# Mandibular Nerve > Mandibular nerve V3 for MBBS Anatomy: foramen ovale, motor branches to mastication muscles, lingual and inferior alveolar nerves with dental notes. - Canonical URL: https://prepelephant.com/topics/mbbs/anatomy/mandibular-nerve - Exam / course: MBBS · Subject: Anatomy - Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team - First published: 2026-10-02 - Last updated: 2026-10-02 - How to cite: "Mandibular Nerve", PrepElephant, https://prepelephant.com/topics/mbbs/anatomy/mandibular-nerve ## Direct answer Largest of the three trigeminal divisions and the only mixed one, the mandibular nerve carries general sensation from the lower lip and chin, the lower teeth and gums, the anterior two-thirds of the tongue (common sensation), the temple, part of the ear and the temporomandibular joint, and motor supply to the four muscles of mastication plus tensor tympani, tensor veli palatini, mylohyoid and the anterior belly of digastric. Its large sensory and small motor roots unite just below the foramen ovale in the infratemporal fossa. Two of its branches dominate clinical practice: the inferior alveolar nerve endangered by third molar surgery, and the lingual nerve joined by the chorda tympani for taste and salivation. ## What you must remember - Beyond the foramen ovale the nerve gives a meningeal branch, the nervus spinosum, which re-enters the middle cranial fossa through the foramen spinosum with the middle meningeal artery. - The nerve to the medial pterygoid also supplies tensor veli palatini and tensor tympani — three muscles from one small branch, a favourite MCQ. - Motor branches: masseteric, deep temporal (to temporalis), nerves to lateral and medial pterygoid; sensory branches: buccal, auriculotemporal, lingual, inferior alveolar. - The buccal nerve is purely sensory to the cheek and buccal mucosa of the lower gums — buccinator itself is supplied by the facial nerve. - The auriculotemporal nerve encircles the middle meningeal artery, supplies the TMJ and temple skin, and carries postganglionic parasympathetic fibres from the otic ganglion to the parotid gland. - The lingual nerve is joined by the chorda tympani (taste from the anterior two-thirds of the tongue plus parasympathetic drive to the submandibular and sublingual glands via the submandibular ganglion). - The inferior alveolar nerve enters the mandibular foramen, ends as the mental nerve emerging from the mental foramen, and gives the mylohyoid nerve before entering the canal. ## Walking through third molar surgery and the nerves at risk A twenty-four-year-old is listed for surgical removal of an impacted lower third molar; the consent conversation is entirely V3 anatomy. The inferior alveolar nerve runs in the mandibular canal just below the roots, and a panoramic radiograph showing the canal intersecting the roots predicts the risk of numbness of the lower lip and chin on that side via the mental nerve. The lingual nerve lies against the inner aspect of the mandible near the third molar, and lingual paraesthesia with disturbed taste after surgery localises precisely to it. These two deficits — lip and tongue numbness — must be explained separately to the patient because they implicate two different branches of the same division. Now work the technique itself. An inferior alveolar block deposits anaesthetic at the mandibular foramen on the medial side of the ramus; the Gow-Gates technique instead targets the nerve at the neck of the mandibular condyle at a higher level, a viva favourite because it also catches the lingual and buccal nerves with one injection. The buccal nerve is blocked separately for the mucoperiosteum, and the auriculotemporal supply to the joint explains temporomandibular discomfort after long procedures with the mouth open. Post-operatively, documented numbness at review is mapped on the lip, chin and tongue to decide whether the injury is neuropraxia or axonotmesis, guiding referral per current maxillofacial practice. ## Where students slip The classic muddle is the buccal nerve versus the nerve to buccinator: the buccal branch of V3 is sensory, while buccinator is a facial-expression muscle supplied by the facial nerve — a pairing examiners raise in almost every head and neck viva. Second, the auriculotemporal nerve is remembered for the temple but forgotten as the carrier of postganglionic secretomotor fibres from the otic ganglion to the parotid, which is also why it mediates Frey's syndrome after parotidectomy. Third, the chorda tympani is said to join "the lingual nerve" without the detail that it carries taste and parasympathetic fibres but no general sensation — general sensation of the anterior two-thirds travels in the lingual nerve proper from its V3 origin. ## Frequently asked questions ### Which branch of V3 re-enters the cranial cavity? The nervus spinosum, a meningeal branch that passes back through the foramen spinosum with the middle meningeal artery. ### Which nerve is at risk of numbness after lower third molar extraction? The inferior alveolar nerve for the lower lip and chin, and the lingual nerve for the anterior two-thirds of the tongue. ### What does the chorda tympani contribute to the lingual nerve? Taste from the anterior two-thirds of the tongue and preganglionic parasympathetic fibres for the submandibular and sublingual glands. ### Which muscles does the nerve to medial pterygoid supply? Medial pterygoid itself, tensor veli palatini and tensor tympani. ### How does the parotid gland receive its parasympathetic supply through V3? Preganglionic fibres from the glossopharyngeal nerve relay in the otic ganglion, and the postganglionic fibres travel with the auriculotemporal nerve to the gland. ### What is tested by the mental nerve? Sensation of the chin and lower lip, examined at the mental foramen roughly between the apices of the lower premolars.