Head and Neck Anatomy 11-17, 19-22

Question 1

The periodontal ligament anchors the teeth to the surrounding alveolar bone through attachment to which of the following structures?

A) Cementum
B) Dentin
C) Enamel
D) Gingiva
E) Neurovascular bundle

Answer 1

The correct response is Option A.

The dental root is covered by a mineralized layer called cementum. This is anchored to the surrounding alveolar bone by the periodontal ligament (periodontal membrane), which includes Sharpey fibers, to firmly anchor the tooth to the bone as well as sensory fibers. This facilitates the periodontal ligament’s functions of stabilizing the tooth, serving as a shock absorber, and allowing proprioception.

The bulk of the dental root is composed of dentin, but it does not directly attach to the surrounding bone.

The neurovascular bundles enter the tooth at the root apex and provide sensation and blood supply, but they are not a strong mechanical source of attachment.

The enamel is the mineralized cover of the dental crown. It is not attached to the free gingiva, which attaches to the periodontal ligament at the cementoenamel junction.

The gingiva does not directly attach to the bone.

Question 2

During recipient vessel dissection in preparation for a head and neck free flap reconstruction, a nerve that runs deep and roughly parallel to the posterior belly of the digastric muscle is accidentally divided. This patient is most likely to have which of the following dysfunctions as a result?

A) Impaired shoulder elevation
B) Loss of depressor anguli oris movement
C) Paralysis of the hemidiaphragm
D) Tongue deviation
E) Vocal cord paralysis

Answer 2

The correct response is Option D.

The hypoglossal (XII) nerve emerges from the hypoglossal canal in the skull base and runs deep and roughly parallel to the posterior belly of the digastric in the upper neck, eventually innervating the intrinsic and extrinsic muscles of the tongue (except for the palatoglossus, which is innervated by the vagus [X] nerve). Division of the nerve results in ipsilateral tongue paralysis. The posterior belly of the digastric muscle is known as the “resident’s friend” because it acts as a useful anatomic landmark for several critical structures in the neck. It lies directly superficial to the branches of the external carotid artery, the internal carotid artery, jugular vein, and hypoglossal (XII) nerve.

The marginal mandibular nerve, a branch of the facial (VII) nerve, innervates the depressor anguli oris and depressor labii inferioris, which are the facial mimetic muscles responsible for frowning. It runs superficial to the posterior belly of the digastric muscle but deep to the platysma muscle. It is often injured in surgery of the neck region.

The vagus (X) nerve exits the cranium via the jugular foramen and courses from superior to inferior within the carotid sheath between the internal jugular vein and common carotid artery. It has diverse functions including supplying the larynx, pharynx, heart, esophagus, stomach, and small and large intestines. Transection of the vagus (X) nerve in the neck can result in vocal cord paralysis, among other dysfunctions.

The spinal accessory (XI) nerve innervates the sternocleidomastoid and trapezius muscles. Therefore, its division results in impaired shoulder mobility. Although it lies deep to the posterior belly of the digastric muscle, it courses inferiorly and posteriorly, crossing the internal jugular vein, rather than parallel to the muscle, to enter the posterior triangle of the neck. The phrenic nerve originates from cervical spinal nerves (C3-C5) and is found in the floor of the posterior triangle of the neck and is not found deep to the posterior belly of the digastric.

Question 3

An 8-year-old boy is brought to the clinic for evaluation of a congenital ear deformity characterized by an unfolded antihelix. During the embryological period, which of the following structures failed to develop appropriately?

A) First pharyngeal cleft
B) First pharyngeal pouch
C) Second pharyngeal arch
D) Third pharyngeal arch
E) Third pharyngeal pouch

Answer 3

The correct response is Option C.

The ear development starts during the third month of gestation from six hillocks that arise on the first and second arches.

The first pharyngeal cleft develops into the external auditory meatus. The second through fourth pharyngeal clefts are usually obliterated due to the expansion of the second pharyngeal arch.

The first pharyngeal pouch develops into the auditory tube and middle ear cavity. The second through fourth pharyngeal pouches are not related to ear development, nor is the third pharyngeal arch. The second pouch becomes the palatine tonsils’ crypts, while the third pouch forms parathyroid glands and thymus. The fourth pouch differentiates into parathyroid glands and parafollicular cells of the thyroid gland. The cartilaginous component of the third pharyngeal arch gives rise to part of the hyoid bone.

Question 4

A 65-year-old man presents with facial flushing and sweating with eating 4 weeks after undergoing parotidectomy. Which of the following tests will be most likely to establish the diagnosis?

A) Cottle maneuver
B) Ice pack test
C) Jones test
D) Minor iodine-starch test
E) Schirmer test

Answer 4

The correct response is Option D.

Auriculotemporal syndrome, or Frey syndrome, can occur after parotidectomy and less commonly after trauma, other facial surgeries (e.g., rhytidectomy), and neck dissection. It results from abnormal innervation (synkinesis) of sweat glands from the postganglionic parasympathetic fibers in the parotid. Symptoms include flushing, sweating, neuralgia, burning, and itching in response to gustatory stimulus. Diagnosis of Frey syndrome is based on clinical history, but the diagnosis can be confirmed with the Minor iodine-starch test: the ipsilateral face is painted with iodine and the patient is challenged with a sialogogue (e.g., lemon juice). Areas of gustatory sweating will turn blue.

The Jones test assesses patency of the lacrimal drainage system. The Cottle maneuver assesses the internal nasal valve. The ice pack test is used to assess myasthenic ptosis. The Schirmer test is a tear production test that can be used to assess dry eyes before blepharoplasty.

Question 5

A 7-year-old boy sustains a deep laceration over the right side of the face. A photograph is shown. Injury to the parotid (Stensen) duct is suspected. At the anterior edge of the parotid gland, the duct should lie immediately superficial to which of the following structures?

A) Deep subcutaneous fat
B) Masseteric fascia
C) Submuscular aponeurotic system (SMAS)
D) Superficial parotid fascia
E) Temporoparietal fascia

Answer 5

The correct response is Option B.

The parotid gland is the largest of the three paired salivary glands (parotid, submandibular, and sublingual). It has two lobes, the deep and superficial, each of which is enveloped in a fascial sheath (parotid sheath) and between which passes the facial vein and nerve. The superficial lobe lies lateral (superficial) to the masseter muscle, and the deep lobe lies between the mastoid process and the mandibular ramus. The parotid, or Stensen, duct arises from the deep lobe of the parotid gland and receives contributions from the superficial lobe as it travels anteriorly. After exiting the anterior edge of the superficial lobe, the duct passes directly over the masseter muscle, crosses over the anterior edge of the masseter, extends medially and anteriorly over and through the buccinator muscle, and enters into the mouth via the parotid papilla, typically located opposite the second maxillary molar. The course of the duct has classically been described as following a line connecting the tragus and the midportion of the upper lip, but there is significant variation, and some studies report that this line should end in the lower half of the upper lip. The laceration shown in the photograph is just at the anterior border of the parotid and, at this level, the duct should be passing over the masseter muscle and its fascia. The course of the duct is below the superficial lobe of the parotid and, therefore, well below the subcutaneous tissue and the submuscular aponeurotic system (SMAS), which is confluent with the platysma inferiorly and the temporoparietal fascial superiorly. Superficial parotid fascia defines the layer of fascia that invests the superficial lobe of the parotid gland.

Question 6

A 7-year-old girl presents with a tender and erythematous right pretragal abscess. Upon inquiring about the pit inferior to it, her parents report only recent drainage, despite presence since birth. They deny hearing deficits but report a family history of a similar defect. Facial cellulitis and excess granulation tissue are also noted on physical examination. Photographs are shown. Malformation of which of the following embryological structures most likely accounts for these findings?

A) Hillocks
B) Meatal plug
C) Otic capsule
D) Otic vesicle
E) Tubotympanic recess

Answer 6

The correct response is Option A.

Auricular hillocks are ectodermal derivatives of the first pharyngeal groove and are responsible for the formation of external ear structures (e.g., auricle and external auditory canal [EAC]). Incomplete fusion of the auricular hillocks (defective closure of the dorsal 1st pharyngeal groove) results in preauricular sinus. This is the only answer choice that contributes to the development of the external ear.

The meatal plug is an ectodermal derivative of the first pharyngeal groove (extends from the medial end of the EAC), which largely degenerates/canalizes, but is responsible for formation of the surface layer of the tympanic membrane. Persistence of the meatal plug results in conductive congenital deafness.

The otic vesicle is an ectodermal derivative of the developing brain that is responsible for formation of inner ear structures (e.g., saccule, utricle, semicircular and cochlear ducts, and membranous cochlea including the spiral organ of Corti). Abnormal development of the membranous labyrinth results in sensorineural congenital deafness.

The otic capsule is derived from mesenchyme of the first and second pharyngeal arches, surrounds/is induced by the otic vesicle, and is responsible for formation of inner ear structures (e.g., bony labyrinth). Abnormal development of the bony labyrinth results in sensorineural congenital deafness.

The tubotympanic recess is an endodermal derivative of the first pharyngeal pouch, responsible for the formation of middle ear structures (e.g., auditory tube, tympanic cavity, etc.). Abnormal/under-development of the middle ear structures increases the risk for chronic otitis media and can have an effect on conductive hearing.

Question 7

A 4-year-old boy is seen following a pitbull bite to his face. The periorbital findings are shown in the photograph. A stent is placed and the ends of the stent are advanced across the canaliculus. The ends of the stent will enter the nasal cavity in which of the following locations?

A) Above the superior turbinate
B) Below the superior turbinate
C) Above the middle turbinate
D) Below the middle turbinate
E) Above the inferior turbinate
F) Below the inferior turbinate

Answer 7

The correct response is Option F.

Reconstruction of the lacrimal apparatus is a critical step in addressing this patient’s periorbital wounds. Failure to properly manage this aspect of the injury will lead to epiphora and the inevitable need for a secondary procedure to manage tear drainage. Delayed reconstruction of this injury would likely require a conjunctivodacryocystorhinostomy, a surgically created conduit between the eyelid and the nose. The best initial management of this lacrimal apparatus disruption is as described—placement of a stent through the canaliculi, into the lacrimal duct (contained within the maxillary bone), and into the nose. The exit point of the nasolacrimal duct is via the valve of Hasner, below the inferior turbinate. It is here that the ends of the stent can be identified and retrieved, although this is often quite challenging.

The frontal, maxillary, and anterior ethmoid sinus cells drain into the middle meatus, just below the middle turbinate. The sphenoid sinus and posterior ethmoid sinuses drain into the sphenoethmoid recess, between the nasal septum and the superior turbinate.

