Trigeminal Nerve - Maxillary

Trigeminal Nerve - Maxillary Branch (V2)

• The maxillary branch (V2) is a major division of the trigeminal nerve (CN V).
• It is essential for dental professionals to understand this branch.
• The nerve's function includes sensing facial touch, pain, and temperature as well as controlling muscles used for chewing.
• Key learning objectives include describing its function, outlining the anatomical regions it supplies, and explaining its relevance to dentistry.

GDC Learning Outcomes

• Relevant dental, oral, craniofacial, and general anatomy should be described and applied to patient management.

Intended Learning Outcomes

• Describe the function of the maxillary branch of the trigeminal nerve (CN V).
• Outline the anatomical regions the maxillary branch supplies.
• Explain the relevance of the maxillary branch of the trigeminal nerve to dentistry.

Nerve Roots

• Each trigeminal nerve is made up of two roots; one motor (thinner) root, and one sensory (thicker) root.
• The trigeminal nerve is responsible for sensing facial touch, pain, and temperature. It also controls muscles involved in chewing.
• Distinguish the trigeminal nerve from the facial nerve (CN VII), which controls other facial movements.

What is Supplied?

• Sensory (afferent) roots:
  • Maxillary dentition
  • Mandibular dentition
  • Skin of the face and head
  • Oral mucosa
  • Nasal mucosa
  • Air sinuses
  • Meninges
• Motor (efferent) roots:
  • Muscles of mastication (Masseter, Temporalis, Medial pterygoid, Lateral pterygoid, Anterior belly of digastric)
  • Mylohyoid
  • Tensor tympani
  • Tensor veli palatini

Brain Origin

• The trigeminal nerve originates from the pons.
• It has one motor nucleus and three sensory nuclei.

Pathway from Skull

• The three branches of the trigeminal nerve emerge from the middle cranial fossa.
• The Ophthalmic nerve (V1) exits via the superior orbital fissure (SOF).
• The Maxillary nerve (V2) exits via the foramen rotundum and travels through the pterygopalatine fossa, before exiting via the infraorbital foramen.
• The Mandibular nerve (V3) exits via the foramen ovale.

Gasserian Ganglion

• The three divisions of the trigeminal nerve come together at the Gasserian ganglion within the brainstem.
• Signals traveling through the trigeminal nerve reach specialized clusters of neurons called the trigeminal nerve nucleus.

Ophthalmic Nerve (V1)

• The smallest division, it's a sensory nerve.
• Carries information to the brain via the superior orbital fissure of the sphenoid bone.
• The superior orbital fissure is also traversed by cranial nerves II, IV, and VI.
• It supplies the conjunctiva, cornea, eyeball, orbit, forehead, ethmoidal and frontal sinuses, and portions of the dura mater.

Branches of Ophthalmic Nerve

• Lacrimal: Supplies the conjunctiva and skin covering the lateral part of the upper eyelid; tear production.
• Frontal: Supplies mucous membrane lining frontal sinus, skin, and conjunctiva covering upper eyelid, as well as skin on the forehead and scalp.
• Nasociliary: Sensory branches to the ciliary ganglion, including long ciliary nerves, posterior ethmoidal nerves, and infratrochlear nerve.

Pterygo-maxillary fissure

• Located between the posterior surface of the maxilla and the pterygoid process of the sphenoid bone.
• It fills a triangular gap between the lower ends of the medial and lateral pterygoid plates.
• The pterygomaxillary fissure leads into the area entered by the foramen rotundum and maxillary nerve.

Maxillary Nerve (V2)

• Exits the cranium via the foramen rotundum.
• Travels into the pterygopalatine fossa and divides into branches.
• Divides into: Zygomatic, Infraorbital, Posterior Superior Alveolar, and Pterygopalatine nerves.
• Supplies maxillary teeth, supporting structures, hard and soft palate, maxillary sinus, and skin over the middle part of the face.

Infra-orbital Nerve

• The terminal branch of the maxillary nerve
• Enters the orbit at the inferior orbital fissure and runs through the infraorbital groove.
• Exits the orbit at the infraorbital foramen.
• Branches into middle superior alveolar, anterior superior alveolar, and terminal branches (palpebral, nasal, and labial).

Terminal Branches

• Arise at the infraorbital foramen and provide sensation to various facial areas:
• Palpebral nerve: lower eyelid skin.
• Nasal nerve: sides of nose.
• Labial nerve: upper lip, labial gingivae, anterior maxillary teeth, and cheek skin over the maxilla.

Posterior Superior Alveolar Nerve (C)

• Leaves the pterygopalatine fossa through the pterygomaxillary fissure.
• Supplies the buccal gingivae of the maxillary molars.
• Pierces bone to provide maxillary sinus innervation and supply maxillary molars.

Middle & Anterior Superior Alveolar Nerves (G)

• Arise from the infraorbital nerve in the orbit.
• Middle: supplies maxillary premolars and the mesiobuccal root of the first maxillary molar.
• Anterior: supplies maxillary incisors and canines.

Pterygopalatine Nerves

• Greater Palatine: Passes through greater palatine canal to greater palatine foramen; supplies hard palate mucosa, except for around the incisive papilla.
• Lesser Palatine: Passes through greater palatine canal to lesser palatine foramen; supplies the soft palate.
• Nasopalatine: Enters nasal cavity through sphenopalatine foramen; supplies part of the nasal septum and oral mucosa around the incisive papilla.

Zygomatic Nerve

• Travels anteriorly to enter the orbit via the inferior orbital fissure.
• Divides into:
  • Zygomaticotemporal nerve: sensory innervation to temple.
  • Zygomaticofacial nerve: innervates skin on cheeks.
• Perforates the orbicularis oculi muscle.

Trigeminal and Facial Nerve Examination

• A clinical procedure for evaluating trigeminal and facial nerve function. Methods may include sensory testing and motor function assessments.

Summary

• The trigeminal nerve is the fifth cranial nerve.
• It has three main branches: ophthalmic (V1), maxillary (V2), and mandibular (V3).
• The ophthalmic nerve enters the orbit through the superior orbital fissure.
• The maxillary nerve leaves the cranium via the foramen rotundum.
• The maxillary nerve supplies the maxillary teeth, hard palate, maxillary sinus, and skin overlying the middle part of the face.