Diseases of the Oral Cavity and Salivary Glands Practice Questions

Q: What is the investigation of choice for parotid fistula?

Sialogram. ### Explanation **Correct Answer: D. Sialogram** **Why it is the Investigation of Choice:** A **sialogram** (sialography) is the gold standard for investigating a parotid fistula. It involves the injection of a radio-opaque contrast medium into the Stensen’s duct followed by imaging. In the case of a fistula, the contrast will be seen leaking from the ductal system or gland parenchyma into the fistulous tract, effectively demonstrating the **site, size, and origin** of the leak. It also helps differentiate between a ductal fistula (injury to the main duct) and a glandular fistula (injury to the parenchyma), which is crucial for surgical planning. **Analysis of Incorrect Options:** * **A. CT Scan:** While useful for identifying tumors or abscesses, a routine CT lacks the dynamic contrast flow needed to pinpoint a fine fistulous communication. * **B. X-ray:** Plain radiographs are primarily used to detect radiopaque sialoliths (stones) but cannot visualize soft tissue tracts or fluid leaks. * **C. Starch Iodine Test (Minor’s Test):** This is the investigation of choice for **Frey’s Syndrome** (gustatory sweating), not a parotid fistula. It identifies sweat production on the skin, whereas a fistula involves the leakage of saliva. **High-Yield Clinical Pearls for NEET-PG:** * **Frey’s Syndrome:** Occurs due to aberrant regeneration of auriculotemporal nerve fibers. * **Management of Parotid Fistula:** Initial management is conservative (anti-sialagogues like Glycopyrrolate, pressure dressings). If it fails, surgical options include tympanic neurectomy (to cut parasympathetic supply) or parotidectomy. * **Sialography Contraindication:** It should never be performed during **acute infection** (sialadenitis) as it can retrograde spread the infection.

Q: What is the most common site for a minor salivary gland tumor?

Palate. **Explanation:** The **palate** (specifically the junction of the hard and soft palate) is the most common site for minor salivary gland tumors [1], accounting for approximately **50%** of all such cases. Minor salivary glands are distributed throughout the upper aerodigestive tract, but their highest density is found in the palatal mucosa. **Analysis of Options:** * **B. Palate (Correct):** Due to the high concentration of minor salivary tissue, this is the primary site [1]. A key surgical pearl is that a swelling on the palate is more likely to be a minor salivary gland tumor than a primary bone tumor. * **A. Cheek (Buccal Mucosa):** While minor salivary glands exist here, tumors are significantly less common than in the palate. * **C. Sublingual Gland:** This is a **major** salivary gland, not a minor one. While it is the least common site for major salivary gland tumors, it has the highest malignancy rate (approx. 80%). * **D. Tongue:** Tumors can occur here (usually at the base or lateral borders), but the frequency is much lower compared to the palatal distribution. **High-Yield NEET-PG Pearls:** 1. **The 50% Rule:** Approximately 50% of all minor salivary gland tumors are **malignant** [2] (unlike the parotid, where 80% are benign). 2. **Most Common Benign Minor Tumor:** Pleomorphic Adenoma (most common site: Palate [1]). 3. **Most Common Malignant Minor Tumor:** Adenoid Cystic Carcinoma (most common site: Palate). 4. **Overall Most Common Salivary Tumor:** Pleomorphic Adenoma of the Parotid Gland.

Q: What is the best method to differentiate a periapical cyst from a periapical granuloma?

Histologically. ### Explanation The differentiation between a periapical cyst (radicular cyst) and a periapical granuloma is a classic dilemma in oral pathology. While both represent inflammatory responses to a non-vital tooth, the **gold standard** for differentiation is **histological examination**. **1. Why Histology is Correct:** The defining feature of a **periapical cyst** is the presence of a pathological cavity lined by **stratified squamous epithelium** (derived from the Malassez epithelial rests). In contrast, a **periapical granuloma** consists of a solid mass of chronic inflammatory tissue (lymphocytes, plasma cells, and macrophages) and granulation tissue **without** an epithelial lining. Since this distinction is microscopic, only a biopsy can provide a definitive diagnosis. **2. Why Other Options are Incorrect:** * **Radiographically:** Both lesions appear as well-defined radiolucencies at the apex of a tooth. While cysts are often larger (>20mm) and have a sclerotic border, these features are not pathognomonic. Studies show that radiographic interpretation alone is unreliable for distinguishing between the two. * **Clinically:** Both conditions are often asymptomatic and associated with a non-vital (necrotic) tooth. They may both present with mild swelling or sensitivity to percussion, making clinical differentiation impossible. **High-Yield Clinical Pearls for NEET-PG:** * **Periapical Granuloma:** The most common sequel of chronic pulpitis. It is *not* a true granuloma (lacks epithelioid histiocytes/giant cells). * **Radicular Cyst:** The most common cyst of the jaws. * **Rushton Bodies:** Eosinophilic, linear, or curved inclusions found in the epithelial lining of radicular cysts (High-yield histological finding). * **Treatment:** Both usually respond to Root Canal Treatment (RCT); however, large cysts may require surgical enucleation.