Question 8

A 20-year-old man is brought to the emergency department after sustaining a stab wound to the neck during a violent assault. Physical examination shows an expanding neck hematoma and stridor. Intraoperative exploration shows a deep laceration to the anterior lateral neck at the level of thyroid cartilage and profuse extravasation of blood from the carotid sheath. According to anatomical zone-based classification of penetrating neck injuries, which of the following zones is involved?

A) Zone 1
B) Zone 2
C) Zone 3
D) Zone 4

Answer 8

The correct response is Option B.

“Penetrating neck injury represents 5-10% of all trauma cases. It is important for clinicians to be familiar with management principles, as mortality rates can be as high as 10%.”

Penetrating neck injury describes trauma to the neck that has breached the platysma muscle. The most common mechanism of injury worldwide is a stab wound from violent assault, followed by gunshot wounds, self harm, road traffic accidents, and other high velocity objects. The neck is a complex anatomical region containing important vascular, aerodigestive, and neurological structures that are relatively unprotected. Arterial injury occurs in approximately 25% of penetrating neck injuries; carotid artery involvement is seen in approximately 80% and vertebral artery in 43%.

Hard signs indicating immediate explorative surgery in penetrating neck injury:

Shock

Pulsatile bleeding or expanding hematoma

Audible bruit or palpable thrill

Airway compromise

Wound bubbling

Subcutaneous emphysema

Stridor

Hoarseness

Difficulty or pain when swallowing secretions

Neurological deficits

The assessment and management of penetrating trauma to the neck has traditionally centered on the anatomical zone-based classification first described by Monson et al. in 1969

Zone 1 extends from clavicles to cricoid, zone 2 from cricoid to angle of mandible, and zone 3 from angle of mandible to skull base.

There are only 3 zones in penetrating neck injuries.

Question 9

A 2-year-old boy is evaluated because of a soft, nontender, noncompressible glabellar mass that has progressively grown since birth. A photograph is shown. Which of the following is the most appropriate next step in management before scheduling surgery?

A) Corticosteroid injections
B) MRI
C) Plain film x-ray study
D) Propranolol trial
E) Observation

Answer 9

The correct response is Option B.

The differential diagnosis for a lesion in this location with the findings described include dermoid cyst, hemangioma, and encephalocele. Osteoma, which is a benign bony tumor, is unlikely because of patient age and examination findings. The noncompressible quality of the lesion makes hemangioma and encephalocele less likely. Propranolol therapy after 12 months of age is unlikely to help, even if the lesion is a hemangioma. If the lesion is a hemangioma, then observation would be appropriate, but because the lesion is still growing, this diagnosis is questionable. Corticosteroid injections are only moderately helpful in treating a hemangioma, but they are contraindicated for dermoid cysts and encephalocele. Diagnosis is the next step with a goal of ruling out intracranial communication, as it will impact the surgical approach. MRI is the best option. Plain x-rays films would not provide adequate information for management.

Question 10

A 12-year-old boy with a thyroglossal duct cyst undergoes a Sistrunk procedure. Which of the following structures are resected during this procedure?

A) Cyst and cyst tract only
B) Cyst, cyst tract, and middle third of the cricothyroid cartilage
C) Cyst, cyst tract, and middle third of the hyoid bone
D) Cyst, cyst tract, and middle third of the thyroid cartilage
E) Cyst, cyst tract, and the pyramidal lobe of the thyroid

Answer 10

The correct response is Option C.

The Sistrunk procedure is the operation of choice for thyroglossal duct cysts. This operation involves resection of the cyst, the cyst tract, and the middle third of the hyoid bone. In the Sistrunk procedure, the thyroid cartilage is not removed, nor is the cricothyroid cartilage. If, upon exploration, the distal tract is found to be in communication with the pyramidal lobe of the thyroid, then the communication should be excised. Despite this, resection of the pyramidal lobe of the thyroid is not a standard component of the Sistrunk procedure.

Question 11

Which of the following cranial nerves develops within the first branchial arch?

A) Facial (VII)
B) Glossopharyngeal (IX)
C) Hypoglossal (XII)
D) Trigeminal (V)
E) Vagus (X)

Answer 11

The correct response is Option D.

The trigeminal nerve (cranial nerve V) develops from the first branchial arch and gives rise to the malleus and incus. The ligaments associated with the first branchial arch are the anterior ligament of the malleus and the sphenomandibular ligament. The muscles of the first branchial arch include the muscles of mastication (masseter, temporalis, medial pterygoid, lateral pterygoid), tensor veli palatini, tensor tympani, mylohyoid, and the anterior belly of the digastric. The first pouch is associated with the external auditory canal and middle ear space.

The facial nerve (cranial nerve VII) develops from the second branchial arch and gives rise to the stapes, styloid, and the upper body of the hyoid. It includes the stylohyoid ligament. The associated muscles are facial expression muscles, stapedius, stylohyoid, and the posterior belly of the digastric. The second pouch is associated with the tonsillar fossa.

The glossopharyngeal nerve (cranial nerve IX) develops from the the third branchial arch and gives rise to the lower body of the hyoid. Its muscle is the stylopharyngeus, and the pouch is associated with the inferior parathyroid gland and the thymus.

The fourth branchial arch is associated with the larynx. The muscles associated with this arch are the laryngeal, pharyngeal, and soft palate. The pouch is associated with the superior parathyroid gland and the thyroid gland.

Question 12

A newborn female presents with a large intraoral mass arising from alveolar mucosa of the lower jaw that does not cause any airway obstruction. Photographs are shown. Which of the following is the most likely pathology of the lesion?

A) Congenital epulis
B) Hemangiopericytoma
C) Odontogenic keratocyst
D) Rhabdomyosarcoma
E) Teratoma

Answer 12

The correct response is Option A.

Congenital epulis is a rare, benign tumor of the oral cavity that is found in newborns. They are considered a form of granular cell tumor that can lead to mechanical obstruction, resulting in respiratory distress or difficulty eating. Surgical excision is the treatment of choice and recurrence after excision is rare. The female-to-male ratio is 10:1. It is observed three times more frequently on the maxilla than the mandible. They are solitary in most cases, but can be large and multiple.

Teratomas and rhabdomyosarcomas of the mandible are even more rare and are usually seen in the older patient population; they are not seen in the neonatal population.

Hemangiopericytomas are rare, vascular neoplasms that originate from vascular pericytes. They can occur anywhere in the body, including the mandible. They are slow-growing and present in the older patient population. The likelihood of presentation in a neonate is exceedingly low.

Odontogenic keratocysts are rare and benign, but locally aggressive lesions of the posterior mandible. They most commonly present in the third decade of life. They make up 19% of jaw cysts.

Question 13

The inferior oblique muscle of the orbit is innervated by which of the following cranial nerves?

A) Oculomotor (III)
B) Trochlear (IV)
C) Trigeminal (V)
D) Abducens (VI)
E) Facial (VII)

Answer 13

The correct response is Option A.

The inferior oblique muscle receives its nerve supply from the oculomotor nerve, or cranial nerve III. The other voluntary muscles within the orbit that receive their innervation from the oculomotor nerve are the levator palpebrae superioris, superior rectus, medial rectus, and inferior medial rectus muscles. The superior oblique muscle is innervated by the trochlear nerve (cranial nerve IV). The lateral rectus muscle is innervated by the abducens nerve (cranial nerve VI).

The inferior oblique is the only one of these muscles that does not arise from the apex of the orbit. It originates from the medial floor of the orbit just posterior to the infraorbital rim. It runs laterally, posteriorly, and upward, crossing inferior to the inferior rectus, and inserting on the posterior half of the globe beneath the lateral rectus insertion. Its action is to elevate the globe, producing upward gaze of the pupil. Risk of iatrogenic injury to the inferior oblique is greatest with transconjunctival surgical approach to the orbit. Therefore, with this procedure, care must be exercised to place the periosteal incision along the anterior aspect of the infraorbital rim.

Question 14

A patient undergoes extraction of a fully impacted mandibular third molar. During corticotomy of the mandible, protection of the adjacent soft tissue is necessary to avoid injury to which of the following nerves?

A) Facial
B) Hypoglossal
C) Inferior alveolar
D) Infraorbital
E) Lingual

Answer 14

The correct response is Option E.

Protection of the lingual border of the mandible during extraction of mandible wisdom teeth is critically necessary because of the close proximity of the lingual nerve to the lingual border of the mandible. This nerve can be inadvertently injured if not routinely protected during third molar extractions.

Question 15

During embryological development, which of the following structures is derived from the same pharyngeal arch as the antihelix?

A) Mandible
B) Maxilla
C) Mylohyoid
D) Stapes
E) Tensor veli palatini

Answer 15

The correct response is Option D.

The pharyngeal arches are created during embryological development by the migration of the neural crest cells and the surrounding pharyngeal endoderm and mesoderm. The first four pharyngeal arches are the most prominent and have unique nervous, arterial, muscular, and bony components. The muscular components of the first pharyngeal arch are innervated by the trigeminal nerve (cranial nerve V) and include the muscles of mastication, as well as the anterior digastric, mylohyoid, tensor tympani, and tensor veli palatini. The maxillary artery supplies blood to the components of the first pharyngeal arch. The greater wing of the sphenoid, as well as the incus, the malleus, maxilla, zygomatic, mandible, and temporal bones comprise the bony components of the first pharyngeal arch. The second pharyngeal arch is innervated by the facial nerve (cranial nerve VII) and receives blood supply from the stapedial artery. The bony components of the second pharyngeal arch include the stapes, styloid process, stylohyoid ligament, lesser horn, and upper body of the hyoid. The muscular components of the second pharyngeal arch include the muscles of facial expression, as well as the posterior digastric, stylohyoid, and stapedius.

During embryological development of the external ear, the antihelix, antitragus, and lobule are derived from the three posterior hillocks of the second pharyngeal arch, while the tragus, the root of the helix, and the superior helix are derived from the three anterior hillocks of the first pharyngeal arch.

Question 16

A 12-month-old boy presents for evaluation of a soft, fixed lateral brow mass that has been enlarging since it was first noted at 2 months of age. A photograph is shown. The parents report that the mass does not change in size during crying or activity, nor did it change in size during recurrent pink eye infections. Which of the following is the most likely diagnosis?

A) Branchial cleft cyst
B) Dermoid cyst
C) Hemangioma
D) Lacrimal gland
E) Lymphatic malformation

Answer 16

The correct response is Option B.

Dermoid cyst is the correct answer and the most common cause of a lateral brow mass in an infant. If it were a hemangioma, its size would change during crying or any activity that increases blood flow. Lacrimal gland ptosis is unlikely in a child but can be seen in the adult population, and can be ruled out if the mass is above the orbital rim, as seen in the photograph. The mass is not in the distribution of any of the different types of branchial cleft cysts. Lymphatic malformations typically change in size during infections.

