Cranial nerve V maxillary & mandibular division

Question 1

What foramen do the branches of the trigeminal nerve pass through?

Answer 1

V1 superior orbital fissure
V2 foramen rotundum
V3 foramen obale

Question 2

How does the trigeminal nerve reach the areas of the face?

Answer 2

Supraorbital foramen: CNV1 Supraorbital nerve
Infraorbital foramen: CNV2 Infraorbital nerve
Mental foramen: CNV3 mental nerve

Question 3

What does the general somatic afferent fibres of the trigeminal nerve supply?

Answer 3

Face, anterior half of the scalp, mucous membranes of oral, nasal cavities and paranasal sinuses, Nasopharynx, part of ear and external acoustic meatus, part of tympanic membrane, orbital contents and conjunctiva, dura mater in anterior and middle cranial fossa

Question 4

What are nuclei?

Answer 4

Grey mater - a collection of cell bodies located in the CNS.

Question 5

What nuclei are the different fibres of trigeminal nerve in? (sensory)

Answer 5

Proprioceptive fibres in mesencephalic nucleus
Fibres of touch and pressure in chief sensory nucleus (main/principal)
Fibres of pain and temperature in the spinal trigeminal nucleus

Question 6

Describe the trigeminothalamic pathway

Answer 6

Mesencephalic nucleus has the cell bodies of a 1st order neurone (only nucleus to do this). From this it will synapse with the 2nd order neurone. This will decussate to reach the ventral posterior nucleus of the thalamus. From this the third order neurones whose cell bodies are in the thalamus will reach the cerebral cortex. If sensory it will reach the post central gyrus of the brain.

Question 7

Describe the sneeze and cough reflexes

Answer 7

Perceived by the sensory fibres of the trigeminal nerve (trigeminal sensory nucleus) as they will innervate the mucosa in the nasal cavity. From here fibres will enter. They will synapse with an interneuron which will synapse with CNIX, CNX, CNXI as well as fibres of the phrenic nerve that will go to the diaphragm and nerves to abdominal muscles to produce a cough.

Question 8

Describe the jaw jerk reflex

Answer 8

Hammer to the mandible will stimulate proprioceptors located in the masseter and temporalis. Information will go to trigeminal mesencephalic nucleus. From here it will synapse with the trigeminal motor nucleus with LMNs. These will innervate through CNV3, the temporalis and masseter to jerk the jaw.

Question 9

General course of CNV2

Answer 9

Originates in trigeminal ganglion. Exits middle cranial fossa through foramen rotundum, getting into the pterygopalatine fossa. Then goes anteriorly and the Infraorbital nerve will exit.

Question 10

What are the branches of the maxillary nerve

Answer 10

Meningeal branch
Zygomatic nerve
Ganglionic branches to sensory root of pterygopalatine ganglion
Posterior superior alveolar nerve
Infraorbital nerve
Greater and lesser palatine nerves
Posterior superior lateral nasal branches
Nasopalatine nerve
Pharyngeal nerve

Question 11

What branches does the zygomatic nerve give off?

Answer 11

Zygomaticofacial branch
Zygomaticotemporal branch
Communicating branch to lacrimal nerve

Question 12

Where do the greater and lesser palatine nerves run?

Answer 12

Run inferiorly from the pterygopalatine ganglion, through the palatine canal and exit via the greater and lesser palatine foramina.

Question 13

What do the greater and lesser palatine nerves innervate?

Answer 13

Mucosa and glands of the hard palate and the adjacent gingiva. Lesser palatine nerve also supply the soft palate.

Question 14

What does the nasopalatine nerve innervate?

Answer 14

Medial wall of the nasal cavity
Mucosa, gingiva and glands near to the incisors

Question 15

How does the nasopalatine nerve travel?

Answer 15

Travels inferiorly through the nasal septum and through the incisive canal and fossa, getting into the palate.

Question 16

What does the posterior superior alveolar nerve innervate?

Answer 16

Maxillary sinus
Molar teeth and it’s adjacent buccal gingivae

Question 17

How does the posterior superior alveolar nerve travel?

Answer 17

Branch at the pterygopalatine fossa. Exits through the pterygomaxillary fissure. Enters the infratemporal fossa. Travels lateral and inferiorly to enter the posterior surface of the maxilla, via a small foramen.

Question 18

What does the Infraorbital nerve innervate?

Answer 18

Upper teeth
Middle superior alveolar nerve also innervates the maxillary sinus

Question 19

How does the Infraorbital nerve travel?

Answer 19

Leaves pterygopalatine fossa through the inferior orbital fissure. Runs through the Infraorbital groove in the orbital floor and travels anteriorly in the Infraorbital canal. Branches into the middle superior and anterior superior alveolar nerves.

Question 20

What is the superior alveolar dental plexus?

Answer 20

Anterior, middle and posterior superior alveolar nerves

Question 21

What is the nerve of the pterygoid canal (vidian)?

Answer 21

Originates in the middle cranial fossa.
Forms when the greater petrosal nerve of CNVII and deep petrosal nerve of internal carotid plexus meet.

Question 22

The nerve of the pterygoid canal goes into the pterygopalatine fossa where it joins the pterygopalatine ganglion and has branches carrying parasympathetic fibres. Which branches carries these fibres?

Answer 22

Zygomatic nerve, greater and lesser palatine nerves, nasopalatine nerve

Question 23

Which nerves does the mandibular nerve give off before it branches into anterior and posterior divisions?

Answer 23

Nervous spinosus to enter the foramen spinosum
Nerve to medial pterygoid

Question 24

Each division gives 4 branches. What are the branches of the anterior division of mandibular nerve, and are they motor or sensory?

Answer 24

Deep temporal
Nerve to masseter
Nerve to lateral pterygoid
Buccal nerve
ALL MOTOR

Question 25

Each division gives 4 branches. What are the branches of the posterior division of mandibular nerve, and are they motor or sensory?

Answer 25

Auriculotemporal nerve
Lingual nerve
Inferior alveolar nerve
Nerve to mylohyoid (ONLY MOTOR POSTERIOR BRANCH, REST ARE SENSORY)

Question 26

What sensory areas does the mandibular nerve innervate?

Answer 26

Skin of lower face, teeth, lower lip, anterior part of external ear, part of external acoustic meatus.

Question 27

What needs to be blocked when doing a restoration?

Answer 27

When doing a restoration, must focus on the block of the nerve itself. Can be superficial, middle or deep. Deep cavities will be closer to the pulp.

Question 28

What needs to be blocked when doing an extraction?

Answer 28

When doing an extraction, the tooth is being separated from the gingiva, so not just this needs to be blocked but also the palatine nerve and anterior, middle and posterior superior alveolar nerves (same in mandible with mandibular branches). Lingual nerve innervates all of the lingual surfaces of gingiva, buccal all buccal surfaces and mental all mental surfaces.

Question 29

Standard IANB procedure

Answer 29

Thumb placed at deepest concavity of the anterior ascending ramus.
Site of injection is located midway between midpoint of the thumb and the pterygomandibular raphe.
Needle is advanced 15-25mm parallel to the occlusal plane or the contralateral premolars until there is bone contact.