Auriculotemporal nerve
Encyclopedia
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.
(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.
. It then crosses over the root of the zygomatic process of the temporal bone, deep to the superficial temporal artery
.
.
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.
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 parotitis, a cause of which is "mumps", will be carried by the auriculotemporal nerve.
after removal of the lateral pterygoid muscle
."
Mandibular nerve
The mandibular nerve is the largest of the three branches of the trigeminal nerve.-Roots:It is made up of two roots:* a large sensory root proceeding from the inferior angle of the trigeminal ganglion....
that runs with the superficial temporal artery
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 bifurcates into the superficial temporal artery and maxillary artery....
and vein, and provides sensory innervation to various regions on the side of the head.
Origin
The auriculotemporal nerve arises as two roots from the posterior division of the mandibular nerveMandibular nerve
The mandibular nerve is the largest of the three branches of the trigeminal nerve.-Roots:It is made up of two roots:* a large sensory root proceeding from the inferior angle of the trigeminal ganglion....
(The mandibular nerve is a branch of the trigeminal nerve
Trigeminal nerve
The trigeminal nerve contains both sensory and motor fibres. It is responsible for sensation in the face and certain motor functions such as biting, chewing, and swallowing. Sensory information from the face and body is processed by parallel pathways in the central nervous system...
). These roots encircle the middle meningeal artery
Middle meningeal artery
The middle meningeal artery is typically the third branch of the first part of the maxillary artery, one of the two terminal branches of the external carotid 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 medialy 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 auricleEar
The ear is the organ that detects sound. It not only receives sound, but also aids in balance and body position. The ear is part of the auditory system....
. It then crosses over the root of the zygomatic process of the temporal bone, deep to the superficial temporal artery
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 bifurcates into the superficial temporal artery and maxillary 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. There, it 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 temporomandibular jointTemporomandibular joint
The temporomandibular joint is the joint of the jaw and is frequently referred to as TMJ. There are two TMJs, one on either side, working in unison. The name is derived from the two bones which form the joint: the upper temporal bone which is part of the cranium , and the lower jaw bone called the...
.
The parasympathetic root (inferior) carries postganglionic fibers to the parotid gland
Parotid gland
The paired parotid glands are the largest of the salivary glands. They are each found wrapped around the mandibular ramus, and secrete saliva through Stensen's ducts into the oral cavity, to facilitate mastication and swallowing and to begin the digestion of starches.-Location:The parotid glands...
. These parasympathetic, preganglionic secretomotor
Secretomotor
Secretomotor refers to the capacity of a structure to induce a gland to secrete a substance .Secretomotor nerve endings are frequently contrasted with sensory neuron endings and motor nerve endings. An example of secretomotor activity can be seen with the lacrimal gland, which secretes the aqueous...
fibers originate from the glossopharyngeal nerve (CN IX) as one of its branches, the lesser petrosal nerve
Lesser petrosal nerve
The lesser petrosal nerve consists of parasympathetic fibres. It leaves the tympanic plexus to synapse in the otic ganglion, and eventually provide parasympathetic innervation to the parotid gland....
. 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
Frey's syndrome
Frey's syndrome is a food related syndrome which can be congenital or acquired specially after parotid surgery and can persist for life.The symptoms of Frey's syndrome are redness and sweating on the cheek area adjacent to the ear...
). 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.
External links
- "Illustration of the nerves within the infratemporal fossaInfratemporal fossa
The infratemporal fossa is an irregularly shaped cavity, situated below and medial to the zygomatic arch.* anteriorly, by the infratemporal surface of the maxilla and the ridge which descends from its zygomatic process...
after removal of the lateral pterygoid muscle
Lateral pterygoid muscle
The lateral pterygoid is a muscle of mastication with two heads. It lies superiorly to the medial pterygoid.-Origin and insertion:...
."
- http://www.dartmouth.edu/~humananatomy/figures/chapter_47/47-2.HTM