Diseases of the Oral Cavity and Salivary Glands — MCQs

Diseases of the Oral Cavity and Salivary Glands Indian Medical PG Practice Questions and MCQs

Question 31: A person experiences throbbing pain at night. What is the most likely cause?

A. Acute pulpal degeneration (Correct Answer)
B. Acute periodontal abscess
C. Chronic pulpitis
D. Cellulitis

Explanation: ### Explanation The correct answer is **Acute pulpal degeneration** (often associated with acute pulpitis). **1. Why Acute Pulpal Degeneration is correct:** The hallmark of acute pulpal inflammation or degeneration is **throbbing, lancinating pain** that characteristically worsens at **night** or when the patient lies down. This occurs due to the "closed box" anatomy of the tooth. When the pulp is inflamed, intrapulpal pressure increases. In a recumbent (lying down) position, there is an increase in cephalic blood pressure and venous congestion in the head and neck area. This further elevates the pressure within the rigid pulp chamber, compressing the nerve endings and causing intense, nocturnal throbbing pain. **2. Why the other options are incorrect:** * **Acute periodontal abscess:** While painful, the pain is usually dull, localized, and exacerbated by percussion (tapping the tooth) or chewing, rather than specifically by lying down at night. * **Chronic pulpitis:** This is often asymptomatic or presents with mild, intermittent "grumbling" pain. The pulp is not under the same acute pressure as in the acute phase. * **Cellulitis:** This presents with diffuse, firm, and painful swelling of the soft tissues with systemic symptoms (fever, malaise). The pain is constant and associated with visible external or intraoral swelling, not just nocturnal throbbing. **3. NEET-PG High-Yield Pearls:** * **Reversible vs. Irreversible Pulpitis:** If the pain stops immediately after removing a stimulus (like cold water), it is *reversible*. If the pain lingers or occurs spontaneously (especially at night), it is *irreversible* (degeneration). * **Management:** The definitive treatment for acute pulpal degeneration is **Root Canal Treatment (RCT)** or extraction. * **Referred Pain:** Pulpal pain is often poorly localized and can be referred to the ear (via the auriculotemporal nerve) or the opposite jaw, but it never crosses the midline.

Question 32: Facial nerve paralysis is commonly associated with which of the following conditions?

A. Pleomorphic adenoma
B. Epidermoid carcinoma
C. Warthin's tumour
D. Lymphoepithelial carcinoma (Correct Answer)

Explanation: **Explanation:** The presence of **facial nerve paralysis** in a patient with a parotid mass is a classic clinical red flag indicating **malignancy**. Benign tumors, even when large, rarely cause nerve deficits because they grow slowly and displace rather than invade neural tissue. **1. Why Lymphoepithelial Carcinoma is correct:** Lymphoepithelial carcinoma (LEC) is a rare, high-grade malignant tumor of the salivary glands. It is strongly associated with the **Epstein-Barr Virus (EBV)** and is most common in specific ethnic groups (Inuit, Chinese). Because it is an aggressive, infiltrative malignancy, it frequently invades the facial nerve, leading to lower motor neuron facial palsy. **2. Why the other options are incorrect:** * **Pleomorphic Adenoma (Option A):** This is the most common benign salivary gland tumor. While it can grow to a massive size, it is encapsulated and does not invade nerves. Facial palsy in a suspected pleomorphic adenoma should raise suspicion of malignant transformation into *Carcinoma ex-pleomorphic adenoma*. * **Epidermoid Carcinoma (Option B):** Also known as Squamous Cell Carcinoma (SCC) of the salivary gland. While it is malignant and can cause nerve palsy, it is much rarer as a primary parotid tumor compared to the aggressive nature of LEC in specific demographic contexts. * **Warthin’s Tumour (Option C):** This is the second most common benign tumor (adenolymphoma). It is almost exclusively found in the parotid gland and is often bilateral, but it never causes facial nerve paralysis. **Clinical Pearls for NEET-PG:** * **Most common malignant tumor of the parotid:** Mucoepidermoid carcinoma. * **Malignancy with the highest propensity for perineural invasion:** Adenoid cystic carcinoma (often presents with pain and early nerve involvement). * **Rule of Thumb:** Any parotid mass + Facial nerve palsy = Malignancy until proven otherwise. * **EBV Association:** Lymphoepithelial carcinoma of the salivary gland is histologically identical to undifferentiated nasopharyngeal carcinoma.

