Head and Neck Congenital Flashcards
Formation of the primary palate begins during which of the following weeks of gestation?
(A) First
(B) Third
(C) Fifth
(D) Eighth
(E) Eleventh
The correct response is Option C.
Formation of the primary palate begins during the fifth week of gestation and is completed by the end of the sixth week of gestation. Anatomically, it is located anterior to the incisive foramen. The premaxilla only contains the central and lateral incisors.
The internal carotid artery supplies which of the following arteries of the scalp?
(A) Frontalis
(B) Occipitalis
(C) Parietal
(D) Posterior auricular
(E) Supraorbital
The correct response is Option E.
The supraorbital and supratrochlear arteries are branches of the internal carotid artery via the ophthalmic artery and, therefore, receive their blood supply from the internal carotid. The arteries of the scalp travel through the subcutaneous fat from the periphery toward the vertex, then anastomose in the midline with branches of the ophthalmic artery. If the internal carotid artery is thrombosed, branches of the external carotid arteries supply blood to the anterior part of the scalp through the angular and ophthalmic arteries.
The frontalis and parietal arteries are branches of the superficial temporal artery, which in turn branches from the external carotid arteries. The occipitalis and posterior auricular arteries are also branches of the external carotid arteries.
A 38-year-old woman sustains an injury to the auriculotemporal nerve during superficial parotidectomy for removal of a mixed tumor. Which of the following is the most likely postoperative finding?
(A) Numbness of the concha, helix, lobule, and temporal skin
(B) Numbness of the tragus, external auditory canal, and temporal skin
(C) Numbness of the entire pinna and paralysis of the temporalis muscle
(D) Paralysis of the auricularis anterior, superior, and posterior muscles
(E) Paralysis of the temporalis muscle
The correct response is Option B.
Injury to the auriculotemporal nerve is most likely to result in numbness of the tragus, external auditory meatus, tympanum, and temporal skin. The auriculotemporal nerve is a branch of the mandibular division of the trigeminal nerve (V3). The fascicles of this nerve divide soon after the nerve originates to allow for passage of the middle meningeal artery. The nerve then courses between the sphenomandibular ligament and the neck of the condyle, emerges from behind the temporomandibular joint, and travels toward the posterior surface of the upper portion of the parotid gland, where it may be vulnerable to injury during parotidectomy. It ascends with the superficial temporal vessels over the posterior zygomatic arch and divides into three branches, which provide cutaneous sensory innervation to the tragus, external acoustic meatus, tympanic membrane, and temporal region. Minor branches of the auriculotemporal nerve convey secretomotor fibers to the parotid gland and articular fibers to the temporomandibular joint.
The concha and antihelix receive sensory innervation from the auricular branch of the vagus (X) nerve. Sensory innervation to the helix and lobule is supplied by the great auricular nerve and lesser occipital nerve, which are derived from C2-3.
The auricularis anterior, superior, and posterior muscles receive motor innervation from the temporal and posterior auricular branches of the facial (V) nerve.
The temporalis muscle is innervated by the deep temporal nerves, which are derived from the anterior, or motor, branch of the mandibular division of the trigeminal nerve (V3).
A 10-month-old boy is brought to the office because of the ocular defect shown in the photograph. Which of the following is the correct term for this anomaly?
A) Anophthalmia
B) Coloboma
C) Congenital cataract
D) Palpebral fissure
E) Tessier No. 6 cleft
Coloboma is a congenital ocular defect of the eyelid, iris, retina, choroid, or optic disk. The defects can range in size from a small notch to a large structural cleft. Palpebral colobomas are thought to arise from a localized growth disturbance, while colobomas of the iris, retina, and optic disk arise from defective closure of the optic fissure. Upper eyelid coloboma rarely affects vision; large defects of the lower eyelid can lead to corneal ulceration. Anophthalmia is total absence of the eye. A congenital cataract is a lens opacity that is present in 1:4000 to 1:10,000 newborns. The size and location determine the effect on vision. The palpebral fissure is the natural opening between the upper and lower eyelids. A Tessier No. 6 cleft involves the inferolateral aspect of the lower eyelid, inferior orbital rim, and the zygoma. This cleft often has an associated lower eyelid coloboma and is related to Treacher Collins syndrome.
A 45-year-old woman comes to the office because she has had a 4-week history of a rapidly enlarging left parotid mass. On physical examination, the patient has ptosis of the left eyebrow and is unable to fully close the left eye or depress the left lower lip. The most likely cause of these findings is tumor involvement at which of the following foramina at the base of the skull?
A ) Jugular
B ) Lacerum
C ) Ovale
D ) Rotundum
E ) Stylomastoid
The correct response is Option E.
A history of a progressive facial paralysis associated with a parotid mass suggests the diagnosis of a malignant parotid tumor. The temporal, zygomatic/buccal, and ramus mandibularis branches are affected, indicating that the main trunk of the facial nerve is invaded by tumor. 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.
A 45-year-old man comes to the office for follow-up examination 3 months after undergoing surgical repair of a through-and-through laceration of the left cheek. During the procedure, an injury to the parotid duct was noted and repaired. He says he feels fine, but he now has difficulty playing the trumpet because he is unable to create sufficient air pressure in his mouth. Which of the following muscles was most likely also severed?
A ) Buccinator
B ) Levator labii superioris
C ) Masseter
D ) Risorius
E ) Zygomaticus major
The correct response is Option A.
The buccinator muscle is the only muscle of facial expression that compresses the cheeks, which is an essential function for playing air-based instruments such as the trumpet. Both the buccinator and the orbicularis oris compress the lips, also necessary for playing trumpets. The buccinator muscle ordinarily contributes to the function of forming a food bolus during mastication. The path of the parotid duct typically leaves the parotid gland from its anterior border and courses superficially to the masseter muscle toward the mid cheek and then pierces the substance of the buccinator muscle, reaching the mucosa of the oral cavity opposite the maxillary second molar.
The levator labii superioris, the risorius, and the zygomaticus major muscles all have a function that contributes to separating the lips, which releases the pressure from inside the mouth. These muscles arise from bone and fascia and attach to the lips. The masseter, which originates in the zygomatic arch and inserts on the lateral surface of the ramus, elevates the mandible. The masseter has no role in holding intrabuccal or lip pressure.
A 55-year-old woman has numbness of the earlobe after undergoing biopsy of an internal jugular lymph node. The most likely cause is injury to which of the following structures?
(A) Auricular branch of the vagus nerve
(B) Auriculotemporal nerve
(C) Great auricular nerve
(D) Posterior auricular nerve
(E) Ventral ramus of the first cervical root
The correct response is Option C.
This 55-year-old woman has numbness of the earlobe due to injury to the great auricular nerve. This nerve arises from the second and third cervical nerves and emerges from the posterior border of the sternocleidomastoid muscle, then travels anterosuperiorly between the sternocleidomastoid and platysma muscles and divides into auricular, facial, and mastoid branches. The auricular branch provides sensation to the earlobe and posterior two thirds of the ear and is prone to injury during surgery in the region of the upper lateral neck.
The auricular branch of the vagus nerve, also known as Arnold’s nerve, arises from the superior ganglion, receives a contribution from the glossopharyngeal nerve, and travels along the temporal bone, emerging through the auricular fissure between the mastoid process and external auditory meatus. It supplies sensation to the posterior aspect of the ear and external auditory meatus.
