Face and Parotid

Question 1

Describe the three types of Le Fort fractures.

Answer 1

Type 1: horizontal maxillary fracture separates the upper teeth from the upper face.
Type 2: pyramidal fracture separates the upper teeth + the nasal bones from the upper face.
Type 3: horizontal fracture through the orbits, superior to the nasal bones - craniofacial disjunction.

Question 2

What is the philtrum? What is the glabella?

Answer 2

The philtrum is the indent thingy in the middle of the upper lip.

The glabella is the space between the eyebrows.

Question 3

Describe the fascial layers of the face.

Answer 3

There is a superficial fascia with a lot of fat but NO DEEP FASCIA except for in the regions of the parotid glands, masseter, and temporalis muscles. The deep fascia around these are extensions of the investing fascia around the neck.

Question 4

Loss of elastin and collagen fibers in the skin results in ______.

Answer 4

wrinkles

Question 5

Botox blocks the release of __________ at the neuromuscular junction.

Answer 5

acetylcholine

Question 6

A 13-year-old girl visits her pediatrician complaining of loss of sensitivity in her lower eyelid, the skin below her right eye, and in her upper lip and teeth.
Which of the following sites is the most likely location for the nerve lesion responsible for these signs and symptoms?

a) Foramen spinosum
b) Foramen ovale
c) Foramen rotundum
d) Superior orbital fissure
e) Petrotympanic fissure

Which nerve(s) has been affected in this case?

Answer 6

c) Foramen rotundum

V2

Question 7

CN V originates from the _____.

Answer 7

pons

Question 8

Which branch(es) of the trigeminal nerve carry sensory fibers? Where do these cell bodies live?

Answer 8

All three branches have sensory fibers. Cell bodies live in the trigeminal ganglion.

Question 9

Where in the skull is the trigeminal ganglion located?

Answer 9

Middle cranial fossa

Question 10

Which branch(es) of the trigeminal nerve have motor fibers?

Answer 10

V3 only - for 8 muscles of mastication.

Question 11

Name the foramen that each branch of the trigeminal nerve exits the skull.

Answer 11

V1 goes through the superior orbital fissure.
V2 goes through the foramen rotundum.
V3 goes through the foramen ovale.

Question 12

Which nerve supplies general sensation to the inside of the cheeks?

Answer 12

Long buccal (V3)

Question 13

Trigeminal neuralgia is likely caused by enlargement of which blood vessel?

Answer 13

The superior cerebellar artery

Question 14

What types of fibers does the facial nerve (CN VII) contain?

Answer 14

1. Somatic motor for muscles of facial expression and scalp.
2. Somatic sensory to the tragus of the ear.
3. Visceral motor (glands - parasympathetic) to the lacrimal and mucosal glands of the nasal cavity and soft palate via the greater petrosal and the submandibular and sublingual glands via the chorda tympani.
4. Special sensory - taste from the anterior 2/3 of the tongue via the chorda tympani.

Question 15

Nerves from CN VII pierce the _______ gland after exiting the ________ foramen.

Answer 15

parotid after exiting the stylomastoid foramen.

Question 16

The buccinator muscle is supplied by the ______ branch of CN VII, while the cutaneous sensation of the skin covering the buccinator is provided by CN ____.

Answer 16

motor innervation to buccinator is done with the buccal branch of CN VII but the skin is done by V3 (long buccal branch of V3).

Question 17

The parotid gland duct pierces the _______ muscle.

Answer 17

buccinator

Question 18

The _______ is the smallest skeletal muscle in the body. It attaches to the _______ to dampen vibrations from the tympanic membrane and is innervated by CN _____.

Answer 18

stapedius muscle, attaches to the stapes, innervated by CN VII

Question 19

What are the two parasympathetic nerves associated with CN VII? What does each one do?

Answer 19

Greater petrosal nerve: visceral motor to the lacrimal gland and glands in mucosa of nasal cavity and palate.

Chorda tympani: visceral motor to the submandibular and sublingual glands and special sensory to the anterior 2/3 of the tongue.

Question 20

Describe the pathway of parasympathetic fibers of the chorda tympani from the brainstem to its targets.

Answer 20

Cell bodies in the superior salivary nucleus –> piggyback CN VII motor fibers through the facial canal –> split off into the middle ear and out the petrotympanic fissure –> piggyback on the lingual nerve (V3) to the tongue (special sense anterior 2/3) or to the submandibular ganglion where synapse happens (for visceral motor to glands) –> postganglionic fiber distribution on the lingual artery to the submandibular and sublingual glands.

