Trigeminal Nerve Mandibular Branch hard

Trigeminal Nerve - Mandibular Branch (V3)

• The mandibular branch (V3) is the largest of the three divisions of the trigeminal nerve.

• It exits the skull through the foramen ovale.

• It has both sensory and motor fibers.

• Sensory functions include supplying sensation to the:

  • Mandibular teeth and supporting structures
  • Mucosa of the anterior 2/3 of the tongue and floor of the mouth
  • Skin of the lower face
  • Parts of the temporal region and outer ear

• Motor functions involve the muscles of mastication, including:

  • Muscles of mastication
  • Mylohyoid
  • Anterior belly of digastric
  • Tensor veli palatini
  • Tensor tympani

• Shortly after leaving the skull, it divides into a small anterior trunk and a larger posterior trunk.

• Branches before division include:

  • Meningeal branch
  • Nerve to medial pterygoid muscle

Branches of V3

• Anterior Trunk Branches:

  • Masseteric nerve (mainly motor-mastication muscles)
  • Deep temporal nerves (mainly motor-mastication muscles )
  • Nerve to lateral pterygoid muscle (mainly motor-mastication muscles)
  • Long buccal nerve (sensory—skin of cheek and mucous membrane)

• Posterior Trunk Branches:

  • Auriculotemporal nerve (sensory—area above and in front of ear)
  • Lingual nerve (sensory—anterior 2/3 of tongue, joined by chorda tympani(facial nerve); secretory motor function)
  • Inferior alveolar nerve (sensory—lower teeth, branches become mental nerve, also lower chin)
  • Mylohyoid nerve (motor—only motor nerve from posterior division)

Muscles of Mastication

• Medial pterygoid nerve (motor):

  • Enters deep surface of the muscle
  • Also supplies tensor tympani and tensor veli palatini (dampening loud sounds, opening auditory tube during yawning/swallowing.)
  • Elevates jaw.

• Masseter

  • Masseteric nerve is the first anterior trunk branch.
  • Crosses between coronoid process and mandible condyle.
  • Gives an articular branch to the TMJ.
  • Elevates mandible (mouth closure)

• Temporalis

  • Anterior and deep temporal nerves.
  • Elevates mandible (mouth closure)

• Lateral pterygoid:

  • Nerve to lateral pterygoid may run part way with the long buccal nerve.
  • Depresses mandible (mouth opening) and produces other movements.

Long Buccal Nerve

• The only sensory branch of the anterior trunk
• Emerges between heads of lateral pterygoid.
• Runs on the lateral surface of the buccinator muscle, close to the retromolar fossa of the mandible.
• Gives branches to the skin of the cheek.
• Pierces buccinator to supply buccal sulcus and buccal gingivae of mandibular molars and premolars.

Auriculotemporal Nerve (A)

• First branch of the posterior trunk
• Sensory
• Autonomic to parotid gland (fibers from otic ganglion).
• 2 roots that unite & run backward under lateral pterygoid muscle, lying between condyle and sphenomandibular ligament.
• Emerges between TMJ and external auditory meatus.
• Finally, ascends on the side of the head.

Lingual Nerve

• Second branch of posterior trunk
• Sensory: anterior 2/3 of tongue and floor of mouth.
• Unites with the chorda tympani branch of the facial nerve and receives parasympathetic fibers for submandibular and sublingual glands.
• Emerges from under lateral pterygoid muscle, curves downward and forward between ramus of mandible and medial pterygoid muscle (pterygomandibular space).
• Lies anterior to but deeper than the inferior alveolar nerve.
• Passes toward the floor of the mouth
• Twists around the submandibular duct.
• Enters tongue behind the sublingual salivary gland.

Inferior Alveolar (Dental) Nerve

• Sensory and motor

• Descends deep to lateral pterygoid muscle, behind lingual nerve.

• Enters the mandibular foramen.

• Travels in inferior dental or mandibular canal in mandible.

• Divides near premolars into mental nerve and incisive nerve.

• Mental nerve emerges at the mental foramen.

• Incisive nerve runs anteriorly in incisive canal.

• Branches of Inferior Alveolar Nerve:

  • Mylohyoid nerve (motor): Given off before mandibular foramen. Runs in mylohyoid groove/supplies mylohyoid muscle & anterior belly of digastric. Depresses or elevates the hyoid.
  • Mental nerve. Supplies skin of chin and lower lip, labial gingiva of mandibular teeth.
  • Incisive nerve. Innervates mandibular incisors and canines.

Nerve Block Procedures

• ID nerve block procedures
• Mental nerve block procedures

Trigeminal and Facial Nerve Examination

• Procedure and evaluation of the function.

Summary

• Trigeminal nerve is the largest (5th) cranial nerve.
• Has three divisions: ophthalmic, maxillary, and mandibular.
• Mandibular nerve exits via the foramen ovale.
• Supplies mandibular teeth, supporting structures, anterior 2/3 tongue, and floor of mouth and muscles of mastication.

Test your knowledge on the mandibular branch (V3) of the trigeminal nerve, including its functions and branches. This quiz covers both sensory and motor components along with anatomical details relevant to the V3 division. Perfect for students studying anatomy or neuroscience.