The auriculotemporal nerve is a sensory branch of the trigeminal nerve. This nerve branch courses posterior to the external pterygoid muscle, emerges from beneath the parotid gland, crosses the zygoma, and travels in a superior direction. The anterior auricular branches of this nerve supply sensory innervation to the anterior upper helix and tragus.
The posterior auricular nerve arises from the facial nerve at the stylomastoid foramen, receives a contribution from the auricular branch of the vagus nerve, and supplies two nerve branches, one of which joins with the mastoid branch of the great auricular nerve and another that joins with the lesser occipital nerve. Both branches provide sensibility to the posterior side of the pinna and the concha. The posterior auricular nerve supplies motor innervation to the posterior auricular and occipitalis muscles.
The ventral ramus of the first cervical root courses parallel to the vertebral artery and supplies motor innervation to the rectus capitis muscles.
In the temporal region, the frontal branch of the facial nerve is located within which of the following layers?
A ) Subcutaneous tissue
B ) Superficial temporal fascia
C ) Superficial layer of the deep temporal fascia
D ) Superficial temporal fat pad
E ) Deep layer of the deep temporal fascia
The correct response is Option B.
As depicted in the image shown, the temporal or frontal branch of the facial nerve is found within the superficial temporal or temporoparietal fascia. In the temporal region, the facial nerve can be injured with a coronal approach. The layers from superficial to deep in this region include: (1) skin, (2) subcutaneous tissue, (3) superficial temporal fascia also known as the temporoparietal fascia, (4) superficial layer of the deep temporal fascia, (5) superficial temporal fat pad, (6) deep layer of the deep temporal fascia, (7) temporalis muscle.
When the coronal flap is raised, as soon as the yellow superficial temporal fat pad is seen beneath the superficial layer of the deep temporal fascia, the superficial layer of the deep temporal fascia must be incised and included with the coronal flap to protect the frontal branch, which is in the superficial temporal fascia (temporoparietal fascia), one layer superficial to this.
A 7-year-old boy is brought to the office for consultation regarding the congenital nerve palsy shown. The affected nerve is derived from which of the following branchial arches?
(A) First
(B) Second
(C) Third
(D) Fourth
(E) Fifth
The correct response is Option B.
The facial nerve (cranial nerve VII) is derived from the second branchial arch and consists primarily of motor fibers that are distributed to the muscles of facial expression. Branchial arches begin to develop in the fourth week as neural crest cells migrate into the head and neck region. By the end of the fourth week, four pairs of branchial arches are visible externally. The fifth and sixth arches are small and not visible on the surface of the embryo yet. The branchial arches are separated by prominent clefts called branchial grooves.
Which of the following muscles contributes to Passavant’s ridge?
(A) Middle pharyngeal constrictor
(B) Styloglossus
(C) Stylopharyngeus
(D) Superior pharyngeal constrictor
(E) Tensor veli palatini
The correct response is Option D.
During gagging, forceful contraction of the superior pharyngeal constrictor and levator palatini muscles may produce Passavant’s ridge, which is a bulge on the posterior pharynx above the arch of the atlas. In patients with velopharyngeal incompetence (VPI), this ridge may be activated as a compensatory mechanism and may serve as a reference point during surgery to correct VPI.
The other muscles listed are not involved in Passavant’s ridge. The middle pharyngeal constrictor muscle arises from the hyoid bone and is inferior to the superior pharyngeal constrictor. The styloglossus and stylopharyngeus muscles both originate from the medial aspect of the styloid process. Then the styloglossus passes down to the tongue; the stylopharyngeus passes down to the pharyngeal wall. The tensor veli palatini muscle originates broadly from the scaphoid fossa of the medial pterygoid plate and the lateral eustachian tube. The fibers of this muscle pass around the pterygoid hamulus and attach to the shelf of the posterior hard palate.
A 42-year-old man is scheduled to undergo surgical excision of a lesion of the lower lip. During anesthetic blockade of the mental nerve prior to the procedure, the nerve foramen can be located beneath the apex of which of the following mandibular teeth?
(A) Central incisor
(B) Cuspid
(C) First molar
(D) Lateral incisor
(E) Second bicuspid
The correct response is Option E.
During anesthetic blockade of the mental nerve, the nerve foramen can be found beneath the apex of the second bicuspid tooth. This nerve, which is the terminal branch of the inferior alveolar nerve, supplies sensory innervation to the skin and mucous membranes of the lower lip as well as the skin of the anterior mandible and chin.
It is important to have knowledge of the location of the mental nerve and its foramen in order to prevent injury during reduction of anterior mandibular fractures or osseous sliding genioplasty procedures.
Because the inferior alveolar nerve is a branch of the mandibular division of the trigeminal nerve (V3), it may be injured during sagittal split osteotomy procedures. Affected patients will have numbness in the distribution of the inferior alveolar nerve postoperatively.
Which of the following nerves supplies sensation to the superior anterior aspect of the helix of the ear?
(A) Arnold
(B) Auriculotemporal
(C) Great auricular
(D) Greater occipital
(E) Lesser occipital
The correct response is Option B.
Sensation to the external ear is provided by the great auricular nerve, auricular branch of cranial (X) nerve (Arnold nerve), the auriculotemporal nerve, a branch of the mandibular branch of cranial (V) nerve (trigeminal nerve), and the lesser occipital nerve. Sensation to the superior anterior aspect of the helix is provided by the auriculotemporal nerve. The Arnold nerve provides sensation to the ear canal, whereas the posterior aspect of the external ear is provided by the lesser occipital nerve and most of the inferior two thirds of the external ear is provided by the great auricular nerve. The greater occipital nerve provides sensation to the skin and the posterior aspect of the scalp.
Which of the following anatomic structures of the ear originates from the second (hyoid) pharyngeal arch?
(A) Antitragus
(B) Helical root
(C) Superior helix
(D) Tragus
The correct response is Option A.
During the sixth week of fetal gestation, the anatomic subunits of the auricle arise from six hillocks that are derived from the first and second pharyngeal arches.
The anterior three hillocks from the first (or mandibular) pharyngeal arch ultimately develop into the tragus, helical root, and superior helix.
The antihelix, antitragus, inferior helix, and lobule form from the fourth through sixth posterior hillocks from the second (or hyoid) pharyngeal arch.
The structures that arise from the first pharyngeal arch typically drain into the parotid lymph nodes, and structures from the second pharyngeal arch drain into the cervical lymph nodes.
Which of the following branchial arches gives rise to the stylopharyngeus muscle?
(A) First
(B) Second
(C) Third
(D) Fourth
(E) Fifth
The correct response is Option C.
The stylopharyngeus is the only muscle derived from the third branchial arch. This muscle, which receives its innervation from the glossopharyngeal (IX) nerve, is part of the intrinsic musculature of the larynx.
The muscles of mastication, the anterior belly of the digastric, the mylohyoid, the tensor tympani, and the tensor veli palatini are derived from the first branchial arch. These muscles are innervated by the trigeminal (V) nerve. The muscles of facial expression, the posterior belly of the digastric, the stylohyoid, and the stapedius are derived from the second branchial arch and are innervated by the facial (VII) nerve. The fourth branchial arch gives rise to the constrictor muscles of the pharynx, the cricothyroid, the levator veli palatini, the palatopharyngeus, and the palatoglossus. The superior laryngeal branch of the vagus (X) nerve supplies their innervation. The fifth branchial arch is only present in rudimentary forms and is often combined with the sixth branchial arch during any embryologic investigation. The intrinsic muscles of the larynx, except for the cricothyroid and stylopharyngeus, as well as the striated muscles of the esophagus are derivatives. These muscles are innervated by the recurrent laryngeal branch of the vagus (X) nerve.
