Head and Neck Anatomy Flashcards
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
C) Olfactory dysfunction from nasal surgery
Because 80% of a meal’s flavor is aresult 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.
How much flavor is from olfactory input?
80%
Gustatory rhinorrhea
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.
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
D) Rotundum
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 branchesof the maxillary division of the trigeminal nerve.
foramen rotundum (maxillary (V2) nerve
Adenoid cystic carcinoma
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.
What passes through the stylomastoid foramen?
Facial nerve and stylomastoid artery
What passes through the foramen lacerum?
Internal carotid artery
What passes through the foramen ovale?
Mandibular V3 nerve, accessory meningeal artery
The lesser petrosal nerve can be transmitted as well.
What passes through the foramen rotundum?
Maxillary V2 nerve
What passes through the jugular foramen?
Glossopharyngeal IX, Vagus X, spinal accessory XI
Where does the internal carotid artery exit the skull?
Foramen lacerum
Where does the mandibular V3 nerve exit the skull?
Foramen ovale
Where does the maxillary V2 nerve exit the skull?
Foramen rotundum
Where does the glossopharyngeal IX nerve exit the skull?
Jugular foramen
Where does the vagus X nerve exit the skull?
Jugular foramen
Where does the spinal accessory XI nerve exit the skull?
Jugular foramen
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
A) Choanal atresia
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.
Paradoxical cyanosis (cyanosis that is relieved by crying) in a newborn
Choanal atresia
Presentation of choanal atresia
Paradoxical cyanosis (cyanosis that is relieved by crying) is a classic symptom because newborns are obligate nose breathers.
Paradoxical cyanosis
Cyanosis that is relieved by crying
Cause of lingual thyroid
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.
Cystic hygromas
Lymphatic malformations in the head and neck region
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
A ) Buccinator
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 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.
Only muscle of facial expression that compresses the cheeks
Buccinator
Course of the parotid duct
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 buccinator muscle ordinarily contributes to:
The buccinator muscle ordinarily contributes to the function of forming a food bolus during mastication.
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
E ) Lingual
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.
What supplies general sensation for the anterior two thirds of the tongue?
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.
What supplies taste in the anterior two thirds of the tongue?
Taste in the anterior two thirds ofthe tongue is supplied by the chorda tympani from the facial nerve. The chorda tympani joins the lingual nerve and runs anteriorly in its sheath.
Lingual nerve
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.
Chorda tympani
Taste in the anterior two thirds ofthe 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:
Mucosa of the posterior third of the tongue
What supplies the mucosa of the posterior third of the tongue?
Glossopharyngeal nerve
What does the hypoglossal nerve supply?
Motor to the tongue
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
B ) Stapedius
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 thechorda tympani and stapedial nerve, patients also experience a change in taste and a decreased ability to accommodate (ie, dampen) loud noises.
Why do patients experience a change in taste and a decreased ability to accommodate (ie, dampen) loud noises w/ Bells palsy?
Because the conduction block is proximal to thechorda tympani and stapedial nerve.
Where is the maximum conduction block in 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.
Tensor tympani muscle
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 innervated by
Trigeminal nerve
The levator veli palatini muscle is innervated by
Vagus nerve
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)
A ) Auricular branch of the vagus (X)
The auricular branch of the vagus nerve (Arnold nerve) carries sensory input from the ipsilateral concha and oropharynx.
Arnold nerve
The auricular branch of the vagus nerve (Arnold nerve) carries sensory input from the ipsilateral concha and oropharynx.
Auriculotemporal nerve
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.
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
E ) Stylomastoid
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.
A 5-year-old boy is brought to the office because of a 10-day history of inflammation of a midline neck mass that his parents first noticed 1 year ago. Physical examination shows a 35-mm mass just inferior to the hyoid bone. Which of the following is the most likely diagnosis? A ) Branchial cleft remnant B ) Lingual thyroid gland C ) Mucoepidermoid carcinoma D ) Reactive lymph node E ) Thyroglossal duct cyst
E ) Thyroglossal duct cyst
The patient described has a thyroglossal duct cyst. Thyroglossal duct cysts can form anywhere along the thyroglossal duct, which extends from the foramen cecum of the tongue to the final position of the thyroid gland in the neck, below the laryngeal cartilage.