Question 17

A 24-month-old infant is evaluated because of a mass on the lower lip that her parents first noticed 1 month ago. Physical examination shows a mucosal lesion of the right lower lip that is round, clear, translucent, soft, and measures approximately 0.5 cm in diameter. Which of the following is the most appropriate next step in management?

A) CT scan of the face without contrast
B) Excisional biopsy
C) Fine-needle aspiration
D) MRI of the face with contrast
E) Ultrasonography of the lesion

Answer 17

The correct response is Option B.

The lesion described is a mucocele, which is a type of cyst likely caused by minor salivary gland mucin seepage. They are most frequently on the lower lip mucosa away from the midline, but they can present anywhere there is oral mucosa. A minority of these resolve on their own, therefore, the majority of the time an excisional biopsy is recommended.

Imaging is not indicated for this type of lesion. Fine-needle aspiration is not indicated.

Question 18

A 23-year-old African-American man presents with a raised thickened scar on his anterior chest that he complains is pruritic and unattractive. It was removed by another provider 4 years earlier and has slowly recurred over the past year. On examination, the lesion extends beyond the initial borders of the scar and is firm and hyper-pigmented. On review of his prior pathology report, which of the following histologic characteristics is most likely?

A) Greater ratio of type III to type I collagen
B) Multitude of myofibroblasts and smooth muscle actin
C) Parallel collagen bundles
D) Thick, wavy, and randomly oriented collagen fibers

Answer 18

The correct response is Option D.

In patients with abnormal or excessive scar tissue formation, treatment and prognosis will be driven by the correct diagnosis of a keloid versus a hypertrophic scar. This patient presents with a recurrent keloid of the chest. His clinical history supports this diagnosis by recurrence after resection, growth extending beyond the original border of the lesion, late recurrence after several years, and continued growth over several years without regression or improvement. Hypertrophic scars are less likely to recur, contained within the original boundaries of the lesion, often regress somewhat within a year, and recur earlier in the postoperative period if they are to recur. Both hypertrophic scars and keloid scars can be pruritic.

Pathologic analysis of keloids reveals more type I collagen than type III collagen, similar to normal skin. Hypertrophic scars will exhibit increased type III collagen and pro-fibrotic collagen cross-linking. Keloid growth is thought to be impacted by cell-signaling between keratinocytes and fibroblasts, but hypertrophic scar production requires an abundance of myofibroblasts expressing smooth muscle actin. While hypertrophic scars have parallel collagen fibrils and bundles, keloids are characterized histologically by thick, randomly oriented collagen fibrils that are not organized into bundles.

Question 19

Which of the following structures contributes to the formation of the mandibular body and ramus?

A) First branchial arch
B) First branchial cleft
C) Second branchial arch
D) Second branchial cleft

Answer 19

The correct response is Option A.

The first branchial arch contributes to the formation of the mandible, the tragus, and the anterior helix.

The first branchial cleft gives rise to the external auditory canal. The second branchial arch contributes to the formation of the majority of the external ear–the antitragus, remainder of the helix, antihelix, and crura all arise from the second branchial arch. The second branchial cleft is typically obliterated during development, but may persist in the form of a second branchial cleft cyst.

Question 20

Which of the following cranial nerves develops with the first branchial arch?

A) Facial (VII)
B) Glossopharyngeal (IX)
C) Hypoglossal (XII)
D) Trigeminal (V)
E) Vagus (X)

Answer 20

The correct response is Option D.

The first branchial arch is associated with the trigeminal nerve (V), second branchial arch with the facial nerve (VII), third branchial arch with the glossopharyngeal (IX), fourth branchial arch with the superior laryngeal (X), and sixth branchial arch with the recurrent laryngeal (X).

Question 21

The stylopharyngeus muscle is innervated by which of the following nerves?

A) Facial (VII)
B) Glossopharyngeal (IX)
C) Hypoglossal (XII)
D) Trigeminal (V)
E) Vagus (X)

Answer 21

The correct response is Option B.

The pharyngeal muscles are all innervated by the vagus (X) nerve, except the stylopharyngeus muscle, which is innervated by the glossopharyngeal nerve (IX).

The trigeminal nerve (V) is responsible for facial and oral sensation. The maxillary branch (V2) is responsible for sensation of the upper teeth, upper lip, hard palate, cheeks, and nasopharyngeal mucosa. The mandibular branch (V2) provides sensory fibers for the lower teeth, lower mucosa of the mouth and the anterior two-thirds of the tongue. The facial nerve (VII) provides motor innervation of the muscles of facial expression and the posterior bellies of the stylohyoid and digastric muscles. The vagus nerve (X) provides motor innervation to all of the pharyngeal muscles except the stylopharyngeus muscle. The hypoglossal nerve (XII) provides motor innervation to the intrinsic and extrinsic tongue muscles and also provides motor innervation to the geniohyoid muscle through the ansa cervicalis.

Question 22

Which of the following structures is formed from the same branchial arch as the vagus (X) nerve?

A) Inferior parathyroid glands
B) Lesser horn of hyoid
C) Levator veli palatini
D) Maxillary artery
E) Styloid process

Answer 22

The correct response is Option C.

Each of the six branchial arches gives rise to a branch of the aortic arch, a cranial nerve, muscular structures, and skeletal structures. The fourth branchial arch gives rise to the right proximal subclavian artery, the aortic arch, the vagus (X) nerve, the superior laryngeal nerve, the intrinsic muscles of the levator veli palatini, cricothyroid muscles, laryngeal cartilages, and the superior parathyroid glands.

The styloid process is derived from the second branchial arch, along with the stapedial and hyoid arteries, the facial (VII) nerve, the muscles of facial expression, the stapes, the lesser horn of the hyoid bone, and the crypts of the palatine tonsils.

The maxillary artery is derived from the first branchial arch, along with the trigeminal (V) nerve, the muscles of mastication, anterior belly of the digastric muscle, tensor tympani, tensor veli palatini, mylohyoid, mandible, incus and malleus, maxilla, vomer, zygoma, and temporal bone.

The inferior parathyroid glands are derived from the third branchial arch, along with the common carotid artery, internal carotid artery, glossopharyngeal (IX) nerve, stylopharyngeus muscle, greater horn of the hyoid bone, and thymus.

The lesser horn of the hyoid bone is derived from the second branchial arch.

Question 23

A 9-year-old boy is brought to the office for evaluation of a nodule on the neck that appeared 1 week ago. The nodule measures 2 cm and is slightly to the right of midline. A photograph is shown. The lesion is slightly tender. Which of the following is the most appropriate management of this lesion?

A) Excision of lesion with any tract and a section of hyoid bone
B) Excision of lesion with any tract and a section of thyroid cartilage
C) Excision of lesion with any tract only
D) Fine-needle aspiration with cytology
E) Intralesional sclerotherapy under image guidance

Answer 23

The correct response is Option A.

Thyroglossal duct cysts are neck lesions that usually present during childhood, often after a localized inflammation or infection. They are usually neck lesions near the midline. Some may move with swallowing if they are close to the base of the tongue, but not all exhibit this finding. The congenital thyroglossal duct is the remnant of the descent of the developing thyroid gland, and it runs from the foramen cecum of the base of the tongue, down to the thyroid. Imaging is typically by ultrasound, but other modalities, including radioisotope scans to rule out ectopic thyroid tissue or confirm the location of the normal thyroid gland, have been suggested to avoid excising ectopic thyroid gland.

The Sistrunk procedure shows less recurrence and is a complete excision, including any associated tract, and about a 1-cm section of hyoid bone. Although proposed in 1928, this is still the most commonly recommended approach for thyroglossal duct cysts.

Fine-needle aspiration is appropriate for thyroid nodules, which are unlikely to present in an acute manner in this population.

Sclerotherapy is used for vascular anomalies and likely would have presented earlier on in childhood.

Question 24

A newborn has a pretragal cystic mass with a sinus tract visible in the external auditory meatus. Which of the following is the most likely diagnosis?

A) Dermoid cyst
B) First branchial cleft cyst
C) Second branchial cleft cyst
D) Third branchial cleft cyst
E) Vascular cystic lesion

Answer 24

The correct response is Option B.

The first branchial cleft develops into the external auditory canal. The second, third, and fourth branchial clefts merge to form the sinus of His, which will normally become involuted. When a branchial cleft is not properly involuted, a branchial cleft cyst forms. Occasionally, both the branchial pouch and branchial cleft fail to become involuted, and a complete fistula forms between the pharynx and skin.

First branchial cleft cysts are divided into type I and type II. Type I cysts are located near the external auditory canal. Most commonly, they are inferior and posterior to the tragus (base of the ear), but they may also be in the parotid gland. Type II cysts appear at the angle of the mandible and may involve the submandibular gland.

The second branchial cleft accounts for 95% of branchial anomalies, and they are most frequently identified along the anterior border of the upper third of the sternocleidomastoid muscle and adjacent to the muscle. However, these cysts may present anywhere along the course of a second branchial fistula, which proceeds from the skin of the lateral neck, between the internal and external carotid arteries, and into the palatine tonsil. Therefore, a second branchial cleft cyst is part of the differential diagnosis of a parapharyngeal mass.

Third branchial cleft cysts are rare. A third branchial fistula extends from the same skin location as a second branchial fistula (recall that the clefts merge during development); however, a third branchial fistula courses posterior to the carotid arteries and pierces the thyrohyoid membrane to enter the larynx, terminating on the lateral aspect of the pyriform sinus. Third branchial cleft cysts occur anywhere along that course (eg, inside the larynx), but they are characteristically located deep to the sternocleidomastoid muscle.

Congenital dermoid cysts of the face typically occur at the lateral orbit overlying the ZF suture, and vascular cyst lesions can be located anywhere on the face but do not present with sinus tracts into the EAC.

Question 25

Which of the following structures contributes to the formation of the tragus?

A) First branchial arch
B) First branchial cleft
C) Second branchial arch
D) Second branchial cleft

Answer 25

The correct response is Option A.

The first branchial arch contributes to the formation of the tragus and anterior helix.

The first branchial cleft is incorrect. It gives rise to the external auditory canal.

The second branchial arch is incorrect. It contributes to the formation of the majority of the external ear – the antitragus, remainder of the helix, antihelix, and crura all arise from the second branchial arch.

The second branchial cleft is incorrect. It is typically obliterated during development, but may persist in the form of a second branchial cleft cyst.

