Cranial Nerve V: Trigeminal Nerve Branches

Trigeminal Ganglion

*AKA Gasserian Ganglion *Located on anterior surface of petrous portion of temporal bone *No preganglionic parasympathetic fibers, but many postganglionic parasympathetic fibers travel w/ Trigeminal Nerve branches

V1: Ophthalmic Nerve

*Afferent *Conjunctiva, cornea, eyeball, orbit, forehead, ethmoid & frontal sinuses, part of dura mater *Carries info to brain through superior orbital fissure 3 Branches Frontal Nasociliary Lacrimal

V2: Maxillary Nerve Zygomatic Nerve

*Afferent/sensory *Formed by merger of Zygomaticofacial & Zygomaticotemporal nerves *Conveys postganglionic parasympathetic fibers for lacrimal gland & lacrimal nerve Location *Runs posteriorly along lateral orbit floor *Enters pterygopalatine fossa through inferior orbital fissure *Joins V2

V2: Maxillary Nerve Infraorbital Nerve

*Afferent/sensory *Formed by merger of cutaneous branches from upper lip, medial cheek, lower eyelid, side of nose Location *Runs through IO foramen *Travels posteriorly through IO canal & groove *Through inferior orbital fissure through pterygopalatine fossa *Joins ASA nerve

V2: Maxillary Nerve Nasopalatine Nerve

*Afferent/sensory for: Anterior hard palate Lingual gingiva of mx anteriors Nasal septal tissues Communicates w/ GP nerve ling of canines Location *Originates in mucosa of anterior palate *Lingual to mx anterior teeth *Right & left NP nerves enter incisive canal through incisive foramen beneath incisive papilla *Travels along nasal septum

V3: Mandibular Nerve Posterior Branch: Lingual Nerve

*Afferent/sensory for: Body of tongue Floor of mouth Lingual gingiva of md teeth *Communicates with submandibular ganglion Location *Travels along lateral surface of tongue *Passes laterally under duct of submandibular gland *Runs between medial pterygoid muscle & mandible *Anterior & medial to IA nerve *Ascends to join posterior trunk of V3

V3: Mandibular Nerve Posterior Branch: Mental Nerve

*Afferent/sensory for: Chin Lower lip Labial mucosa of md premolars & anteriors Location *Enters mental foramen between apices of premolars *Merges w/ incisive nerve to form IA nerve in mandibular canal

V3: Mandibular Nerve Posterior Branch: Auriculotemporal Nerve

*Afferent/sensory for: External ear Scalp *Carries postganglionic parasympathetic fibers to parotid salivary gland that arise from CN IV (petrosal branch of hypoglossal nerve) after relaying in Otic Ganglion *Communicates w/ facial nerve near ear Location *Runs deep in lateral pterygoid muscle & neck of mandible; encircles middle meningeal artery *Joins posterior trunk of V3

V3: Mandibular Nerve Posterior Branch: Incisive Nerve

*Afferent/sensory for: Mandibular premolars & anterior teeth Location *Forms plexus by joining dental & interdental branches from md premolars and anteriors *Merges w/ mental nerve to form IA nerve in mandibular canal *Crossover common with contralateral incisive nerve

V3: Mandibular Nerve Posterior Branch: Inferior Alveolar Nerve

*Afferent/sensory for: Mandibular teeth Location *Formed by merger of incisive & mental nerves *Travels posteriorly through mandibular canal *Forms plexus by joining dental, interdental, & interradicular branches from md posterior teeth *Exits mandible through mandibular foramen *Travels lateral to medial pterygoid muscle in pterygomandibular space *Joins posterior trunk of V3 *Is bifid in some patients (double md canal on x-ray)

V2: Maxillary Nerve Anterior Superior Alveolar Nerve

*Afferent/sensory for: Mx central incisors Lateral incisors Canines Area gingiva Plexus formed by merger of dental & interdental branches Location *Ascends along anterior wall of mx sinus *Joins IO nerve in IO canal *Often crosses midline

V2: Maxillary Nerve Posterior Superior Alveolar Nerve

*Afferent/sensory for: Mx molars (except B root of 1st) Area periodontium Mx sinus mucous membranes Buccal gingiva (external branch) Plexus formed by merger of dental & interdental and interradicular branches Location *Internal branches exit PSA foramina on mx tuberosity & joins external branches *Joins IO or Maxillary nerve in pterygopalatine fossa

V2: Maxillary Nerve Middle Superior Alveolar Nerve

*Afferent/sensory for: Mx premolars Mesiobuccal root of mx 1st molar Area periodontium Overlying buccal gingiva Plexus formed by merger of dental & interdental and interradicular branches Location *Ascends to join IO in lateral wall of mx sinus *MSA not present in all patients