Question 33: A 50-year-old male with a history of chronic smoking and alcohol intake presents with an oral cavity lesion. What is the most probable diagnosis?

A. Ranula
B. Erythroplakia
C. Carcinoma of the tongue (Correct Answer)
D. Cancrum oris

Explanation: ***Carcinoma of the tongue*** - **Chronic smoking** and **alcohol intake** are the strongest risk factors for **oral squamous cell carcinoma**, particularly affecting the tongue in middle-aged males. - The combination of both risk factors significantly increases the likelihood of **malignant transformation** in oral cavity tissues. *Ranula* - A **retention cyst** of the sublingual salivary gland that presents as a **translucent, bluish swelling** on the floor of the mouth. - Not associated with **smoking** or **alcohol** consumption and typically occurs in younger individuals. *Erythroplakia* - A **premalignant lesion** appearing as a **red, velvety patch** in the oral cavity with high malignant potential. - While associated with smoking and alcohol, it represents a **precancerous condition** rather than established carcinoma. *Cancrum oris* - Also known as **noma**, this is a **necrotizing ulcerative condition** primarily affecting **malnourished children** in developing countries. - Not related to **smoking** or **alcohol** use and has a distinct demographic profile different from this patient.

Question 34: What is the most common histological type of carcinoma of the tongue?

A. Squamous cell carcinoma (Correct Answer)
B. Adenoid cystic carcinoma
C. Basal cell carcinoma
D. Transitional cell carcinoma

Explanation: **Explanation:** **1. Why Squamous Cell Carcinoma (SCC) is correct:** The tongue is lined by **stratified squamous epithelium**. Malignant transformation of this lining due to chronic irritation (tobacco, betel nut, alcohol, or sharp teeth) leads to Squamous Cell Carcinoma. It accounts for approximately **90-95%** of all oral cavity cancers. The most common site on the tongue is the **lateral border** (middle third), followed by the ventral surface. **2. Why other options are incorrect:** * **Adenoid Cystic Carcinoma:** This is a malignant tumor of the **minor salivary glands**. While it can occur in the oral cavity (especially the palate), it is far less common than SCC. It is known for its characteristic "perineural invasion." * **Basal Cell Carcinoma (BCC):** BCC typically affects the **skin** (sun-exposed areas) and is almost never found on mucosal surfaces like the tongue. * **Transitional Cell Carcinoma:** This histological type is characteristic of the **urinary tract** (bladder/ureter) or the oropharynx/nasopharynx (Schneiderian mucosa), but not the mobile tongue. **3. NEET-PG High-Yield Pearls:** * **Most common site of Oral Cavity Cancer:** Lower lip (globally), but in India, it is the **buccal mucosa** (due to tobacco/betel nut chewing—often called the "Indian Oral Sulcus"). * **Most common site of Tongue Cancer:** Lateral border. * **Lymphatic Spread:** Tongue tip drains to Submental nodes (Level Ia); Lateral borders drain to Submandibular (Level Ib) and then to Deep Cervical nodes. * **Prognosis:** Carcinoma of the **posterior 1/3 (base)** of the tongue has a worse prognosis than the anterior 2/3 because it is often diagnosed late and has richer lymphatic drainage.

Question 35: Which of the following is NOT a vital part of the physical examination for patients with temporomandibular joint (TMJ) complaints?