Question 26

A 51-year-old woman is scheduled to undergo a lower lip reduction. Blockade of the mental nerve is planned for anesthesia. The most appropriate site for injection of the mental foramen blockade is the mucosa below which of the following teeth?

A) Canine
B) Central incisor
C) Lateral incisor
D) Second bicuspid
E) Second molar

Answer 26

The correct response is Option D.

The mental nerve foramen is located near the second bicuspid or first molar along the border of the mandible. This nerve will give sensation to the lower lip. The other answers are too distal or mesial for the mental nerve foramen.

Question 27

Early replacement of an avulsed tooth is critical to increasing its chance of long-term survival because it minimizes further damage to which of the following structures?

A) Cementum
B) Dentin
C) Enamel
D) Periodontal ligament
E) Pulp

Answer 27

The correct response is Option D.

Avulsion of a permanent tooth is one of the most serious dental injuries that may be encountered by a plastic surgeon. Without prompt intervention, the tooth may be lost, committing the patient to a bone graft, an implant, or lifelong prosthodontic appliance. When a permanent tooth is fully avulsed, exposure of the periodontal ligament can lead to its desiccation and cell death within an hour of injury. The long-term viability of a tooth with a dry time of greater than 60 minutes is poor. If the tooth cannot be immediately replanted, it should be stored in a neutral medium such as milk, saliva (in the mouth), or Hanks balanced storage solution. Enamel and cementum make the hard outer layer of the tooth (enamel at the crown and cementum at the root) and are relatively resistant to damage with an avulsion. Dentin is the thick layer deep to the enamel/cementum, which makes up the bulk of the tooth and is not typically injured in a clean avulsion. The pulp contains the neurovascular supply of the tooth. In a complete avulsion, the pulp will become nonviable and will need to be removed with a root canal procedure after the tooth has become stable. However, with appropriate treatment, the tooth can survive after the pulp has been removed.

Question 28

The muscles of facial expression, the posterior belly of the digastric muscle, and the stapedius muscle are derived from which of the following pharyngeal arches?

A) First
B) Second
C) Third
D) Fourth
E) Sixth

Answer 28

The correct response is Option B.

The pharyngeal, or branchial, arches are developmental structures derived from all three germ layers and also contain neural crest cells. These arches give rise to bony, cartilaginous, vascular, muscular, and neural structures of the head and neck.

The second pharyngeal arch gives rise to the muscles of facial expression, posterior belly of the digastric muscle, and the stapedius muscle. These muscles are innervated by the facial nerve (VII), which also arises from this arch.

The first pharyngeal arch gives rise to the muscles of mastication, anterior belly of the digastric, mylohyoid, tensor tympani, and tensor veli palatini muscles as well as the trigeminal nerve (V). The third pharyngeal arch gives rise to the stylopharyngeus muscle as well as the glossopharyngeal nerve (IX). The fourth pharyngeal arch gives rise to the cricothyroid muscle and all intrinsic muscles of the soft palate except the tensor veli palatini, as well as the superior laryngeal nerve (X). The sixth pharyngeal arch gives rise to the intrinsic muscles of the larynx except the cricothyroid muscle as well as the recurrent laryngeal nerve (X). The fifth pharyngeal arch does not give rise to structures in humans.

Question 29

A 6-year-old boy is brought to the office because of a draining sinus in the midline of the neck. His mother reports that the drainage developed after he had an upper respiratory infection a few weeks ago. Physical examination shows a palpable mass in the mid third of the neck that moves upward when the patient protrudes his tongue. Which of the following is the most likely diagnosis?

A) Infected sebaceous cyst
B) Infected thyroid gland
C) Lymph node
D) Thyroglossal duct cyst
E) Type II branchial cleft cyst

Answer 29

The correct response is Option D.

During embryologic development, the thyroid gland descends from the foramen caecum to the midline of the neck. The tract in descent is typically absorbed but sometimes remains. This can be secondarily infected from infections of the head and neck. Rarely, the thyroid gland does not fully descend into its position in the midline neck.

Diagnosis of this mass over other types of midline mass include elevation of the mass on tongue protrusion. This is because of the remaining attachment to the base of the tongue.

Lymph nodes can present in the midline, but they are infrequent at the level of the hyoid and typically do not drain percutaneously. A type II branchial cleft cyst presents laterally, not in the midline. Infected sebaceous cysts can drain in any hair-bearing area, but do not move with protrusion of the tongue.

Question 30

A 32-year-old woman with bilateral masseter hypertrophy comes to the physician because she wants to have a more heart-shaped face. She has normal occlusion otherwise. Which of the following is the most appropriate initial treatment option for this patient?

A) Injection of botulinum toxin type A 30 to 50 U into the area of the masseter bulk
B) Intraoral debulking of the deep masseteric muscles
C) Sagittal split of the mandible with retrusion
D) Selective denervation of the masseter muscles
E) Use of an orthodontic dental appliance to realign the dentition

Answer 30

The correct response is Option A.

One of the determinants of beauty is facial shape. For a woman, a heart-shaped face is considered youthful and attractive. With a history of bruxism, masseter hypertrophy changes the face into a more square, masculine shape. Botulinum injections can reduce the facial bulk, redefine the lower facial width, and make the face more youthful and heart-shaped.

The other surgical options are associated with significant morbidity and may not give the desired shape. Orthodontic care is used for patients whose malocclusion has altered the facial shape.

Question 31

A 5-year-old child is brought to the office for evaluation of several supernumerary teeth. Which of the following is most characteristic regarding this anomaly?

A) More common in the primary dentition than in the secondary dentition
B) More frequent in the maxilla than in the mandible
C) More prevalent in females than in males
D) Occurs most often from disruption during the morphodifferentiation stage of tooth development
E) Typically associated with ectodermal dysplasia

Answer 31

The correct response is Option B.

Hyperdontia is an anomaly of number of teeth and occurs most frequently in the maxilla (90%). It occurs during the initiation or proliferation stage. Morphodifferentiation issues lead to an anomaly of enamel/dentin/cementin composition. It is more common in males (2:1). It is 5 times more common in permanent dentition than in primary dentition. Finally, ectodermal dysplasia is associated with hypodontia.

Question 32

Which of the following is the most common origin of the superior thyroid artery?

A) Bifurcation of the carotid artery
B) Common carotid artery
C) External carotid artery
D) Internal carotid artery

Answer 32

The correct response is Option C.

The origin of the superior thyroid artery is predictable and most commonly it arises from the external carotid artery. It has, however, been described to arise from all three of the other options, just less frequently.

Question 33

A 6-year-old girl with cerebral palsy is evaluated for sialorrhea. Medical treatment has been unsuccessful. Surgical intervention for drooling control is planned. Which of the following glands contributes the most to basal salivary production?

A) Lacrimal
B) Minor salivary
C) Parotid
D) Sublingual
E) Submandibular

Answer 33

The correct response is Option E.

Daily saliva production is on the scale of 500 to 2000 mL per day. Excessive drooling in patients with cerebral palsy or other severe neurologic impairment is caused by inefficient swallowing. The submandibular glands contribute the most to basal salivary production, approximately 60%. The parotid gland contributes approximately 20% to basal salivary production. Sublingual glands and minor salivary glands each contribute 10%. The lacrimal gland is responsible for production of the aqueous layer of the tear film.

Question 34

Which of the following tooth types is most commonly the last one to erupt when the primary teeth are replaced by permanent teeth?

A) Maxillary canine
B) Maxillary central incisor
C) Maxillary first molar
D) Maxillary first premolar
E) Maxillary lateral incisor

Answer 34

The correct response is Option A.

Aside from the third molars, the maxillary canines are typically the last teeth to erupt of the available options (around 11 to 12 years of age). It is important to give the tooth a large area of viable bone to traverse and become supported by, and alveolar bone grafting is typically performed well in advance of the eruption of the maxillary canine in order to preserve the native tooth.

The maxillary central incisor is often the second permanent tooth a child will erupt, typically at age 7 to 8 years.

The maxillary lateral incisor is often the third permanent tooth a child will erupt, typically at age 8 to 9 years.

The maxillary first premolar is often the fourth permanent tooth a child will erupt, typically at age 10 to 12 years.

The maxillary first molar is often the first permanent tooth a child will erupt, typically at age 6 to 7 years.

Question 35

Which of the following surgeries addresses the most common anatomic site of obstruction in patients with obstructive sleep apnea?

A) Bilateral sagittal split osteotomy
B) Geniohyoid advancement
C) Septoplasty
D) Tracheostomy
E) Uvulopalatopharyngoplasty

Answer 35

The correct response is Option E.

The answer is uvulopalatopharyngoplasty (UP3). The mainstay of UP3 surgery is to remove the uvula and lateral oropharyngeal tissues. The most common site of obstruction in obstructive sleep apnea (OSA) patients is the retropalatal area, including the lateral pharyngeal walls. This latter anatomic area is even more important if the patient has never had a tonsillectomy; in this case, the tonsils are removed in continuity with UP3. UP3 generally decreases the various indexes documented during a sleep study, such as the apnea-hypopnea index, by about 50%. Thus, those at the border of severe and moderate sleep apnea can see their reported indexes go to a level that can be managed by lifestyle changes without the need for a continuous positive airway pressure (CPAP) machine. On the other hand, in patients with very high indexes, these procedures merely make the disease less severe and may allow for a lower setting on the CPAP machine. Although the CPAP machine which applies positive pressure transnasally to patients can “cure” OSA, their compliance rates are low.

There are other procedures that can help with OSA, such as a septoplasty or those that deal with the tongue base (e.g., geniohyoid advancement), but neither directly treats the most common site of obstruction. A tracheostomy is a curative treatment for OSA, but it completely bypasses all of the obstructive points without addressing them. A tracheostomy has much morbidity, including a measurable mortality rate, and is reserved for life-threatening cases of OSA. A sagittal split operation of the mandible is used for occlusion, not OSA.

Question 36

A 50-year-old man who underwent superficial parotidectomy for a benign tumor 9 months ago comes to the office because of a 6-month history of gustatory sweating. Which of the following nerves carries the parasympathetic postganglionic nerve fibers to the parotid gland in a healthy patient?

A) Auriculotemporal
B) External carotid plexus
C) Facial (VII)
D) Great auricular
E) Marginal mandibular

Answer 36

The correct response is Option A.

Although it is most commonly seen after parotidectomy, Frey syndrome has also been encountered after condylar fracture of the mandible and treatment. The syndrome is thought to result from damage to auriculotemporal parasympathetic nerve fibers with subsequent aberrant regeneration and innervation of sympathetic fibers to the sweat glands.

The facial, inferior alveolar, greater auricular, and lingual nerves are not thought to be the underlying cause of Frey syndrome.

