Diseases of the Oral Cavity and Salivary Glands — MCQs
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Reversible pulpitis changes to irreversible pulpitis primarily because of?
Bilateral parotid enlargement is seen in:
Which of the following is NOT a high-grade salivary gland malignancy?
A 17-year-old girl notices a small, sensitive, gray-white area forming along the lateral border of her tongue 2 days before the end of her final examinations. On examination, the girl is afebrile. There is a shallow, ulcerated, 0.3-cm lesion with an erythematous rim. No specific therapy is given, and the lesion disappears within 2 weeks. The history shows that the girl does not use tobacco or alcohol. Which of the following is the most probable diagnosis?
What is the difference between nicotinic stomatitis and papillary hyperplasia?
What is the most common cause of dry mouth in adults?
The most common malignant tumor of the gingiva is:
Bilateral parotid enlargement does not occur in which of the following conditions?
Which of the following is true about Odontogenic keratocyst?
Which oral lesion is associated with ulcerative colitis?
Diseases of the Oral Cavity and Salivary Glands Indian Medical PG Practice Questions and MCQs
Question 41: Reversible pulpitis changes to irreversible pulpitis primarily because of?
- A. Vascular strangulation
- B. Reduced host resistance
- C. Invasion of microorganisms (Correct Answer)
- D. An increase in microbial virulence
Explanation: **Explanation:** The transition from reversible to irreversible pulpitis is a critical threshold in endodontics. In **reversible pulpitis**, the pulp is inflamed but vital, and the inflammation is typically a response to stimuli (like caries or thermal changes) without direct bacterial infection of the pulp tissue itself. **Why "Invasion of Microorganisms" is correct:** The primary driver for the progression to **irreversible pulpitis** is the **direct invasion of microorganisms** into the pulp chamber. Once bacteria and their byproducts (toxins, enzymes) penetrate the dentinal tubules and reach the pulp, they trigger an intense, persistent inflammatory response. The high intrapulpal pressure caused by this infection leads to tissue necrosis, making the condition "irreversible" as the pulp can no longer heal even if the initial stimulus is removed. **Analysis of Incorrect Options:** * **Vascular strangulation:** While once a popular theory (suggesting increased pressure cuts off blood supply at the apex), it is now considered a *consequence* of advanced inflammation/necrosis rather than the primary *cause* of the transition. * **Reduced host resistance:** While host factors influence the speed of progression, they do not trigger the transition; the presence of the pathogen is the requisite factor. * **Increase in microbial virulence:** It is the *presence* and *location* (invasion) of the microbes that matters most, rather than a change in their inherent virulence. **High-Yield Clinical Pearls for NEET-PG:** * **Reversible Pulpitis:** Characterized by sharp pain that lasts only a few seconds after the stimulus (cold/sweet) is removed. * **Irreversible Pulpitis:** Characterized by **spontaneous pain**, lingering pain after stimulus removal, and pain that worsens when lying down (due to increased cephalic blood pressure). * **Key Histopathology:** Reversible pulpitis shows focal hyperemia and edema; Irreversible pulpitis shows micro-abscess formation and liquefaction necrosis.
Question 42: Bilateral parotid enlargement is seen in:
- A. Wegener's granulomatosis
- B. Sjögren's syndrome
- C. Kimura's disease
- D. All of the above (Correct Answer)
Explanation: **Explanation:** Bilateral parotid enlargement is a significant clinical finding that can result from systemic inflammatory, autoimmune, or infiltrative processes. **1. Sjögren’s Syndrome:** This is a chronic autoimmune disorder characterized by lymphocytic infiltration of exocrine glands. It classically presents with the triad of xerostomia (dry mouth), keratoconjunctivitis sicca (dry eyes), and **bilateral, painless parotid swelling** (seen in about 50% of patients). **2. Wegener’s Granulomatosis (Granulomatosis with Polyangiitis):** While primarily affecting the upper and lower respiratory tracts and kidneys, it can involve the salivary glands in approximately 1-2% of cases. It typically presents as a firm, bilateral parotid enlargement due to necrotizing granulomatous inflammation. **3. Kimura’s Disease:** This is a chronic inflammatory condition (common in young Asian males) characterized by painless subcutaneous swelling in the head and neck region, often involving the **major salivary glands bilaterally**. It is associated with peripheral eosinophilia and elevated serum IgE levels. **Clinical Pearls for NEET-PG:** * **Differential Diagnosis for Bilateral Parotid Swelling:** * **Infectious:** Mumps (most common viral cause), HIV. * **Endocrine/Metabolic (Sialadenosis):** Diabetes mellitus, chronic alcoholism, malnutrition (bulimia/anorexia). * **Autoimmune:** Sjögren’s, Sarcoidosis (Heerfordt’s syndrome: Uveitis + Parotitis + Facial palsy). * **Drugs:** Iodine, Phenylbutazone. * **High-Yield Fact:** If a patient with Sjögren’s syndrome has persistent, hard parotid swelling, suspect a transformation into **MALT Lymphoma**. * **Warthin’s Tumor:** The only salivary gland tumor that is frequently bilateral (though often metachronous).