A 4-year-old boy is brought to the office for treatment and evaluation of lid ptosis. On examination, bilateral lagophthalmos, poor levator excursion, and severe ptosis are noted. Which of the following is the most likely diagnosis?
A) Blepharophimosis syndrome
B) Congenital epiblepharon
C) Congenital euryblepharon
D) Fraser cryptophthalmos syndrome
E) Treacher Collins syndrome
Blepharophimosis syndrome is the only diagnosis listed that is associated with congenital ptosis.
Blepharophimosis syndrome is associated with a tetrad of findings including ptosis, telecanthus, epicanthus inversus, and decreased horizontal lid fissure. In type I blepharophimosis, patients have epicanthus inversus and ptosis. In type II, findings include telecanthus, ptosis, ectropion of the lower lids, absent epicanthal folds, and insufficient skin in all lids. Type III is notable for telecanthus, ptosis, hypertelorism, slanting palpebral fissures, and insufficient eyelid skin. Correction involves a variety of techniques including, but not limited to, Z-plasty, transnasal wiring of the medial canthal tendon, and ptosis correction with frontalis suspension. Other abnormalities of the blepharophimosis syndrome include flattening of the nasal dorsum, hypoplasia of the superior orbital rim, as well as forehead and ear deformities.
In epiblepharon, the eyelashes are vertical as a result of excess pretarsal muscle and skin overriding the margin of the eyelid, often affecting the lower lids. This causes corneal irritation. If the condition does not resolve spontaneously in the first few years of life, correction involves shortening of the anterior lamella through excision of a horizontal piece of skin and orbicular muscle. Epiblepharon may also be caused by trauma, burns, or fractures.
Euryblepharon refers to widening of the palpebral fissure both laterally and vertically caused by a shortage of eyelid tissue. Treatment involves corneal protection and may require surgical correction with standard techniques used for ectropion repair.
Cryptophthalmos is a failure in embryonic development of the lid fold. The eye is buried in the developing cover of the epithelium and does not differentiate normally. It may be associated with other congenital abnormalities such as syndactyly, cardiac, facial, and ear defects.
Treacher Collins syndrome is a maxillary-zygomatic cleft with a coloboma of the lower eyelid and absent eyelashes.
The mylohyoid muscle is innervated via which of the following nerves?
A ) Accessory
B ) Glossopharyngeal
C ) Hypoglossal
D ) Mandibular
E ) Maxillary
The correct response is Option D.
The mylohyoid muscle is a flat, triangular muscle that with its opposite forms the muscular floor of the oral cavity. It originates from the oblique line of the mandible from the mandibular symphysis to the last molar tooth and inserts along the body of the hyoid bone in median fibrous raphe from the mandibular symphysis to the hyoid bone. The mylohyoid muscle elevates the floor of the mouth during swallowing and elevates the hyoid bone, which pushes the tongue upward during swallowing or tongue protrusion. This muscle also lowers the mandible and assists in opening the mouth, mastication, sucking, and blowing.
The primary motor innervation to the mylohyoid muscle is the mylohyoid branch of the inferior alveolar nerve of cranial nerve V (mandibular nerve). This nerve is a branch of the mandibular or third division of the trigeminal nerve. The two major nerves of the third division of the trigeminal nerve are the lingual nerve and the inferior alveolar nerve. The maxillary nerve is a branch of the second division of the trigeminal nerve and provides sensation to the ipsilateral face, side of the nose, lip, and upper teeth. The hypoglossal nerve (cranial nerve XII) provides motor innervation to the tongue. This nerve supplies all intrinsic muscles and all but one extrinsic muscle of the tongue. The exception is the palatoglossus muscle, which is supplied by cranial nerve X. The spinal accessory nerve, which is cranial nerve XI, supplies motor innervation to the sternocleidomastoid and trapezius muscles. The glossopharyngeal nerve (cranial nerve IX) is a complex nerve that supplies efferent nerve innervation to the parotid gland and carries sensations to the carotid body and carotid sinus. This nerve also provides general sensation to the posterior one third of the tongue, the skin of the external ear, and the internal surface of the tympanic membrane and supplies taste for the posterior one third of the tongue.
Which of the following foramina of the middle cranial fossa hosts passage of the oculomotor (III), trochlear (IV), and abducens (VI) nerves?
(A) Optic canal
(B) Ovale
(C) Rotundum
(D) Spinosum
(E) Superior orbital fissure
The correct response is Option E.
The foramen that allows passage of the oculomotor (III), trochlear (IV), and abducens (VI) cranial nerves is the superior orbital fissure, which is located at the orbital apex. This foramen also transmits the lacrimal, frontal, and nasociliary nerves; the sympathetic branches; the superior and inferior ophthalmic veins; the orbital branch of the middle meningeal artery; and the recurrent branch of the lacrimal artery. Hemorrhage or traumatic edema inside this foramen causes a unique collection of symptoms due to compression and loss of function of the traveling nerves, termed superior orbital fissure syndrome. The apex of the orbit also contains two other foramina: the optic canal, which transmits the optic (II) nerve and the ophthalmic artery, and the inferior orbital fissure, which allows passage of the infraorbital and zygomatic nerves. The foramen rotundum communicates between the middle cranial fossa and the pterygopalatine fossa. The maxillary division of the trigeminal (V) nerve is the only structure that passes through this foramen. The foramen ovale links the middle cranial fossa to the infratemporal fossa and transmits the mandibular division of the trigeminal nerve, the lesser petrosal branch of the glossopharyngeal (IX) nerve, the accessory meningeal branch of the maxillary artery, and an emissary vein. The foramen spinosum, located adjacent to the foramen ovale, also sits between the middle cranial and the infratemporal fossae. The foramen spinosum contains the meningeal branch of the mandibular division of the trigeminal nerve and the middle meningeal artery and vein.
The levator veli palatini muscle is innervated by which of the following nerves?
A ) Facial (VII)
B ) Hypoglossal (XII)
C ) Mandibular branch of the trigeminal (V)
D ) Maxillary branch of the trigeminal (V)
E ) Vagus (X)
The correct response is Option E.
The levator veli palatini (levator muscle) is a muscular sling in the posterior palate that is critical for palatal closure. Embryologically, the muscle arises from the fourth pharyngeal arch and, as a result, is innervated by the pharyngeal plexus, a derivative of the vagus (X) nerve. The two portions of the levator muscle arise from the eustachian tube and sphenoid bone while inserting into the other levator muscle in the midline of the soft palate. The function of the levator muscle is to elevate and posteriorly reposition the soft palate against the posterior nasal wall to assist in speech. This closes the velopharyngeal port while opening the eustachian tubes. The vagus also innervates several other muscles involved in normal speech development: the palatoglossus, the pharyngeal constrictors, the musculus uvulae, and the palatopharyngeus. The palatoglossus muscles form the anterior tonsillar pillars and lift the base of the tongue. The musculus uvulae originate from the palatine aponeurosis and the posterior nasal spine and insert into the uvula. With speech, these muscles will contract, causing a bulging of the soft palate and subsequent velopharyngeal closure. The uvula is lifted and bent backward.
