2. Topographic anatomy of the maxillofacial region: nerve supply, blood supply and lymph supply, facial bones forming the skeleton, muscles / mimic, chewing, etc.

Question 1

Cranial nerve responsible for the sense of smell

Answer 1

• The olfactory nerve (CN I)
• Information to the brain by passing through the cribiform plate of the ethmoid bone.

Question 2

How the optic nerve (CN II) functions and what happens if it is damaged

Answer 2

• Transmits visual information to the brain.
• Damage=> homonymous hemianopsia (loss of vision on one side) or bitemporal hemianopsia (loss of peripheral vision)

Question 3

Cranial nerves that control eye movement, and how they are tested

Answer 3

• Oculomotor (CN III), trochlear (CN IV), and abducens (CN VI) nerves
• Tested by observing how the eye follows an object in different directions
• Damage=>double vision (diplopia) due to unsynchronized eye movements

Question 4

Divisions of the trigeminal nerve (CN V) and their functions

Answer 4

• Ophthalmic (V1): sensory innervation to the upper part of the face.
• Maxillary (V2): sensory innervation to the middle part of the face.
• Mandibular (V3): sensory innervation to the lower part of the face and motor innervation to the muscles of mastication

Question 5

Function of the facial nerve (CN VII) and what happens when it is damaged

Answer 5

• Controls the muscles of facial expression
• Damage=> facial palsy, person cannot move the muscles on one or both sides of their face
• Bell’s palsy common temporary condition associated with facial nerve damage

Question 6

Role of the vestibulocochlear nerve (CN VIII)

Answer 6

• Splits into the vestibular and cochlear nerves.
• Vestibular part is responsible for balance
• Cochlear part transmits auditory information, allowing hearing

Question 7

Functions of the glossopharyngeal nerve (CN IX)

Answer 7

• Innervates the stylopharyngeus muscle
• Sensory innervation to the oropharynx and back of the tongue
• Parasympathetic innervation to the parotid gland

Question 8

How damage to the vagus nerve (CN X) manifests clinically

Answer 8

• Loss of parasympathetic innervation=> increased blood pressure and heart rate
• Symptoms=> hoarse voice and difficulties in swallowing

Question 9

Signs of hypoglossal nerve (CN XII) damage

Answer 9

• Fasciculations (muscle twitching) and atrophy of the tongue muscles
• Upper motor neuron damage=> muscle weakness without atrophy or fasciculations

Question 10

Arteries that primarily supply the maxillofacial region

Answer 10

• Branches of the external carotid artery
• Including the facial artery, maxillary artery, and lingual artery

Question 11

Venous drainage of the maxillofacial region

Answer 11

• Mainly through the facial vein, which drains into the internal jugular vein
• Pterygoid plexus also contributes to venous drainage=>
  *Connects with the cavernous sinus and the maxillary vein

Question 12

Role of lymph nodes in the maxillofacial region

Answer 12

• Filtering lymphatic fluid and trapping pathogens
• Key lymph nodes=> submandibular, submental, and cervical lymph nodes=>
• Drain lymph from the face, mouth, and neck

Question 13

Bones that form the skeleton of the maxillofacial region

Answer 13

• Mandible, maxilla, zygomatic bones
• Nasal bones, lacrimal bones, palatine bones
• Inferior nasal conchae, and the vomer

Question 14

Primary muscles involved in facial expression

Answer 14

• Orbicularis oculi, orbicularis oris
• Zygomaticus major and minor
• Buccinator, and the frontalis muscle

Question 15

Muscles are responsible for mastication (chewing)

Answer 15

• Masseter, temporalis, medial pterygoid, and lateral pterygoid muscles
• Innervated by the mandibular branch of the trigeminal nerve (V3).

Question 16

How muscles of facial expression innervated

Answer 16

Facial nerve (CN VII).