Question 43: Which of the following is NOT a high-grade salivary gland malignancy?
- A. Basal cell adenocarcinoma (Correct Answer)
- B. Mucoepidermoid carcinoma
- C. Adenoid cystic carcinoma
- D. Salivary duct carcinoma
Explanation: **Explanation:** Salivary gland malignancies are classified into low, intermediate, and high grades based on their clinical behavior, histological features, and metastatic potential. **1. Why Basal Cell Adenocarcinoma is the correct answer:** Basal cell adenocarcinoma is considered a **low-grade malignancy**. It is the malignant counterpart of basal cell adenoma. While it is locally invasive and can recur, it has a low rate of distant metastasis and an excellent prognosis (over 90% 10-year survival rate). It should not be confused with high-grade entities. **2. Analysis of Incorrect Options:** * **Mucoepidermoid Carcinoma (MEC):** This is the most common malignant salivary gland tumor. While it can be low-grade, it frequently presents as a **high-grade** tumor (especially in the parotid), characterized by rapid growth and early metastasis. * **Adenoid Cystic Carcinoma (ACC):** This is a **high-grade** malignancy known for its relentless growth, **perineural invasion** (causing pain/palsy), and "Swiss-cheese" appearance. It has a high propensity for late distant metastasis (especially to the lungs). * **Salivary Duct Carcinoma:** This is a highly aggressive, **high-grade** malignancy that histologically resembles high-grade ductal carcinoma of the breast. It carries a very poor prognosis. **High-Yield Clinical Pearls for NEET-PG:** * **Most common salivary tumor (overall):** Pleomorphic Adenoma. * **Most common malignant salivary tumor:** Mucoepidermoid Carcinoma. * **Tumor with highest incidence of perineural invasion:** Adenoid Cystic Carcinoma. * **Hot Spot:** The **Parotid gland** is the most common site for salivary tumors, but the **Sublingual gland** has the highest *percentage* of tumors being malignant (approx. 80%).
Question 44: A 17-year-old girl notices a small, sensitive, gray-white area forming along the lateral border of her tongue 2 days before the end of her final examinations. On examination, the girl is afebrile. There is a shallow, ulcerated, 0.3-cm lesion with an erythematous rim. No specific therapy is given, and the lesion disappears within 2 weeks. The history shows that the girl does not use tobacco or alcohol. Which of the following is the most probable diagnosis?
- A. Aphthous ulcer (Correct Answer)
- B. Herpes simplex stomatitis
- C. Leukoplakia
- D. Oral thrush
Explanation: ### Explanation **Correct Answer: A. Aphthous Ulcer** The clinical presentation is classic for an **Aphthous Ulcer** (canker sore). These are painful, recurrent, shallow ulcers characterized by a **gray-white pseudomembranous center** surrounded by an **erythematous (red) halo**. Key diagnostic features in this case include: * **Trigger:** Stress (final examinations) is a well-known precipitant. * **Appearance:** Small (<1 cm), shallow, and well-circumscribed. * **Course:** Self-limiting, typically resolving within 7–14 days without scarring. * **Demographics:** Common in children and adolescents; not associated with tobacco or alcohol. --- ### Why the other options are incorrect: * **B. Herpes Simplex Stomatitis:** Primary infection usually presents with multiple vesicles that rupture into ulcers, often accompanied by systemic symptoms like fever and lymphadenopathy. Recurrent herpes (cold sores) typically occurs on the keratinized mucosa (lips/gingiva), whereas aphthous ulcers occur on non-keratinized mucosa (lateral tongue/buccal mucosa). * **C. Leukoplakia:** This presents as a persistent, white patch or plaque that **cannot be scraped off**. It is a premalignant condition strongly associated with tobacco use and is usually painless and chronic, not transient. * **D. Oral Thrush (Candidiasis):** This presents as creamy white, curd-like patches. Unlike aphthous ulcers, these patches can be **scraped off**, leaving a raw, bleeding surface. It is typically seen in immunocompromised patients or those using steroids/antibiotics. --- ### High-Yield NEET-PG Pearls: * **Mikulicz’s Ulcer:** Another name for Minor Aphthous Ulcers (the most common type, <10 mm). * **Major Aphthous Ulcers (Sutton’s Disease):** Larger (>1 cm), deeper, more painful, and may leave a scar. * **Behçet’s Syndrome:** Consider this if aphthous ulcers are associated with genital ulcers and uveitis. * **Management:** Usually symptomatic (topical steroids or benzocaine). No systemic workup is needed for a single, self-limiting episode.
