Trigeminal Nerve - Mandibular Branch (V3) PDF

Trigeminal Nerve – Mandibular Branch (V3) Gulshana Choudhury Module: Oral and Dental Sciences GDC Learning Outcomes 1.1.5 Describe relevant and appropriate dental, oral, craniofacial and general anatomy and explain their application to patient management Intended Learning Outcomes Describe th...

Trigeminal Nerve – Mandibular Branch (V3) Gulshana Choudhury Module: Oral and Dental Sciences GDC Learning Outcomes 1.1.5 Describe relevant and appropriate dental, oral, craniofacial and general anatomy and explain their application to patient management Intended Learning Outcomes Describe the function of the mandibular branch of the trigeminal nerve (CN V3) Outline the anatomical regions it supplies Explain the relevance of the mandibular branch of the trigeminal nerve to dentistry Trigeminal Nerve The largest cranial nerve Knowledge of this nerve is very important for dental professionals 3 Divisions Ophthalmic (V1) Maxillary (V2) Mandibular (V3) Mandibular Branch (V3) Largest of the 3 divisions of the Trigeminal nerve Leaves skull at Foramen Ovale Contains both sensory and motor fibres What is supplied? Sensory Motor 1. Mandibular teeth & 1. Muscles of mastication supporting structures 2. Mylohyoid 2. Mucosa of anterior 2/3 3. Anterior belly of tongue & floor of mouth digastric 3. Skin of lower face 4. Tensor veli palatini 4. Parts of temporal region and 5. Tensor tympani outer ear Anatomical Course Shortly after it leaves skull it divides into a Small Anterior trunk Larger Posterior trunk Branches from nerve before division: 1. Meningeal branch 2. Nerve to medial pterygoid muscle Branches of V3 Anterior Trunk Branches 1. Masseteric nerve 2. Deep temporal nerves 3. Nerve to lateral pterygoid muscle 4. Long buccal nerve Posterior Trunk Branches 1. Auriculotemporal nerve 2. Lingual nerve 3. Inferior alveolar nerve Muscles of mastication Medial pterygoid nerve: (Motor) Enters deep surface of the muscle Also supplies tensor tympani & tensor veli palatini Action: Elevates the jaw Muscles of mastication Masseter Masseteric nerve is first branch of anterior trunk Crosses to masseter between coronoid process & condyle of mandible Gives an articular branch to TMJ Elevates the mandible (mouth closing) Temporalis Anterior & deep temporal nerves Elevates the mandible (mouth closing) Lateral pterygoid Nerve to lateral pterygoid may run part way with long buccal Long Buccal Nerve The only sensory branch of the anterior trunk Emerges between heads of lateral pterygoid & runs on lateral surface of buccinator muscle in cheek, close to retromolar fossa of mandible Gives branches to skin of cheek Pierces buccinator to supply buccal sulcus & buccal gingivae of mandibular molars & premolars Auriculotemporal Nerve (A) First branch of posterior trunk Sensory Autonomic to parotid gland due to fibres from otic ganglion 2 roots unite & run backwards under lateral pterygoid muscle to lie between condyle & sphenomandibular ligament Emerges between TMJ & external auditory meatus Finally ascends on side of head Lingual Nerve 2nd branch of posterior trunk Sensory Unites with chorda tympani branch of facial nerve & receives parasympathetic fibres for submandibular & sublingual glands Emerges from under lateral pterygoid muscle & curves downwards & forwards between ramus of mandible & medial pterygoid muscle i.e. the pterygomandibular space Lies anterior to but deeper than inferior alveolar nerve Then passes towards floor of mouth Lingual Nerve Twists around the submandibular duct Enters tongue behind sublingual salivary gland Supplies: 1.Mucosa covering anterior 2/3 dorsum of tongue 2.Under surface of tongue 3.Floor of mouth 4.Lingual gingivae of mandibular teeth Inferior Alveolar (dental) Nerve Sensory and motor Descends deep to lateral pterygoid muscle behind lingual nerve Enters Mandibular Foramen Travels in inferior dental or mandibular canal in mandible Divides near premolars into mental nerve & incisive nerve Mental nerve emerges at mental foramen Incisive nerve runs anteriorly Pathway of Inferior Alveolar Nerve Branches of Inferior Alveolar Nerve Mylohyoid nerve (B) Given off just before mandibular foramen Runs in mylohyoid groove to supply mylohyoid muscle & anterior belly of digastric (motor) It depresses the mandible (on a fixed hyoid) or elevates the hyoid in swallowing Branches of Inferior Alveolar Nerve Inferior Alveolar Nerve Supplies mandibular molars & premolars & supporting structures (e.g. gingivae) Mental nerve: Supplies skin of chin & lower lip & labial gingivae of anterior mandibular teeth Incisive nerve: Innervates mandibular incisors & canines ID Nerve Block Summary The trigeminal nerve is the the largest and 5th cranial nerve The trigeminal nerve has three divisions; ophthalmic, maxillary and mandibular The mandibular nerve leaves via foramen ovale The mandibular branch of the trigeminal nerve supplies the mandibular teeth and supporting structures, mucosa of the anterior 2/3 tongue and floor of mouth and muscles of mastication