Diseases of the Oral Cavity and Salivary Glands Practice Questions

Q: All of the following statements regarding stones in the submandibular gland are true except?

Majority of submandibular stones are radiolucent. ### Explanation **1. Why the correct answer is right:** The statement "Majority of submandibular stones are radiolucent" is **false**, making it the correct choice for an "except" question. In reality, **80% of submandibular gland stones are radiopaque** (visible on X-ray). This is because submandibular saliva is highly alkaline and has a high concentration of calcium and phosphate salts, leading to dense calcification of the stones. In contrast, parotid stones are more likely to be radiolucent (only 20% are radiopaque). **2. Analysis of incorrect options:** * **Option A:** True. Approximately 80% of all salivary calculi (sialolithiasis) occur in the submandibular gland [1]. This is due to the long, upward course of Wharton’s duct and the viscous, mucin-rich nature of the saliva. * **Option C:** True. Sialolithiasis is the most common cause of salivary gland obstruction, leading to stasis and potential secondary infection (sialadenitis) [1]. * **Option D:** True. Patients typically present with "mealtime syndrome"—acute, painful swelling of the gland triggered by eating, as saliva production increases against an obstructed duct. **3. Clinical Pearls for NEET-PG:** * **Wharton’s Duct:** The most common site for stone formation. * **Composition:** Submandibular stones have higher calcium content than parotid stones. * **Imaging:** The best initial radiograph for a submandibular stone is an **Intraoral Periapical (IOPA) view** or a **Mandibular Occlusal view**. * **Management:** Small distal stones can be removed via duct incision (sialolithotomy); proximal or intraglandular stones may require gland excision [1]. * **Sialendoscopy:** The modern "gold standard" for both diagnosis and minimally invasive removal of salivary stones [1].

Q: Hairy leukoplakia is characterized by?

EBV infection. **Explanation:** **Hairy Leukoplakia (HL)** is a distinctive white lesion of the oral mucosa, primarily affecting the lateral borders of the tongue. 1. **Why Option B is correct:** The condition is caused by the **Epstein-Barr Virus (EBV)**. In immunocompromised states, EBV undergoes productive replication in the squamous epithelium of the tongue, leading to the characteristic corrugated or "hairy" appearance. It is considered an opportunistic infection. 2. **Why other options are incorrect:** * **Option A:** HL is typically **asymptomatic (painless)**. Patients usually discover it incidentally or due to its texture. * **Option C:** There is a **strong association with HIV**. It is one of the most common oral manifestations of HIV/AIDS and often serves as an early clinical sign of progression to AIDS or a declining CD4 count. * **Option D:** Unlike "Oral Leukoplakia," Hairy Leukoplakia has **no malignant potential**. It is not a pre-cancerous lesion and does not require aggressive surgical excision. **High-Yield Clinical Pearls for NEET-PG:** * **Appearance:** White, non-scrapable, vertical ridges (corrugated) on the lateral margins of the tongue. * **Diagnosis:** Usually clinical; biopsy shows hyperkeratosis, acanthosis, and "balloon cells" in the upper stratum spinosum. * **Treatment:** Generally not required unless for cosmetic reasons (Acyclovir or Podophyllin can be used), but its presence mandates an immediate workup for HIV/immunodeficiency. * **Differentiating Feature:** Unlike Oral Candidiasis, Hairy Leukoplakia **cannot** be scraped off.

Q: Areas of carcinoma of the oral mucosa can be identified by staining with which of the following?

2% toluidine blue. **Explanation:** **1. Why 2% Toluidine Blue is Correct:** Toluidine blue (also known as tolonium chloride) is a **vital acidophilic dye** that has a high affinity for nucleic acids. Malignant and dysplastic cells have a significantly higher DNA/RNA content and increased nuclear-to-cytoplasmic ratios compared to normal cells. When applied to the oral mucosa, the dye selectively stains these areas of high nucleic acid concentration, highlighting suspicious lesions (carcinoma in situ or invasive squamous cell carcinoma) as dark blue. This is a common chair-side screening tool used to demarcate biopsy sites. **2. Why the Other Options are Incorrect:** * **1% Zinc Chloride:** This is primarily used as an astringent or in certain chemical cautery pastes (like Mohs paste), but it has no diagnostic staining properties for malignancy. * **2% Silver Nitrate:** This is a caustic agent used for chemical cauterization of aphthous ulcers or to control minor bleeding (hemostasis). It stains tissues black but is not selective for cancer cells. * **Gentian Violet:** This is an antifungal and antiseptic dye used to treat oral candidiasis (thrush). While it stains the mucosa purple, it does not differentiate between normal and malignant cells. **3. High-Yield Clinical Pearls for NEET-PG:** * **False Positives:** Toluidine blue can also stain inflammatory lesions (like ulcers) because of the high cellular turnover; therefore, a "re-stain" after 10–14 days of anti-inflammatory treatment is often recommended. * **Lugol’s Iodine:** Another vital stain used in the oral cavity and esophagus. Normal squamous epithelium (rich in glycogen) stains brown, while **malignant cells (glycogen-poor) remain unstained.** * **Gold Standard:** Remember that while toluidine blue helps in identifying the site, the definitive diagnosis of oral cancer always requires a **histopathological examination (biopsy).**

Q: A patient presents with a history of recurrent episodes of pain and swelling in the mandibular posterior region and is diagnosed with pericoronitis. The partially erupted 3rd molar was vital. Radiographical examination revealed a well-defined radiolucency on the distal aspect of the affected tooth. What is the most likely diagnosis?