Most common neck mass in children
Reactive lymph nodes are the most common neck mass in children. They are usually found laterally in the submandibular and jugulodigastric areas.
Branchial cleft remnants
Branchial cleft remnants (sinuses and cysts) arise from the branchial apparatus. They are also located laterally, along the anterior border of the sternocleidomastoid muscle, usually just inferior to the angle of the mandible.
Ectopic thyroid glands
Ectopic thyroid glands can be located along the course of the thyroglossal duct and are a result of failure of the thyroid to descend. Unlike thyroglossal duct cysts, they represent the only thyroid tissue present in the patient.
A 4-year-old child has a congenital sinus tract opening at the anterior border of the lower third of the sternocleidomastoid muscle. Which of the following nerves is most likely to be injured during surgical excision of the fistulous tract? A ) Accessory (XI) B ) Facial (VII) C ) Hypoglossal (XII) D ) Lingual E ) Vagus (X)
C ) Hypoglossal (XII)
The second branchial arch descends over the third, resulting in an external opening in the lower neck. The internal opening lies at the anterior aspect of the posterior pillar of the fauces, just behind the tonsil (which is the junction between the second and third branchial arches). Usually, the fistula will follow the carotid sheath upwards before crossing the hypoglossal (XII) nerve and passing between the internal and external carotid arteries to reach the tonsillar fossa.
Treatment of branchial cleft cyst
Excision to prevent recurrence
Junction between the 2nd and 3rd branchial arches
The second branchial arch descends over the third, resulting in an external opening in the lower neck. The internal opening lies at the anterior aspect of the posterior pillar of the fauces, just behind the tonsil (which is the junction between the second and third branchial arches).
What nerve is at risk when excising a branchial cleft sinus or fistula?
Usually, the fistula will follow the carotid sheath upwards before crossing the hypoglossal (XII) nerve and passing between the internal and external carotid arteries to reach the tonsillar fossa. As a result, the hypoglossal nerve is at risk during surgery.
A 20-year-old man comes to the emergency department because of a deep laceration of the lower lip. Bilateral mental nerve blocks will be used to anesthetize the lip properly prior to repair. Which of the following is the most appropriate landmark for needle placement for the blocks? A ) Mandibular second premolar B ) Maxillary canine C ) Oral commissure D ) Retromolar fossa E ) Sigmoid notch
A ) Mandibular second premolar
The inferior alveolar nerve enters the mandible on the medial side of the ramus about 10 mm below the sigmoid notch. It then courses through the canal closest to the buccal cortical plate in the region of the ramus, angle, and down to the third molar with an average distance of 1.8 mm ± 1 mm. The nerve then swerves away at a position of 4.1 mm + 1 mm from the buccal cortex as it passes the region of the first and second molars. As it traverses the mandibular body, it is lowest and closest to the inferior cortex (7.5 + 1.5 mm) near its exit site at the level of the first molar and second premolar via the mental foramen on the anterior surface of the mandible. The mental nerve supplies the skin of the lower lip and chin right up to the midline.
Where does the inferior alveolar nerve enter the mandible?
The inferior alveolar nerve enters the mandible on the medial side of the ramus about 10 mm below the sigmoid notch.
How does the inferior alveolar nerve course through the mandible?
After entering the mandible on the medial side of the ramus about 10 mm below the sigmoid notch, the inferior alveolar nerve then courses through the canal closest to the buccal cortical plate in the region of the ramus, angle, and down to the third molar with an average distance of 1.8 mm ± 1 mm. The nerve then swerves away at a position of 4.1 mm + 1 mm from the buccal cortex as it passes the region of the first and second molars. As it traverses the mandibular body, it is lowest and closest to the inferior cortex (7.5 + 1.5 mm) near its exit site at the level of the first molar and second premolar via the mental foramen on the anterior surface of the mandible.