A. Soft-tissue symmetry
B. Joint tenderness and sounds
C. Soft-palate length (Correct Answer)
D. Range of motion of the mandible

Explanation: **Explanation:** The Temporomandibular Joint (TMJ) is a complex ginglymoarthrodial joint. Examination focuses on the functional relationship between the mandible, the glenoid fossa of the temporal bone, and the associated muscles of mastication. **Why Soft-palate length is the correct answer:** Soft-palate length is an anatomical feature relevant to **obstructive sleep apnea (OSA)** and oropharyngeal assessment (Mallampati score), but it has no functional or structural relationship with the TMJ. It does not influence jaw movement, joint stability, or myofascial pain associated with TMJ disorders (TMD). **Analysis of incorrect options:** * **Soft-tissue symmetry (A):** Essential to rule out muscular hypertrophy (e.g., masseteric hypertrophy), inflammatory swelling, or tumors that may mimic or cause TMJ dysfunction. * **Joint tenderness and sounds (B):** Palpation of the joint (pre-auricular or via the external auditory canal) identifies synovitis. Auscultation/palpation for **clicking** (suggests disc displacement with reduction) or **crepitus** (suggests osteoarthritis) is a diagnostic hallmark. * **Range of motion (D):** Measuring maximal interincisal opening (normal: 40–50 mm) and lateral/protrusive movements is critical to identify trismus, internal derangement, or ankylosis. **High-Yield Clinical Pearls for NEET-PG:** * **Costen’s Syndrome:** An older term for TMD presenting with ear pain, tinnitus, and dizziness. * **Muscle of Mastication:** The **Lateral Pterygoid** is the most commonly involved muscle in TMJ dysfunction (it pulls the articular disc forward). * **Imaging of Choice:** **MRI** is the gold standard for visualizing the articular disc position; **Non-contrast CT** is best for bony changes/ankylosis. * **Trismus:** Defined as an inability to open the mouth due to muscle spasm; often the first sign of tetanus or a complication of peritonsillar abscess.

Question 36: Invasion of the perineural space is a characteristic feature of which of the following tumors?

A. Pleomorphic adenoma
B. Warthin's tumor
C. Mucoepidermoid carcinoma
D. Adenoid cystic carcinoma (Correct Answer)

Explanation: ### Explanation **Correct Answer: D. Adenoid cystic carcinoma** **Why it is correct:** Adenoid cystic carcinoma (ACC) is notorious for its **neurotropic spread**, meaning it has a high propensity for **perineural invasion (PNI)**. The tumor cells track along the nerve sheaths, often extending far beyond the visible margins of the tumor. This characteristic explains several clinical features of ACC: * **Pain:** Early onset of pain is common due to nerve involvement. * **Nerve Palsy:** Facial nerve paralysis is a frequent presenting sign in parotid ACC. * **Skip Lesions:** The tumor can "jump" along the nerve, leading to high rates of local recurrence even after surgical excision. **Why the other options are incorrect:** * **A. Pleomorphic adenoma:** This is the most common *benign* salivary gland tumor. While it can have an irregular pseudocapsule, it does not invade nerves. * **B. Warthin’s tumor:** Also known as Papillary Cystadenoma Lymphomatosum, this is a *benign* tumor almost exclusively found in the parotid gland. It is associated with smoking and is often bilateral, but it is non-invasive. * **C. Mucoepidermoid carcinoma:** This is the most common *malignant* salivary gland tumor. While it is invasive, its hallmark is the presence of mucus-secreting, epidermoid, and intermediate cells. It does not show the same characteristic affinity for perineural spaces as ACC. **High-Yield Clinical Pearls for NEET-PG:** * **Most common site for ACC:** Minor salivary glands (especially the palate). * **Histology:** Classic **"Swiss-cheese" appearance** (Cribriform pattern) is the most common histological subtype. * **Metastasis:** ACC is known for **distant metastasis to the lungs** (hematogenous spread), which can occur many years after the primary treatment. * **Prognosis:** It has a slow clinical course but a poor long-term prognosis due to late recurrences.