The facial (VII) nerve innervates the muscles of facial animation, including the buccinator.
The hypoglossal (XII) nerve provides motor function to the tongue.
The trigeminal (V) nerve has three individual branches. The first branch, the ophthalmic division, is strictly a sensory branch. The second, or maxillary, division is also sensory. The third branch, the mandibular division, is the largest branch and is a mixed sensory and motor branch. Embryologically, the mandibular division arises from the first branchial (or mandibular) arch and provides motor function to the muscles arising from this arch. These muscles include the temporal, masseter, pterygoids, mylohyoid, tensor tympani, and the anterior belly of the digastric. It also innervates the tensor veli palatini. This muscle arises from the eustachian tube and medial pterygoid plate, wraps around the hamulus, and then inserts into the midline of the soft palate. During swallowing, these muscles tense the soft palate, opening the eustachian tube and allowing the tongue to move food posteriorly.
Which of the following muscles can function to close off the oral cavity from the oropharynx?
(A) Levator veli palatini
(B) Musculus uvulae
(C) Palatoglossus
(D) Palatopharyngeus
(E) Tensor veli palatini
The correct response is Option C.
The palatoglossus is a paired muscle that elevates the posterior tongue and pulls it against the soft palate, separating the oral cavity from the oropharynx. The muscle attaches to the side of the tongue on one end and the palatine aponeurosis on the other.
The levator veli palatini elevates the soft palate during swallowing and yawning. It attaches superiorly to the cartilage of the auditory tube and the petrous part of the temporal bone and inferiorly to the palatine aponeurosis.
The palatopharyngeus muscle is part of the palatopharyngeal arch, attaching to the lateral wall of the pharynx, the hard palate, and the palatine aponeurosis. During swallowing, it tenses the soft palate while pulling the walls of the pharynx superiorly, medially, and anteriorly, effectively closing off the nasopharynx from the oropharynx.
The tensor veli palatini also tenses the soft palate and opens the eustachian tube during yawning and swallowing. It extends from the palatine aponeurosis to the medial pterygoid plate and spine of the sphenoid bone and the cartilage of the eustachian tube.
The musculus uvulae pulls the uvula superiorly and shortens it. The muscle fills the substance of the uvula, attaching to its mucosa and to the posterior nasal spine and palatine aponeurosis.
An otherwise healthy 15-year-old boy is brought to the office by his parents because he has had painless swelling of the hard palate for the past year. A photograph of his mouth is shown. Physical examination shows a lesion that is solid, firm, fixed, noncompressible, nontender, and covered with healthy palatal mucosa. Which of the following is the most likely diagnosis?
(A) Craniofacial fibrous dysplasia
(B) Maxillary torus
(C) Skull base glioma
(D) Squamous cell carcinoma
(E) Submucous cleft palate
The correct response is Option B.
In an otherwise healthy young patient with a solid asymptomatic lesion consistent with bone on the hard palate, the most likely diagnosis is a maxillary torus or torus palatinus.
Maxillary and mandibular tori are benign osteoblastic tumors and tend to be well encapsulated, circumspect, submucosal, and expand gradually without invading adjacent structures. Torus palatinus occurs on the midline of the hard palate and requires treatment only if it becomes symptomatic or interferes with function.
Fibrous dysplasia is a benign tumor of bony origin that may present as a component of McCune-Albright syndrome (polyostotic fibrous dysplasia) or as a localized condition of the craniofacial skeleton, usually the upper facial skeleton. An isolated palatal occurrence of fibrous dysplasia would be highly unlikely.
Gliomas are believed to be encephaloceles that have lost their intracranial connections. External gliomas usually appear at or just lateral to the nasal root as reddish, firm, noncompressible, lobular lesions with cutaneous telangiectasia. The do not transilluminate or pulsate. Skull base gliomas are usually intranasal, and while potentially being associated with bony defects, would not present in this fashion.
Although squamous cell carcinoma frequently presents as an intraoral mass, it is not the most likely diagnosis in a healthy, young patient with a hard bony lesion of the palate.
Submucous cleft palates present with bifid uvulas, a bony notch or defect at the edge of the hard palate, and a zona pellucida, or thin, bluish, strip of mucosa in the midline of the soft palate secondary to diastasis of the levator muscle.
A 48-year old woman comes to the office because she has had persistent epiphora since she sustained a naso-orbital-ethmoid fracture one year ago. Jones I fluorescein dye test is performed. If the results of this test are normal, in which of the following locations is the dye most likely to be found?
(A) Inferior meatus
(B) Lower canaliculus
(C) Middle meatus
(D) Nasolacrimal duct
(E) Upper canaliculus
The correct response is Option A.
Epiphora is the accumulation of tears that are not evacuated by the lacrimal drainage system. The tears will often overflow onto the cheek. Injuries to the lacrimal drainage system have been reported to occur in 5% to 21% of patients sustaining naso €‘orbito €‘ethmoid trauma. Jones I and Jones II dye testing can be used to diagnose the level of obstruction.
In a Jones I dye test, fluorescein dye is instilled into the conjunctival sac. A cotton €‘tipped applicator is placed under the inferior turbinate, the site of the inferior meatus. In a positive test, dye flows through the lacrimal system and exits at the inferior meatus. Dye is recovered on the applicator. In a negative test, no dye is recovered. This indicates an obstruction in the lacrimal drainage system.
The Jones II dye test is performed to localize the level of obstruction within the drainage system. This test is performed immediately after the Jones I test. An irrigation cannula is inserted into the punctum. Saline is irrigated through the cannula. If dye-stained fluid is obtained in the nose, the test is positive, and a partial obstruction of the lacrimal drainage system is diagnosed. If no dye is obtained in the nose, the test is negative. If dye exits the other canaliculus, the obstruction is in the lower portion of the system. If no dye returns through the other canaliculus, but dye refluxes through the same canaliculus, then the obstruction is in the upper part of the system.
Patients with paralysis of the trigeminal nerve have loss of function of which of the following muscles?
(A) Levator veli palatini
(B) Palatopharyngeus
(C) Stylohyoid
(D) Stylopharyngeus
(E) Tensor veli palatini
The correct response is Option E.
Because the tensor veli palatini muscle receives its motor innervation from the trigeminal (V) nerve, a patient who has paralysis of this nerve will experience a loss of function of the tensor veli palatini, which is a derivative of the first branchial arch. In contrast, the anatomically adjacent levator veli palatini muscle is a derivative of the fourth branchial arch and is innervated by the superior laryngeal branch of the vagus (X) nerve. The palatopharyngeus muscle has this same origin and innervation. The stylohyoid muscle is derived from the second branchial arch and innervated by the facial (VII) nerve, while the stylopharyngeus muscle is derived from the third branchial arch and innervated by the glossopharyngeal (IX) nerve.
Anesthesia of the nasal side wall is best accomplished through infiltration of which of the following nerves?
(A) Buccal
(B) Dorsal nasal
(C) Infraorbital
(D) Infratrochlear
(E) Zygomaticofacial
The correct response is Option C.