Question 37

A 17-year-old boy is brought to the emergency department because of profuse bleeding from a stab wound to the neck above the angle of the mandible anterior to the sternocleidomastoid muscle. After airway stabilization is established, vascular repair of a laceration of the jugular vein is performed. Where is this injury located?

A) Posterior triangle
B) Zone I
C) Zone II
D) Zone III

Answer 37

The correct response is Option D.

Effective treatment of penetrating neck injuries depends on a thorough understanding of neck anatomy. The neck houses vital structures from six organ systems: The vascular system includes the innominate, subclavian, axillary, carotid, jugular, and vertebral vessels. The respiratory system includes the larynx, trachea, and the lung. The digestive system includes the pharynx and esophagus. The neurologic system includes the spinal cord, brachial plexus, cranial nerves, and the sympathetic chain. The endocrine system includes the thyroid and parathyroid. The skeletal system includes the cervical spine.

Anatomy of the neck may be considered using two anatomical paradigms: the concept of “triangles” and the concept of “zones.” The triangles are divided into anterior and posterior, while the zones are divided in a cranial/caudal orientation anterior to the sternocleidomastoid muscle. An understanding of both is important when considering penetrating injuries.

The neck may be divided into two triangles, anterior and posterior to the sternocleidomastoid muscle. The anterior triangle is bordered anteriorly by the midline, posteriorly by the sternocleidomastoid muscle, and superiorly by the lower edge of the mandible. Most vital structures are located in the anterior triangle. The posterior triangle is located within the boundaries of the sternocleidomastoid muscle anteriorly, inferiorly by the clavicle, and the anterior border of the trapezius muscle posteriorly. Trauma to the posterior triangle, excluding the spine, carries a much lower likelihood of significant injury.

Zone I is in the inferior neck and includes the base of the neck and thoracic inlet. It extends from the sternal notch and clavicles to the cricoid cartilage. Zone I contains the thoracic outlet vasculature, vertebral and proximal carotid arteries, apices of the lungs, trachea, esophagus, spinal cord, and thoracic duct.

Zone II is in the mid-neck and continues cephalad from the cricoid cartilage to the angle of the mandible, and contains the jugular veins, vertebral and common carotid arteries, and internal and external branches of the carotid arteries. It also includes nonvascular structures including the trachea, esophagus, larynx, and spinal cord.

Zone III (upper neck) includes the region above the angle of the mandible up to the base of the skull and contains the pharynx along with the jugular veins, vertebral arteries, and the distal portion of the internal carotid arteries. Its caudal border is distal to the common carotid arteries.

Portions of the jugular vein are located in all three zones. Only Zone III is located above the angle of the mandible.

Question 38

A 60-year-old man undergoes microvascular anastomosis. The proximal facial artery off the external carotid artery is to be dissected and used as a recipient vessel. During the procedure, a large, overlying, nerve-like structure is inadvertently transected. Which of the following is the most likely consequence?

A) Dysarthria
B) Lip elevation
C) Shoulder drop
D) Tongue numbness
E) Vocal cord paralysis

Answer 38

The correct response is Option A.

The facial artery generally starts as part of the lingual-facial trunk, then travels below the hypoglossal nerve before it enters into the submandibular gland and along the lateral border of the mandible. Failure to recognize this structure could cause injury and subsequent loss of motor function of the ipsilateral tongue. Ipsilateral hypoglossal (XII) nerve injury causes the tongue to move toward the side of damage, resulting in dysarthria, and problems moving solid food to the oropharynx.

Vocal cord paralysis is related to a recurrent laryngeal or vagus (X) nerve injury, which could happen after superior laryngeal artery or common carotid dissection, respectively.

Shoulder drop is related to accessory (XI) nerve injury, which has anatomic relation to the occipital artery.

Tongue numbness is from an injury to the lingual nerve (related mostly to the laryngeal artery and submandibular duct).

Lip elevation is related to a marginal mandibular (V3) nerve injury—this nerve runs with the facial artery lateral to the mandible, but not below the margin of the mandible.

Question 39

An 11-month-old male infant is noted by his parents to have a painless, progressive, right maxillary growth. At an outside facility, an incisional biopsy is performed. The pathology shows sinonasal myxoma. Postoperative MRI shows residual tumor with surrounding inflammation. Which of the following is the most appropriate treatment plan?

A) Chemotherapy and radiation therapy
B) Chemotherapy only
C) Curettage debulking of the tumor
D) Surgical resection with clear margin
E) Observation

Answer 39

The correct response is Option D.

Myxomas are slow-growing benign tumors. When they present in the infant face, they are most common in the maxilla or mandible. They present as a painless, progressive facial swelling and should be surgically removed with a clear margin. These tumors should have a clear margin to prevent incomplete resection and continued growth. They are not always well circumscribed, so a normal margin or tissue plane should be resected with the tumor.

Question 40

A 20-year-old woman with a history of bruxism is evaluated because of a 3-year history of gradual widening of the lower third of the face. Physical examination shows rectangular appearance of the face; occlusion shows no abnormalities. Anteroposterior x-ray study discloses bone spurs at both angles of the mandible. Which of the following is the most appropriate next step in management?

A) Excision of the submandibular gland
B) Injection of botulinum toxin type A to the masseter muscle
C) Marginal mandibulectomy
D) Suction-assisted lipectomy of the cheek
E) Superficial parotidectomy

Answer 40

The correct response is Option B.

The patient described has bilateral masseter hypertrophy. Treatment options for this condition include muscle relaxants, injection of botulinum toxin type A, or resection of the internal layer of the masseter muscle.

Superficial parotidectomy is indicated for benign and malignant tumors of the parotid gland.

Resection of the submandibular gland is indicated for recurrent sialadenitis (infection) or obstructive sialodocholithiasis (salivary stones), as well as for benign tumors such as pleomorphic adenomas.

Marginal mandibulectomy may be indicated for certain benign and malignant tumors of the intraoral cavity.

Suction-assisted lipectomy will not treat masseter hypertrophy.

Question 41

A 22-year-old man is brought to the emergency department after sustaining a stab wound to the face. The patient is hemodynamically stable, and physical examination shows a laceration that extends from the tragus of the right ear to the right oral commissure. Which of the following is the most likely primary complication of saliva extravasating into the wound because of parotid duct injury?

A) Parotid gland atrophy
B) Salivary fistula
C) Sialocele
D) Wound infection
E) Xerostomia

Answer 41

The correct response is Option C.

If parotid duct injury is not repaired immediately, saliva can leak into the surrounding soft tissues. This leakage most commonly increases the risk for sialocele (pseudocapsule), followed by salivary fistula formation. Wound infection, parotid gland atrophy, and xerostomia (dry mouth) are uncommon. Studies have shown that correction of the more common complications may require surgical or medical treatments such as use of anti-sialogogues, radiation therapy, parasympathetic denervation (tympanic denervation), cauterization of the fistulous tract, reconstruction of the duct, or superficial or total parotidectomy.

Question 42

An otherwise healthy term 6-month-old male infant is evaluated for a mobile, firm, well-circumscribed mass at the right lateral brow in the area of the zygomaticofrontal suture. Which of the following procedures is the most appropriate next step in management?

A) CT scan
B) Fine-needle aspiration of the mass
C) MRI
D) Surgical excision of the mass
E) Ultrasonography

Answer 42

The correct response is Option D.

Dermoid cysts are common in the lateral brow. They present as firm, well-circumscribed, slow-growing masses that have the potential for infection or continued growth. Surgical excision is recommended and no imaging is required. CT scan or MRI require sedation and are unnecessary risks for this patient with a lateral dermoid. Midline masses do require imaging because of the risk for intracranial excision.

Question 43

A 24-year-old man with a history of left facial trauma and condylar fracture of the mandible is evaluated because of redness and perspiration of the left cheek and ear after ingesting certain foods. Aberrant regeneration of which of the following nerves is the most likely cause of this patient’s symptoms?

A) Auriculotemporal
B) Facial
C) Great auricular
D) Inferior alveolar
E) Lingual

Answer 43

The correct response is Option A.

Although it is most commonly seen after parotidectomy, Frey syndrome has also been encountered after condylar fracture of the mandible and treatment. The syndrome is thought to result from damage to auriculotemporal parasympathetic nerve fibers with subsequent aberrant regeneration and innervation of sympathetic fibers to the sweat glands.

The facial, inferior alveolar, greater auricular, and lingual nerves are not thought to be the underlying cause of Frey syndrome.

Question 44

A 12-hour-old male newborn has cyanosis that improves with crying. Which of the following is the most likely diagnosis?

A) Choanal atresia
B) Laryngomalacia
C) Macroglossia
D) Micrognathia
E) Subglottic stenosis

Answer 44

The correct response is Option A.

Choanal atresia is a unilateral or bilateral anatomic abnormality of the posterior nasal passages and choanae, which prevents nasal gas exchange in newborns. The classic presentation of bilateral choanal atresia is cyanosis that improves with crying. Nasal airway obstruction can also become apparent when attempting to breast-feed the baby. On clinical examination, there would be no fogging of a mirror when held under the nares. The remaining abnormalities are other causes of respiratory obstruction in the pediatric patient.

Question 45

A 54-year-old man comes to the office because of swelling of the left side of the face 3 days after cholecystectomy. Physical examination shows erythema and purulent drainage from the parotid duct. Which of the following is the most appropriate initial management?

A) Antibiotic therapy and sialogogues
B) Aspiration of the mass
C) Incision and drainage of the mass
D) Oral cultures and oral cavity antibiotic irrigation
E) Superficial parotidectomy

Answer 45

The correct response is Option A.

Initial treatment of acute suppurative sialadenitis begins with aggressive medical management. This includes prompt fluid and electrolyte replacement, oral hygiene, reversal of salivary stasis, and antimicrobial therapy. Stimulation of salivary flow is done by use of sialogogues such as lemon drops. Warm soaks and massage promote secretion and drainage of the gland.

Oral cultures are typically contaminated by oral flora and therefore do not direct antibiotic treatment. Needle aspiration is more accurate in isolating the cause of suppurative parotitis.

Incision and drainage is reserved for cases resistant to medical management. Surgical removal of the gland is not recommended in the case of an actively infected gland.

Question 46

A 65-year-old man undergoes surgery for management of a subtotal massive squamous cell carcinoma of the posterior larynx. History includes chemoradiation and subsequent bilateral selective neck dissections for persistent disease 9 months ago. An anterolateral thigh free flap is chosen for reconstruction, but the operative notes state that both external carotid systems were sacrificed. Which of the following recipient vessels is most appropriate in this patient?

A) Facial
B) Internal mammary
C) Occipital
D) Subclavian
E) Transverse cervical

Answer 46

The correct response is Option E.

