Parotid Gland and Face

Question 1

Loss of sensation from the temporal region and loss of secretory function of the parotid gland would be caused by interruption of which nerve?
- Auriculotemporal
- Chorda tympani
- Deep temporal, posterior
- Facial
- Great auricular

Answer 1

The auriculotemporal nerve is a branch of the mandibular division of the trigeminal nerve (V3). It has two important functions: First, it carries postganglionic parasympathetic fibers to the parotid gland. These fibers come from the otic ganglia, where they synapsed with the presynaptic fibers from the glossopharyngeal nerve (CN IX). Second, the auriculotemporal nerve provides sensory innervation to the skin of anterosuperior ear, part of the external auditory meatus, and the temporomandibular joint.

Question 2

An elderly man presented with severe pain beneath the left eye, radiating into the lower eyelid, lateral side of the nose and upper lip. What nerve was involved?

Buccal
Infraorbital
Mental
Supratrochlear
Zygomatic

Answer 2

The infraorbital nerve is a cutaneous nerve from the maxillary division of trigeminal nerve (V2). It innervates the skin of the lateral nose, lower eyelid, upper lip and zygomatic region.

Question 3

During a face lift operation on a 48-year-old woman, the plastic surgeon inadvertently cut the marginal mandibular branch of the facial nerve. Which of the following muscles would be paralyzed because of the injury?

Buccinator
Depressor anguli oris
Levator anguli oris
Levator labii superioris
Stylohyoid

Answer 3

depressor anguli oris

The marginal mandibular branch of the facial nerve provides motor innervation to the muscles of facial expression near the lower lip and chin–right where you find depressor anguli oris.

Question 4

As a result of a face lift operation, a 46-year-old woman noticed an asymmetry of the inferior lip and could not fully depress the angle of her mouth on the right side. Which of the following nerves was most likely damaged during the surgery?

zygomatic (VII)
buccal (VII)
mental (V3)
marginal mandibular (VII)
infraorbital (V2)

Answer 4

marginal mandibular branch

Depressor anguli oris is the muscle that depresses the angle of the lip–it is innervated by the marginal mandibular branch of the facial nerve.

Question 5

An elderly woman complained of a severe pain, felt above the right eye radiating to the upper eyelid, side of the nose and forehead. Branches of which of the following nerves convey pain sensations from areas of the skin described?

maxillary (V2)
greater auricular nerve
ophthalmic (V1)
mandibular (V3)
facial (VII)

Answer 5

ophthalmic (v1)

The ophthalmic division of the trigeminal nerve provides sensory innervation to the skin of the nose, upper eyelid, and forehead.

Question 6

Due to multiple salivary calculi (stones) in the submandibular duct, the submandibular gland of a 45-year-old individual was surgically removed. What major artery directly related to the gland was of special concern to the surgeon?

lingual
superior thyroid
facial
ascending pharyngeal
maxillary

Answer 6

facial

The facial artery arises from the external carotid and winds toward the inferior border of the mandible, crossing over the submandibular gland. So, if the submandibular gland was removed, the facial artery might be damaged.

Question 7

To study the compensatory response of selective suprahyoid muscles in elevating the hyoid bone, an experiment was designed in which the posterior belly of the digastric and stylohyoid muscles were paralyzed by drugs. The muscular branches of which of the following nerves must be chemically interrupted to produce paralysis in both muscles?

inferior alveolar
facial
hypoglossal
glossopharyngeal
lingual

Answer 7

The facial nerve (CN VII) provides motor innervation to the posterior belly of the digastric and the stylohyoid muscle

Question 8

Which nerve provides motor innervation to the buccinator muscle?

Auriculotemporal nerve
Buccal branches of VII
Buccal nerve
Mandibular division of V
Marginal mandibular nerve

Answer 8

buccal branches of VII

The buccal branches of the facial nerve provide motor innervation to the buccinator muscle. Remember, these buccal branches of the facial nerve are motor nerves only–they do not do any sensory innervation. Don’t mix this nerve up with the buccal nerve, which is a branch of the mandibular division of the trigeminal nerve (V3)! The buccal nerve is a sensory nerve only–it does not innervate any muscles; it only gives sensory innervation to the skin of the cheek and the mucosal lining of the cheek.

Question 9

Which nerve carries postganglionic parasympathetic fibers to the parotid gland?