Question 45: What is the difference between nicotinic stomatitis and papillary hyperplasia?
- A. Multiple dots at the periphery
- B. Rings at the center
- C. A small centrally placed dot (Correct Answer)
- D. Rings at the periphery
Explanation: ### Explanation The key to distinguishing between these two conditions lies in the **anatomical involvement of the minor salivary glands**. **1. Why the Correct Answer is Right:** * **Nicotinic Stomatitis (Smoker’s Palate):** This is a reactive change seen in heavy pipe or cigar smokers. The heat and chemicals cause hyperkeratosis of the hard palate. The characteristic feature is the presence of multiple greyish-white papules with **a small centrally placed red dot**. This red dot represents the **inflamed and dilated orifice of a minor salivary gland duct**. * **Papillary Hyperplasia (Denture Stomatitis):** This is typically associated with ill-fitting dentures or candidal infection. It presents as a "cobblestone" appearance with multiple small, pebble-like projections. Crucially, it **lacks the central punctate red dots** because it is a generalized tissue overgrowth rather than a specific inflammation of the ductal openings. **2. Analysis of Incorrect Options:** * **Options A & D (Dots/Rings at periphery):** These are not characteristic of either condition. In Nicotinic Stomatitis, the dots are central to the individual papules, distributed across the hard palate. * **Option B (Rings at the center):** While the papules may appear circular, the diagnostic hallmark is the *punctum* (dot) of the duct, not a ring. **3. Clinical Pearls for NEET-PG:** * **Reversibility:** Nicotinic stomatitis is usually **reversible** once smoking is discontinued. * **Malignancy Risk:** Despite the name "stomatitis," it is generally considered **benign** and not premalignant (unlike leukoplakia), though it indicates heavy tobacco use which increases risk for other cancers. * **Location:** Always occurs on the **hard palate**; the soft palate is usually protected by the thickness of the minor salivary gland aggregates. * **Differential Diagnosis:** Always rule out **Inflammatory Papillary Hyperplasia** by checking for a history of 24-hour denture wear.
Question 46: What is the most common cause of dry mouth in adults?
- A. Tranquilizers
- B. Antihistaminics (Correct Answer)
- C. Insulin
- D. Birth control pills
Explanation: **Explanation:** **Xerostomia (Dry Mouth)** is a common clinical condition characterized by a subjective feeling of oral dryness, usually resulting from reduced salivary flow. **Why Antihistaminics are the correct answer:** Antihistaminics (specifically first-generation H1 blockers like Diphenhydramine) are the most frequent pharmacological cause of dry mouth. The underlying mechanism is their **anticholinergic (antimuscarinic) effect**. Salivary secretion is primarily mediated by parasympathetic stimulation via muscarinic (M3) receptors. Antihistaminics block these receptors, leading to decreased aqueous secretion from the salivary glands. Given their widespread over-the-counter use for allergies and colds, they are the most common culprit among the options provided. **Analysis of Incorrect Options:** * **A. Tranquilizers:** While certain antipsychotics and benzodiazepines can cause xerostomia, they are less commonly used by the general adult population compared to antihistaminics. * **C. Insulin:** Insulin itself does not cause dry mouth. In fact, xerostomia is a symptom of *uncontrolled diabetes* (due to polyuria and dehydration), not the insulin treatment. * **D. Birth control pills:** These are generally not associated with significant salivary gland dysfunction or xerostomia. **NEET-PG High-Yield Pearls:** * **Most common overall cause of Xerostomia:** Drug-induced (Anticholinergics, Antihistaminics, Antidepressants, Diuretics). * **Most common systemic disease causing Xerostomia:** Sjögren’s Syndrome (autoimmune destruction of exocrine glands). * **Radiotherapy:** Xerostomia is the most common late complication of head and neck radiation (permanent damage occurs at doses >25-30 Gy). * **Management:** Frequent sips of water, artificial saliva, or Sialogogues (e.g., **Pilocarpine**, a muscarinic agonist).
