Diseases of the Oral Cavity and Salivary Glands Practice Questions

Q: A cyst arising from an unerupted permanent tooth is termed:

Dentigerous cyst. ### Explanation **Correct Answer: A. Dentigerous cyst** A **Dentigerous cyst** (also known as a follicular cyst) is an odontogenic cyst that develops from the accumulation of fluid between the reduced enamel epithelium and the crown of an **unerupted or impacted tooth**. * **Pathophysiology:** It originates at the cemento-enamel junction (CEJ). As the cyst grows, it encloses the crown of the tooth while the root remains outside the cyst sac. * **Common Site:** The most frequently involved tooth is the **mandibular third molar**, followed by the maxillary canine. * **Radiology:** It typically appears as a well-defined, unilocular radiolucency surrounding the crown of an unerupted tooth. **Why other options are incorrect:** * **B. Epulis:** This is a non-specific clinical term for any tumor-like gingival swelling (e.g., fibrous epulis, pregnancy tumor). It is a soft tissue lesion, not a bony cyst associated with unerupted teeth. * **C. Odontogenic Keratocyst (OKC):** While also an odontogenic cyst, it arises from the **dental lamina** rather than the follicle of an unerupted tooth. It is known for its aggressive behavior, high recurrence rate, and association with **Gorlin-Goltz syndrome**. Unlike dentigerous cysts, OKCs often expand in an anteroposterior direction within the marrow. **High-Yield Clinical Pearls for NEET-PG:** * **Most common odontogenic cyst:** Radicular cyst (associated with a non-vital/carious tooth). * **Most common developmental odontogenic cyst:** Dentigerous cyst. * **Radiological sign:** "Snow-plow" effect (displacement of adjacent teeth). * **Complications:** If left untreated, a dentigerous cyst can transform into an **Ameloblastoma** or, rarely, Squamous Cell Carcinoma. * **Treatment:** Enucleation and extraction of the involved tooth.

Q: Which of the following head and neck tumors has the worst prognosis?

Adenoid cystic carcinoma. **Explanation:** The prognosis of salivary gland tumors depends on their histological grade, growth pattern, and tendency for local or distant spread. **Why Adenoid Cystic Carcinoma (ACC) is the correct answer:** Among the options provided, **Adenoid Cystic Carcinoma** is notorious for its aggressive biological behavior. While it is often slow-growing, it has a hallmark characteristic of **perineural invasion** (creeping along nerves), making complete surgical resection difficult and leading to high rates of local recurrence. Most importantly, it has a high propensity for **late distant metastasis** (most commonly to the lungs), which can occur even decades after initial treatment, resulting in a poor long-term survival rate. **Analysis of Incorrect Options:** * **Acinic Cell Carcinoma:** This is generally considered a low-grade malignancy with a relatively favorable prognosis and low metastatic potential compared to ACC. * **Cystadenolymphoma (Warthin’s Tumor):** This is a **benign** salivary gland tumor (typically involving the parotid). It has an excellent prognosis as it does not metastasize. * **Mucoepidermoid Carcinoma:** The prognosis here is highly variable depending on the grade. While high-grade variants are aggressive, the overall group includes many low-grade cases that have a much better prognosis than ACC. **High-Yield Clinical Pearls for NEET-PG:** * **Most common site for ACC:** Submandibular gland and minor salivary glands (palate). * **Histological appearance:** Classic "Swiss-cheese" or cribriform pattern. * **Nerve Involvement:** ACC is the most common tumor to cause facial nerve palsy in the parotid gland. * **Warthin’s Tumor:** Associated with smoking, often bilateral/multicentric, and shows "Hot spots" on Technetium-99m pertechnetate scan.

Q: The oral mucosa becomes rigid, blanched and opaque in which of the following conditions?

