Cadaver Temporal Bone Dissection - The Jos Experience

Abstract

Background: The temporal bone is made up of nebulous complex neurovascular structure. A good grasp of this complex anatomy is necessary for the otologic surgeon in dissecting the temporal bone for various otologic surgeries and skills development. Method: The land marks for the dissections were suprameatal crest, a perpendicular line through the spine of Henle and posterior wall of the external auditory meatus of the temporal bones connected by a tangent directly overlying he mastoid antrum. Cutting burr of 6mm was used to mark out the lines above. At the juncture; the bones were deepened to expose the dural plate, sinodural angle and the posterior wall of the external meatus. Moving from one land mark to another. Otologic surgeries such as mastoidectomies, facial nerve exploration and cochlear implantation were performed. Result: All the cadavers (100%) were adult males. The suprameatal crest, dural plate, aditus antrum, horizontal semi-circular canal, facial nerve, facial recess, Sigmoid plate, herald air cells, oval and round windows were present in the eighteen temporal bones. Eighteen canal wall ups and wall down mastoidectomies and cochlear implantation were performed. Spine of Henle was present in 3(16.7)%, cribrifossae, highly, moderately and poorly pneumatized, herald air cells, wide mastoid avity, narrow mastoid cavity, tympanic membranes remnants, incus and stapes were present in 16(88.9)%, 12(66.7)%, 2(11.1)%, 4(22.4)%, 13(72.2)%, 16(88.9)%, 2(11.1)%, 11(61.1)%, 12(66.7)% and 6(33.3)% respectively. Conclusion: Temporal bone dissection provides the learning curve in understanding anatomic features and the variations that pose challenge in otologic surgeries.