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The auriculotemporal nerve is a branch of the
mandibular nerve In neuroanatomy, the mandibular nerve (V) is the largest of the three divisions of the trigeminal nerve, the fifth cranial nerve (CN V). Unlike the other divisions of the trigeminal nerve ( ophthalmic nerve, maxillary nerve) which contain only ...
(CN V3) that runs with the
superficial temporal artery In human anatomy, the superficial temporal artery is a major artery of the head. It arises from the external carotid artery when it splits into the superficial temporal artery and maxillary artery. Its pulse can be felt above the zygomatic a ...
and vein, and provides sensory innervation to various regions on the side of the head.


Structure


Origin

The auriculotemporal nerve arises from the
mandibular nerve In neuroanatomy, the mandibular nerve (V) is the largest of the three divisions of the trigeminal nerve, the fifth cranial nerve (CN V). Unlike the other divisions of the trigeminal nerve ( ophthalmic nerve, maxillary nerve) which contain only ...
(CN V3). The mandibular nerve is a branch of the
trigeminal nerve In neuroanatomy, the trigeminal nerve ( lit. ''triplet'' nerve), also known as the fifth cranial nerve, cranial nerve V, or simply CN V, is a cranial nerve responsible for sensation in the face and motor functions such as biting and che ...
(CN V), and the mandibular nerve exits the skull through the foramen ovale.Gray's Anatomy for Students, 2nd edition (2010), Drake Vogel and Mitchell, Elseview These roots encircle the middle meningeal artery (a branch of the mandibular part of the maxillary artery, which is in turn a terminal branch of the external carotid artery). The roots encompass the middle meningeal artery then converge to form a single nerve.


Course

The auriculotemporal nerve passes between the neck of the mandible and the sphenomandibular ligament. It gives off parotid branches and then turns superiorly, posterior to its head and moving anteriorly, gives off anterior branches to the auricle. It then crosses over the root of the zygomatic process of the temporal bone, deep to the
superficial temporal artery In human anatomy, the superficial temporal artery is a major artery of the head. It arises from the external carotid artery when it splits into the superficial temporal artery and maxillary artery. Its pulse can be felt above the zygomatic a ...
.


Innervation

The ''somatosensory root (superior)'' originates from branches of the mandibular nerve (CN V3), which pass through the
otic ganglion The otic ganglion is a small parasympathetic ganglion located immediately below the foramen ovale in the infratemporal fossa and on the medial surface of the mandibular nerve. It is functionally associated with the glossopharyngeal nerve and inn ...
without synapsing. Then they form the somatosensory (superior) root of the auriculotemporal nerve. The two roots re-unite, and shortly after the branching of secretomotor fibers to the parotid gland (parotid branches), the auriculotemporal nerve comprises exclusively somatosensory fibers, which ascend to the superficial temporal region. There, it supplies the auricle, external acoustic meatus, outer side of the
tympanic membrane In the anatomy of humans and various other tetrapods, the eardrum, also called the tympanic membrane or myringa, is a thin, cone-shaped membrane that separates the external ear from the middle ear. Its function is to transmit sound from the a ...
and the skin in the temporal region (superficial temporal branches). It also carries a few articular branches that go on to supply the temporomandibular joint. The ''parasympathetic root (inferior)'' carries postganglionic fibers to the
parotid gland The parotid gland is a major salivary gland in many animals. In humans, the two parotid glands are present on either side of the mouth and in front of both ears. They are the largest of the salivary glands. Each parotid is wrapped around the ma ...
. These parasympathetic, preganglionic secretomotor fibers originate from the
glossopharyngeal nerve The glossopharyngeal nerve (), also known as the ninth cranial nerve, cranial nerve IX, or simply CN IX, is a cranial nerve that exits the brainstem from the sides of the upper medulla, just anterior (closer to the nose) to the vagus nerve. ...
(CN IX) as one of its branches, the
tympanic nerve The tympanic nerve (Jacobson’s nerve) is a branch of the glossopharyngeal nerve found near the ear. It gives sensation to the middle ear, the Eustachian tube, the parotid gland, and Mastoid cells, mastoid air cells. It gives parasympathetic to ...
, which enters the
tympanic cavity The tympanic cavity is a small cavity surrounding the bones of the middle ear. Within it sit the ossicles, three small bones that transmit vibrations used in the detection of sound. Structure On its lateral surface, it abuts the external auditor ...
through the
inferior tympanic canaliculus The inferior tympanic canaliculus is a small passage of the tympanic branch of the glossopharyngeal nerve and inferior tympanic artery. In the bony ridge dividing the carotid canal from the jugular fossa is the small inferior tympanic canalicul ...
. The
tympanic nerve The tympanic nerve (Jacobson’s nerve) is a branch of the glossopharyngeal nerve found near the ear. It gives sensation to the middle ear, the Eustachian tube, the parotid gland, and Mastoid cells, mastoid air cells. It gives parasympathetic to ...
and postganglionic sympathetic fibers, which come with the arteries-related head, make the
tympanic plexus In the tympanic cavity, the tympanic nerve (a branch of CN IX) divides into branches which, along with sympathetic fibres from the carotid plexus, form the tympanic plexus. This plexus is located on the surface of the promontory. This tympanic p ...
on the promontorium. This plexus gives off the
lesser petrosal nerve The lesser petrosal nerve (also known as the small superficial petrosal nerve) is the general visceral efferent (GVE) component of the glossopharyngeal nerve (CN IX), carrying parasympathetic preganglionic fibers from the tympanic plexus to the p ...
. This nerve synapses in the otic ganglion and its postganglionic fibers form the inferior, parasympathetic root of the auriculotemporal nerve. The two roots re-unite and shortly after the "united" auriculotemporal branch gives off parotid branches, which serve as secretomotor fibers for the parotid gland.