Where does the inferior alveolar nerve exit the mandible?
Its exit site is at the level of the first molar and second premolar via the mental foramen on the anterior surface of the mandible.
What does the mental nerve supply?
The mental nerve supplies the skin of the lower lip and chin right up to the midline.
The maxillary canine can be used as a landmark for:
The maxillary canine may be used as a landmark for needle insertion toward the infraorbital foramen during infiltration of the infraorbital nerve.
The maxillary second molar is a landmark used for:
The maxillary second molar is a landmark typically used to locate the opening of theStensen duct
The retromolar fossa is the preferred location for:
The retromolar fossa, posterior to the mandibular third molar, is the preferred location for needle insertion to anesthetize the buccal nerve, which normally supplies sensibility to the central cheek.
The sigmoid notch is used as a landmark to reference:
The sigmoid notch is used as a landmark to reference the location of the inferior alveolar nerve.
The mandibular second premolar can be used as a landmark for:
Block of the mental nerve
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
B ) Superficial temporal fascia
Layers from superficial to deep in the temporal area
(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.
Preventing injury to the facial nerve in a coronal approach
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.
In what layer is the frontal branch of the facial nerve found in the temporal region?
The temporal or frontal branch of the facial nerve is found within the superficial temporal or temporoparietal fascia.
The optic nerve passes through which of the following bones of the orbit? A ) Ethmoid B ) Frontal C ) Lacrimal D ) Maxilla E ) Sphenoid
E ) Sphenoid
The lesser wing of the sphenoid forms the posterior aspect of the roof of the orbit and transmits the optic nerve and ophthalmic artery through the optic canal.
The superior orbital fissure transmits
The superior orbital fissure transmits the lacrimal nerve, frontal nerve, trochlear nerve, superior and inferior branches of the oculomotor nerve, the nasociliary nerve, and the abducens nerve.
What contains the superior orbital fissure
The greater wing of the sphenoid
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)
E ) Vagus (X)
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.
Embryological origin of the levator palatini muscle
Embryologically, the levator palatini muscle arises from the fourth pharyngeal arch and, as a result, is innervated by the pharyngeal plexus, a derivative of the vagus (X) nerve.
Ophthalmic division of the trigeminal nerve
The first branch, the ophthalmic division, is strictly a sensory branch.
Maxillary division of the trigeminal nerve
The second, or maxillary, division is also sensory.
Mandibular division of the trigeminal nerve
The third branch, the mandibular division, is the largest branch and is a mixed sensory and motor branch.
Embryological division of the mandibular nerve
Embryologically, the mandibular division arises from the first branchial (or mandibular) arch and provides motor function to the muscles arising from this arch.
Muscles innervated by the _________ division of the trigeminal nerve
Temporal, masseter, pterygoids, mylohyoid, tensor tympani, and the anterior belly of the digastric.
It also innervates the tensor veil palatini.
The anatomy of the tensor veil palatini
The tensor veil palatini arises from the eustachian tube and medial pterygoid plate, wraps around the hamulus, and then inserts into the midline of the soft palate.
What happens to the eustachian tube during swallowing?
During swallowing, the soft palate is tensed, opening the eustachian tube and allowing the tongue to move food posteriorly.
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
B ) Lateral pterygoid
The origin ofthe 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.
Anatomy of the digastric muscle
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.
Function of the digstric muscle
It depresses the mandible (inferior movement) or elevates the hyoid.
Anatomy of the lateral pterygoid
The origin ofthe 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.
Function of the medial pterygoid
Elevates the mandible
Function of the lateral pterygoid in a subcondylar fracture
Draws the proximal fragment forward
Anatomy of the masseter
The masseter originates in the zygomatic arch and inserts on the lateral surface of the ramus.
Anatomy of the temporalis muscle
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.