When performing head and neck microsurgery, a strong background in the vascular anatomy of that region is imperative. As chemotherapy regimens have become commonplace for laryngopharyngeal cancers, so have the challenges of failures which generally require surgery. These cases have much higher complication rates, including fistulas, strictures, and carotid injury, among others. This case demonstrates another complexity that is increasingly observed, the “vascular or vessel-depleted neck.” The facial and occipital arteries are branches of the external system and would not be available. The subclavian is generally not a viable option due to its size, location, and potential complications through dissection. The internal mammary system has potential, but requires dissection through the ribs and has morbidities and the potential need of vein grafts. Generally speaking, even radical neck dissections do not sacrifice the transverse cervical vessels as they are usually used as the caudal margin. A number of reports have detailed the usefulness of these vessels as recipients in cases like the one described.

Question 47

Which of the following cranial nerves provides parasympathetic innervention of the parotid gland?

A) V
B) VII
C) VIII
D) IX
E) X

Answer 47

The correct response is Option D.

Innervation of the parotid gland comes from parasympathetic fibers that travel with the glossopharyngeal nerve (cranial nerve IX). It also receives taste sensation (afferent) from the posterior one-third of the tongue.

The maxillary nerve of cranial nerve V (V2) is a sensory nerve and receives sensation from the mid face.

Parasympathetic fibers (efferent) innervate the submandibular and sublingual glands via the chorda tympani. Afferent fibers, via the chorda tympani, send taste sensation of the anterior two-thirds of the tongue.

The vestibulocochlear nerve (cranial nerve VIII) supplies sound and equilibrium to the brain.

The auricular branch of the vagus nerve (cranial nerve X), innervates the external acoustic meatus. Stimulation of the vagus nerve can lead to reflex coughing (Arnold reflex).

Question 48

Which of the following muscles is associated with the hyoid or second branchial arch?

A) Lateral pterygoid
B) Levator veli palatini
C) Posterior digastric
D) Stylopharyngeus
E) Thyroarytenoid

Answer 48

The correct response is Option C.

The first branchial arch, also known as the mandibular arch, has the trigeminal nerve (ophthalmic, maxillary, and mandibular branches) as its neurologic component. The muscles of mastication (i.e., temporalis, masseter, medial, and lateral pterygoids); mylohyoid; anterior digastric; tensor tympanic; and the tensor veli palatini are the muscle components. The cartilaginous bar gives rise to the premaxilla; maxilla, zygomatic bone; part of the temporal bone; incus; malleus; anterior malleolar ligament; and the sphenomandibular ligament. The pharyngeal pouch and groove develop the tubotympanic recess (tympanic cavity, mastoid antrum and pharyngotympanic tube, internal acoustic meatus, tympanic membrane, adenoids). The vascular element largely disappears, but gives rise to the maxillary and external carotid arteries.

The second branchial arch, also known as the hyoid arch, accounts for 95% of all branchial arch anomalies. The cranial nerve is the facial nerve. It supplies the muscles of facial expression; buccinators; stapedius; stylohyoid; posterior digastric; auricular and platysma muscles. The skeletal contributions from Reichert’s cartilage include the stapes, styloid process, stylohyoid ligament, and hyoid (lesser cornu and upper part of body). The pharyngeal pouch and groove shape the crypts of the palatine tonsil and the cervical sinus. The vascular component again primarily disappears but forms the stapedial and hyoid arteries.

Third branchial cleft anomalies are rare. The glossopharyngeal nerve sends motor innervation to only the stylopharyngeus. The cartilaginous bar forms the hyoid (greater cornu and lower part of body). The pharyngeal pouch and groove give rise to the inferior parathyroids, thymus, and cervical sinus. The vascular elements contribute to the internal carotid and common carotid.

The fourth branchial arch is supplied by the vagus nerve (superior laryngeal, inferior laryngeal). Musculature innervated includes the cricothyroid and all intrinsic muscles of the soft palate, including the levator veli palatini. The thyroid and epiglottic cartilage develop from the cartilaginous bar. The pharyngeal pouch and groove form the superior parathyroids, and the thyroid parafollicular cells. The right fourth aortic arch forms the subclavian artery, while the left fourth aortic arch forms the aortic arch.

The sixth branchial arch also is supplied by the vagus nerve (recurrent laryngeal nerve). This area supplies all intrinsic muscles of the larynx (except the ciricothyroid-fourth arch). This includes the thyroarytenoid muscle, which makes up the primary mass of the vocal fold. It consists of two parts, the ventricularis and vocalis. Skeletal derivations form the cricoid, arytenoid, corniculate, and cuneiform cartilages. The right sixth aortic arch gives rise to the right pulmonary artery and the left sixth aortic arch forms the left pulmonary artery and the ductus arteriosus.

Question 49

A 6-year-old boy is brought to the emergency department because of a laceration of the hard palate. Repair of the laceration with local anesthesia for greater palatine nerve block is planned. As the anterior portion is sutured in place, the patient feels pain. Which of the following additional nerve blocks is most appropriate?

A) Anterior superior alveolar
B) Infraorbital
C) Lesser palatine
D) Middle superior alveolar
E) Sphenopalatine

Answer 49

The correct response is Option E.

The sphenopalatine nerve arises from the incisive foramen and provides sensation to the anterior hard palate. Blockade of this nerve is essential for adequate blockade of the palatal mucosa for laceration repair.

The anterior superior alveolar nerve arises from the second branch of the trigeminal nerve before it exits the infraorbital foramen. The nerve supplies the maxillary anterior teeth and is part of the superior dental plexus of nerves that also includes the middle superior alveolar and the posterior superior alveolar nerves.

The infraorbital nerve provides sensation to the ipsilateral lateral nose, upper lip, and cheek.

The lesser palatine descends through the greater palatine foramen and provides innervation to the soft palate and uvula.

Question 50

A 4-year-old boy is brought for evaluation because his mother is concerned about a growth on his neck. Physical examination shows a nontender mass in the midline of the neck that moves vertically when the patient swallows. Which of the following is the most likely cause of this patient’s condition?

A) Failure of vascular apoptosis at 12 weeks’ gestation
B) Failure of the thyroglossal duct to atrophy
C) Ossification of cartilage from the second and third pharyngeal arches
D) Persistent ectopic parathyroid tissue in the neck
E) Persistent ectopic parathyroid tissue in the neck

Answer 50

The correct response is Option B.

The patient described has a persistent thyroglossal duct cyst.

The thyroid gland is the first of the body’s endocrine glands to develop, at approximately 24 days’ gestation. The gland originates as a proliferation of endodermal epithelial cells on the median surface of the developing pharyngeal floor known as the foramen cecum. The foramen cecum originates from between the first and second pouches and represents the opening of the thyroglossal duct into the tongue. Descent of the thyroid gland carries it anterior to the hyoid bone and anterior to the laryngeal cartilages. As the thyroid gland descends, it forms its mature shape. The thyroid completes its descent in the seventh gestational week, coming to rest in its final location immediately anterior to the trachea.

If the thyroglossal duct does not atrophy, then the remnant can manifest clinically as a thyroglossal duct cyst. While half of these generally midline cystic masses are located at or just below the level of the hyoid bone, they may be located and can track anywhere from the thyroid cartilage up the base of the tongue. Because the hyoid bone develops in an anterior direction and may surround the thyroglossal duct, the surgeon should resect the central portion on the hyoid bone along with the cyst.

The thyroid gland is ensheathed by the visceral fascia, which attaches it firmly to the laryngoskeleton (i.e., Berry ligament). This firm attachment of the gland to the laryngoskeleton is responsible for movement of the thyroid gland and related structures during swallowing. This also causes a thyroglossal duct cyst to move on physical examination.

Ectopic thyroid gland may occur anywhere along the path of initial descent of the thyroid, although it is most common at the base of the tongue, just posterior to the foramen cecum.

Ectopic parathyroid glands occur in 15 to 20% of patients. The glands may be located anywhere near or even within the thyroid or thymus. For example, if parathyroid IVs do not descend entirely, they may be located as high as the bifurcation of the common carotid artery. Conversely, if parathyroid IVs do not release from the thymus, they may be located intrathoracically, as low as the aortopulmonary window. Other common ectopic locations include the anterior mediastinum, posterior mediastinum, and retroesophageal and prevertebral regions. However, even when the parathyroid glands are in an ectopic location, they still often are symmetrical from side to side, making localization somewhat easier.

Ossification of cartilages from the second and third pharyngeal arches gives rise to the hyoid bone.

Question 51

Which of the following structures (A-E) is responsible for anchoring the tooth in its socket?

Answer 51

The correct response is Option D.

The periodontal ligament is responsible for keeping the tooth anchored. Enamel is the outer protective layer of the tooth. Dentine, enamel, cementum, and pulp are the four major components of the tooth but none are responsible for anchoring the tooth.

Question 52

A 32-year-old woman comes to the office for consultation regarding cosmetic improvement of her nose. On examination, facial animation (smiling) causes marked descent of the nasal tip, shortening of the upper lip, and a transverse crease in the mid philtral area. These findings are most consistent with the action of which of the following muscles?

A) Depressor septi nasi
B) Nasalis
C) Procerus
D) Risorius
E) Zygomaticus major

Answer 52

The correct response is Option A.

A deformity upon facial animation characterized by descent of the nasal tip, shortening of the upper lip, and a transverse crease in the mid philtral area may be created or accentuated by the action of the depressor septi nasi muscles. These are small, paired muscles located on each side of the nasal septum, which originate at the medial crura foot plates and insert either on the incisive fossa of the maxilla or into the fibers of the orbicularis oris muscle.

Physical examination upon facial animation should be part of the routine preoperative evaluation of the rhinoplasty patient. Those who present with the dynamic deformity as described may benefit from excision or transection of the depressor septi nasi muscles. Several surgical techniques have been described, as well as the use of botulinum toxin type A.

The nasalis muscle compresses the cartilaginous part of the nose and draws the ala toward the septum. Although this may generate some depression of the tip of the nose, it should not cause shortening of the upper lip.

The procerus muscle depresses the medial angle of the eyebrows, creating transverse rhytides over the bridge of the nose. The risorius muscles retract the angles of the mouth, as in a grinning expression. The zygomaticus major muscles draw the angles of the mouth posteriorly and superiorly, as in laughing. These muscles do not cause depression of the tip of the nose.

Question 53

During the period of mixed dentition, which of the following is the first permanent tooth to erupt?

A) Mandibular canine
B) Mandibular first molar
C) Mandibular first premolar
D) Maxillary central incisor
E) Maxillary lateral incisor

Answer 53

The correct response is Option B.