Clinical significance

This nerve, as it courses posteriorly to the condylar head, is frequently injured in temporomandibular joint (TMJ) surgery, causing an ipsilateral
paresthesia Paresthesia is an abnormal sensation of the skin (tingling, pricking, chilling, burning, numbness) with no apparent physical cause. Paresthesia may be transient or chronic, and may have any of dozens of possible underlying causes. Paresthesias a ...
of the auricle and skin surrounding the ear. It is the main nerve that supplies the TMJ, along with branches of the masseteric nerve and the deep temporal. After a parotidectomy, the nerves from the Auriculotemporal Nerve that previously innervated the parotid gland can reattach to the sweat glands in the same region. The result is sweating along the cheek with the consumption of foods (
Frey's syndrome Frey's syndrome (also known as Baillarger's syndrome, Dupuy's syndrome, auriculotemporal syndrome, or Frey-Baillarger syndrome) is a rare neurological disorder resulting from damage to or near the parotid glands responsible for making saliva, and ...
). Treatment involves the application of an antiperspirant or glycopyrrolate to the cheek, Jacobsen's neurectomy along the middle ear promontory, and lifting of the skin flap with the placement of a tissue barrier (harvested or cadaveric) to interrupt the misguided innervation of the sweat glands. Pain from parotitis, a condition that can be caused by
mumps MUMPS ("Massachusetts General Hospital Utility Multi-Programming System"), or M, is an imperative, high-level programming language with an integrated transaction processing key–value database. It was originally developed at Massachusetts Gene ...
, will be carried by the auriculotemporal nerve and great auricular nerve to the brain.


See also

*
Superficial temporal artery In human anatomy, the superficial temporal artery is a major artery of the head. It arises from the external carotid artery when it splits into the superficial temporal artery and maxillary artery. Its pulse can be felt above the zygomatic a ...


Additional images

Image:Gray178.png, Mandible of human embryo 24 mm. long. Outer aspect.


References


External links

* - "Illustration of the nerves within the infratemporal fossa after removal of the lateral pterygoid muscle." * * () * () * http://www.dartmouth.edu/~humananatomy/figures/chapter_47/47-2.HTM {{DEFAULTSORT:Auriculotemporal Nerve Mandibular nerve