Trigeminal Nerve: Maxillary Branch (V2)

Trigeminal Nerve (V) - Maxillary Branch (V2)

• The function and relevance of the maxillary branch of the trigeminal nerve to dentistry is described
• Anatomical regions supplied by the maxillary branch are outlined

Trigeminal Nerve

• The largest cranial nerve
• Knowledge of the nerve is important for dental professionals
• Has three divisions: Ophthalmic (V1), Maxillary (V2), and Mandibular (V3)

Nerve Roots

• Each nerve is a short trunk composed of a thinner motor and a thicker sensory root
• Responsible for sensing facial touch, pain, and temperature
• Controls muscles used for chewing
• Is distinct from the facial nerve (cranial nerve VII), which controls all other facial movements

Supply

• Sensory roots supply maxillary and mandibular dentition, skin of face and head, oral and nasal mucosa, air sinuses, and meninges
• Motor roots supply muscles of mastication (masseter, temporalis, medial and lateral pterygoid), anterior belly of digastric, mylohyoid, tensor tympani, and tensor veli palatini muscles

Brain Origin

• Arises from the pons
• Composed of one motor nucleus and three sensory nuclei

Pathway from Skull

• The three branches exit from the middle cranial fossa:
• The Ophthalmic nerve enters the orbit through the superior orbital fissure (SOF)
• The Maxillary nerve leaves via foramen rotundum (FR) into the pterygopalatine fossa, then through the infra-orbital canal to the infra-orbital foramen
• The Mandibular nerve leaves via foramen ovale (FO)

Gasserion Ganglion & Trigeminal Nerve Nucleus

• The three divisions of the trigeminal nerve come together in the Gasserion ganglion
• Within the brain stem, signals travel through the trigeminal nerve to specialized clusters of neurons in the trigeminal nerve nucleus

Ophthalmic Nerve (V1)

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

Branches of Ophthalmic Nerve

• Lacrimal Nerve: Supplies conjunctiva and skin covering the lateral part of the upper eyelid, responsible for tear production
• Frontal Nerve: consists of the Supra-orbital and Supratrochlear nerves and supplies the mucous membrane lining the frontal sinus, skin and conjunctiva covering the upper eyelid, skin over the forehead and scalp
• Nasociliary Nerve: Consists of sensory branches to the ciliary ganglion, the long ciliary nerves, posterior and anterior ethmoidal nerves, and the infratrochlear nerve

Pterygo-maxillary Fissure

• Lies between the posterior surface of the maxilla and the pterygoid process of the sphenoid bone
• It fills the triangular gap between the lower ends of the medial and lateral pterygoid plates
• The pterygomaxillary fissure (C) leads into it
• Is entered via the foramen rotundum & maxillary nerve

Maxillary Nerve (V2)

• Exits via the foramen rotundum and passes into the upper part of the pterygopalatine fossa
• Divides into the Zygomatic, Infraorbital, Posterior Superior Alveolar and Pterygopalatine nerves
• Consists of only sensory fibers
• Is the nerve of the maxillary process on the embryonic face
• Supplies the maxillary teeth and supporting structures, hard and soft palate, maxillary sinus, much of the nasal cavity, and skin overlying the middle part of face

Infra-Orbital Nerve

• The terminal branch of the maxillary nerve
• Enters the orbit at the inferior orbital fissure and runs in infra-orbital groove
• Exits the orbit at the infra-orbital foramen and runs onto the face
• Branches of the nerve include: Middle and Anterior superior alveolar nerves, and 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 of anterior maxillary teeth, & the skin of the cheek overlying the body of the maxilla

Posterior Superior Alveolar Nerve (C)

• Leaves the pterygopalatine fossa through the pterygomaxillary fissure
• Runs onto the tuberosity of the maxilla and supplies a branch to the buccal gingivae of maxillary molars
• Pierces bone to supply the maxillary sinus and maxillary molar teeth (3rd, 2nd, and palatal & disto-buccal root of 1st)

Alveolar Nerves (G)

• Arise from the intra-orbital nerve in the orbit
• Middle Alveolar Nerves supplies the maxillary premolars and the mesio-buccal root of the first maxillary molar
• Anterior Alveolar Nerves supplies the maxillary incisors & canine

Pterygopalatine Nerves

• Greater Palatine, Lesser Palatine, and Nasopalatine nerves

Greater Palatine Nerve

• Passes through the greater palatine canal and onto the hard palate at the greater palatine foramen.
• Gives off nasal branches in canal mucosa of lateral wall of nasal fossa
• On palate, it supplies much of the mucosa of the hard palate & palatal gingivae, except for the tissue around the incisive papilla

Lesser Palatine Nerve

• Passes through the greater palatine canal to the lesser palatine foramen
• Supplies the soft palate

Nasopalatine Nerve

• Enters the nasal cavity through the sphenopalatine foramen
• Supplies part of the nasal septum and passes through the incisive canal on the hard palate
• Supplies oral mucosa around the incisive papilla

Zygomatic Nerve

• Travels anteriorly to enter orbit via the inferior orbital fissure
• Divides into:
  • Zygomaticotemporal nerve: Sensory innervation to temple
  • Zygomaticofacial nerve: Emerges on the face through the zygomaticofacial foramen, perforating the orbicularis oculi; it innervates skin on the prominence of the cheeks

Summary of Key Points

• The trigeminal nerve is the 5th and largest cranial nerve, with three divisions: ophthalmic, maxillary, and mandibular
• The ophthalmic nerve enters the orbit through the superior orbital fissure (SOF)
• The maxillary nerve exits via the foramen rotundum (FR)
• The maxillary nerve supplies the maxillary teeth and supporting structures, hard and soft palate, maxillary sinus, and skin overlying the middle part of the face