petrotympanic

Petrotympanic refers to a small anatomical feature or region associated with the temporal bone, most commonly the fissure known as the petrotympanic fissure (fissura petrotympanica). This narrow passage connects the tympanic cavity of the middle ear with the infratemporal fossa, located between the petrous part and the tympanic part of the temporal bone. The fissure serves as a conduit for nerves and vessels passing between these regions and is a recognizable landmark in skull base anatomy.

The petrotympanic fissure transmits two principal structures: the chorda tympani nerve, a branch of the facial nerve, and the anterior tympanic artery, a branch often arising from the maxillary artery. The chorda tympani carries taste fibers from the anterior two-thirds of the tongue and preganglionic parasympathetic fibers to the sublingual and submandibular glands. After traversing the middle ear, the chorda tympani typically exits the skull through the fissure to join the lingual nerve in the infratemporal fossa.

Clinical relevance centers on the fissure’s contents, particularly during otologic surgery or temporal bone trauma. Injury to the chorda tympani can result in taste disturbance and altered salivation on the affected side. Fractures or pathological processes involving the petrotympanic region may affect both the nerve and the accompanying artery, influencing middle-ear function and oral sensation.

See also: chorda tympani, tympanic cavity, petrous temporal bone, infratemporal fossa.