[Lambs' temporal bone anatomy under didactic aspects].

UNLABELLED Human temporal bones in teaching ear surgery are rare. The lamb's temporal bone might be a possible alternative. MATERIAL AND METHODS Temporal bones of the lamb were dissected with a typical temporal bone lab drilling program. We included a mastoidectomy, endaural approaches, but also analyzed the outer appearance, the external ear canal and the hypotympanon. Some steps differed from preparation done in humans. The morphometric results were compared to the known anatomy of human in order to verify the lambs' temporal bone for suitability in otosurgic training. RESULTS The lambs' temporal bone appears smaller than the human one. We found a bullous extended hypotympanon located under the external ear canal. The tympanic membrane is very similar to the human one. The external ear canal is smaller and shorter. The ossicular chain shows analogies to human one. DISCUSSION This study shows, that especially the middle ear, the tympanic membrane and the external ear canal are morphologically equal to the structures found in human temporal bones. The lamb seems feasible for teaching the anatomy of the ear. The smaller scales of some structures, especially the outer components of the temporal bone are a disadvantage. CONCLUSIONS The lamb seems to be an alternative in teaching ear surgery.