Auriculotemporal nerve
Lesser petrosal nerve
Glossopharyngeal nerve
Great auricular nerve
Marginal mandibular nerve

Answer 9

Auriculotemporal nerve

The auriculotemporal nerve is a branch of the mandibular division of the trigeminal nerve (V3). It has two important functions: First, it carries postganglionic parasympathetic fibers to the parotid gland. These fibers come from the otic ganglia, where they synapsed with the presynaptic fibers from the glossopharyngeal nerve (CN IX). These presynaptic fibers were carried to the otic ganglia by the lesser petrosal nerve. Second, the auriculotemporal nerve provides sensory innervation to the skin of anterosuperior ear, part of the external auditory meatus, and the temporomandibular joint.

Question 10

A patient is unable to wink; what muscle is affected?

frontalis
levator palpebrae superioris
orbicularis oculi
superior tarsal
zygomaticus major

Answer 10

orbicularis oculi

Orbicularis oculi is a muscle of facial expression that closes the eyelid for winking. It is innervated by the temporal and zygomatic branches of the facial nerve.

Question 11

What structure lies deepest in the parotid gland?

External carotid artery
External jugular vein
Facial artery
Facial nerve
Retromandibular vein

Answer 11

external carotid artery

The facial nerve, retromandibular vein, and external carotid artery all course through the parotid gland. From superficial to deep, they are arranged nerve, vein, artery.

Question 12

A deep laceration of the face in the middle of the parotid gland could affect the:

External jugular vein
Facial nerve
Glossopharyngeal nerve
Hypoglossal nerve
Lingual artery

Answer 12

facial nerve

The facial nerve travels through the parotid gland–it could become injured if there was a deep laceration through the parotid gland. Two other structures found within the parotid gland which might be damaged: the retromandibular vein and the external carotid artery. The nerve is the most superficial structure in the gland. Then, the vein is under the nerve, and the artery is the deepest structure in the gland.

Question 13

Pain elicited from an infected facial wound is primarily conveyed by what nerve?

Facial
Great auricular
Hypoglossal
Transverse cervical
Trigeminal

Answer 13

trigeminal

The trigeminal nerve is the nerve that supplies sensory innervation to the skin of the face, so pain sensations will be carried through this nerve. It has 3 divisions. The ophthalmic division (V1) is a sensory nerve that passes through the superior orbital fissure and supplies sensory innervation to the eyeball, conjunctiva, nasal mucosa, medial portion of the nose, upper eyelid, forehead, and scalp. The maxillary division (V2) is a sensory nerve that provides sensory innervation to the cheek, upper lip, lateral portion of nose and lower eyelid. The mandibular division (V3) is a sensory and motor nerve–it supplies the lower lip and chin and the lateral portion of the cheek. V3 also provides motor innervation to the muscles of mastication, tensor veli palatini, mylohyoid, the anterior belly of the digastric, and tensor tympani.

Question 14

Inability to close the lips relates to the action of which muscle?

Anterior belly of the digastric
Mylohyoid
Orbicularis oris
Platysma
Zygomaticus major

Answer 14

Orbicularis oris

Orbicularis oris is a muscle of facial expression. It surrounds the lips, and allows for pursing of the lips.

Question 15

Which muscle will not be affected when the mandibular division of the trigeminal nerve (V3) is anesthetized?

Anterior belly of digastric
Buccinator
Medial pterygoid
Mylohyoid
Temporalis

Answer 15

Buccinator

Buccinator is innervated by the facial nerve (CN VII). It allows the corner of the mouth to be pulled laterally, and it allows the cheek to be pulled against the teeth. It is an important muscle for mastication, but it’s not innervated by a branch of the mandibular division of the trigeminal nerve.

Question 16

A 38-year-old female patient complained of parotid pain that increased while eating. Intraoral examination detected some pus oozing from the parotid duct opening. What was the most likely anatomical reference that the physician considered to locate the parotid duct opening?

• Mucosa of the sublingual caruncle behind the central incisor teeth
• Mucosa of the cheek across the 2nd upper (maxillary) molar tooth
• Mucosa of the floor of the mouth along the sublingual fold
• Mucosa of the cheek across the 2nd lower (mandibular) molar tooth

Answer 16

The parotid duct opens into the vestibule of the mouth, draining into the mucosa of the cheek near the second upper molar tooth. The duct drains the parotid gland across the masseter and through the cheek. It passes through the buccinator muscle, and pours saliva into the vestibule of the mouth.

