The auriculotemporal nerve is a branch of the mandibular nerve (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 (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 chewin ...

(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 The middle meningeal artery ('' la, arteria meningea media'') is typically the third branch of the first portion of the maxillary artery. After branching off the maxillary artery in the infratemporal fossa, it runs through the foramen spinosum to ...

(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

then converge to form a single nerve.

Course

The auriculotemporal nerve passes between the neck of the mandible and the

sphenomandibular ligament The sphenomandibular ligament (internal lateral ligament) is one of the three ligaments of the temporomandibular joint. It is situated medially to - and generally separate from - the articular capsule of the joint. Superiorly, it is attached to the ...

. 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

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 The ear canal (external acoustic meatus, external auditory meatus, EAM) is a pathway running from the outer ear to the middle ear. The adult human ear canal extends from the pinna to the eardrum and is about in length and in diameter. Struct ...

, 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 air ...

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 In anatomy, the temporomandibular joints (TMJ) are the two joints connecting the jawbone to the skull. It is a bilateral synovial articulation between the temporal bone of the skull above and the mandible below; it is from these bones that it ...

. 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 The adjective secretomotor refers to the capacity of a structure (often a nerve) to induce a gland to secrete a substance (usually mucus or serous fluid). Secretomotor nerve endings are frequently contrasted with sensory neuron endings and motor n ...

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 oblongata, medulla, just anterior (closer to the nose) to t ...

(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 auditory ...

through the inferior tympanic canaliculus. The

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 pl ...

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

(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 ar ...

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, an ...

). 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 Parotitis is an inflammation of one or both parotid glands, the major salivary glands located on either side of the face, in humans. The parotid gland is the salivary gland most commonly affected by inflammation. Etymology From Greek παρωτῖ ...

, a condition that can be caused by mumps, will be carried by the auriculotemporal nerve and

great auricular nerve The great auricular nerve is a cutaneous nerve of the head. It originates from the cervical plexus, with branches of spinal nerves C2 and C3. It provides sensory nerve supply to the skin over the parotid gland and the mastoid process of the tempor ...

to the brain.

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 The lateral pterygoid muscle (or external pterygoid muscle) is a muscle of mastication. It has two heads. It lies superior to the medial pterygoid muscle. It is supplied by pterygoid branches of the maxillary artery, and the lateral pterygoid ner ...

." * * () * () * http://www.dartmouth.edu/~humananatomy/figures/chapter_47/47-2.HTM {{DEFAULTSORT:Auriculotemporal Nerve Mandibular nerve