The auriculotemporal nerve is a branch of the mandibular nerve. This nerve provides the sensory innervation to the different parts of the head, especially on the sides of the head.
The auriculotemporal nerve originates as two roots, from the first branch of the posterior trunk of the mandibular nerve. The two roots which arise, run backward, encircle the middle meningeal artery and then unite to form a single trunk.
The nerve then continues backward between the sphenomandibular ligament and the neck of the mandible, superficial to the maxillary artery. The auriculotemporal nerve is closely related to the parotid gland.
Behind the neck of the mandible, this nerve turns upwards and travels on the temple region of the skull, behind the superficial temporal vessels.
Auriculotemporal Nerve Branches
The auriculotemporal nerve divides into five more branches. These five branches are
- Anterior auricular
- Superficial temporal
- External auditory meatus branch
The anterior auricular branches of the auriculotemporal nerve provide the sensory nerve supply to the skin that overlies the tragus area and also the adjacent part of the helix region.
The ‘helix’ is the outer rim of the ear that extends from the region where the ear attaches to the scalp in the upper region (root) to the termination of the cartilage at the earlobe.
The posterior regions of the temporomandibular joint get the sensory nerve supplies from the articular branches. The parotid gland gets its secretomotor and sensory nerve supply from the parotid branches of the auriculotemporal nerve.
The skin that covers the temple region of the head is innervated by the superficial temporal branches.
The skin of the external auditory meatus and the tympanic membrane are innervated by the external auditory meatus branch of the auriculotemporal nerve.
The Significance of The Auriculotemporal Nerve
As mentioned earlier, this nerve is very important for the sensory functions of the area near the head, ears, parotid gland, and TMJ.
Because of its anatomical proximity to the temporomandibular joint, it is frequently injured during the surgery of the TMJ. This may cause ipsilateral paresthesia which affects the area of the auricle and skin surrounding the ear.
Parasthesia is a condition characterized by abnormal dermal sensation which may not have an apparent physical cause. Ipsilateral means something which occurs on the same side of the body.
Also, because of the auriculotemporal nerve’s close proximity to the parotid gland, it may get affected during a procedure of parotidectomy. Parotidectomy is the surgical excision of the parotid gland.
Sometimes after the parotidectomy procedures, the auriculotemporal nerve that innervated the parotid gland re-attaches itself to the sweat glands in the region. Because of this, the sweat glands may start acting funny and mimic the parotid gland.
And because of this, the affected person may sweat along the cheek, while eating food. This condition is called ‘Frey’s Syndrome’.You can read about Frey’s syndrome from this Wikipedia link.