The infraorbital nerve, which is the terminal branch of the maxillary division of the trigeminal nerve (V2), supplies sensation to the nasal side wall, ala, upper lip, lower eyelid, and medial aspect of the upper cheek. Anesthesia of this nerve is best accomplished by introducing the needle just lateral to the nasal ala and directing it to a point 0.5 cm below the central section of the infraorbital rim, directly into the foramen rotundum.
The buccal nerve is a branch of the mandibular division of the trigeminal nerve (V3). It arises from the surface of the buccinator muscle to supply sensation to the central cheek. Appropriate anesthesia is achieved by injecting the nerve at its origin on the mandibular nerve between the sigmoid notch of the mandible and lateral pterygoid plate.
The dorsal nasal nerve and infratrochlear nerve are branches of the nasociliary nerve, which is derived from the ophthalmic division of the trigeminal nerve (V1). The dorsal nasal nerve branches from the anterior ethmoidal nerve, then emerges at the distal end of the nasal bones to supply sensation to the skin of the dorsal nose from that point distally to the nasal tip. The infratrochlear nerve supplies sensation to the skin of the root of the nose and medial upper eyelid.
The zygomaticofacial nerve is a branch of the zygomatic nerve, which is derived from the maxillary division of the trigeminal nerve (V2). It emerges through one or two foramina just lateral to the infraorbital rim and supplies sensation to the skin over the zygoma and upper portion of the central cheek.
The deep division of the supraorbital nerve provides sensation to which of the following areas?
(A) Central forehead
(B) Central scalp
(C) Nasal radix
(D) Temporal forehead
(E) Temporal scalp
The correct response is Option B.
Knowledge of the anatomy of the supraorbital nerve is crucial for minimizing the risk for nerve injury and subsequent numbness during endoscopic forehead lifting. The supraorbital nerve is a branch of the ophthalmic division of the trigeminal nerve (V1). This nerve arises from a foramen or notch along the superior orbital rim, and then divides immediately into deep and superficial branches. The deep division courses laterally toward the superior temporal line of the skull, and then continues to the coronal suture to supply sensation to the central frontoparietal scalp. In contrast, the superficial branch divides into multiple branches, each of which courses cephalad into the frontalis muscle to supply sensation to the central forehead and hairline.
Sensation to the nasal radix is supplied by the supratrochlear and infratrochlear nerves, while the maxillary and mandibular branches of the trigeminal nerve (V2 and V3) supply sensation to the temporal forehead. Sensation to the temporal scalp is supplied by the occipital nerve.
Which of the following nerves supplies sensory innervation to the buccal mucosa?
(A) Trigeminal (V) nerve
(B) Facial (VII) nerve
(C) Glossopharyngeal (IX) nerve
(D) Vagus (X) nerve
(E) Lingual nerve
The correct response is Option A.
The buccal branch of the trigeminal (V) nerve provides sensation to the buccal mucosa. It is important for the surgeon to know the anatomy of this nerve branch to plan and perform neurotized free flap reconstruction and reinnervation of the intraoral cavity.
The buccal branch of the facial (VII) nerve innervates the muscles surrounding the buccal mucosa.
The glossopharyngeal (IX) and vagus (X) nerves do not provide sensory innervation to the intraoral mucosa.
The lingual nerve provides sensation to a portion of the tongue.
An otherwise healthy 20-year-old woman comes to the office because she has had a painless lump on the left floor of the mouth for the past three weeks. The lump has increased in size during the past week. Physical examination shows a fluctuant, 2-cm blue mass that is not tender to palpation. Which of the following is the most likely diagnosis?
(A) Lingual thyroid
(B) Ranula
(C) Thyroglossal duct cyst
(D) Torus
(E) Vascular anomaly
The correct response is Option B.
A ranula is a mucocele or mucous extravasation phenomenon in the floor of the mouth, arising from the ducts of the sublingual or submandibular glands, often as a sequela of obstruction of the sublingual gland. It usually presents as a unilateral swelling of the floor of the mouth that is fluctuant and tinted blue or glossy white. Treatment includes marsupialization or surgical excision including the sublingual gland. The ranula may herniate through the muscles of the floor of the mouth and present as a €œplunging ranula € or cervical mass.
A lingual thyroid is an uncommon condition in which the embryonic thyroid gland does not descend into the neck and presents as a firm, nontender mass at the tongue base.
A thyroglossal duct cyst represents residual epithelium-lined tracts that trace the path of descent of the thyroid and can be found anywhere in the paramedial region of the neck but are usually in the midline.
A torus is an exostosis and is a slow-growing, hard mass arising from the palate or mandible. The enlargement consists of bone covered by mucosa. Excision is indicated for tori that become symptomatic or bothersome.
Vascular anomalies are present at birth and grow with the patient. It would be unusual for a vascular anomaly to initially present in an adult.
The external auditory meatus develops from which of the following embryologic structures?
(A) First branchial arch
(B) Second branchial arch
(C) Third branchial arch
(D) First branchial groove
(E) Second branchial groove
The correct response is Option D.
Development of the six branchial arches occurs within the walls of the anterior foregut during the fourth week of gestation, as neural crest cells migrate into the future head and neck region and alternating ridges and depressions develop. Each branchial arch is composed of endoderm, ectoderm, and mesoderm. During development, a series of clefts forms to create the branchial grooves externally and the pharyngeal pouches internally. The branchial grooves are lined with surface ectoderm and the pharyngeal pouches are lined with foregut endoderm.
During the sixth week of gestation, six hillocks appear on the first (mandibular) and second (hyoid) branchial arches, which give rise to the auricle. The first branchial arch gives rise to the anterior (first through third) hillocks, and the second branchial arch gives rise to the posterior (fourth through sixth) hillocks. By the end of the eighth week of gestation, the auricle assumes its characteristic shape following differential growth and fusion of the hillocks.
The external auditory meatus develops from the dorsal aspect of the first branchial groove, which is a cleft between the first and second branchial arches.
The second, third, and fourth branchial grooves are obliterated within the cervical sinus during the later stages of embryologic development. The cervical sinus develops as a result of caudal overgrowth of the second branchial arch.
A 1-year-old male infant is brought to the office because of congenital ptosis of the left eye. On examination, the eyelid margin covers 4 mm of the upper limbus, and levator excursion is 4 mm. Which of the following is the most appropriate treatment?
A) Fasanella-Servat procedure
B) Frontalis suspension with sling
C) Levator advancement
D) Müller muscle resection
E) Observation
The correct answer is option b.
With more than 4 mm of the upper limbus covered by the eyelid margin, the ptosis is considered severe, and with levator function at 4 mm, it is considered poor. Therefore, a frontalis suspension is the appropriate procedure. It can achieve excellent symmetry and long-lasting results. Most patients with congenital ptosis have severe ptosis and poor levator function and will need frontalis suspension. Ptosis is defined by how much the upper limbus is covered by the lid margin at rest and forward gaze. It is 1 to 2 mm normally. Ptosis: Mild = 2 mm Moderate = 3 mm Severe = 4+ mm Levator function: Excellent = 12–15 mm Good = 8–12 mm Fair = 5–7 mm Poor = 2–4 mm In terms of treatment: Fasanella-Servat: mild ptosis and good levator function Frontalis suspension: severe ptosis and poor levator function Levator advancement: moderate ptosis and fair levator function Müller muscle resection: mild ptosis, fair to good levator function
A 2-year-old boy presents with swelling over the bridge of the nose that has been present since birth. The swelling has been slowly increasing in size and he has hypertelorism. The swelling is soft, compressible, and it transilluminates. There are visible and palpable pulsations, and the mass enlarges when the patient cries. Which of the following is the most likely diagnosis?
