Trigeminal

Trigeminal nerve is the fifth cranial nerve, also known as CN V. It is responsible for sensation in the face and motor functions such as biting and chewing. The nerve is divided into three branches: the ophthalmic nerve (V1), the maxillary nerve (V2), and the mandibular nerve (V3).

Anatomy

The trigeminal nerve is the largest of the cranial nerves. It has both sensory and motor functions. The sensory function provides the tactile, proprioceptive, and nociceptive afferents to the face and mouth. The motor function activates the muscles of mastication, the tensor tympani, tensor veli palatini, mylohyoid and anterior belly of the digastric.

Branches

The trigeminal nerve divides into three branches:

• Ophthalmic nerve (V1) - This is the smallest of the three divisions. It provides sensory innervation to the skin of the forehead, upper eyelid, and dorsum of the nose, the cornea, ciliary body, and iris, the lacrimal gland and conjunctiva, the part of the mucous membrane of the nasal cavity, and the dura mater in the anterior cranial fossa.
• Maxillary nerve (V2) - This provides sensory innervation to the skin of the cheek, the lower eyelid, the nares and upper lip, the upper teeth and gums, the nasal mucosa, the palate and roof of the pharynx, the maxillary, ethmoid and sphenoid sinuses, and the meninges of the anterior and middle cranial fossae.
• Mandibular nerve (V3) - This is the largest of the three divisions. It has both a sensory part and a motor part. The sensory part provides innervation to the skin of the lower lip, the lower teeth and gums, the chin and jaw (except the angle of the jaw, which is supplied by C2-C3), parts of the external ear, and parts of the meninges. The motor part supplies the muscles of mastication.

Clinical significance

The trigeminal nerve may be involved in several pain syndromes, including trigeminal neuralgia, cluster headaches, and migraine. Trigeminal neuralgia, also known as tic douloureux, is a severe facial pain disorder that is often triggered by normal facial movements or activities such as eating, talking, or brushing the teeth.

See also

• Cranial nerves
• Trigeminal ganglion
• Trigeminal nerve injuries

References

Trigeminal Resources
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