Anatomy of the medial pterygoid muscle
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 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
B ) Inferior meatus
The nasolacrimal duct, which maintains the drainage of the nasolacrimal system, drains into the inferior meatus just below the inferior concha
Where does the nasolacrimal duct drain into?
The nasolacrimal duct, which maintains the drainage of the nasolacrimal system, drains into the inferior meatus just below the inferior concha.
The auditory tube opens into:
The auditory tube opens into the nasopharynx just posterior to the inferior concha.
The sphenoid sinus drains into:
The sphenoid sinus drains into the sphenoethmoid recess superior and posterior to the superior concha.
The posterior ethmoid air cells drain into:
The posterior ethmoid air cells drain into the superior meatus.
The nasofrontal duct drains into:
The middle meatus
The maxillary sins drains into:
The middle meatus
Where do structures drain into the nose?
Posterior ethmoid air cells: Superior meatus.
Sphenoid sinus drains into: sphenoethmoid recess superior and posterior to the superior concha
Nasofrontal duct: Middle meatus
Maxillary sinus: Middle meatus
Auditory tube: Nasopharynx just posterior to the inferior concha.
Nasolacrimal duct: inferior meatus just below the inferior concha
The mylohyoid muscle is innervated via which of the following nerves? A ) Accessory B ) Glossopharyngeal C ) Hypoglossal D ) Mandibular E ) Maxillary
D ) Mandibular
What forms the muscular floor of the oral cavity
The mylohyoid muscle is a flat, triangular muscle that with its opposite forms the muscular floor of the oral cavity.
Anatomy of the mylohyoid muscle
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.
Function of the mylohyoid muscle
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.
Motor innervation of the mylohyoid muscle
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.
Major nerves of the 3rd 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.
What is the exception for motor innervation of the tongue?
The exception is the palatoglossus muscle, which is supplied by cranial nerve X.
The other muscles: The hypoglossal nerve (cranial nerve XII) provides motor innervation to the tongue. This nerve suppliesall intrinsic muscles and all but one extrinsic muscle of the tongue.
Innervation of the tongue?
The hypoglossal nerve (cranial nerve XII) provides motor innervation to the tongue. This nerve suppliesall intrinsic muscles and all but one extrinsic muscle of the tongue. The exception is the palatoglossus muscle, which is supplied by cranial nerve X.
Innervation of the palatoglossus muscle
Cranial nerve X
The spinal accessory nerve suplies:
The spinal accessory nerve, which is cranial nerve XI, supplies motor innervation to the sternocleidomastoid and trapezius muscles.
The glossopharyngeal nerve supplies:
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.
What supplies efferent nerve innervation to the parotid gland?
The glossopharyngeal nerve (cranial nerve IX)
What carries sensations to the carotid body and carotid sinus.
The glossopharyngeal nerve (cranial nerve IX)
Innervation of the sternocleidomastoid muscle
Spinal accessory nerve
Innervation of the trapezius muscles
Spinal accessory nerve
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
B ) Second
Congenital midline cervical clefts are a result of:
Congenital midline cervical clefts are a result of a failure of fusion of the paired second branchial arches in the midline during embryogenesis.
Features of congenital midline cervical cleft
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 limitneck movement. There is some degree of retrognathia and variable degrees of clefting of the lip and mandible.
Anomalies associated with midline cervical cleft
Anomalies that have been found in association with midline cervical cleft are thyroglossal duct cysts and ectopic bronchogenic cysts.
When do branchial arches develop?
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.
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
C ) Mental
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.
To block the inferior alveolar nerve:
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.
Infraorbital nerve block results in:
Numbness of the upper lip and nasal sidewall can be accomplished with blockade of the infraorbital nerve.
Nasal palatine anesthetic produces:
Nasal palatine anesthetic produces numbness of the external nose.
Sphenopalatine nerve blockade produces:
Sphenopalatine nerve blockade produces anesthesia in the internal nose and palate.