Question 47: The most common malignant tumor of the gingiva is:
- A. Malignant melanoma
- B. Sarcoma
- C. Fibrosarcoma
- D. Squamous cell carcinoma (Correct Answer)
Explanation: **Explanation:** **Squamous Cell Carcinoma (SCC)** is the most common malignant tumor of the gingiva, accounting for over 90% of all gingival malignancies. The gingiva is lined by stratified squamous epithelium; chronic irritation from tobacco, alcohol, or poor oral hygiene leads to dysplastic changes in these keratinocytes, eventually progressing to invasive SCC. Clinically, it often presents as an exophytic growth or a non-healing ulcer, frequently mimicking common dental conditions like epulis or chronic periodontitis, which can lead to a delay in diagnosis. **Why other options are incorrect:** * **Malignant Melanoma:** While the oral cavity is a site for mucosal melanoma, it is rare (less than 1% of oral malignancies). It typically presents as a pigmented lesion on the hard palate or maxillary gingiva. * **Sarcoma & Fibrosarcoma:** These are malignant tumors of mesenchymal (connective tissue) origin. While they can occur in the jaw bones or soft tissues of the mouth, they are significantly less common than epithelial tumors like SCC. **High-Yield Clinical Pearls for NEET-PG:** * **Most common site for Oral SCC:** Tongue (lateral border) > Floor of the mouth > Gingiva. * **Gingival SCC** is more common in the **mandible** (lower jaw) than the maxilla, usually in the molar and premolar regions. * **"Verrucous Carcinoma" (Ackerman’s tumor)** is a specific low-grade variant of SCC often associated with smokeless tobacco (betel nut chewing) and commonly involves the gingivobuccal sulcus. * **Field Cancerization:** This concept explains why patients with one oral SCC are at high risk for developing synchronous or metachronous primary tumors in the upper aerodigestive tract.
Question 48: Bilateral parotid enlargement does not occur in which of the following conditions?
- A. Sjogren's syndrome
- B. Sarcoidosis
- C. SLE (Correct Answer)
- D. Chronic pancreatitis
Explanation: **Explanation:** The correct answer is **SLE (Systemic Lupus Erythematosus)**. While SLE is a systemic autoimmune disease that can affect multiple organs, it typically involves the salivary glands only when it occurs in association with **Secondary Sjogren’s Syndrome**. Isolated, primary bilateral parotid enlargement is not a recognized clinical feature of SLE itself. **Analysis of Options:** * **Sjogren’s Syndrome:** This is a classic cause of bilateral, painless, or slightly tender parotid enlargement. It involves lymphocytic infiltration and destruction of exocrine glands (Sicca complex). * **Sarcoidosis:** Known as **Heerfordt’s Syndrome** (Uveoparotid fever) when it presents with parotid enlargement, uveitis, and facial nerve palsy. It is a common cause of bilateral parotid swelling due to non-caseating granulomas. * **Chronic Pancreatitis:** This falls under the category of **Sialadenosis** (Sialosis). Sialadenosis refers to non-inflammatory, non-neoplastic bilateral parotid swelling often associated with metabolic or systemic conditions, including chronic alcoholism, malnutrition, and chronic pancreatitis. **High-Yield Clinical Pearls for NEET-PG:** * **Sialadenosis (Bilateral Swelling):** Remember the "3 Ds": **D**rugs (Guanethidine), **D**iet (Malnutrition/Bulimia), and **D**iseases (Diabetes, Liver Cirrhosis, Pancreatitis). * **Warthin’s Tumor:** The most common **neoplastic** cause of bilateral parotid enlargement (though often metachronous). * **Mumps:** The most common **viral** cause of acute bilateral parotid swelling in children. * **Heerfordt’s Syndrome:** A pathognomonic presentation of Sarcoidosis involving the parotid gland.
Question 49: Which of the following is true about Odontogenic keratocyst?