Submucous fibrosis. **Explanation:** **Oral Submucous Fibrosis (OSMF)** is a chronic, progressive, premalignant condition characterized by juxta-epithelial inflammatory reaction followed by **fibroelastic change** of the lamina propria. 1. **Why the correct answer is right:** The hallmark of OSMF is the excessive deposition of collagen in the oral mucosa. This leads to the mucosa becoming **rigid** (due to vertical fibrous bands), **blanched** (due to decreased vascularity from fibrosis), and **opaque/marble-like** in appearance. Clinically, this manifests as a progressive inability to open the mouth (trismus) and a burning sensation when eating spicy food. It is strongly associated with **Areca nut (betel nut)** chewing. 2. **Why the incorrect options are wrong:** * **Pemphigus vulgaris:** An autoimmune blistering disorder characterized by flaccid bullae and painful erosions (Nikolsky sign positive). It causes mucosal "sloughing," not rigidity or blanching. * **Lupus erythematosus:** Oral involvement typically presents as "discoid" lesions with a central atrophic area and peripheral radiating white striae, often associated with ulceration, but not generalized rigidity. * **Ehlers-Danlos syndrome:** A connective tissue disorder characterized by hypermobility and tissue **fragility/laxity**. It is the opposite of rigidity; patients often show the *Gorlin sign* (ability to touch the tip of the nose with the tongue). **High-Yield Clinical Pearls for NEET-PG:** * **Etiology:** Areca nut is the primary risk factor (contains alkaloids like arecoline that stimulate collagen synthesis). * **Clinical Sign:** "Hockey-stick" uvula or bud-shaped uvula due to fibrosis. * **Pre-malignant Potential:** OSMF has a high malignant transformation rate (approx. 7–13%) to **Squamous Cell Carcinoma**. * **Treatment:** Cessation of habit, intralesional steroids, and hyaluronidase; surgical intervention for severe trismus.

Q: Which of the following lesions is considered a doubtful premalignant lesion for oral malignancy?

Oral lichen planus. **Explanation:** The classification of oral premalignant lesions is based on their potential for malignant transformation. In clinical practice, these are categorized into **precancerous lesions** (morphologically altered tissue) and **precancerous conditions** (generalized states associated with a significantly increased risk of cancer). **Why Oral Lichen Planus (OLP) is the correct answer:** OLP is classified as a **precancerous condition**. It is considered a "doubtful" or controversial premalignant lesion because its malignant transformation rate is very low (0.5% to 2%). Many experts argue that cases of OLP that turn into squamous cell carcinoma were actually "lichenoid dysplasia" from the outset. Due to this clinical ambiguity and low transformation rate compared to other lesions, it is often termed a doubtful premalignant lesion. **Analysis of Incorrect Options:** * **Leukoplakia (Option A):** The most common precancerous lesion. While most are benign, it has a definitive transformation rate of 3–5%. * **Chronic Hyperplastic Candidiasis (Option B):** Also known as Candidal Leukoplakia, it has a high malignant transformation rate (approx. 10–15%) and is a well-established premalignant lesion. * **Erythroplakia (Option C):** This is the **most dangerous** premalignant lesion. It has the highest transformation rate (>50%), with many cases already showing cellular atypia or carcinoma in situ at the time of biopsy. **NEET-PG High-Yield Pearls:** * **Highest malignant potential:** Erythroplakia. * **Most common site for Oral Cancer:** Lateral border of the tongue. * **Speckled Leukoplakia:** A mix of red and white patches; carries a higher risk than homogenous leukoplakia. * **Patterson-Kelly (Plummer-Vinson) Syndrome:** A precancerous condition associated with post-cricoid carcinoma.

Q: What is the most likely diagnosis in a man with a 3-month history of migratory lesions on the tongue?

Geographic tongue. ### Explanation **Correct Answer: A. Geographic Tongue (Benign Migratory Glossitis)** The hallmark of **Geographic Tongue** is its dynamic and migratory nature. It is a benign inflammatory condition characterized by areas of dekeratinization (loss of filiform papillae) appearing as smooth, red patches with raised, white/yellowish circinate borders. The "migratory" history is the key clinical clue: the lesions heal in one area and reappear in another over days or weeks, changing the tongue's appearance like a shifting map. It is usually asymptomatic but may cause sensitivity to spicy foods. **Why the other options are incorrect:** * **B. Oral Candidiasis:** Presents as white, "curd-like" plaques that can be scraped off, leaving an erythematous base. It does not migrate and is often associated with immunosuppression or antibiotic use. * **C. Lichen Planus:** Typically presents as **Wickham’s striae** (reticular white lines) or erosive lesions. While chronic, these lesions are relatively stationary and do not shift locations rapidly across the tongue. * **D. Oral Hairy Leukoplakia:** Caused by the **Epstein-Barr Virus (EBV)** in HIV-positive patients. It presents as white, corrugated (hairy) patches on the **lateral borders** of the tongue that cannot be scraped off. It is not migratory. **High-Yield Clinical Pearls for NEET-PG:** * **Histology:** Shows "Munro’s microabscesses" (neutrophils in the stratum corneum), similar to psoriasis. * **Associations:** Often linked with fissured tongue and occasionally associated with HLA-B15. * **Management:** Reassurance is the mainstay. Topical steroids or zinc supplements may be used if symptomatic.

