Nerous system

• The Gulshana Choudhury presentation covers the maxillary branch (V2) of the trigeminal nerve, within the context of Oral and Dental Sciences.
• It references GDC (General Dental Council) learning outcomes regarding dental, oral, craniofacial, and general anatomy and its application to patient management.
• The material intends to describe the function and anatomical regions supplied by the maxillary branch of the trigeminal nerve (CN V), and explain its relevance to dentistry.
• The trigeminal nerve is the largest cranial nerve, knowledge of which is very important for dental professionals.
• It has 3 divisions: ophthalmic, maxillary, and mandibular.

Nerve Roots

• Each nerve is a short trunk composed of two closely adapted roots:
• A thinner motor root
• A thicker sensory root
• The trigeminal nerves function in sensing facial touch, pain, temperature, and controls muscles used for chewing.
• The trigeminal nerve is distinct from the facial nerve (cranial nerve VII) which controls other facial movements.

Areas Supplied

• Sensory (afferent) root supplies:
• Maxillary dentition and mandibular dentition
• Skin of face and head
• Oral and nasal mucosa
• Air sinuses
• Meninges
• Motor (efferent) root supplies:
• Muscles of mastication (masseter, temporalis, medial and lateral pterygoid, and anterior belly of digastric)
• Mylohyoid
• Tensor tympani
• Tensor veli palatini
• The trigeminal nerve arises from the pons.
• Its nuclei include one motor nucleus and three sensory nuclei.

Pathway

• From the middle cranial fossa, the three branches exit at:
• The ophthalmic branch enters orbit through the superior orbital fissure (SOF).
• The maxillary branch leaves via foramen rotundum (FR) into pterygopalatine fossa, then through the infra-orbital canal to the infra-orbital foramen.
• The mandibular branch leaves via foramen ovale (FO).
• The three divisions of the trigeminal nerve come together in the Gasserion ganglion.
• Within the brain stem, the signals travelling through the trigeminal nerve reach specialised clusters of neurones called the trigeminal nerve nucleus.

Ophthalmic Nerve (V1)

• The ophthalmic nerve (V1) is the first division of the sensory root of the trigeminal nerve.
• It carries information to the brain via the superior orbital fissure of the sphenoid bone.
• In addition to the ophthalmic nerve, cranial nerves II, IV, and VI also traverse the superior orbital fissure.
• It is the smallest division, serving as an afferent nerve for the conjunctiva, cornea, eyeball, orbit, forehead, ethmoidal and frontal sinuses, and portions of the dura mater.
• Branches include the lacrimal, frontal, and nasociliary nerves.
• The lacrimal nerve supplies the conjunctiva and skin covering the lateral part of upper eyelid and is responsible for tear production.
• The frontal nerve branches into the supra-orbital and supratrochlear nerves.
• It supplies the mucous membrane lining the frontal sinus, skin and conjunctiva covering the upper eyelid, and skin over the forehead and scalp.
• The nasociliary nerve's sensory branches reach to the ciliary ganglion and include the long ciliary, posterior ethmoidal, anterior ethmoidal, and infratrochlear nerves.

Pterygo-Maxillary Fissure

• The 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) leades into the it.
• Entered by the foramen rotundum and the maxillary nerve.

Maxillary Nerve (V2)

• The maxillary nerve (V2) is composed of only sensory fibres.
• It also supplies nerve of maxillary process on embryonic face
• The maxillary branch exits via the foramen rotundum and passes into the upper part of the pterygopalatine fossa where it divides into zygomatic, infraorbital, posterior superior alveolar, and pterygopalatine branches.
• It supplies the maxillary teeth and supporting structures, hard and soft palate, maxillary sinus, much of nasal cavity, and skin overlying middle part of face.
• Its terminal branch is the infra-orbital nerve.
• The infra-orbital nerve enters orbit at the inferior orbital fissure and runs in the infra-orbital groove.
• It leaves orbit at the infra-orbital foramen to run onto the face.
• Branches include the middle superior alveolar nerve, anterior superior alveolar nerve, and terminal branches that are palpebral, nasal and labial.
• The infraorbital nerve emerges onto the face through the infra orbital foramen and divides into the three terminal branches.
• The Palpebral nerve supplies skin of lower eyelid.
• The Nasal nerve supplies skin of side of nose.
• The Labial nerve supplies skin and oral mucosa of upper lip, labial gingivae of anterior maxillary teeth, and skin of cheek overlying the body of the maxilla.

Posterior Superior Alveolar

• The posterior superior alveolar nerve leaves pterygopalatine fossa through pterygo-maxillary fissure.
• the posterior superior alveolar nerve runs onto tuberosity of maxilla & sends branch to supply buccal gingivae of maxillary molars.
• This Pierces bone to supply maxillary sinus & maxillary molar teeth (3rd, 2nd & palatal & disto-buccal root of 1st).

Middle and anterior superior alveolar

• Arise from infra-orbital nerve in the orbit.
• The middle portion supplies the maxillary premolars & the mesio-buccal root of the first maxillary molar.
• The anterior portion supplies the maxillary incisors & canine.

Pterygopalatine Nerves

• Composed to the:
• Greater palatine nerve
• Lesser palatine nerve
• Nasopalatine nerve
• The greater palatine nerve passes through greater palatine canal & onto hard palate at the greater palatine foramen (4).
• It gives off nasal branches in canal to the mucosa of lateral wall of nasal fossa.
• On palate, it supplies much of mucosa of the hard palate & palatal gingivae, except round incisive papilla.
• The lesser palatine nerve passes through greater palatine canal to lesser palatine foramen (5).
• And supplies soft palate.
• The nasopalatine nerve enters nasal cavity through sphenopalatine foramen.
• And supplies part of nasal septum
• Passes through incisive canal on hard palate.
• The nasopalatine supplies oral mucosa around incisive papilla.

Zygomatic Nerve

• Travels anteriorly to enter orbit via inferior orbital fissure
• Divides into:
• Zygomaticotemporal nerve – Sensory innervation to temple
• Zygomaticofacial nerve:
• Emerges on the face through zygomaticofacial foramen, perforating orbicularis oculi.
• Innervates skin on the prominence of the cheeks.
• The trigeminal nerve is the 5th and largest cranial nerve with three divisions: ophthalmic, maxillary and mandibular
• The ophthalmic nerve enters orbit through the superior orbital fissure (SOF).
• The maxillary nerve leaves via foramen rotundum. supplies maxillary teeth and supporting structures, hard and soft palate, maxillary sinus and skin overlying middle part of face
• The maxillary nerve supplies the maxillary teeth and supporting structures, hard and soft palate, maxillary sinus and skin overlying middle part of face.