A)Encephalocele
B) Glioma
C) Hemangioma
D) Nasal dermoid cyst
E) Nasopharyngeal angiofibroma
The correct response is Option A.
Encephaloceles are neural tube defects that result in sac-like protrusions of the meninges (meningocele) or brain and meninges (meningoencephalocele) in various locations along the cranium, such as between the forehead and nose (including naso-orbital, frontonasal, and nasoethmoidal locations) or on the back of the skull. They tend to be soft, compressible masses that transilluminate that may be sessile or pedunculated. Biopsy may result in a cerebrospinal fluid leak.
Glioma is a mass of ectopic neural tissue that does not transilluminate.
Hemangiomas are benign vascular lesions that are present at birth and characterized by a rapid growth phase around the age of 1 to 6 months, followed by gradual involution over 1 to 12 years. They have no intracranial connection and no cerebral pulsations. Nasopharyngeal angiofibromas, also known as juvenile nasopharyngeal angiofibromas, are benign but locally invasive vascular tumors that occur almost exclusively in adolescent males. They present with unilateral or bilateral nasal obstruction, frequent epistaxis or blood-tinged nasal discharge. Nasal dermoid cyst is a benign cystic lesion that does not pulsate and does not transilluminate.
A 23-year-old man comes to the office for evaluation of unilateral blepharoptosis. On examination, the excursion of the eyelid margin is measured from downgaze to upgaze while the eyebrow is manually fixed against the supraorbital rim. Which of the following would best approximate the normal excursion distance of levator function for this patient?
A) 2 to 6 mm
B) 7 to 11 mm
C) 12 to 16 mm
D) 17 to 21 mm
E) 21 to 25 mm
The correct answer is option c.
Levator function is measured indirectly by determining the excursion of the eyelid margin as the patient looks from downgaze to upgaze. The eyebrow is manually fixed against the supraorbital rim during this measurement, preventing the frontalis muscle from contributing to eyelid movement. Many patients subconsciously raise their eyebrow in a compensatory effort to elevate the drooping eyelid, a beneficial finding in individuals requiring frontalis suspension. Normal adults typically demonstrate 12 to 16 mm of levator function. Lesser measurements may indicate the presence of a developmental or acquired myopathy.
Which of the following muscles of facial expression is innervated on its anterior surface?
(A) Depressor anguli oris
(B) Levator anguli oris
(C) Levator labii superioris
(D) Orbicularis oris
(E) Zygomaticus major
The correct response is Option B.
The muscles of facial expression receive their innervation from cranial nerve VII (facial nerve). The facial nerve innervates the muscles of facial expression along the posterior surface of the muscle in most cases. The exceptions to this rule include the levator anguli oris, the buccinator, and the mentalis muscle. At the modiolus, the fibers of the levator anguli oris coalesce with fibers of the zygomaticus major, orbicularis oris, risorius, buccinator, and depressor anguli oris. The levator anguli oris lies deep to the other muscles and receives its innervation along its anterior surface.
A 26-year-old woman is being evaluated because she has had complete left-sided, flaccid facial paralysis since she awoke 3 hours ago. She also has a metallic taste in her mouth and hypersensitivity to sound. Denervation of which of the following muscles is the most likely cause of the hypersensitivity to sound?
A ) Levator palatini
B ) Stapedius
C ) Tensor tympani
D ) Tensor veli palatini
E ) Zygomaticus major
The correct response is Option B.
The 26-year-old woman described has the typical history of Bell palsy. In patients with Bell palsy, the entire nerve is inflamed, but the maximum conduction block is either in the meatal or labyrinthine segments. Because the conduction block is proximal to the chorda tympani and stapedial nerve, patients also experience a change in taste and a decreased ability to accommodate (ie, dampen) loud noises.
When an acoustic tumor causes facial paralysis, the paralysis is usually slowly progressive. Patients generally present with a hearing loss, not a hypersensitivity to noise.
The tensor tympani muscle attaches to the malleus and is innervated by the trigeminal nerve, not the facial nerve. The tensor veli palatini muscle is also innervated by the trigeminal nerve and is responsible for active dilatation of the eustachian tube. Blockage of the eustachian tube would cause a hearing loss.
The zygomaticus major muscle is innervated by the facial nerve. Denervation causes a decreased ability to smile, not hearing loss. The levator palatini muscle is innervated by the vagus nerve.
A 6-year-old boy who underwent repair of a unilateral cleft lip and palate in infancy is brought to the office by his parents because he has had a sensation of numbness in the left anterior mobile tongue for the past two days, since he underwent repair of a palatal fistula during orotracheal intubation. During that procedure, the oral cavity and palate were retracted for two hours with a Dingman retractor. Which of the following nerves was most likely damaged during the procedure?
(A) Glossopharyngeal (IX)
(B) Lingual
(C) Mental
(D) Recurrent laryngeal
(E) Superior laryngeal
The correct response is Option B.
The lingual nerve provides sensation to the anterior two thirds of the tongue. Injury to the lingual nerve is a rare complication of airway manipulation. Virtually all equipment associated with airway management and/or oral cavity retraction has been implicated in its damage. Examples include direct laryngoscopy, tracheal intubation, laryngeal mask airway, and tonsillectomy. The etiology of lingual nerve damage is likely compression of the nerve in the floor of mouth against the mandible caused by forceful compression of the floor of mouth. The mental nerve exits the mental foramen just below the first or second premolar and supplies sensation to the lower lip and chin. The superior laryngeal nerve provides sensory innervation to the supraglottis. The glossopharyngeal nerve provides sensory innervation and taste sensation to the base of the tongue. The recurrent laryngeal nerve provides motor innervation to the laryngeal musculature.
A 2-month-old infant is referred for evaluation because he has an abnormal head shape. Physical examination shows low-set ears; short, webbed fingers; and duplicate great toes. A CT scan shows sagittal and lambdoid synostosis. A mutation in which of the following genes is most likely responsible for these findings?
A) FGFR1
B) FGFR2
C) FGFR3
D) RAB23
E) TWIST1
The correct response is Option D.
This child has Carpenter syndrome. This syndrome is caused by a mutation in the RAB23 gene, which is located on chromosome 6. Carpenter syndrome is inherited in an autosomal recessive manner, but is can also be caused by de novo mutation in RAB23. In addition to synostosis, symbrachydactyly and preaxial polydactyly are found in patients with Carpenter syndrome. Mutations in the other genes listed are all associated with syndromic craniosynostoses.
Fibroblast growth factor receptor (FGFR) mutations have been associated with several differing syndromes: FGFR1 mutations cause Pfeiffer syndrome, FGFR2 mutations cause Apert and Crouzon syndromes, and FGFR3 mutations cause Muenke syndrome.
A mutation of the TWIST1 gene causes Saethre-Chotzen syndrome.
A 45 year old man who is employed as a construction worker comes to the office because of pain in the small and ring fingers of the nondominant left hand. He says the pain worsens and the fingers become blotchy on exposure to cold. He has smoked one pack of cigarettes daily for 30 years. Examination shows subungual hemorrhages in the small finger and a digital brachial index of 0.4. Arteriography shows segmental occlusion of the ulnar artery at the wrist. Which of the following is the most appropriate management of this patient €™s condition?