Q: Which of the following is the most common tumor of the salivary gland?

Pleomorphic adenoma. **Explanation:** **Pleomorphic Adenoma** (Option D) is the most common tumor of the salivary glands, accounting for approximately 60–70% of all salivary gland neoplasms. It is a benign mixed tumor containing both epithelial and mesenchymal elements. It most frequently involves the **parotid gland** (80% of cases), where it typically presents as a slow-growing, painless, firm swelling in the superficial lobe. **Analysis of Incorrect Options:** * **Mucoepidermoid Carcinoma (Option A):** This is the most common **malignant** salivary gland tumor in both adults and children. While common, its overall incidence is lower than that of the benign Pleomorphic Adenoma. * **Warthin’s Tumor (Option B):** Also known as Papillary Cystadenoma Lymphomatosum, it is the second most common benign tumor of the parotid. It is strongly associated with smoking and is the most common salivary tumor to present bilaterally or multicentrically. * **Acinic Cell Tumor (Option C):** This is a low-grade malignant tumor. It is unique because it is often bilateral (second only to Warthin’s) but is significantly rarer than Pleomorphic Adenoma. **High-Yield NEET-PG Pearls:** * **Rule of 80s for Parotid Tumors:** 80% are parotid, 80% are benign, 80% are Pleomorphic Adenoma, and 80% occur in the superficial lobe. * **Most common site for minor salivary gland tumors:** The Palate. * **Malignancy Risk:** The smaller the gland, the higher the risk of malignancy (e.g., Sublingual gland tumors are rare but ~80% are malignant). * **Carcinoma ex pleomorphic adenoma:** Refers to the malignant transformation of a long-standing Pleomorphic Adenoma.

Q: Pain in the tonsillar fossa and upper neck is characteristic of?

Eagle's syndrome. **Explanation:** **Eagle’s Syndrome** (also known as Stylohyoid Syndrome) occurs due to an **elongated styloid process** (greater than 3 cm) or calcification of the stylohyoid ligament. This anatomical variation causes compression of cranial nerves (V, VII, IX, or X) or the carotid arteries. Patients typically present with a dull, nagging pain in the **tonsillar fossa and upper neck**, often triggered by swallowing or turning the head. A sensation of a "foreign body" in the throat (globus pharyngeus) and referred otalgia are also common. Diagnosis is confirmed by palpating the styloid process in the tonsillar fossa and via imaging (X-ray or CT). **Analysis of Incorrect Options:** * **Ape’s Syndrome:** This is not a recognized medical term. It is likely a distractor for "Apert Syndrome," which is a craniofacial synostosis characterized by skull deformities and syndactyly (fused fingers/toes). * **Sickler’s Syndrome:** This is a distractor. "Sickle Cell Disease" is a hematological disorder, and "Stickler Syndrome" is a genetic connective tissue disorder involving hearing loss and retinal detachment, but neither presents with localized tonsillar fossa pain. * **Usher’s Syndrome:** A genetic condition characterized by the combination of sensorineural hearing loss and progressive vision loss due to retinitis pigmentosa. **Clinical Pearls for NEET-PG:** * **Treatment:** The definitive treatment is surgical shortening of the styloid process via a **trans-oral** or **trans-cervical** approach. * **Differential Diagnosis:** Must be differentiated from Glossopharyngeal Neuralgia (which presents with paroxysmal, lancinating pain). * **Anatomy:** The styloid process is derived from the **2nd branchial arch** (Reichert’s cartilage).