Question 21

Describe the afferent pathway of taste fibers as they travel from the anterior 2/3 of the tongue to the brain.

Answer 21

Tongue –> efferent visceral motor fibers of the chorda tympani –> follow the lingual nerve for a bit, branch off –> back through the petrotympanic fissure and through middle ear –> hop on CN VII –> geniculate ganglion where taste sensory cell bodies live –> brain stem.

Question 22

Describe the pathway of parasympathetic fibers of the greater petrosal from the brainstem to its targets.

Answer 22

Cell bodies in the superior salivatory nucleus –> piggyback CN VII motor fibers through the internal acoustic meatus –> split off anteriorly, out the hiatus for the greater petrosal n. and meet up with the DEEP petrosal nerve (postganglionic sympathetic from the internal carotid a.), forming the vidian nerve –> through the vidian canal into the pterygopalatine fossa where parasympathetics from the greater petrosal synapse at the pterygopalatine ganglion –> postganglionic parasympathetic fibers hop on V1 and V2 to go to the lacrimal gland and nasal cavity/hard palate, respectively.

Question 23

Bell’s palsy is associated with a viral disease that can affect all or part of the ______ nerve. A lesion at the trunk of the nerve as it travels through the _______ _______ _______ may also cause it. Name two clinical signs of this disease.

Answer 23

can affect all or part of the facial nerve.

also may be caused by a lesion as the nerve travels through the internal acoustic meatus

Clinical signs:

1. One side of the face droops when the patient tries to smile.
2. Difficulty closing the eye on the affected side due to paralysis of the orbicularis oculi muscle.

Question 24

What causes Ramsay-Hunt syndrome Type II aka herpes zoster oticus? What are six clinical features?

Answer 24

Reactivation of varicella virus in the geniculate ganglion of the facial nerve.

Clinical features:

1. Paralysis of facial muscles unilaterally.
2. Pain around one ear.
3. Sounds seem louder on one side.
4. Loss of taste on anterior tongue.
5. Drooling out the corner of the mouth due to buccinator paralysis.
6. Changes in amount of tears or saliva.

Question 25

The facial artery is a branch of the _______ ________ artery and pierces the _________ gland deep to the mandible. It terminates as the _______ artery after it ascends the anterior part of the face.

Answer 25

its a branch of the external carotid artery, pierces the submandibular gland and terminates as the angular artery.

Question 26

Which vein, artery, and nerves run within the parotid gland?

Answer 26

Retromandibular vein, external carotid artery and its branches, terminal branches of the facial nerve (CN VII), and the auriculotemporal nerve (V3)

Question 27

The parotid duct pierces the _______ muscle and opens into the oral cavity opposite the ______ _______ ______ tooth.

Answer 27

pierces the buccinator muscle and opens into the oral cavity opposite the 2nd maxillary molar tooth.

Question 28

Sialography is used to visualize a blockage in…?

Answer 28

in salivary gland ducts

Question 29

Describe the somatic sensory and special sensory innervation of the tongue.

Answer 29

Anterior 2/3: lingual nerve (CN V3) does somatic sensory, chorda tympani (CN VII) does the special sensory.

Posterior 1/3: both special and somatic sensory are done by the glossopharyngeal nerve (CN IX).

Question 30

Describe the pathway of the glossopharyngeal nerve (IX) in its innervation of the parotid gland.

Answer 30

Inferior salivatory nucleus –> out the jugular foramen, tympanic nerve of Jacobson branches off –> out the tympanic cannaliculus into the middle ear –> forms a plexus with other sympathetics to form the lesser petrosal nerve in the inner ear –> comes out middle cranial fossa –> through foramen ovale into the infratemporal fossa –> otic ganglion on the medial side of the trunk of V3 for pre-post parasympathetic synapse –> joins auriculotemporal nerve to get to the parotid.

Question 31

Muscles of facial expression are innervated by CN ____, while most of the muscles of mastication are innervated by CN _____.

Answer 31

facial expression: CN VII

mastication: CN V3

Question 32

Describe the two compartments of the temporo-mandibular joint.

Answer 32

The upper compartment is the sliding compartment, the lower compartment is a hinge.

Question 33

If the jaw is opened too far, which location might the head of the mandible dislocate?

Answer 33

anteriorly - lockjaw

Question 34

Which nerve provides sensation for the TMJ?

Answer 34

Auriculotemporal nerve (V3)

Question 35

Name some symptoms of TMJ disease.

Answer 35

Headaches, pain in face and around ear, clicking, locking of the joint.