Trigeminal Nerve - Maxillary Branch (V2)

Trigeminal Nerve - Maxillary Branch (V2)

• The trigeminal nerve is the largest cranial nerve.
• Knowledge of this nerve is crucial for dental professionals.
• It has three divisions: ophthalmic (V1), maxillary (V2), and mandibular (V3).
• The maxillary branch (V2) functions in sensing facial touch, pain, and temperature.
• It also controls muscles used for chewing.
• Its function is important for dentistry.

Intended Learning Outcomes

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

Nerve Roots

• Each trigeminal nerve is a short trunk made up of two roots.
• Motor root (thinner).
• Sensory root (thicker).
• The trigeminal nerve is distinct from the facial nerve (CN VII), which controls other facial movements.

What is Supplied?

• Sensory (afferent) roots:
  • Maxillary dentition
  • Mandibular dentition
  • Skin of 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

• Arises from the pons.
• Contains one motor nucleus and three sensory nuclei.

Pathway from Skull

• The three branches of the trigeminal nerve exit the middle cranial fossa at different locations.
  • Ophthalmic (V1) exits through the superior orbital fissure.
  • Maxillary (V2) exits via the foramen rotundum, then through pterygopalatine fossa and infra-orbital canal to infraorbital foramen.
  • Mandibular (V3) exits via the foramen ovale.

Gasserion Ganglion

• The three divisions of the trigeminal nerve come together in the Gasserion ganglion area.
• Within the brain stem, signals traveling through the trigeminal nerve reach specialized clusters of neurons called the trigeminal nerve nucleus.

Ophthalmic Nerve (V1)

• The smallest division of the trigeminal nerve.
• Serves as an afferent nerve to the conjunctiva, cornea, eyeball, orbit, forehead, ethmoidal and frontal sinuses, and portions of the dura mater.
• Carries information to the brain via the superior orbital fissure of the sphenoid bone.
• Traversed by cranial nerves II, IV and VI as well.

Branches of Ophthalmic Nerve

• Sub-branches of the ophthalmic nerve innervate the following areas:
• Lacrimal nerve
• Frontal nerve
• Nasociliary nerve

Pterygo-maxillary Fissure

• Lies between the posterior surface of the maxilla and the pterygoid process of the sphenoid bone.
• Fills the triangular gap between the lower ends of the medial and lateral pterygoid plates.
• The pterygomaxillary fissure leads into the pterygopalatine fossa.
• It is entered by the maxillary nerve through the foramen rotundum.

Maxillary Nerve (V2)

• Exits the skull via the foramen rotundum and enters the pterygopalatine fossa.
• Divides into four branches:
  • Zygomatic
  • Infraorbital
  • Posterior Superior Alveolar
  • Pterygopalatine

Maxillary Nerve (V2) -Additional Points

• Sensory fibers only.
• Parts of the nerve originate from the embryonic maxillary process.
• It supplies the maxillary teeth and supporting structures, the hard and soft palate, the maxillary sinus, and much of the nasal cavity.
• It also supplies skin over the middle part of the face.

Infraorbital Nerve

• The terminal branch of the maxillary nerve.
• Enters the orbit at the inferior orbital fissure and runs in the infra-orbital groove.
• Exits the orbit at the infra-orbital foramen and runs onto the face.
• Divides into three branches:
  • Middle superior alveolar nerve
  • Anterior superior alveolar nerve
  • Terminal branches (palpebral, nasal, labial).

Terminal Branches

• Arise at the infra-orbital foramen.
• Palpebral nerve supplies the skin of the lower eyelid.
• Nasal nerve supplies the skin of the side of the nose.
• Labial nerve supplies the skin and oral mucosa of the upper lip, labial gingivae, anterior maxillary teeth, and skin of the cheek.

Posterior Superior Alveolar Nerve (C)

• Leaves the pterygopalatine fossa via pterygomaxillary fissure.
• Runs onto the tuberosity of the maxilla and innervates the buccal gingiva of the maxillary molars.
• Pierces bone to reach maxillary sinus and innervates the maxillary molar teeth (3rd, 2nd, 1st).

Middle & Anterior Superior Alveolar Nerves (G)

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

Pterygopalatine Nerves

• Three branches of the maxillary nerve located within the pterygopalatine fossa:
  • Greater Palatine
  • Lesser Palatine
  • Nasopalatine

Greater Palatine Nerve

• Passes through the greater palatine canal and exits onto the hard palate at the greater palatine foramen.
• Supplies most of the hard palate mucosa and palatal gingiva, excluding the incisive papilla.
• Gives off nasal branches in the lateral nasal fossa.

Lesser Palatine Nerve

• Passes through the greater palatine canal and exits at lesser palatine foramen.
• Supplies the soft palate.

Nasopalatine Nerve

• Enters the nasal cavity through the sphenopalatine foramen.
• Supplies part of the nasal septum.
• Passes through the incisive canal on the hard palate and supplies the 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 the temple)
  • Zygomaticofacial nerve (innervates skin of the cheek).
• Emerges on the face through zygomaticofacial foramen, and innervates skin on the prominence of the cheeks.

Summary

• The trigeminal nerve is the 5th and largest cranial nerve.
• The trigeminal nerve has three divisions (ophthalmic, maxillary, and mandibular).
• The ophthalmic nerve goes through the superior orbital fissure.
• The maxillary nerve passes through the foramen rotundum.
• The maxillary nerve supplies maxillary teeth, supporting structures, hard/soft palate, maxillary sinuses, and facial skin.

Additional information

• Diagrams and anatomical illustrations of the nerve pathways and structures related to cranial nerves.
• Important terms and concepts related to the branches of the maxillary nerve.
• Potential clinical significance, and relevance for various dental procedures.
• Techniques and approaches to anesthetic interventions in relation to the maxillary nerve.