OF AN OTOLOGIC COMPLICATION DURING TMJ ARTHROSCOPY - A CASE-REPORT

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.