Paradental cyst.. ### Explanation The correct diagnosis is **Paradental Cyst** (also known as Craig’s cyst). **1. Why Paradental Cyst is correct:** A paradental cyst is an inflammatory odontogenic cyst that typically occurs on the **distal or buccal aspect** of a **partially erupted mandibular third molar** with a history of **pericoronitis**. * **Key Diagnostic Feature:** The tooth involved is **vital**. * **Pathogenesis:** Inflammation (pericoronitis) stimulates the epithelial rests of Malassez or the reduced enamel epithelium, leading to cyst formation. Radiographically, it appears as a well-defined radiolucency distal to the tooth. **2. Why other options are incorrect:** * **Dentigerous Cyst:** This is a developmental cyst that attaches to the **cemento-enamel junction (CEJ)** and encloses the crown of an **unerupted** tooth. In this case, the tooth is partially erupted and the radiolucency is specifically distal. * **Eruption Cyst:** This is essentially a soft-tissue analog of a dentigerous cyst. It presents as a bluish, fluctuant swelling on the alveolar ridge over an erupting tooth, rather than a deep distal radiolucency. * **Periapical (Radicular) Cyst:** This is the most common inflammatory cyst, but it occurs at the **apex** of a **non-vital** tooth due to pulp necrosis. The question specifies the tooth is vital. **Clinical Pearls for NEET-PG:** * **Location:** Most common in the mandibular 3rd molar (distal) or mandibular 1st/2nd molars (buccal—where it is called a **Buccal Bifurcation Cyst**). * **Vitality:** Always check tooth vitality; if the tooth is vital and there is a history of pericoronitis, think Paradental Cyst. * **Treatment:** Enucleation of the cyst; extraction of the involved third molar is usually necessary.

Q: What is the recommended treatment for a mucocele on the lower lip?

Excision with removal of adjacent salivary glands. ### Explanation **Correct Answer: C. Excision with removal of adjacent salivary glands** **1. Why Option C is Correct:** A mucocele (specifically the **extravasation type**, which is most common on the lower lip) occurs due to the traumatic rupture of a minor salivary gland duct, leading to the accumulation of mucus in the surrounding submucosal tissue. The definitive treatment is **surgical excision of the cyst**. However, to prevent **recurrence**, it is mandatory to remove the **offending minor salivary gland** and any adjacent minor glands involved in the field. If the gland is left behind, it will continue to secrete mucus, leading to the formation of a new mucocele. **2. Why Other Options are Incorrect:** * **Incision (A):** Simply incising the lesion (I&D) will lead to temporary decompression, but the lesion will almost certainly recur as soon as the wound heals because the underlying secretory gland remains functional. * **Excision (B):** While excision of the cyst wall is necessary, "excision" alone (without addressing the minor salivary glands) is incomplete and carries a high risk of recurrence. * **Biopsy (D):** While a biopsy can confirm the diagnosis, it is not a "treatment." Since mucoceles are usually diagnosed clinically based on their characteristic bluish, translucent appearance and history of trauma, the primary goal is therapeutic excision. **3. NEET-PG High-Yield Pearls:** * **Most common site:** Lower lip (due to frequent trauma/biting). * **Ranula:** A mucocele occurring in the floor of the mouth, usually arising from the **sublingual gland**. * **Plunging Ranula:** A clinical variant that extends below the mylohyoid muscle into the neck, presenting as a soft cervical swelling. * **Histology:** Extravasation mucoceles lack a true epithelial lining (they are "pseudocysts" lined by granulation tissue).

Question 1

All of the following statements regarding stones in the submandibular gland are true except?

Accepted Answer

Majority of submandibular stones are radiolucent

Answer

80% of stones occur in the submandibular gland

Answer

Stones are the most common cause of obstruction within the submandibular gland

Answer

Patient presents with acute swelling in the region of the submandibular gland

Question 2

Hairy leukoplakia is characterized by?

Accepted Answer

EBV infection

Answer

Pain

Answer

No association with HIV

Answer

Pre-cancerous

Question 3

Areas of carcinoma of the oral mucosa can be identified by staining with which of the following?

Accepted Answer

2% toluidine blue

Answer

1% zinc chloride

Answer

2% silver nitrate

Answer

Gentian violet

Question 4

A patient presents with a history of recurrent episodes of pain and swelling in the mandibular posterior region and is diagnosed with pericoronitis. The partially erupted 3rd molar was vital. Radiographical examination revealed a well-defined radiolucency on the distal aspect of the affected tooth. What is the most likely diagnosis?

Accepted Answer

Paradental cyst.

Answer

Dentigerous cyst.

Answer

Eruption cyst.

Answer

Periapical cyst.

Question 5

What is the recommended treatment for a mucocele on the lower lip?

Accepted Answer

Excision with removal of adjacent salivary glands

Answer

Incision

Answer

Excision

Answer

Biopsy

Diseases of the Oral Cavity and Salivary Glands — MCQs

Diseases of the Oral Cavity and Salivary Glands — MCQs

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