Head and Neck Congenital Flashcards
A 6-month-old infant is brought to the office because of abnormal head tilt and limited range of motion of the neck. Physical examination shows a 3-cm firm mass on the right side of the neck above the clavicle. Which of the following physical findings is most likely associated with this condition?
A) Flexion of the head toward the left shoulder
B) Flexion of the neck toward the left shoulder
C) Limited lateral flexion toward the left shoulder
D) Limited lateral flexion toward the right shoulder
E) Rotation of the head to the right shoulder
The correct response is Option C.
Torticollis is a congenital neck deformity involving shortening of the sternocleidomastoid muscle. The symptoms are head tilt and limited range of motion in the neck, and there is usually a firm mass in the body of the sternocleidomastoid muscle. The majority of the symptoms resolve in the first year of life. Occasionally, large portions of the muscle may become fibrotic, necessitating surgical release.
On physical examination, findings include flexion of the head and neck toward the ipsilateral shoulder, rotation of the head and neck to the contralateral shoulder, and a lack of lateral flexion toward the contralateral shoulder. In the case of right-sided torticollis, the findings would be:
- Flexion of the head and neck toward the right shoulder
- Rotation of the head and neck toward the left shoulder
- Limited lateral flexion toward the left shoulder
2018
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.
2010
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.
2010
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.
2010
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.
2010
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.
- foramen lacerum: internal carotid artery
- foramen ovale: mandibular (V3) nerve
- foramen rotundum: maxillary (V2) nerve
The glossopharyngeal (IX), vagus (X), and spinal accessory (XI) nerves emerge from the jugular foramen.
2010
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
The correct response is Option E.
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. Normally, the thyroglossal duct atrophies and disappears. However, a remnant of it may persist and form a cyst in the tongue or anterior midline of the neck, most commonly inferior to the hyoid bone. Thyroglossal duct cysts are often asymptomatic unless they become infected, as this one has.
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 (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.
Lingual thyroid glands are a type of ectopic thyroid located within the tongue. 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.
Mucoepidermoid carcinomas are salivary gland malignancies found in children, and they most commonly appear within the parotid gland.
2010
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)
The correct response is Option C.
The child described has a branchial cleft sinus or fistula, which is an embryologic remnant of the cleft between the second and third branchial arches. The fistulas can be bilateral in up to 30% of cases. Histologically, they are lined with stratified squamous epithelium but may also have some pseudostratified columnar ciliated epithelium in their walls. They also contain keratin, hair follicles, sweat glands, and sebaceous glands. They must be completely excised to prevent recurrence.
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. As a result, the hypoglossal nerve is at risk during surgery.
The facial (VII) nerve is not in the vicinity of the fistula. The facial nerve is intimately related to first branchial arch sinuses and cysts.
The spinal accessory (XI) nerve is in the posterior triangle of the neck and is not in the vicinity of the surgical field to remove this type of fistula.
The lingual nerve lies at a higher level and is safe.
The left recurrent laryngeal nerve arises from the vagus (X) nerve low in the neck before hooking around the subclavian artery and passing medially behind the common carotid artery to reach the groove between the trachea and the esophagus. As a result of this anatomy, it too is out of harm’s way.
The vagus (X) nerve lies in the carotid sheath behind, and somewhat between, the internal jugular vein and the common carotid artery. The fistula lies on the other side of the great vessels. At the carotid bifurcation, the vagus nerve is lateral to the fistulous tract and stands less chance of injury than does the hypoglossal nerve.
2010
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
The correct response is Option A.
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.
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 typically used to locate the opening of the Stensen duct.
The oral commissure is used for facial aesthetic measurements and not for nerve blocks.
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 location of the inferior alveolar nerve.
2010
