Tympanic membrane retraction adherent to other structures within the middle ear. Some retractions continue to progress and grow more deeply into the ear. This can result in erosion of bone. As the middle ear is only a narrow space, the eardrum only has to retract a short distance before it touches boney structures within the middle ear such as the ossicles. It may become adherent to these bones and in some cases, this contact leads to erosion of the bone. As well as ossicular erosion, the bone of the ear canal (e.g. the scutum) and even bone over the cochlea (the promontory) can
Tympanic nerve then distributed via the auriculotemporal nerve (branch of the trigeminal nerve) to the parotid gland. This nerve may be involved by paraganglioma, in this location referred to as glomus jugulare or glomus tympanicum tumours. Tympanic nerve The tympanic nerve (nerve of Jacobson) is a branch of the glossopharyngeal nerve found near the ear. It arises from the petrous ganglion, and ascends to the tympanic cavity through a small canal, the inferior tympanic canaliculus, on the under surface of the petrous portion of the temporal bone on the ridge which separates the carotid canal from the jugular fossa. In the tympanic