Q: Blockage along the course of a minor salivary duct, leading to pooling of saliva behind the obstruction and localized swelling, is known as:

Retention mucocele. **Explanation:** **1. Why Retention Mucocele is Correct:** A **Retention Mucocele** (Mucous Retention Cyst) occurs due to a partial or complete **obstruction** of a minor salivary gland duct (often by a sialolith or scar tissue). This leads to the pooling of saliva within the ductal system, causing it to dilate and form a swelling lined by **epithelium**. The key distinction here is the mechanism: it is a "retention" phenomenon behind an anatomical blockage. **2. Analysis of Incorrect Options:** * **Ranula:** This is a specific type of mucocele occurring in the **floor of the mouth**, usually arising from the sublingual gland. While it involves saliva pooling, the question specifically describes the general mechanism of minor salivary duct blockage. * **Mucous Extravasation Mucocele:** This is the most common type of mucocele. It is caused by **trauma** (e.g., lip biting) that ruptures the duct, causing saliva to leak into the surrounding stroma. Unlike the retention type, it lacks an epithelial lining (it is a pseudocyst). * **Sialolithiasis:** This refers to the formation of a stone (calculus) within the duct. While a stone can *cause* a retention mucocele, the resulting localized swelling of pooled saliva itself is defined as the mucocele. **3. High-Yield Clinical Pearls for NEET-PG:** * **Most Common Site:** The **lower lip** is the most common site for mucoceles (usually extravasation type). * **Histology:** Retention mucoceles are **true cysts** (epithelial lining), whereas extravasation mucoceles are **pseudocysts** (granulation tissue lining). * **Plunging Ranula:** A clinical variant where the mucus extravasates below the mylohyoid muscle, presenting as a swelling in the neck. * **Treatment:** Surgical excision of the cyst along with the involved minor salivary gland to prevent recurrence.

Q: Which of the following is not an absolute contraindication for extraction of teeth?

Acute abscess with tooth. ### Explanation The correct answer is **D. Acute abscess with tooth**. In modern dental and ENT practice, an **acute abscess** is considered a **relative contraindication**, not an absolute one. While traditional teaching suggested waiting for the infection to localize, current clinical guidelines advocate for "surgical drainage through extraction." Removing the offending tooth provides an immediate pathway for pus to drain, removes the source of infection, and accelerates healing. If the patient is covered with systemic antibiotics and the site can be adequately anesthetized, extraction is often the treatment of choice. #### Analysis of Incorrect Options: * **A. Uncontrolled Diabetes:** This is an absolute contraindication because hyperglycemia impairs leukocyte function and wound healing. Extraction can lead to severe complications like **osteomyelitis** or life-threatening infections (e.g., Ludwig’s Angina). * **B. Uncontrolled Hypertension:** This is an absolute contraindication due to the risk of intraoperative cardiovascular events (stroke or MI) and the potential for prolonged, uncontrollable post-extraction hemorrhage. * **C. Leukemia:** This is an absolute contraindication because patients are severely immunocompromised and have profound thrombocytopenia. Extraction can lead to fatal septicemia or uncontrollable bleeding. #### High-Yield Clinical Pearls for NEET-PG: * **Absolute Contraindications:** Uncontrolled systemic diseases (Diabetes, HTN, Cardiac failure), Blood dyscrasias (Leukemia, Hemophilia), and recent Myocardial Infarction (within 6 months). * **Radiotherapy:** Avoid extraction in teeth within the field of radiation to prevent **Osteoradionecrosis**. * **Bisphosphonates:** Patients on IV bisphosphonates are at high risk for **MRONJ** (Medication-Related Osteonecrosis of the Jaw) following extraction.