Question 37: What is the pathognomonic finding in sialography for Sjogren syndrome?

A. Pruning of the tree
B. Leafless fruit laden tree
C. Both pruning of the tree and leafless fruit laden tree (Correct Answer)
D. None of the above

Explanation: ### Explanation **Sjogren Syndrome** is a chronic autoimmune disorder characterized by lymphocytic infiltration of the exocrine glands, primarily the salivary and lacrimal glands. This leads to progressive destruction of the glandular acini. **Why Option C is Correct:** Sialography in Sjogren syndrome reveals a characteristic pattern due to the destruction of the ductal system and the formation of small cavities (sialectasis). 1. **Leafless fruit-laden tree (Cherry blossom appearance):** This refers to the presence of multiple small, globular collections of contrast material (the "fruit" or "blossoms") within the gland parenchyma. These represent punctate sialectasis. 2. **Pruning of the tree:** As the disease progresses, the peripheral small ducts are destroyed or obstructed, leaving only the main ductal system visible. This lack of secondary and tertiary branching gives the appearance of a "pruned" tree. **Why other options are incorrect:** * **Option A & B:** While both are correct descriptions, they represent different stages or features of the same pathological process in Sjogren syndrome. Selecting only one would be incomplete. **High-Yield Clinical Pearls for NEET-PG:** * **Gold Standard Diagnosis:** Minor salivary gland biopsy (usually from the lower lip) showing lymphocytic aggregates (Focus score ≥ 1). * **Schirmer’s Test:** Used to quantify decreased lacrimation (positive if <5 mm wetting in 5 minutes). * **Serology:** Positive for Anti-Ro (SS-A) and Anti-La (SS-B) antibodies. * **Malignancy Risk:** Patients with Sjogren syndrome have a 40-fold increased risk of developing **B-cell Non-Hodgkin Lymphoma** (MALToma). * **Sialography Contraindication:** Should never be performed during an acute phase of infection/sialadenitis.

Question 38: Major aphthous ulcers are seen in which of the following conditions?

A. Crohn’s disease
B. Behçet’s Syndrome
C. Celiac sprue
D. AIDS (Correct Answer)

Explanation: **Explanation:** **Major Aphthous Ulcers (Sutton’s Disease)** are characterized by large (>1 cm), deep, painful ulcers that often scar and take weeks to heal. While minor aphthae are common in the general population, major aphthous ulcers are a hallmark of severe systemic immunosuppression, most notably **AIDS**. 1. **Why AIDS is the correct answer:** In HIV-infected patients, as the CD4 count drops, the prevalence and severity of oral ulcers increase. Major aphthous ulcers in AIDS are often "giant," persistent, and can involve the oropharynx or esophagus, leading to severe odynophagia. They are considered a significant clinical marker of advanced HIV progression. 2. **Analysis of Incorrect Options:** * **Crohn’s Disease:** Typically presents with "cobblestone" mucosa or linear, deep fissured ulcers. While aphthous-like ulcers occur, they are usually not the "major" variant. * **Behçet’s Syndrome:** Characterized by the triad of oral ulcers, genital ulcers, and uveitis. While oral ulcers are a primary diagnostic criterion, they are typically **minor** aphthous ulcers (recurrent and multiple) rather than the deep, scarring major type. * **Celiac Sprue:** Associated with recurrent **minor** aphthous stomatitis due to nutritional deficiencies (Iron, B12, Folate) resulting from malabsorption. **NEET-PG High-Yield Pearls:** * **Minor Aphthous:** Most common (80%), <1 cm, heal without scarring (7-10 days). * **Major Aphthous:** >1 cm, deep, heal with **scarring**, associated with HIV/AIDS. * **Herpetiform Ulcers:** Tiny, multiple (up to 100), pin-head sized clusters; not related to the Herpes virus. * **Treatment:** Topical steroids (Triamcinolone) are first-line; Thalidomide is used for refractory major ulcers in AIDS patients.

