Trigeminal Nerve (V3) Anatomy and Branches: A Detailed Review

Trigeminal Nerve (V3) Anatomy

The trigeminal nerve (V3), also known as the mandibular nerve, has an anterior trunk (mainly motor) and a posterior trunk (sensory). It supplies taste sensory innervation to the anterior part of the dorsum of the tongue via fibers of CN7. Before dividing into two terminal trunks, there are two lateral branches:

• Meningeal branch: Sensory, supplies the dura mater of the middle cranial fossa.
• Medial pterygoid muscle nerve: Motor nerve, supplies the medial pterygoid muscle from the deep side. It also innervates the tensor veli palatini and tensor tympani muscles.

Anterior Trunk Branches

• Buccal nerve: Sensory, supplies the skin of the cheek, mucosa of the posterior and inferior portion of the vestibule, and the buccal side of the gums of molars and premolars.
• Deep temporal nerve: Motor, supplies the temporalis muscle. There are two branches: anterior (branch of the buccal nerve, supplies the anterior portion of the temporalis muscle) and posterior (divides with the masseteric nerve and supplies the posterior portion of the temporalis muscle).
• Masseteric nerve: Motor, supplies the masseter muscle from the medial side; provides sensory innervation to the temporomandibular joint (TMJ).
• Lateral pterygoid muscle nerve: Motor, innervates the lateral pterygoid muscle.

Posterior Trunk Branches

• Auriculotemporal nerve: Supplies the skin of the temporal region and ear; also innervates the parotid gland with fibers from CN IX via the otic ganglion.
• Lingual nerve: Supplies the mucosa of the anterior portion of the tongue, floor of the mouth, and lingual side of the mandible. Also innervates the submandibular and sublingual glands with CN VII.
• Inferior alveolar nerve: Its motor fibers innervate the mylohyoid and digastric (anterior belly) muscles. This nerve gives off four branches:
• Mylohyoid nerve: Supplies the mylohyoid muscle and anterior belly of the digastric muscle.
• Inferior dental nerve: Supplies the inferior molars and premolars.
• Mental nerve: Sensory innervation to the chin and lower lip.
• Incisive nerve: Supplies the canine and incisor roots.

Cranial Nerve Passages

1. Cribriform plate: [Olfactory nerve]
2. Optic canal: [Optic nerve, ophthalmic artery]
3. Superior orbital fissure: [Oculomotor nerve, trochlear nerve; lacrimal, frontal, and nasociliary branches of ophthalmic nerve V1; abducens nerve, superior ophthalmic vein]
4. Foramen rotundum: [Maxillary nerve V2]
5. Foramen ovale: [Mandibular nerve V3, accessory meningeal artery]
6. Foramen spinosum: [Middle meningeal artery and vein; meningeal branch of mandibular nerve]
7. Carotid canal: [Internal carotid artery; internal carotid nerve plexus]
8. Internal acoustic meatus: [Facial nerve, vestibulocochlear nerve, labyrinthine artery]
9. Jugular foramen: [Inferior petrosal sinus, glossopharyngeal nerve, vagus nerve, accessory nerve, sigmoid sinus, posterior meningeal artery]
10. Foramen Magnum: [Medulla oblongata, meninges, vertebral arteries, spinal roots of accessory nerves]