Q: What is the recommended treatment for a calculus within the submandibular salivary gland?

Removal of the gland. ### Explanation The management of submandibular sialolithiasis (calculi) depends primarily on the **location** of the stone. **1. Why "Removal of the gland" is correct:** When a calculus is located **within the substance of the submandibular gland** (intrastructural/intraglandular), it causes chronic inflammation, recurrent infection, and eventual fibrosis of the glandular parenchyma. In such cases, simple removal of the stone is technically difficult and often fails to restore gland function. Therefore, **submandibular gland excision (Sialadenectomy)** is the definitive treatment of choice to prevent recurrent sialadenitis. **2. Analysis of Incorrect Options:** * **Removal of sinus:** This is irrelevant. While a chronic infection might lead to a cutaneous fistula or sinus, the primary pathology is the stone within the gland, necessitating gland removal. * **Dichotomy:** This is not a standard surgical term for salivary stone management. * **Milking of the stone:** This technique is only applicable for **small, distal stones** located near the punctum (opening) of Wharton’s duct. It is ineffective and potentially traumatic for stones located deep within the gland. **3. High-Yield Clinical Pearls for NEET-PG:** * **Wharton’s Duct:** The most common site for salivary calculi (80%) due to the alkaline pH, high calcium/mucin content, and the upward (antigravity) course of the duct. * **Radiopacity:** 80% of submandibular stones are radiopaque (visible on X-ray), whereas 80% of parotid stones are radiolucent. * **Clinical Presentation:** "Mealtime syndrome"—recurrent pain and swelling of the gland triggered by the sight or smell of food. * **Surgical Landmark:** During submandibular gland removal, the **marginal mandibular nerve** must be protected (it lies superficial to the gland). * **Intraductal Stones:** If the stone is in the duct (not the gland), the treatment is **Sialolithotomy** (incision over the duct).

Q: What is the most common precancerous lesion for oral malignancy?

Leukoplakia. **Explanation:** **Leukoplakia** is the most common precancerous (potentially malignant) lesion of the oral cavity. It is clinically defined as a white patch or plaque that cannot be characterized clinically or pathologically as any other disease and cannot be scraped off. The malignant transformation rate ranges from 1% to 5%, though certain types (like non-homogeneous or speckled leukoplakia) carry a much higher risk. Chronic irritation from tobacco (smoking/chewing) and alcohol are the primary etiological factors. **Analysis of Incorrect Options:** * **Chronic hypertrophic candidiasis:** While this is considered a "premalignant condition" with a significant risk of dysplasia, it is far less common than leukoplakia in the general population. * **Dental ulcers:** These are usually traumatic (due to sharp teeth or ill-fitting dentures). While a chronic non-healing ulcer must be biopsied to rule out malignancy, the ulcer itself is not a classic "precancerous lesion" unless it is a manifestation of an underlying malignancy. * **Atrophic glossitis:** This is a clinical finding (smooth tongue) often seen in nutritional deficiencies (Vitamin B12, Iron). While it is associated with the **Plummer-Vinson Syndrome** (which is a precancerous *condition*), it is not the most common lesion. **NEET-PG High-Yield Pearls:** * **Most common site for Leukoplakia:** Buccal mucosa and commissures. * **Highest risk of transformation:** Speckled leukoplakia (Erythroleukoplakia) has a higher risk than homogenous leukoplakia. * **Precancerous Lesion vs. Condition:** A *lesion* is a localized change (e.g., Leukoplakia, Erythroplakia), whereas a *condition* is a generalized state associated with increased risk (e.g., Oral Submucous Fibrosis, Lichen Planus). * **Erythroplakia:** Though less common than leukoplakia, it has the **highest malignant potential** among all oral lesions.

Q: Which of the following conditions is characterized by a "hot nodule"?

