Mandibular Nerve

Mand Ma ndib ibul ular ar Nerv Nerve e

Introduction •

Its the largest branch of trigeminal nerve. It is a mixed mixed nerve with two roots ots : large large sensor sensory y root oot smal smalll mot motor root oot  –  –

Introduction •

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The sensory root of the mandibular division originates at the inferior angle of  the trigeminal ganglion The motor arises in the motor cells located in the pons & medulla.

Course •

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The two roots emerge from the cranium separately through the foramen ovale , the motor root lying medial to sensory . They unite just outside the skull and form the main trunk of the Mandibular nerve.

Course •

This trunk lies in the infratemporal fossa and remains undivided for only 2 to 3 mm before it splits into a small anterior a large posterior division  –  –

Mandibular Nerve: Supply •

It supplies  –

the teeth and gums of the mandible,

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the skin of the temporal region,

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the auricule,

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the lower lip, the lower part of the face,

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muscles of mastication,

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it also supplies the mucous membrane of the anterior two-thirds of the tongue

Branches of Mandibular Nerve

Branches from Undivided Nerve •

NERVE TO MEDIAL PTERYGOID MUSCLE  –

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A branch of the motor root passes to innervate the medial pterygoid muscle. This branch passes without interruption to inervate the tensor veli palatini and the tensor tympani muscles.

NERVOUS SPINOSUS  –

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It arises outside the skull then passes into the middle cranial fossa to supply the dura & mastoid cells.

Anterior Division •

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Nerve to lateral pterygoid muscle:The pterygoid nerve enters the medial side of the lateral pterygoid muscle to provide its motor nerve supply. Nerve to masseter muscle: the masseter nerve passes above the lateral pterygoid to transverse the mandibular notch. Nerve to temporal muscles : its again divided in 2 branch  –

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Anterior deep temporal nerve - It supplies deep part of the temporal the anterior portion of the temporal muscle. Posterior deep temporal nerve- It passes upwards to the deep part of the temporal muscle.

Anterior Division •

Long buccal nerve- it passes downward, anteriorly and laterally between the two heads of lateral pterygoid muscle. It supplies  –

Buccinator muscle

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Mucous membrane of cheek

POSTERIOR DIVISION •

It is mainly sensory but also carries some motor components. This division extends downwards and medially and then branches into:  –

Auriculotemporal nerve

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Lingual nerve

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Inferior alveolar nerve

Auriculotemporal nerve •

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it arises by a medial and lateral root.

These roots embrance the middle meningeal artery and unite behind the artery just below the foramen spinosum. It passes with superficial temporal artery in its upward course and divides into numerous branches

Lingual nerve •

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As it decends , lies between the internal pterygoid muscle and the ramus of the mandible. The nerve lies parallel to the inferior alveolar nerve but medial and anterior to it . It then passes deep to reach the side of the base of the tongue. At the side of the tongue it lies below the lateral lingual sulcus. It has communications with the chorda tympani of facial nerve

Inferior alveolar nerve •

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It is the largest branch of the posterior division of mandibular part of the trigeminal nerve. It descends with the inferior alveolar artery, at first beneath the Pterygoideus plexus, Then between the sphenomandibular ligament and the ramus of the mandible to the mandibular foramen

Inferior alveolar nerve •

It then passes forward in the mandibular canal, beneath the teeth, as far as the mental foramen, where it divides into two terminal branches, incisive and mental. The branches of the inferior alveolar nerve are the mylohyoid, dental, incisive, and mental.  –

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Inferior alveolar nerve •

Mylohyoid nerve derived from the inferior alveolar just before it enters the mandibular foramen.  –

Reaching the under surface of the Mylohyoideus supplies this muscle Dental branches Supply the molar and premolar teeth.  –

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Inferior alveolar nerve •

Incisive branch supplies the canine and incisor teeth

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Mental nerve  –

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Emerges at the mental foramen, Divides into three branches; •

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one descends to the skin of the chin two ascend to the skin and mucous membrane of the

Otic Ganglion (ganglion oticum) •

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The otic ganglion is a small, ovalshaped, flattened ganglion of a reddish-gray color. Situated immediately below the foramen ovale. Lies on the medial surface of the mandibular nerve.

Otic Ganglion – Relation:  –

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Laterally, with the trunk of the mandibular nerve at the point where the motor and sensory roots join; Medially  with the cartilaginous part of the auditory tube  ,

Posteriorly  with the middle meningeal artery.  ,

Otic Ganglion – Roots & Branches:

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