Q: In Frey's syndrome, what is the neurotransmitter involved?

Acetylcholine. **Explanation:** **Frey’s Syndrome (Auriculotemporal Syndrome)** occurs due to the aberrant regeneration of nerve fibers following parotid surgery (parotidectomy) or trauma. 1. **Why Acetylcholine is correct:** The physiological basis of this syndrome lies in the **parasympathetic** nervous system. Normally, the **auriculotemporal nerve** carries postganglionic parasympathetic fibers that use **acetylcholine** to stimulate salivary secretion from the parotid gland. After injury, these regenerating parasympathetic fibers mistakenly grow into the overlying skin to innervate sweat glands and small blood vessels. Since sweat glands are also stimulated by cholinergic (acetylcholine) fibers, the stimulus intended for salivation (like seeing or smelling food) results in localized sweating and flushing of the temple area instead. 2. **Why the other options are incorrect:** * **Epinephrine & Norepinephrine:** These are the primary neurotransmitters of the sympathetic nervous system. While sweat glands are anatomically part of the sympathetic system, they are a unique exception as they are **cholinergic** (stimulated by acetylcholine). * **Serotonin:** This is a monoamine neurotransmitter primarily involved in mood regulation and GI motility; it has no role in the secretomotor pathway of the parotid or sweat glands. **High-Yield Clinical Pearls for NEET-PG:** * **Diagnosis:** Confirmed by the **Minor’s Starch-Iodine Test** (the area turns blue-black upon sweating). * **Prevention:** Interposition of barriers like the **Acellular Dermal Matrix** or **Sternocleidomastoid (SCM) flap** during surgery. * **Treatment:** Topical **Glycopyrrolate** or **Botulinum toxin (Botox)** injections (which block acetylcholine release).

Question 1

What is the investigation of choice for parotid fistula?

Accepted Answer

Sialogram

Answer

CT Scan

Answer

X-ray

Answer

Starch iodine Test

Question 2

What is the treatment for leukoplakia?

Accepted Answer

Surgical excision and cryotherapy

Answer

Radiation therapy

Answer

Topical chemotherapy

Answer

Repositioning of ill-fitting dentures

Question 3

All of the following are true about dental abnormalities EXCEPT:

Accepted Answer

Dentigerous cysts are most common in the upper third molars.

Answer

Dental cysts develop at the apices of carious teeth with necrotic pulp.

Answer

Dentigerous cysts contain unerupted teeth.

Answer

Ameloblastoma is the most common odontogenic tumor.

Question 4

What is the most common site for a minor salivary gland tumor?

Accepted Answer

Palate

Answer

Cheek

Answer

Sublingual gland

Answer

Tongue

Question 5

All the following are true regarding a ranula EXCEPT?

Accepted Answer

A cyst with an epithelial lining, confined to the sublingual salivary gland

Answer

A pseudocyst with no connection to the salivary gland

Answer

Will change size following chewing and swallowing

Answer

Formed due to obstruction of the submandibular or minor salivary glands

Question 6

What is the best method to differentiate a periapical cyst from a periapical granuloma?

Accepted Answer

Histologically

Answer

Radiographically

Answer

Clinically

Answer

None of the above

Question 7

Which of the following is the most common tumor of the salivary gland?

Accepted Answer

Pleomorphic adenoma

Answer

Mucoepidermoid tumor

Answer

Warthin's tumor

Answer

Acinic cell tumor

Question 8

Which of the following is not an indication for radiotherapy in pleomorphic adenoma of the parotid gland?

Accepted Answer

Second histologically benign recurrence

Answer

Involvement of the deep lobe

Answer

Microscopically positive margins

Answer

Malignant transformation

Question 9

Pain in the tonsillar fossa and upper neck is characteristic of?

Accepted Answer

Eagle's syndrome

Answer

Ape's syndrome

Answer

Sickler's syndrome

Answer

Usher's syndrome

Question 10

In Frey's syndrome, what is the neurotransmitter involved?

Accepted Answer

Acetylcholine

Answer

Epinephrine

Answer

Norepinephrine

Answer

Serotonin

Diseases of the Oral Cavity and Salivary Glands — MCQs

Diseases of the Oral Cavity and Salivary Glands — MCQs

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