Auriculotemporal nerve

Nerve: Auriculotemporal nerve
Sympathetic connections of the otic and superior cervical ganglia. (Auriculotemporal labeled at top right.)
Distribution of the maxillary and mandibular nerves, and the submaxillary ganglion.
Latin	n. auriculotemporalis
Gray's	subject #200 895
Innervates	temple
From	mandibular nerve

The auriculotemporal nerve is a branch of the mandibular nerve that runs with the superficial temporal artery and vein, and provides sensory innervation to various regions on the side of the head.

Structure

Origin

The auriculotemporal nerve arises as two roots from the posterior division of the mandibular nerve (The mandibular nerve is a branch of the trigeminal nerve). 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 then converge to form a single nerve.

Course

The auriculotemporal nerve passes laterally to the neck of the mandible, 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

Innervation

The somatosensory root (superior) originates from branches of the mandibular nerve, which pass through the otic ganglion 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. Supplies the auricle, external acoustic meatus, outer side of the tympanic membrane and the skin in the temporal region (superficial temporal branches). It also carries a few articular branches which go on to supply the temporalmandibular joint.

The parasympathetic root (inferior) carries postganglionic fibers to the parotid gland. These parasympathetic, preganglionic secretomotor fibers originate from the glossopharyngeal nerve (CN IX) as one of its branches, the lesser petrosal nerve. 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 surgery, causing an ipsilateral parasthesia of the auricle and skin surrounding the ear. Actually, 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). 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 related to a condition call parotiditis, or commonly referred to as " the mumps" will be carried by the auriculotemporal nerve.

See also

• Superficial temporal artery

Additional images

Mandible of human embryo 24 mm. long. Outer aspect.

External links

• SUNY Figs 27:03-04 - "Illustration of the nerves within the infratemporal fossa after removal of the lateral pterygoid muscle."
• MedEd at Loyola GrossAnatomy/h_n/cn/cn1/cnb3.htm
• Auriculotemporal+nerve at eMedicine Dictionary
• lesson4 at The Anatomy Lesson by Wesley Norman (Georgetown University) (mandibularnerve)
• cranialnerves at The Anatomy Lesson by Wesley Norman (Georgetown University) (V)
• http://www.dartmouth.edu/~humananatomy/figures/chapter_47/47-2.HTM