The stage of mixed dentition is defined as the age range in which there are both deciduous (primary) and permanent (secondary) teeth erupted in the oral cavity at the same time. Normally, the mandibular and maxillary teeth erupt in a slightly different pattern. This usually occurs at age 6 to 7 years and is completed by age 11 to 12 years. In the maxilla, the order of eruption is as follows: first molar, central incisor, lateral incisor, first premolar, second premolar, canine, second molar, and third molar. In the mandible, the order is slightly different and is as follows: first molar, central incisor, lateral incisor, canine, first premolar, second premolar, and second molar. The permanent first molars erupt between ages 6 and 7 years, the central and lateral incisors erupt between ages 6 and 8 years, and the first premolars erupt between ages 8 and 9 years. The first tooth to erupt is the permanent mandibular first molar, which erupts first in a position posterior to the deciduous second molar. There are no premolars in deciduous teeth.

Question 54

A 22-year-old man comes to the emergency department after he sustained a machete laceration of the left cheek extending from the tragus through the midpoint of the upper lip. The wound is full thickness along the central third. Examination shows left upper lip droop and flattening of the associated nasolabial fold. Which of the following structures were most likely injured?

A) Lacrimal sac, mandibular branch of the facial nerve, and pterygoid muscle
B) Maxillary sinus, zygomatic branch of the facial nerve, and pterygoid muscle
C) Parotid duct, buccal branch of the facial nerve, and masseter muscle
D) Zygomatic arch, zygomatic branch of the facial nerve, and orbicular muscle

Answer 54

The correct response is Option C.

The middle third of a line drawn between the tragus and the middle of the upper lip defines the course of the parotid duct. The buccal and zygomatic branches of the facial nerve lie in close proximity to the parotid duct, which lies superficial to the masseter muscle. Deep penetrating trauma in this region is likely to injure all three of these structures. Evidence of injury to the zygomatic or buccal branch of the facial nerve with a central cheek laceration should raise concern for a parotid duct injury.

The lacrimal sac is outside of the described zone of injury, as is the mandibular branch of the facial nerve. The pterygoid muscle is deep to the mandible and would be outside of the described zone of injury.

The maxillary sinus and the zygomatic branch of the facial nerve could have been injured, but not in combination with the pterygoid muscle, which is outside the zone of injury.

Concomitant injury of the zygomatic arch and zygomatic branch of the facial nerve is possible, but because this injury was full thickness in the central third, the orbicularis muscle would not have been involved.

Question 55

A 4-year-old girl is brought to the office because of a congenital mucous-draining skin sinus located on the lower third of the neck, overlying the anterior border of the left sternocleidomastoid muscle. On physical examination, swallowing causes noticeable puckering of the sinus. Intraoperative probing shows that it communicates with the left tonsillar fossa. On surgical exploration, which of the following is the most likely ascending course of this sinus?

A) Deep to the hypoglossal nerve
B) Deep to the internal carotid artery
C) Superficial to the posterior belly of the digastric muscle
D) Superficial to the stylohyoid muscle
E) Superficial to the stylopharyngeal muscle

Answer 55

The correct response is Option E.

Surgical exploration is most likely to show the ascending course of this pharyngeal fistula to be superficial to the stylopharyngeal muscle.

Second pharyngeal cleft and pouch anomalies (including cysts, fistulas, and sinuses) account for 67 to 95% of the total anomalies of the pharyngeal apparatus. Cysts are the most common finding, occurring three times more often than fistulas. Fistulas usually present at birth. They derive from the ventral portion of the second pharyngeal cleft and pouch. The external opening is usually found along the anterior border of the sternocleidomastoid muscle, between the hyoid bone superiorly and the suprasternal notch inferiorly. Fistulas have a muscular coat, which is continuous superficially with the platysma and internally with the palatopharyngeal muscle. If this muscle coat is well developed, swallowing causes a pull on the fistulous opening, resulting in puckering.

The anatomical relations between a second pharyngeal cleft and pouch fistula and the surrounding cervical structures are dictated by the embryogenesis of the pharyngeal apparatus. As an anomaly of the second cleft and pouch, the fistula is expected to course deeply to the second arch structures and superficially to the structures derived from the third to sixth arches.

Therefore, the described fistula is expected to course deep to the stylohyoid muscle and posterior belly of the digastric muscle (derived from the second pharyngeal arch), and superficial to the internal carotid artery and stylopharyngeal muscle (derived from the third pharyngeal arch).

The hypoglossal nerve and associated infrahyoid muscles do not develop in the mesenchyme of the pharyngeal apparatus, instead being derived from occipital somites in the paraxial mesoderm. All pharyngeal anomalies derived from ectoderm (e.g., fistulas) will be found superficial to the hypoglossal nerve and the infrahyoid strap muscles.

Other cervical structures not mentioned in this scenario but which are relevant to the course of the described fistula include the external carotid artery (second pharyngeal arch) and the glossopharyngeal nerve (third pharyngeal arch). The expected fistula course is deep to the former and superficial to the latter.

Question 56

A 25-year-old man comes to the office for consultation regarding a 10-year history of gradual swelling of the right side of the face. Physical examination shows class I occlusion, normal interincisal distance, and smooth occlusal surfaces on the right molar teeth. The right cheek is enlarged when he clenches the teeth. CT scan shows a right masseter that is twice as large as the left one, and there is an outward curvature of the angle of the mandible. Which of the following is the most appropriate treatment?

A) Condylar reduction
B) Masseter resection
C) Orthodontics
D) Radiation therapy
E) Sagittal split osteotomy

Answer 56

The correct response is Option B.

Benign masseteric hypertrophy may present as a bilateral or a unilateral condition. When unilateral, it is associated with repetitive unilateral clenching of the teeth. Both the masseter and temporalis muscles of the affected side show varying degrees of enlargement. When mild, medical management may be offered first and can include muscle relaxants, anxiolytics, antiepileptic drugs, and botulinum toxin type A. Surgical resection of a portion of the masseter and/or bone contouring are appropriate surgical procedures for correction of the resulting cosmetic deformity.

Unilateral masseteric hypertrophy must be distinguished from unilateral condylar hyperplasia, the latter consisting of the enlargement or overgrowth of the mandibular condyle. Condylar hyperplasia may also present with unilateral facial enlargement (type IB or type II), deviation of the mandibular midpoint toward the unaffected side, class III occlusion on the ipsilateral side, and a crossbite on the contralateral side. Condylar resection is the mainstay of treatment.

Condylar reduction is appropriate for cases of condylar dislocation. This condition can occur unilaterally in patients with a hypermobile or stretched temporomandibular joint, or in patients with dystonia (hyperfunction of the lateral pterygoid muscle). Condylar dislocation occurs suddenly, and causes pain and a class III occlusion on the involved side. Condylar reduction is performed with the aid of muscle relaxants. Eminence surgery may be necessary (eminectomy, eminoplasty).

Orthodontics are unnecessary for someone with bruxism, which is a typical feature of masseteric hypertrophy. However, a mouth guard is appropriate.

Radiation is inappropriate for benign masseteric hypertrophy. It does not correct the underlying cause or the deformity associated with this condition.

Sagittal split osteotomy is indicated in cases of class II or III malocclusion in which reduction or lengthening of the anteroposterior length of the mandible will achieve dental harmony. This procedure is not appropriate for class I occlusion or flaring of the mandibular angle.

Question 57

Which of the following cranial nerves is responsible for parasympathetic innervation to the parotid gland?

A) Trigeminal (V) nerve
B) Vestibulocochlear (VIII) nerve
C) Glossopharyngeal (IX) nerve
D) Vagus (X) nerve
E) Hypoglossal (XII) nerve

Answer 57

The correct response is Option C.

The innervation of the parotid gland comes from parasympathetic fibers of the glossopharyngeal nerve (cranial nerve IX). It also receives taste sensation (afferent) from the posterior one third of the tongue.

The maxillary nerve of cranial nerve V (V2) is a sensory nerve and receives sensation from the mid face.

Parasympathetic fibers (efferent) innervate the submandibular and sublingual glands via the chorda tympani. Afferent fibers, via the chorda tympani, send taste sensation of the anterior two thirds of the tongue.

The vestibulocochlear nerve (cranial nerve VIII) supplies sound and equilibrium to the brain.

The Arnold nerve, also called the auricular branch of the vagus nerve (cranial nerve X), innervates the external acoustic meatus. Stimulation of the Arnold nerve can lead to reflex coughing (Arnold reflex).

Question 58

A 35-year-old woman is evaluated because of numbness of the upper helical rim of the left ear 30 days after she underwent neurosurgical decompression to treat facial pain. Which of the following nerves was most likely injured?

A) Auriculotemporal
B) Glossopharyngeal
C) Great auricular
D) Lesser occipital
E) Vagus

Answer 58

The correct response is Option A.

Knowledge of the innervation of the external ear is critical to the understanding of its embryologic development, as well as in the delivery of adequate local anesthesia for minor surgical procedures. Sensation to the external ear is derived from several cranial and extracranial nerve branches. The great auricular (C2 to C3) and lesser occipital (C2) are cranial nerves which innervate the posterior aspect of the auricle and lobule. While the distribution is variable, in most cases the lesser occipital supplies the superior ear and mastoid region while the great auricular nerve supplies the inferior ear and a portion of the preauricular area. The anterior surface of the ear, including the helix, scapha, and concha, is supplied by the auriculotemporal nerve (V3 trigeminal) and is most likely to be injured in a microvascular decompression for the treatment of trigeminal neuralgia. Branches of the vagus (X) and glossopharyngeal (IX) nerve innervate the external auditory meatus.

The innervation to the external ear follows its embryologic branchial arch origins with the great auricular nerve innervating first branchial arch structures and the auriculotemporal nerve innervating second branchial arch structures. An auriculotemporal nerve block provides anesthesia to the helix and tragus and is approached by injecting 2 to 4 mL of anesthesia superiorly and anteriorly to the tragus. The great auricular nerves and lesser occipital nerves are blocked by injecting 2 to 4 mL of anesthetic to the posterior sulcus from the inferior aspect of the earlobe. This will provide anesthesia to the earlobe and lateral helix.

Question 59

A 50-year-old man undergoes wide local excision and bilateral selective cervical lymphadenectomy because of a 6-month history of invasive squamous cell carcinoma of the anterior floor of the mouth. Free tissue transfer using an anterolateral thigh free flap, including harvest of the lateral femoral cutaneous nerve, reconstructs the ventral glossectomy and floor-of-mouth defect. Which of the following is the most likely recipient nerve for functional sensory recovery of the free flap in this patient?