The muscles of mastication are derived from which of the following branchial arches? A ) First B ) Second C ) Third D ) Fourth E ) Fifth
A ) First
The muscles of mastication (temporalis, masseter, and medial and lateral pterygoids), the mylohyoid, and anterior belly ofthe digastric, and the tensors veli palatini and tympani are derived from the first branchial arch.
Nerve(s) derived from the 1st branchial arch
Mandibular Trigeminal, V2, V3
Nerve(s) derived from the 2nd branchial arch
Hyoid Facial (VII)
Nerve(s) derived from the 3rd branchial arch
Glossopharyngeal (IX)
Nerve(s) derived from the 4th and 6th branchial arches
Superior laryngeal branch of vagus (X) Recurrent laryngeal branch of vagus (X
Nerves vs branchial arches
First-Mandibular Trigeminal, V2, V3
Second-Hyoid Facial (VII)
Third-Glossopharyngeal (IX)
Fourth and Sixth-Superior laryngeal branch of vagus (X) Recurrent laryngeal branch of vagus (X)
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
(A)Inferior meatus
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, dyeflows through the lacrimal system and exits at the inferior meatus.
% of patients with lacrimal drainage system injuries who sustain NOE trauma
Injuries to the lacrimal drainage system have been reported to occur in 5% to 21% of patients sustaining naso-orbito-ethmoid trauma.
Jones I dye test
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, dyeflows 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.
Jones II dye test
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, thetest 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 returnsthrough the other canaliculus, but dye refluxes through the same canaliculus, then the obstruction is in the upper part of the system.
Epiphora
Epiphora is the accumulation of tears that are not evacuated by the lacrimal drainage system.
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
(B)Ranula
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.
What is a ranula?
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.
Presentation of a ranula
It usually presents as a unilateral swelling of the floor of the mouth that is fluctuant and tinted blue or glossy white.
The ranula may herniate through the muscles of the floor of the mouth and present as a plunging ranula or cervical mass.
Treatment of a ranula
Treatment includes marsupialization or surgical excision including the sublingual gland.
Marsupialization
Marsupialization is the surgical technique of cutting a slit into an abscess or cyst and suturing the edges of the slit to form a continuous surface from the exterior surface to the interior surface of the cyst or abscess. Sutured in this fashion, the site remains open and can drain freely. This technique is used to treat a cyst or abscess when a single draining would not be effective and complete removal of the surrounding structure would not be desirable.
Lingual thyroid
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
Thyroglossal duct cyst
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
Torus
A torus is an exostosis andis 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.
At which of the following intraosseous locations is the inferior alveolar nerve farthest from the buccal cortex? (A)Angle (B)First molar (C)Ramus (D)Second premolar (E)Third molar
(B)First molar
The inferior alveolar nerve (IAN) is closest to the lingual cortex at the level of the first and second molars.
As it traverses the mandibular body, it is lowest and closest to the inferior cortex (7.5 ±1.5 mm) near its exit site at the level of the first molar and second premolar.
Where is the inferior alveolar nerve closest to the lingual cortex?
The inferior alveolar nerve (IAN) is closest to the lingual cortex at the level of the first and second molars.
The incidence of nerve transection during sagittal split osteotomy is _____% and usually occurs at:
The incidence of nerve transection during sagittal split osteotomy is 3.5% and usually occurs at the level of the third molar.
In the developing embryo, the stapes is formed from tissues of which of the following visceral arches? (A)First (B)Second (C)Third (D)Fourth (E)Fifth
(B)Second
The first visceral arch ultimately forms the malleus, incus and the structures of the mandible. The second arch forms the stapes, the styloid and the facial musculature. The third arch forms the stylopharyngeus. The fourth, fifth and sixth arches contribute to the pharyngeal and laryngeal muscles as well as the thyroid cartilage.
The first visceral arch ultimately forms:
The first visceral arch ultimately forms the malleus, incus and the structures of the mandible.
The second visceral arch ultimately forms:
The second arch forms the stapes, the styloid and the facial musculature.