Adenolymphoma. **Explanation:** The concept of a "hot nodule" in salivary gland imaging refers to the increased uptake of **Technetium-99m (Tc-99m) pertechnetate** during a radionuclide scan. **1. Why Adenolymphoma is correct:** Adenolymphoma, also known as **Warthin’s tumor**, is unique because it contains a high density of oncocytes and lymphoid stroma. These cells possess an abundance of mitochondria and maintain the ability to concentrate pertechnetate but lack the mechanism to secrete it into the ductal system. This results in the "trapping" of the isotope, appearing as a "hot" (hyperactive) area on the scan. **2. Why other options are incorrect:** * **Mixed Parotid Tumor (Pleomorphic Adenoma):** This is the most common salivary gland tumor. It typically appears as a **"cold nodule"** because the tumor tissue replaces normal acinar cells and does not concentrate the isotope. * **Adenoid Cystic Carcinoma:** As a malignant neoplasm, it lacks the specialized oncocytes required to concentrate Tc-99m. Like most other salivary malignancies and benign tumors (except Warthin’s and Oncocytoma), it appears as a **"cold"** defect. **3. High-Yield Clinical Pearls for NEET-PG:** * **The "Hot Nodule" Duo:** Only two salivary tumors typically show increased uptake: **Warthin’s Tumor** and **Oncocytoma**. * **Warthin’s Tumor Profile:** It is most common in elderly males, strongly associated with smoking, and is the most common salivary tumor to present **bilaterally** (though often metachronous). * **Location:** It almost exclusively occurs in the **parotid gland** (specifically the lower pole/tail). * **Mnemonic:** "Warthin’s is **HOT** (Hot on scan), **OLD** (Elderly), **MEN** (Male predominance), and **SMOKES** (Smoking association)."

Question 1

A cyst arising from an unerupted permanent tooth is termed:

Accepted Answer

Dentigerous cyst

Answer

Epulis

Answer

Odontogenic keratocyst

Answer

None of the above

Question 2

Which of the following head and neck tumors has the worst prognosis?

Accepted Answer

Adenoid cystic carcinoma

Answer

Acinic cell carcinoma

Answer

Cystadenolymphoma

Answer

Mucoepidermoid carcinoma

Question 3

The oral mucosa becomes rigid, blanched and opaque in which of the following conditions?

Accepted Answer

Submucous fibrosis

Answer

Pemphigus vulgaris

Answer

Lupus erythematosus

Answer

Ehlers-Danlos syndrome

Question 4

Which of the following lesions is considered a doubtful premalignant lesion for oral malignancy?

Accepted Answer

Oral lichen planus

Answer

Leukoplakia

Answer

Chronic hyperplastic candidiasis

Answer

Erythroplakia

Question 5

What is the most likely diagnosis in a man with a 3-month history of migratory lesions on the tongue?

Accepted Answer

Geographic tongue

Answer

Oral candidiasis

Answer

Lichen planus

Answer

Oral hairy leukoplakia

Question 6

Blockage along the course of a minor salivary duct, leading to pooling of saliva behind the obstruction and localized swelling, is known as:

Accepted Answer

Retention mucocele

Answer

Ranula

Answer

Mucous extravasation mucocele

Answer

Sialolithiasis

Question 7

Which of the following is not an absolute contraindication for extraction of teeth?

Accepted Answer

Acute abscess with tooth

Answer

Uncontrolled diabetes

Answer

Uncontrolled hypertension

Answer

Leukemia

Question 8

What is the recommended treatment for a calculus within the submandibular salivary gland?

Accepted Answer

Removal of the gland

Answer

Removal of sinus

Answer

Dichotomy

Answer

Milking of the stone

Question 9

What is the most common precancerous lesion for oral malignancy?

Accepted Answer

Leukoplakia

Answer

Chronic hypertrophic candidiasis

Answer

Dental ulcers

Answer

Atrophic glossitis

Question 10

Which of the following conditions is characterized by a "hot nodule"?

Accepted Answer

Adenolymphoma

Answer

Mixed parotid tumor

Answer

Adenoid cystic carcinoma

Answer

All of the above

Diseases of the Oral Cavity and Salivary Glands — MCQs

Diseases of the Oral Cavity and Salivary Glands — MCQs

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