Form & Function MiniClinic VIII — Spring 2004 — 17–19 May

Questions 1. Where does the open into the oral cavity? 2. Where does the open into the oral cavity? 3. What function(s) would be lost if the left lingual were severed at the point where it lies medial to the lower 3rd molar? 4. Which nerve(s) carry taste fibers from the oral cavity and oropharynx? 5. In which direction would a patient’s deviate on protrusion if the patient had a damaged right hypoglossal nerve? 6. At what age would you expect a pediatric patient to have a full complement of primary teeth? 7. An 8-year-old girl was examined by a pediatrician and found to have a painless, superficial, fluctuant swelling below and behind the angle of the jaw on the right side. The skin over the swelling was cool to touch and showed no redness. Careful palpation of the neck revealed two tender, firm lumps matted together beneath the anterior border of the sternocleidomastoid on the right side. The left side of the neck was normal. Examination of the palatine showed moderate hypertrophy on both sides, and a few pustules caused by pus exuding from the on the right side. In the absence of signs of acute infection, a diagnosis of tuberculous cervical lymphadenitis was made. Using your knowledge of anatomy, name the group of lymph nodes involved in the disease. What anatomical structures would tend to limit the spread of this disease in the neck? Since the showing the most advanced stage of the disease was situated below and behind the mandible, which organ in the oral part of the was most likely to have served as the portal of entry to the tubercle bacilli? 8. A radiograph of a patient’s mouth revealed a stone in the right . Where is it possible to palpate the submandibular duct? Where does the duct open into the mouth? Where is the lumen of the submandibular duct narrowest? 9. A patient is suspected of having a lesion of the glossopharyngeal nerve. How would you test the integrity of this cranial nerve?

Answers 1. On the mucosa opposite the upper 2nd molar 2. On the mucosa of the floor of the mouth adjacent to the lingual frenulum. 3. (a) General sensation to the left anterior two-thirds of tongue and floor of mouth (b) Taste sensation to the left anterior two-thirds of tongue (chorda tympani n. traveling with lingual n.) (c) Secretomotor innervation to the glands in the floor of the left side of the mouth (parasympathetics coming from facial n. via chorda tympani n. and submandibular ganglion) 4. CN VII (anterior 2/3 of tongue via chorda tympani; via greater petrosal and greater & lesser palatine ), CN IX (posterior 2/3 of tongue via lingual branches), and CN X (epiglottis and pharyngeal wall via internal laryngeal n.)

F & F MiniClinic VIII — 17–19 May 2004 — 1 5. To the right 6. 24 months 7. Tuberculous cervical lymphadenitis is much less common now than previously due to adequate pasteurization of cows’ milk. The organism commonly gains entrance to the palatine and spreads to the member of the deep cervical group of lymph nodes that drains the tonsil and is situated below and behind the angle of the jaw. The infection may remain localized to this node for some time or involve other neighboring nodes, which become matted together. Once the disease has resulted in the destruction of the interior of the node, the caseating material liquifies and breaks through the capsule of the node. To begin with, the abscess is localized beneath the investing layer of deep cervical fascia. Later, it erodes through the fascia and produces a large cold abscess beneath the skin. This soon becomes secondarily infected and breaks through the skin, to form a discharging sinus. 8. The submandibular duct can be palpated through the floor of the mouth alongside the tongue. It is often possible to palpate a calculus in the duct in this situation. The duct opens into the mouth at the side of the frenulum of the tongue. The narrowest part of the duct is at the orifice. 9. The glossopharyngeal nerve supplies the mucous membrane of the posterior third of the tongue with taste fibers and those for general sensation. These sensations can easily be tested by using appropriate stimuli.

Cases without printed interpretations • Patient Wally N. This 56-year-old seaman consulted a physician regarding a painful “canker sore” on the left edge of his tongue. A long-time user of chewing tobacco, he had noticed the condition for the previous month at sea. After examining the oral cavity and cervical lymph nodes, the physician requests a biopsy and advises the patient not to plan for early sailing. Carcinoma is the diagnosis and surgical removal is indicated. You assist in the operation. The lesion is excised from the left side of the tongue and the floor of the left side of the mouth. During the dissection, it is necessary to remove the left submandibular gland and duct. The lingual nerve on the left side is unavoidably traumatized by the surgical procedure, but it is carefully separated from the tumor where the latter invested it and surrounded the submandibular duct. Immediately following surgery, the left anterior two-thirds of the patient’s tongue lacks all sensation, but sensation improves over the next 2 weeks and returns to normal following his release from hospital. He is scheduled for postoperative radiotherapy to augment the surgical resection. • A young teenager suffered from (infection of the palatine tonsils) and, since her tonsillar infections recurred often, her physician recommended that the palatine tonsils be removed. In the two days following , the girl complained that her tongue felt somewhat numb. This anesthesia was temporary however and she recovered with no other complaints. How could sensory impairment of the tongue be linked with the surgical procedure? • A young woman noticed a painless swelling at the back of her tongue. Thinking it might be a tumor, she visited a local health clinic. Based on the results of a test that revealed that

F & F MiniClinic VIII — 17–19 May 2004 — 2 the swelling took up radioactive iodine, the physician told her that the swelling was probably harmless. What might the swelling be?

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