V2: Maxillary Nerve Greater Palatine Nerve

*Afferent/sensory for: Posterior hard palate Posterior lingual gingiva Communicates anteriorly w/ NP ling to canines Location *Between mucoperiosteum & bone of anterior hard palate *Enters posteriorly through GP foramen near mx 2nd/ 3rd molars *Travels through pterygopalatine canal toward Mx nerve in pterygopalatine fossa; joins nasal branches

V3: Mandibular Nerve Anterior Branch: Long Buccal

*Afferent/sensory for: Skin of cheek Buccal mucous membranes Buccal gingiva of md posterior teeth Location *Travels posteriorly in cheek *Deep in masseter muscle *At level of occlusal plane of last md molar *Crosses in front of anterior border of ramus *Goes between two heads of lateral pterygoid to join anterior trunk of V3 ***Do not confuse with the buccal nerve branch of the facial nerve

V2: Maxillary Nerve Lesser Palatine Nerve

*Afferent/sensory for: Soft palate Palatine tonsils Location *Enters posteriorly through LP foramen in palatine bone near junction w/ pterygoid process of sphenoid bone *Joins GP nerve in pterygopalatine canal *Travels through pterygopalatine canal toward Mx nerve in pterygopalatine fossa; joins nasal branches

V1: Ophthalmic Nerve Lacrimal Nerve

*Carries sensory info for: lateral portion of upper eyelid, conjunctiva, lacrimal gland Other functions: *Delivers postganglionic parasympathetic nerves to lacrimal gland *Responsible for tear production Location: *Runs posterior along lateral roof of orbit *Joins frontal & nasociliary nerves to form V1

V2: Maxillary Nerve

*Carries sensory info for: maxilla overlying skin maxillary sinus nasal cavity Palate Nasopharynx portion of dura mater *Location: Nerve trunk formed in pterygopalatine fossa V2: Maxillary Nerve Branches: 1. Zygomatic 2. Infraorbital 3. Anterior Superior Alveolar 4. Middle Superior Alveolar 5. Posterior Superior Alveolar 6. Greater & Lesser Palatine 7. Nasopalatine

V3: Mandibular Nerve Posterior Branch: Mylohyoid Nerve

*Efferent/motor for: Mylohyoid muscle Anterior belly of digastric Afferent/sensory for: Sometimes for md 1st molar Location *Small branch forming after IA nerve exits mandibular foramen *Pierces sphenomandibular ligament *Runs anteriorly & inferiorly in mylohyoid groove onto inferior surface of mylohyoid muscle

V1: Ophthalmic Nerve Nasociliary Nerve

*Formed by convergence of: 1. Infratrochlear Nerve: from skin of medial eyelids & side of nose 2. Ciliary Nerves: to and from eyeball 3. Anterior Ethmoidal Nerve: from nasal cavity & paranasal sinuses; formed by external & internal nasal nerves

Trigeminal Nerve Overview

*Largest cranial nerve *Sensory and motor components *Most important cranial nerve to RDH *Efferent: muscles of mastication & some cranial muscles *Afferent: teeth, tongue, oral cavity, most skin of face & head Sensory root divisions V1 Ophthalmic: superior orbital fissure V2 Maxillary: foramen rotundum V3 Mandibular: foramen ovale Motor root Accompanies mandibular nerve of sensory root through foramen ovale of sphenoid bone

V3: Mandibular Nerve

*Largest division of trigeminal nerve *Formed by merger of small anterior trunk & large posterior trunk *Motor & sensory (Afferent & Efferent) Location *Joins V1 & V2 in infratemporal fossa to form trigeminal ganglion *Travels through foramen ovale *Anterior Trunk Branches Muscular Buccal *Posterior Trunk Branches Auriculotemporal Lingual Inferior Alveolar Mental Incisive Mylohyoid

V1: Ophthalmic Nerve Frontal Nerve

*Located in orbit *Composed of merger of Supraorbital nerve from forehead and anterior scalp & Supratrochlear nerve from bridge of nose and medial part of upper eyelid and forehead *Runs along roof of orbit *Joins lacrimal & nasociliary nerves to form V1

V3: Mandibular Nerve Anterior Branch: Muscular Branches

1. Deep temporal nerves 2. Lateral pterygoid nerve 3. Masseteric nerve Efferent/motor for: *Temporalis *Lateral pterygoid *Masseter (Has sensory branch to TMJ)

V3: Mandibular Nerve *Meningeal Branches *Muscular Branches

Originating from Undivided V3: 1. Meningeal Branches *Afferent/sensory for: *Part of dura mater 2. Muscular Branches *Efferent motor for: Medial pterygoid Tensor tympani Tensor veli palatini