The third visceral arch ultimately forms:
The third arch forms the stylopharyngeus.
The 4th, 5th and 6th visceral arch ultimately forms:
The fourth, fifth and sixth arches contribute to the pharyngeal and laryngeal muscles as well as the thyroid cartilage.
A 45-year-old man has persistent maxillary sinusitis subsequent to open reduction and internal fixation of pan-facial fractures and a failed course of antibiotics. Surgical enlargement of the ostium of the sinus is planned as a drainage procedure via an endoscopic approach. Direction of the endoscope into which of the following areas within the nasal cavity is most appropriate? (A)Inferior concha (B)Inferior meatus (C)Middle meatus (D)Superior concha (E)Superior meatus
(C)Middle meatus
The natural ostium of the maxillary sinus is located in the middle meatus, corresponding with the posterior portion of the ethmoidal infundibulum. Relative to the sinus, the ostium is located high and toward the back of the medial wall of the sinus, which is suboptimal for drainage by gravity. However, studies show directional movement of the mucosal cilia inside the sinus toward the ostium. Maxillary antrostomy involves enlarging the natural ostium and resecting the uncinate process of the ethmoid with the assistance of endoscopes.
Maxillary antrostomy
Maxillary antrostomy involves enlarging the natural ostium in the middle meatus and resecting the uncinate process of the ethmoid with the assistance of endoscopes.
The sphenopalatine foramen
The sphenopalatine foramen is also located in the superior meatus and connects the nasal cavity with the pterygopalatine fossa.
Dermoid cysts of the nasal dorsum, anterior encephaloceles, and nasal gliomas are all thought to result from failed closure of which of the following structures? (A)Anterior fontanelle (B)Dorsum sellae (C)Fonticulus frontalis (D)Foramen rotundum (E)Metopic suture
(C)Fonticulus frontalis
Failed closure of the fonticulus frontalis, an embryonic fontanelle between the inferior frontal bone and nasal bone, may result in three main types of midline anterior anomalies: nasal dermal sinus, anterior cephalocele, and nasal glioma.
Failed closure of the fonticulus frontalis may result in:
Failed closure of the fonticulus frontalis, an embryonic fontanelle between the inferior frontal bone and nasal bone, may result in three main types of midline anterior anomalies: nasal dermal sinus, anterior cephalocele, and nasal glioma.
Fonticulus frontalis
The fonticulus frontalis is an embryonic fontanelle between the inferior frontal bone and nasal bone; the anterior fontanelle closes by 24 months in 96% of children.
Nasal dermal sinus results from:
Failed closure of the fonticulus frontalis
Anterior cephalocele results from:
Failed closure of the fonticulus frontalis
Nasal glioma results from:
Failed closure of the fonticulus frontalis,
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
(E)Superior orbital fissure
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.
The foramina of the orbit
Superior orbital fissure
The optic canal
The inferior orbital fissure
What passes through the optic canal?
The optic canal, which transmits the optic (II) nerve and the ophthalmic artery
What passes through the inferior orbital fissure?
The inferior orbital fissure, which allows passage of the infraorbital and zygomatic nerves
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
(B)Auriculotemporal
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:
Sensation to the superior anterior aspect of the helix is provided by the auriculotemporal nerve.
Sensation to the ear canal is provided by:
The Arnold nerve provides sensation to the ear canal
Sensation to the posterior aspect of the external ear is provided by:
The posterior aspect of the external ear is provided by the lesser occipital nerve.
Sensation to the inferior two thirds of the external ear is provided by:
Most of the inferior two thirds of the external ear is provided by the great auricular nerve.
An otherwisehealthy 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 thefollowing is the most likely diagnosis? (A)Craniofacial fibrous dysplasia (B)Maxillary torus (C)Skull base glioma (D)Squamous cell carcinoma (E)Submucous cleft palate
(B)Maxillary torus
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
Maxillary and mandibular tori are benign osteoblastictumors 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 (briefest overview)
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.