Question 17

While recovering from a right facial paralysis, a 36-year-old female patient complained that food accumulated between the teeth and the cheek mucosa when chewing. The deficiency of which muscle was most likely the cause of the chewing problem?

Zygomaticus major
Orbicularis oris
Buccinator
Levator labii superioris

Answer 17

Buccinator

Although buccinator is innervated by the buccal branches of the facial nerve and not a branch of V3, the buccinator is an important muscle for mastication. The buccinator keeps the cheek taut so it is not folding over and becoming injured by chewing. It aids mastication by pulling the cheek against the molar teeth so that food does not keep collecting in the vestibule of the mouth. So, if this muscle was injured, the cheek could not press against the molar teeth, and food would fall between the teeth and cheek mucosa while chewing.

Question 18

The parotid space contains all EXCEPT:

External carotid artery
Facial nerve
Intraparotid lymph nodes
Medial pterygoid muscle
Retromandibular vein

Answer 18

medial pterygoid muscle

The medial pterygoid muscle is not in the parotid space. It serves as the anterior boundary of the parotid fossa. The other structures mentioned are all found within the parotid gland.

Question 19

As a result of meningitis, a patient develops Bell’s palsy. One of the symptoms was hyperacusis. What nerve was involved?

Facial
Glossopharyngeal
Oculomotor
Trigeminal
Vagus

Answer 19

Facial

Bell’s palsy is the paralysis of the facial nerve. This means that, on the affected side, the muscles of facial expression will appear flaccid, leading to a loss of expression. The patient will be unable to smile, lift their eyebrow, or close their eyelid on the affected side of the face. Besides the muscles of facial expression, the facial nerve also innervates stapedius, a small muscle in the ear. This muscle serves to dampen the vibrations of the tympanic membrane and quiet sounds. If the facial nerve is paralyzed, stapedius is paralyzed, too. This means that the ear can’t dampen the vibrations from loud sounds, and the patient experiences hyperacusis.

Question 20

Frey’s Syndrome is marked by profuse sweating over one cheek, temple, and surrounding areas of the face, precipitated by eating. The condition may be idiopathic, but often follows parotid surgery. The condition is attributable to abberant reinnervation, the redirection of autonomic fibers normally going to salivary glands being redirected to sweat glands. What is the source of the nerve fibers involved?

Facial
Glossopharyngeal
Oculomotor
Trigeminal
Vagus

Answer 20

Trigeminal

Frey’s syndrome is a condition in which the postganglionic parasympathetic nerves that are contained in the auriculotemporal nerve (which normally supply the parotid gland) are redirected toward the sweat glands overlying the parotid gland. This means that a patient with Frey’s syndrome sweats in the area over the parotid gland while eating. Since the auriculotemporal nerve is a branch of V3, the nerve fibers involved in Frey’s syndrome are from the trigeminal nerve.

Question 21

While recovering from multiple dental extractions, an elderly man experienced a radiating pain affecting the lower eyelid, lateral side of the nose, upper lip and over the zygomatic and temporal areas on the left side. Which nerve is involved in the patient’s perception of pain?

Facial
Opthalmic division of trigeminal
Glossopharyngeal
Mandibular division of trigeminal
Maxillary division of trigeminal

Answer 21

Maxillary division of trigeminal

The trigeminal nerve is the nerve that supplies sensory innervation to the skin of the face. It has 3 divisions. The maxillary division of trigeminal (V2) is the one that’s important for this case–it is a sensory branch of the trigeminal that provides innervation to the skin of the cheek, upper lip, lower eyelid, and the lateral portion of the nose. This is exactly the area that the patient feels pain, so it is the correct answer. The ophthalmic division (V1) is a sensory nerve that passes through the superior orbital fissure and supplies sensory innervation to the eyeball, conjunctiva, nasal mucosa, medial portion of the nose, upper eyelid, forehead, and scalp.

Question 22

The facial muscle most responsible for moving the lips both upward and laterally to produce a smile is:

Buccinator
Levator anguli oris
Levator labii superioris
Platysma
Zygomaticus major

Answer 22

Zygomaticus major

Zygomaticus major is innervated by the zygomatic and buccal branches of the facial nerve. It elevates the corner of the mouth and draws it laterally. Remember zygomaticus major as the “smile” muscle!