(A) Administration of a calcium channel blocker
(B) Intraarterial thrombolysis/fibrinolysis
(C) Resection and reconstruction of segmental ulnar artery
(D) Smoking cessation
(E) Stellate ganglion block
The correct response is Option C.
Hypothenar hammer syndrome (HHS) describes digital ischemic symptoms secondary to either occlusion or aneurysmal dilation of the ulnar artery adjacent to the hamate. Although typically related to activities that involve repetitive trauma (eg, use of vibrating tools) to the palm, evidence exists to suggest that the condition arises in vessels with preexisting abnormalities, even in the absence of trauma.
In cases of critical digital ischemia with characteristic segmental occlusion on arteriography, optimal treatment involves resection of the diseased segment and reconstruction. Reversed vein graft represents the standard bypass conduit; however, as in coronary artery bypass grafting, arterial conduits (inferior epigastric artery) have been suggested as better matched in size and less prone to aneurysmal dilation later.
Calcium channel blockers and sympathetic blockade may alleviate vasospastic responses in the patent vessels distal to the occlusion. These interventions may be combined with surgical therapy and can be considered as primary interventions in patients with less symptomatic hands and a digital brachial index less than 0.7.
Intraarterial thrombolysis should not be used in the setting of the chronic, occlusive disease of HHS.
Smoking has been associated with HHS, but cessation alone in the setting of severe ischemia will not reverse the changes.
During a rhytidectomy procedure, the risk for injury to the great auricular nerve is greatest at which of the following locations?
(A) 1 cm anterior to the tragus
(B) 2 cm posterior to the lobule
(C) 4 cm posterior to the lobule
(D) 6 cm inferior to the tragus
(E) 10 cm inferior to the tragus
The correct response is Option D.
The great auricular nerve emerges from behind the sternocleidomastoid muscle 9 cm below the caudal edge of the external auditory canal and 6 cm inferior to the tragus. The nerve lies posterior and superficial to the submuscular aponeurotic system (SMAS) and platysma at this point and is at greatest risk for injury during rhytidectomy. Injury to this nerve can result in numbness or painful dysesthesias of the lower two thirds of the ear and the adjacent skin of the neck and cheek.
The congenital anomaly shown in the photograph is thought to be caused by which of the following?
A) Failure of fusion of the lateral and maxillary nasal processes
B) Failure of fusion of the maxillary prominence with the medial nasal prominence
C)
Failure of fusion of the medial nasal prominence and the lateral nasal prominence
D) Failure of fusion of the medial nasal prominences
E) Failure of the oronasal membrane to rupture
The correct answer is A.
Proboscis lateralis, which is illustrated in the photograph, is thought to be a failure of fusion between the lateral and maxillary nasal processes. A cleft lip is the result of a failure of fusion of the maxillary prominence with the medial nasal prominence. A midline cleft or Tessier Zero cleft is a result of the failure of fusion of the medial nasal prominences. Choanal atresia is a result of a failure of the oronasal membrane to rupture. Finally, a mandibular cleft or Tessier # 30 cleft is a result of the failure of fusion of the mandibular prominences.
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 2cm 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
The correct answer 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.
In a patient who has undergone Le Fort I osteotomy, which of the following arteries provides the primary blood supply to the maxilla?
(A) Ascending pharyngeal artery
(B) Greater palatine artery
(C) Infraorbital artery
(D) Lesser palatine artery
(E) Posterior superior alveolar artery
The correct response is Option A.
Although the maxilla has an extensive blood supply as a result of its multiple anastomotic connections, much of its vascularity is irreversibly severed during the incisions and mobilization required for the Le Fort I osteotomy. Prior to surgery, the internal maxillary artery supplies blood to the maxilla through the descending palatine, posterior superior alveolar, and infraorbital arteries. However, after a Le Fort I osteotomy is performed, the ascending palatine branch of the facial artery and the palatine branch of the ascending pharyngeal artery provide the primary vascular supply. Both vessels are branches of the external carotid artery and contribute somewhat to the maxillary blood supply prior to surgery.
The greater palatine artery emerges from the greater palatine foramen and courses anteriorly; its arterial branches are distributed to the palate and soft tissue of the roof of the mouth. The lesser palatine artery emerges from the lesser palatine foramen and supplies vascularity to the soft palate and palatine tonsils.
A 70-year-old man is scheduled to undergo wedge resection of a lesion on the lower lip. Physical examination of the lower lip shows an ulcerated, well-circumscribed 5-mm lesion 1 cm medial to the right oral commissure. Which of the following foramina is the most appropriate site for instillation of anesthetic for the procedure?
A ) Inferior alveolar
B ) Infraorbital
C ) Mental
D ) Nasopalatine
E ) Sphenopalatine
The correct response is Option C.
The most appropriate area for block infiltration is an intraoral blockade of the mental nerve. The inferior alveolar nerve travels through the mandible entering at the medial ramal border and exits at the mental nerve at the mental foramen at the level of the first and second bicuspid teeth, 1 cm below the alveolar ridge.
Blockage of the inferior alveolar nerve foramen requires injection at its entry in the posterior mandible, or within the bony canal €”an area not easily accessible.
Numbness of the upper lip and nasal sidewall can be accomplished with blockade of the infraorbital nerve.
Nasal palatine anesthetic produces numbness of the external nose.
Sphenopalatine nerve blockade produces anesthesia in the internal nose and palate.
A neonate has a reddish 1.5-cm mass of the nasal root with overlying cutaneous telangiectasias. A photograph is shown above. On physical examination, the mass is firm, noncompressible, and nonpulsatile. It does not transilluminate or change with Valsalva maneuver. Which of the following is the most likely diagnosis?
(A) Dermoid cyst
(B) Encephalocele
(C) Glioma
(D) Hemangioma
(E) Lipoma
The correct response is Option C.
The findings in this neonate are consistent with a glioma. Nasal gliomas are thought to originate as encephaloceles but fail to maintain their intracranial connections. They may be external, internal, or a combination of both. External gliomas typically appear at or just lateral to the nasal root. They are reddish, firm, noncompressible, lobular lesions that exhibit telangiectasias of the overlying skin, but do not transilluminate or pulsate. Bony defects, intracranial connections, and cerebrospinal fluid leakage occur only rarely. Histologic evaluation shows astrocytic neuroglial cells and fibrous and vascular connective tissue that is covered with skin or nasal mucosa.
A nasal dermoid cyst arises from a dermoid sinus, which is a cutaneous inward passage lined with stratified squamous epithelium. These masses can also be external or internal. An external nasal dermoid is a firm, noncompressible, nonpulsatile lesion that does not transilluminate and may be lobulated. Although bony defects are infrequent, cerebrospinal fluid leakage and meningitis may occur. Nasal dermoid cysts are derived from ectoderm and mesoderm, lined with squamous epithelium, and contain specialized adnexal structures such as hair follicles, pilosebaceous glands, and smooth muscles.