A ) Cervical branch of facial
B ) Great auricular
C ) Hypoglossal
D ) Inferior alveolar
E ) Lingual

Answer 59

The correct response is Option E.

Oral mucosal sensation is important in many stomatognathic functions. Mastication, oral hygiene, phonation, and swallowing can all influence patient quality of life. A proportionally worsening functional impact with an increasing area of anesthesia has been noted. Therefore, restoration of sensibility should be one of the important components of the functional rehabilitation of glossectomy defects.

Although spontaneous reinnervation does occur in noninnervated flaps, it takes a longer period of time to develop, and it may not restore adequate functional sensation, nor does it provide useful tactile sensation or two-point discrimination. These sensory modalities are important in a patient’s ability to handle oral secretions and food boluses.

Microsurgical anastomoses of the lateral femoral cutaneous nerve is most commonly performed to the lingual nerve stump left after tumor extirpation.

The cervical branch is the lowest division of facial motor nerve and would not provide sensory recovery to the freely transferred thigh tissue.

The great auricular nerve provides sensation to the earlobe and can serve as an ideal donor for segmental nerve grafting, if required. Bioprosthetic conduits (nerve tubes) or vein grafts have also been described for this purpose.

The hypoglossal nerve is commonly identified and preserved in selective cervical lymphadenectomy, and, if divided, causes a motor paralysis of the ipsilateral tongue.

The inferior alveolar nerve is part of the trigeminal system (V3) and is not divided during a floor-of-mouth resection and/or glossectomy, unless a segmental mandibulectomy is also performed.

Question 60

Which of the following best describes the anatomical location of the nerve that supplies sensation to the frontoparietal scalp at the level of the forehead?

A ) In the subcutaneous fat
B ) Superficial to the frontalis muscle
C ) Superficial to the galea aponeurosis
D ) Superficial to the periosteum
E ) Through the medial corrugator supercilii muscle

Answer 60

The correct response is Option D.

The supraorbital nerve (SON) supplies sensation to the forehead skin (paramedian) and anterior scalp as well as the frontoparietal scalp. The latter scalp is supplied by the deep division of the nerve, whereas the rest is supplied by its superficial division. Medially passing through the corrugator supercilii muscle is the supratrochlear nerve, which supplies the medial skin of the forehead. The deep division of the SON travels initially (just medial to the superotemporal line) along the temporal periosteum and then more cephalad pierces the deep galea plane and enters the galea fat pat. This information is the key to avoid injury when performing a forehead lift. Also, when planning a bicoronal incision for craniofacial surgery, one can use this information to preserve the sensation of the related scalp. The superficial branch of the SON, on the other hand, travels superficial to the frontalis muscle in the paramedian forehead area.

Question 61

An otherwise healthy 20-year-old woman who underwent functional septorhinoplasty 3 months ago comes to the office because she says her food “does not taste normal.” Physical examination shows that the nasal airway is open and unobstructed. No functional abnormalities are noted. Which of the following is the most likely diagnosis?

A) Gustatory rhinorrhea
B) Neurapraxia of lingual nerve during the surgery
C) Olfactory dysfunction from nasal surgery
D) Taste bud alterations from prescribed antibiotics
E) Tongue injury from intubation

Answer 61

The correct response is Option C.

Because 80% of a meal’s flavor is a result of olfactory input, patients often interpret a loss of smell as a loss of taste. For most patients who complain of chemosensory loss, however, the sense of taste—biologically, the sensation of salt, bitter, sweet, sour, and umami (monosodium glutamate)— which is from cranial nerve V, is intact. In a large prospective study, 7 to 9% of individuals who have undergone various types of nasal surgery experienced a decrease in olfactory function.

Gustatory rhinorrhea is an increasingly recognized complication of septoplasty and rhinoplasty that is associated with clear rhinorrhea postoperatively when the patient eats. This complication is not usually associated with changes in taste. It probably stems from inappropriate nerve regeneration, not dissimilar to gustatory sweating (Frey syndrome) after parotidectomy. Many drugs can affect taste, but usually antibiotics given for this type of surgery would be limited to a short course, and their side effects would almost certainly be resolved. Injury to the tongue and its nerves, including the lingual nerve, is possible, but rare; injury also would have been resolved in a period of 3 months.

Question 62

A 67-year-old woman comes to the office because of a mass on the left side of the roof of the mouth. The patient notes that it has enlarged gradually since she first noticed it 6 months ago. Examination shows a 2-cm mass on the left hard palate and loss of sensation over the left cheek. Examination of a specimen obtained on biopsy shows adenoid cystic carcinoma. Which of the following skull-base foramina is most likely to be involved by this tumor?

A) Jugular
B) Lacerum
C) Ovale
D) Rotundum
E) Stylomastoid

Answer 62

The correct response is Option D.

Adenoid cystic carcinoma of the hard or soft palate is a slow-growing, insidious disease with a tendency to spread via a perineural mechanism along the palatine branches of the maxillary division of the trigeminal nerve. The facial nerve exits the skull base from the stylomastoid foramen. The foramen lacerum, foramen ovale, and the foramen rotundum contain the internal carotid artery, mandibular (V3) nerve, and maxillary (V2) nerve, respectively. The glossopharyngeal (IX), vagus (X), and spinal accessory (XI) nerves emerge from the jugular foramen.

Question 63

A male newborn is evaluated because of persistent cyanosis at birth. The cyanosis is relieved by crying. Physical examination shows normal facies. Which of the following is the most likely diagnosis?

A) Choanal atresia
B) Lingual thyroid
C) Lymphatic malformation
D) Pierre Robin sequence
E) Subglottic stenosis

Answer 63

The correct response is Option A.

The patient described most likely has bilateral choanal atresia. Paradoxical cyanosis (cyanosis that is relieved by crying) is a classic symptom because newborns are obligate nose breathers. The diagnosis was traditionally confirmed by an inability to pass a catheter through the nose into the nasopharynx. CT scans are now routinely obtained and may show narrowing of the posterior nasal cavity because of medial displacement of the lateral nasal wall and pterygoid plates, as well as enlargement of the posterior vomer. Choanal atresia may be isolated or associated with other abnormalities, such as in the CHARGE association (coloboma, heart defects, choanal atresia, retarded growth and development, genital hypoplasia, and ear abnormalities), or with various craniosynostotic syndromes.

Lingual thyroid results from failure of some or all of the thyroid gland to descend from the tuberculum impar of the tongue during embryonic development and presents as a posterior tongue mass that may obstruct the airway. Lymphatic malformations, also known as cystic hygromas when occurring in the head and neck region, are soft, subcutaneous masses that may be associated with respiratory distress when very large. Pierre Robin sequence consists of glossoptosis (posterior displacement of the tongue), micrognathia (small mandible), airway obstruction, and often a cleft palate. Respiratory distress is caused by obstruction by the tongue and is relieved by prone positioning. Congenital subglottic stenosis results in respiratory distress caused by narrowing of the subglottic airway. The stenosis may be membranous, in which there is submucosal hypertrophy of fibrous connective tissue and mucous glands, or cartilaginous, in which the cricoid cartilage is shaped abnormally. None of these entities typically presents with paradoxical cyanosis.

Question 64

Which of the following cranial nerves develops with the first branchial arch?
A) Facial (VII)
B) Glossopharyngeal (IX)
C) Hypoglossal (XII)
D) Trigeminal (V)
E) Vagus (X)

Answer 64

The correct response is Option D.
The first branchial arch is associated with the trigeminal nerve (V), second branchial arch with the facial nerve (VII), third branchial arch with the glossopharyngeal (IX), fourth branchial arch with the superior laryngeal (X), and sixth branchial arch with the recurrent laryngeal (X).

Question 65

The stylopharyngeus muscle is innervated by which of the following nerves?
A) Facial (VII)
B) Glossopharyngeal (IX)
C) Hypoglossal (XII)
D) Trigeminal (V)
E) Vagus (X)

Answer 65

The correct response is Option B.
The pharyngeal muscles are all innervated by the vagus (X) nerve, except the stylopharyngeus muscle, which is innervated by the glossopharyngeal nerve (IX). The trigeminal nerve (V) is responsible for facial and oral sensation. The maxillary branch (V2) is responsible for sensation of the upper teeth, upper lip, hard palate, cheeks, and nasopharyngeal mucosa. The mandibular branch (V2) provides sensory fibers for the lower teeth, lower mucosa of the mouth and the anterior two-thirds of the tongue. The facial nerve (VII) provides motor innervation of the muscles of facial expression and the posterior bellies of the stylohyoid and digastric muscles. The vagus nerve (X) provides motor innervation to all of the pharyngeal muscles except the stylopharyngeus muscle. The hypoglossal nerve (XII) provides motor innervation to the intrinsic and extrinsic tongue muscles and also provides motor innervation to the geniohyoid muscle through the ansa cervicalis.

Question 66

Which of the following structures is formed from the same branchial arch as the vagus (X) nerve?

a. Inferior parathyroid glands
b. Lesser horn of hyoid
c. Levator veli palatini
d. Maxillary artery
e. Styloid process

Answer 66

The correct response Option C.

Each of the six branchial arches gives rise to a branch of the aortic arch, a cranial nerve, muscular structures, and skeletal structures. The fourth branchial arch gives rise to the right proximal subclavian artery, the aortic arch, the vagus (X) nerve, the superior laryngeal nerve, the intrinsic muscles of the levator veli palatini, cricothyroid muscles, laryngeal cartilages, and the superior parathyroid glands.

The styloid process is derived from the second branchial arch, along with the stapedial and hyoid arteries, the facial (VII) nerve, the muscles of facial expression, the stapes, the lesser horn of the hyoid bone, and the crypts of the palatine tonsils.
The maxillary artery is derived from the first branchial arch, along with the trigeminal (V) nerve, the muscles of mastication, anterior belly of the digastric muscle, tensor tympani, tensor veli palatini, mylohyoid, mandible, incus and malleus, maxilla, vomer, zygoma, and temporal bone.

The inferior parathyroid glands are derived from the third branchial arch, along with the common carotid artery, internal carotid artery, glossopharyngeal (IX) nerve, stylopharyngeus muscle, greater horn of the hyoid bone, and thymus.

The lesser horn of the hyoid bone is derived from the second branchial arch.

Reference(s)

1. Adams A, Mankad K, Offiah C, Childs L. Branchial Cleft Anomalies: A Pictorial Review of Embryological Development and Spectrum of Imaging Findings. Insights Imaging. 2016 Feb; 7(1):69-76.
2. Cohen M. Malformations of the Craniofacial Region: Evolutionary, Embryologic, Genetic, and Clinical Perspectives. Am J Med Genet A. 2002 Dec; 115(4):245-68.