Question 39: Patey's operation refers to which of the following procedures?

A. Superficial parotidectomy. (Correct Answer)
B. Total parotidectomy.
C. Deep parotidectomy.
D. All of the above.

Explanation: **Explanation:** **Patey’s operation** is the eponym for **Superficial Parotidectomy**. The parotid gland is divided into a superficial and a deep lobe by the plane of the **Facial Nerve** (specifically the "faciovenous plane of Patey"). In this procedure, the superficial lobe—which constitutes about 80% of the gland—is removed while meticulously identifying and preserving the facial nerve and its branches. This is the standard treatment for benign tumors like Pleomorphic Adenoma located in the superficial lobe. **Analysis of Options:** * **Option A (Correct):** Patey’s operation specifically describes the removal of the gland lateral to the facial nerve. * **Option B (Incorrect):** Total parotidectomy involves removing both the superficial and deep lobes. If the facial nerve is preserved, it is called a "Total Conservative Parotidectomy." If the nerve is sacrificed (usually for malignancy), it is a "Radical Parotidectomy." * **Option C (Incorrect):** Deep parotidectomy refers to the removal of the portion of the gland medial to the facial nerve, usually performed after a superficial parotidectomy has already been completed. **High-Yield Clinical Pearls for NEET-PG:** * **Landmark for Facial Nerve:** The **Tragal Pointer** (nerve is ~1 cm deep and slightly inferior/anterior to it) and the **Tympanomastoid Suture**. * **Most Common Complication:** Temporary facial nerve neuropraxia. * **Frey’s Syndrome:** A late complication caused by aberrant regeneration of auriculotemporal nerve fibers; diagnosed by the **Minor’s Starch-Iodine test**. * **Patey’s Plane:** The plane between the facial nerve and the retromandibular vein.

Question 40: What is the most common route for furcation involvement of the maxillary permanent first molar?

A. Mesial surface (Correct Answer)
B. Distal surface
C. Buccal surface
D. Lingual surface

Explanation: **Explanation:** Furcation involvement refers to the pathological resorption of bone within the interradicular area of multi-rooted teeth, typically resulting from periodontal disease. **Why Mesial is Correct:** The maxillary permanent first molar is a trifurcated tooth with three roots: mesiobuccal, distobuccal, and palatal. It features three furcation entrances: buccal, mesial, and distal. 1. **Anatomical Accessibility:** The **mesial furcation** is the most common site of involvement because the entrance is located significantly closer to the palatal aspect rather than being centered. This makes it highly susceptible to plaque accumulation and difficult for patients to clean. 2. **Proximity to CEJ:** The mesial furcation entrance is often located closer to the Cemento-Enamel Junction (CEJ) compared to the distal entrance, allowing periodontal pockets to reach the furca earlier in the disease process. **Analysis of Incorrect Options:** * **Distal surface:** While distal furcation involvement is common, the entrance is located midway between the buccal and lingual surfaces, making it slightly less prone to initial involvement than the mesial side. * **Buccal surface:** The buccal furcation is generally the least common site for the maxillary first molar because the roots are often wider at the buccal aspect, providing a more robust bone barrier compared to the proximal surfaces. * **Lingual surface:** This is not a standard anatomical furcation entrance for maxillary molars; the palatal root is a single large root, and the "lingual" aspect is actually the space between the mesial and distal entrances on the palatal side. **Clinical Pearls for NEET-PG:** * **Nabers Probe:** The specialized instrument used to detect and measure furcation involvement. * **Glickman’s Classification:** The standard grading system for furcation (Grade I to IV). * **Maxillary vs. Mandibular:** In **mandibular molars** (bifurcated), the **buccal** furcation is more commonly involved than the lingual. * **Root Trunks:** Teeth with short root trunks are more predisposed to early furcation involvement.

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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