Encephaloceles involve herniation of cranial tissue through a skull defect. They may be classified as meningoceles (containing meninges only), meningoencephaloceles (containing meninges and brain), or meningoencephalocystoceles (containing meninges, brain, and part of the ventricular system). External, or sincipital, encephaloceles are soft, bluish, compressible, pulsatile masses that are located at the nasal root and transilluminate. They typically enlarge with crying and Valsalva maneuver.
Hemangiomas are raised lesions that arise from a proliferation of endothelial cells. Most appear shortly after birth and involute spontaneously after a period of rapid growth. Discoloration of the overlying skin is often associated.
Lipomas are soft, skin colored, compressible lesions that do not have cutaneous telangiectasias and do not transilluminate or pulsate. They may appear at the nasal root, but are not predisposed to that location.
During dissection to the level of the digastric tendon in a patient undergoing microsurgical head and neck reconstruction, the hypoglossal nerve can be found in which of the following positions?
(A) Lateral to both the internal and external carotid arteries
(B) Medial to both the internal and external carotid arteries
(C) Lateral to the internal carotid artery and medial to the external carotid artery
(D) Medial to the internal carotid artery and lateral to the external carotid artery
The correct response is Option A.
During preparation of recipient vessels for free tissue transfer in a patient undergoing head and neck reconstruction, the branches of the carotid artery and internal jugular vein are dissected. The digastric tendon is divided or retracted, and then the carotid artery and hypoglossal nerve are exposed. The hypoglossal nerve passes between the internal carotid artery and internal jugular vein. It turns anteriorly, spiraling around the internal carotid artery, and passes under the occipital artery. It then loops across the lateral surface of the external carotid artery and passes deep to the insertion of the stylohyoid muscle and digastric sling before disappearing beneath the posterior edge of the mylohyoid muscle. The surgeon must take great care to avoid injuring the hypoglossal nerve because injury would lead to impaired tongue mobility and potential difficulties with speech and swallowing.
A 35-year-old man is brought to the emergency department following a motorcycle collision. Examination shows swelling and deformity of the mandible. Radiographs show a left subcondylar fracture with the proximal fragment displaced forward. Which of the following muscles is most likely involved in the displacement?
A ) Digastric
B ) Lateral pterygoid
C ) Masseter
D ) Medial pterygoid
E ) Temporalis
The correct response is Option B.
The origin of the lateral pterygoid muscle (shown below) has two components: one that attaches to the temporomandibular joint capsule and disc, and one that attaches to the fovea in the neck of the mandible. Proximally (anteriorly), the superior head attaches to the greater wing of the sphenoid bone, and the inferior head to the lateral surface of the lateral pterygoid plate. Therefore, in a subcondylar fracture, the lateral pterygoid muscle is in position to draw the proximal fragment forward.
The digastric muscle extends from the mastoid process of the temporal bone to the hyoid bone and to the anterior mandible. It depresses the mandible (inferior movement) or elevates the hyoid. The masseter, medial pterygoid, and temporalis elevate the mandible from the region of the ramus, angle, or coronoid process. The masseter originates in the zygomatic arch and inserts on the lateral surface of the ramus. The medial pterygoid originates on the lateral pterygoid plate and the tuberosity of the maxilla and attaches to the medial surface of the angle of the mandible. The temporalis muscle is fan-shaped and originates from the floor of the temporal fossa and inserts in the coronoid process and anterior border of the ramus.
A 20-year-old man comes to the office because he has had paraesthesia of the anterior lateral aspect of the tongue since undergoing removal of the mandibular third molars 3 weeks ago. The most likely cause is injury to which of the following nervous structures?
A ) Chorda tympani
B ) Facial
C ) Glossopharyngeal
D ) Hypoglossal
E ) Lingual
The correct response is Option E.
General sensation of the anterior two thirds of the tongue is supplied by the lingual nerve, which is a branch of the mandibular division of the trigeminal. Taste in the anterior two thirds of the tongue is supplied by the chorda tympani from the facial nerve. The chorda tympani joins the lingual nerve and runs anteriorly in its sheath. The glossopharyngeal nerve supplies the mucosa of the posterior one third of the tongue. The hypoglossal nerve is the motor nerve to the tongue, and the facial nerve is the motor nerve to the face.
A 58-year-old man comes to the office for consultation regarding treatment 3 weeks after receiving a diagnosis of squamous cell cancer of the soft palate. He says he has had pain in the left ear for the past 2 months. Examination of the ear shows no abnormalities. The most likely cause of the pain is involvement of which of the following nerves?
A ) Auricular branch of the vagus (X)
B ) Auriculotemporal
C ) Great auricular
D ) Superficial temporal
E ) Vestibulocochlear (VIII)
The correct response is Option A.
The auricular branch of the vagus nerve (Arnold nerve) carries sensory input from the ipsilateral concha and oropharynx. Chronic external ear pain may alert the astute physician of more serious intraoral pathology.
The auriculotemporal nerve carries sensory information from the anterior and superior external auditory canal, and the great auricular nerve relays sensation from the lower half of the ear.
The lesser occipital nerve provides sensory input from the superior cranial surface of the ear.
Although the superficial temporal nerve is not an anatomically recognized structure, the superficial temporal artery supplies vascular inflow to the anterior external ear.
The 4-month-old boy shown has congenital midline neck and mandibular anomalies, including a mild clefting of the mandible and atrophic skin in the central anterior neck. These anomalies are a result of the incomplete fusion of which of the following paired branchial arches?
A ) First
B ) Second
C ) Third
D ) Fourth
E ) Fifth
The correct response is Option B.
Congenital midline cervical clefts are a result of a failure of fusion of the paired second branchial arches in the midline during embryogenesis. It is a rare anomaly of the anterior neck diagnosed on the basis of the clinical presentation at birth. The most commonly reported features are a cleft of reddened, thinned tissue in the midline, a protuberance of skin superiorly, a blind epithelium-lined sinus tract caudally, and a fibrous subcutaneous cord. The cord may limit neck movement. There is some degree of retrognathia and variable degrees of clefting of the lip and mandible. Other anomalies that have been found in association with midline cervical cleft are thyroglossal duct cysts and ectopic bronchogenic cysts.
Branchial arches begin to develop in the fourth week as neural crest cells migrate into the head and neck region. By the end of the fourth week, four pairs of branchial arches are visible externally. The fifth and sixth arches are small and not yet visible on the surface of the embryo. The branchial arches are separated by prominent clefts called branchial grooves.
The nasolacrimal duct drains into the nose at which of the following anatomic locations?
A ) Inferior concha
B ) Inferior meatus
C ) Middle concha
D ) Middle meatus
E ) Superior concha
The correct response is Option B.
The nasolacrimal duct, which maintains the drainage of the nasolacrimal system, drains into the inferior meatus just below the inferior concha (see diagram). Other structures also drain into the nose. The auditory tube opens into the nasopharynx just posterior to the inferior concha. The sphenoid sinus drains into the sphenoethmoid recess superior and posterior to the superior concha. The posterior ethmoid air cells drain into the superior meatus. The nasofrontal duct,
A patient sustains a laceration of the superior helix of the auricle. Adequate anesthesia is most likely to be obtained with block of which of the following nerves?
(A) Facial (VII)
(B) Glossopharyngeal (IX)
(C) Great auricular
(D) Trigeminal (V)
(E) Vagus (X)
The correct answer is option D
 Superior auricle is innervated by the auriculotemporal nerve, a branch of the mandibular branch of trigeminal (CN V3)
