Trigeminal Nerve 2

Question 1

Where does the mandibular division of the trigeminal nerve pass through as it leaves the trigeminal ganglion?

Answer 1

Foramen ovale

Question 2

Where does the mandibular division pass into after leaving the foramen ovale?

Answer 2

Infratemporal fossa

Question 3

What are the 6 boundaries of the infratemporal fossa?

Answer 3

1. Laterally
   - ramus of mandible
2. Medially
   - lateral pterygoid plate of sphenoid bone
3. Anteriorly
   - posterior aspect of maxilla
4. Posteriorly
   - tympanic plate, mastoid and styloid processes
5. Superiorly
   - infratemporal crest of sphenoid bone
6. Inferiorly
   - angle of the mandible

Question 4

What branches of the trigeminal nerve emerge from the main trunk of the mandibular division?

Answer 4

Sensory
1. Meningeal branch

Motor

2. Branch to tensor tympani
3. Branch to tensor veli palatini
4. Nerve to medial pterygoid

Question 5

List the nerves that emerge from the anterior trunk of the mandibular division

Answer 5

Sensory
1. Buccal nerve

Motor

2. Deep temporal nerves
3. Nerve to lateral pterygoid
4. Masseteric nerve

Question 6

List the nerves that emerge from the posterior trunk of the mandibular division

Answer 6

1. Auriculotemporal nerve
2. Lingual nerve
3. Inferior alveolar nerve

(All sensory except IA nerve is mixed)

Question 7

Where does the mandibular division supply sensation?

Answer 7

1. In the auricle (part of ear)
   - temple
   - mental region (chin)
2. Floor of the mouth
   - lower teeth and gums
3. Anterior 2/3 of the tongue (general somatic afferent) vía the lingual nerve

Question 8

What condition presents with terrible pain, usually in the mandibular division of the trigeminal nerve and occasionally in the maxillary division

Answer 8

Trigeminal neuralgia

Question 9

Describe the general sensory supply to the oral cavity

Answer 9

1. Buccal nerve to cheek and lateral gum
2. Inferior alveolar nerve and it’s branch, the incisive nerve to lower teeth
3. Inferior alveolar nerve to skin of chin and lower lip (both skin and mucous membranes) as the mental nerve

Question 10

What does the motor component of the inferior alveolar nerve supply?

Answer 10

1. The myohyloid

2. The anterior belly of the digastric muscle

Question 11

Describe the general sensory supply to the lower teeth and gums

Answer 11

Lower teeth:

• main trunk of IAN supplies 8-5
• incisive branch of IAN supplies 1-4

Lower gingivae:

• lingual nerve supplies palatal
• buccal nerve supplies posterior buccal
• mental nerve (from IAN) supplies anterior buccal

Question 12

What nerve provides special sensation (taste) to the anterior 2/3 of the tongue?

Answer 12

Chorda tympani

Question 13

Summarise the sensory supply to the anterior 2/3 of the tongue

Answer 13

1. General sensation via mandibular division of trigeminal nerve
2. Taste via facial nerve

Question 14

What muscles are supplied by the motor root of the mandibular division of CN V?

Answer 14

Muscles of mastication:

• temporalis
• masseter
• lateral pterygoid
• medial pterygoid

Muscle in the middle ear:
- tensor tympani

Others:

• tensor palati (Via medial pterygoid branch)
• mylohyoid and anterior belly of digastric (vía IAN)

Question 15

What is shingles?

Answer 15

Reactivation of the varicella zoster virus in the trigeminal ganglion

Question 16

What are signs of shingles?

Answer 16

Erythematous, vesicular, crusting rash and burning sensation

Question 17

What is Hutchison’s sign in relation to shingles?

Answer 17

Cutaneous involvement of the tip of the nose (external branch of nasociliary nerve)

Question 18

What are ocular complications of shingles?

Answer 18

1. Conjunctivitis
2. Keratitis (cornea)
3. Uveitis (anterior chamber of globe)