Analysis of Anatomic Variations in Temporal Bone by Radiology

(LF), dural exposure (DE), high juguler bulb (HJB), position of sigmoid sinus, körner’s septum (KS), aberrant internal carotid artery, mastoid aeration in chronic otitis media and to imply the importance of their recognition before surgery. Materials and methods: Data was obtained retrospectively from 356 temporal bone high resolution computed tomography (HRCT) of 178 patients who underwent tympanoplasty or tympanomastoidectomy. Results: HJB was encountered in 113 ears (32%), KS in 98 ears (28%), anteriorly placed sigmois sinus in 121 ears (34%), low hanging dura in 94 ears (26%), aberrant internal carotid artery in 6 ears (0.02%) of total 356 ears. Mastoid bone pneumatization was classified as aerated mastoids (33%, n=117), diploic mastoids (31%, n=109) and sclerotic mastoids ( 36%, n=130). Conclusion: Recognition of Körner’s septum, facial nerve dehiscence, labyrinthine fistula, low hanging dura, high juguler bulb, anterior placed sigmoid sinus radiologically prior to mastoid surgery is imperative. Preoperative CT scan is mandatory in the evaluation of detailed anatomy of the temporal bone and decreases the possibility of surgical complications.