- A. Most common in females
- B. Not premalignant
- C. Seen in the posterior mandible (Correct Answer)
- D. Treatment is observation
Explanation: **Odontogenic Keratocyst (OKC)**, recently reclassified by the WHO as a keratocystic odontogenic tumor, is a benign but locally aggressive developmental cyst arising from the dental lamina. ### **Explanation of the Correct Option** * **C. Seen in the posterior mandible:** This is the most characteristic clinical feature. Approximately **60-80% of cases** occur in the mandible, with a strong predilection for the **posterior body and ascending ramus**. It typically grows in an anteroposterior direction within the medullary bone without causing significant cortical expansion initially. ### **Analysis of Incorrect Options** * **A. Most common in females:** Incorrect. OKC shows a slight **male predilection** (Ratio ~1.5:1) and most commonly presents in the 2nd to 4th decades of life. * **B. Not premalignant:** Incorrect. While rare, OKC has a recognized potential for **neoplastic transformation** into squamous cell carcinoma. Its aggressive nature and high recurrence rate (up to 30-60%) distinguish it from simple cysts. * **D. Treatment is observation:** Incorrect. Due to its high recurrence rate and aggressive behavior, observation is contraindicated. Treatment involves **surgical enucleation** often combined with adjuvant therapies like **Carnoy’s solution** application or marsupialization to reduce the cyst size before definitive surgery. ### **High-Yield Clinical Pearls for NEET-PG** * **Radiology:** Appears as a well-defined unilocular or multilocular radiolucency with "scalloped" margins. * **Histopathology:** Characterized by a thin lining of parakeratinized stratified squamous epithelium (6–8 layers thick) with a **palisaded basal layer** (tombstone appearance). * **Syndromic Association:** Multiple OKCs are a hallmark of **Gorlin-Goltz Syndrome** (Nevoid Basal Cell Carcinoma Syndrome), which also includes bifid ribs and basal cell carcinomas. * **Aspiration:** Often yields a "cheesy" or "creamy" white material (keratin) with low soluble protein content (<4g/dL).
Question 50: Which oral lesion is associated with ulcerative colitis?
- A. Lichen planus
- B. Pyostomatitis Vegetans (Correct Answer)
- C. Sarcoidosis
- D. Dermatitis herpetiformis
Explanation: **Explanation:** **Pyostomatitis Vegetans (PV)** is a rare but highly specific oral manifestation of **Inflammatory Bowel Disease (IBD)**, most commonly associated with **Ulcerative Colitis** (and occasionally Crohn’s disease). It is characterized by multiple small, friable, cream-colored pustules on an erythematous base, often described as having a **"snail-track" appearance**. These pustules eventually rupture to form vegetating erosions. The severity of the oral lesions often mirrors the activity of the intestinal disease. **Analysis of Incorrect Options:** * **Lichen Planus:** An inflammatory condition affecting the skin and mucous membranes (Wickham striae). While it can be associated with Hepatitis C, it has no direct link to Ulcerative Colitis. * **Sarcoidosis:** A multisystem granulomatous disease. Oral involvement typically presents as non-caseating granulomas or salivary gland enlargement (Heerfordt's syndrome), not PV. * **Dermatitis Herpetiformis:** This is the cutaneous manifestation of **Celiac Disease** (Gluten-sensitive enteropathy), not Ulcerative Colitis. It presents as pruritic vesicles on the elbows, knees, and buttocks. **High-Yield Clinical Pearls for NEET-PG:** * **"Snail-track" ulcers:** Pathognomonic clinical description for Pyostomatitis Vegetans. * **Histology:** Characterized by intraepithelial abscesses filled with **eosinophils** (eosinophilic microabscesses). * **Management:** Treatment of the underlying Ulcerative Colitis (e.g., Sulfasalazine or Corticosteroids) typically leads to the resolution of oral lesions. * **Other IBD associations:** Aphthous ulcers are common in both, but "cobblestoning" of the mucosa is more specific to Crohn’s disease.
Practice by Chapter
Stomatitis
Practice Questions
Oral Ulcers
Practice Questions
Oral Leukoplakia
Practice Questions
Oral Cancers
Practice Questions
Sialadenitis
Practice Questions
Sialolithiasis
Practice Questions
Salivary Gland Tumors
Practice Questions
Ranula
Practice Questions
Xerostomia
Practice Questions
Sjögren's Syndrome
Practice Questions
Oral Manifestations of Systemic Diseases
Practice Questions
Temporomandibular Joint Disorders
Practice Questions
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