Trigeminal Nerve (Mandibular

Branch)Ahmad Fais (1090312)

Aimi Amalina (1091312)

Anatomy of Mandibular

Division of Trigeminal Nerve

Descriptio

n

• The largest of the 3 divisions• Has motor and sensory functions

Source

• Created by a large sensory root & a small motor root• Unite just after passing through the foramen ovale to

enter infratemporal fossa

Course• Immediately give rise to a meningeal branch then

divides into anterior and posterior divisions

Mandibular Division of Trigeminal Nerve

Anterior

Smaller

Mainly motor & 1 sensory branch (Buccal)

Masseteric, Anterior & posterior deep temporal, Medial pterygoid, Lateral

pterygoid, Buccal

Posterior

Larger

Mainly sensory & 1 motor branch (nerve to

mylohyoid)

Auriculotemporal, Lingual, Inferior alveolar,

Mylohyoid nerve

• Passes laterally superior to lateral ptrygoid nerve• Lies anteior to TMJ & posterior to tendon of

temporalis muscle• Crosses the mandibular notch with masseteric artery

to innervate messeter muscle• Also provides a small branch to TMJ

Masseteric

• Pass superior to lateral pterygoid muscle between skull & temporalis muscle while passing deep to the muscle to innervate it

Anterior & Posterior deep temporal

Anterior Division of Mandibular Nerve

• Enters the deep surface of the muscleMedial pterygoid

• Passes into deep surface of muscle• Often arises from the buccal nerve

Lateral pterygoid

• Passes anteriorly between 2 heads of lateral pterygoid muscle• Descends inferior along the lower part of temporalis muscle to appear

from deep to the anterior border of the masseter muscle• Supplies skin over buccinator muscle before passing through it to

supply mucous membrane lining its inner surface & gingiva along the mandibular molars

Buccal

Anterior Division of Mandibular Nerve

• Normally arises by 2 roots between the middle meningeal artery passes• Runs posteriorly just inferior to lateral pterygoid and continues to medial side of the neck of the mandible

• Then it turns superiorly with the superficial temporal vessels between the auricle and condyle of the mandible deep to the parotid gland

• On exiting the parotid gland, it ascends over the zygomatic arch and divides into superficial temporal branches

Auriculotemporal

• Lies inferior to lateral pterygoid and medial and anterior to the inferior alveolar nerve

• The chorda tympani nerve also joins the posterior part• The lingual nerve passes between the medial pterygoid and the ramus of the mandible to pass obliquely to enter the oral cavity bounded by the superior pharyngeal constrictor muscle, medial pterygoid and the mandible

• Supplies the mucous membrane of the anterior 2/3 of the tongue and gingiva on the lingual side of the mandibular teeth

Lingual

Posterior Division of Mandibular Nerve

• The largest branch of the mandibular division• Descends following the inferior alveolar artery inferior to the

lateral pterygoid and finally between the sphenomandibular ligament and the ramus of the mandible until it enters the mandibular foramen

• Innervates all mandibular teeth and the gingiva from the premolars anteriorly to the midline via the mental branch

Inferior Alveolar

• Branches from the inferior alveolar nerve immediately before it enters the mandibular foramen

• Descends in a groove on the deep side of the ramus of the mandible until it reaches the superficial surface of the mylohyoid

• Supplies the mylohyoid and the anterior belly of the digastric muscle

Mylohyoid

Posterior Division of Mandibular Nerve

Clinical Examination

Test the sensory branches by lightly touching the face

with a piece of cotton wool followed by a blunt pin (pain) along the jawline

Test the motor supply: Ask the patient to clench their teeth together, observing

and feeling the bulk of the masseter and temporalis muscles.

Ask the patient to then open their mouth against resistance.

Perform the jaw jerk on the patient by placing left index finger on their chin and striking it with a tendon hammer. This should cause slight protrusion of the jaw

Clinical Examination

Abnormalities Associated with

Mandibular Nerve

Lesions:

Brain lesions, Facial bone fractures/Trauma Abnormal findings:

Facial hypoasthesia or paraesthesia Upon mouth opening:

Mandible deviates toward the paralyzed side when there is unilateral paralysis of the masticatory muscles

mandible droops and no jaw movement is possible with bilateral paralysis Abnormal reflexes

Absent corneal reflex Jaw jerk:

Associated with upper motor neuron lesions : hyperactive or repeating reflex (clonus)

Associated with nuclear or infranuclear lesions, the reflex is absent Weakness and wasting of masticatory muscles

Abnormalities Associated with Mandibular Nerve

Thank You