Diseases of the Oral Cavity and Salivary Glands — MCQs

A 95-year-old man has noted swelling of his lower lip for the past month. On examination, there is a fluctuant, 1-cm nodule with a blue, translucent hue just beneath the oral mucosa on the inside of his lip. The lesion is excised, and microscopic examination shows granulation tissue. What is the most likely etiology for this lesion?

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

Question 231: Which of the following is NOT a treatment option for chronic submucosal fibrosis?

A. Intralesional steroids
B. Antioxidants
C. Excision (Correct Answer)
D. Hyaluronidase

Explanation: **Explanation:** Oral Submucous Fibrosis (OSMF) is a chronic, progressive, premalignant condition characterized by juxta-epithelial inflammatory reactions followed by fibroelastic changes in the lamina propria. **Why Excision is NOT a treatment option:** OSMF is a **generalized field disease** affecting the entire oral mucosa. Surgical excision of the fibrotic bands is generally avoided because the resulting raw area heals by secondary intention or scarring, which often leads to **rebound fibrosis** and further worsening of trismus (lockjaw). Surgery is reserved only for extreme cases where it is combined with skin or mucosal grafting (e.g., radial forearm flap), but simple excision alone is not a standard treatment modality. **Analysis of other options:** * **Intralesional Steroids (A):** These are the mainstay of medical management. They act by inhibiting the inflammatory response and decreasing fibroblast proliferation. * **Antioxidants (B):** Lycopene, Vitamin A, C, and E are used to scavenge free radicals and arrest the progression of the disease. * **Hyaluronidase (D):** This enzyme breaks down hyaluronic acid, decreasing the viscosity of the intercellular matrix and helping to soften the fibrous bands. It is often used in combination with steroids. **Clinical Pearls for NEET-PG:** * **Etiology:** Strongly associated with **Areca nut (Betel nut)** chewing. * **Pathogenesis:** Alkaloids (Arecoline) stimulate fibroblasts to produce excess collagen, while Flavonoids inhibit Collagenase. * **Clinical Feature:** Characterized by "burning sensation" on eating spicy food and "vertical blanched bands" in the buccal mucosa. * **Malignant Transformation:** OSMF has a high malignant transformation rate (approx. 7–13%), most commonly leading to **Squamous Cell Carcinoma**.

Question 232: Stones in the distal portion of Wharton's duct are best visualized by which radiographic view?

A. Standard mandibular occlusal view (Correct Answer)
B. Lateral oblique view of the mandible
C. Panoramic film
D. Intraoral periapical radiograph (IOPA)

Explanation: **Explanation:** **1. Why the Standard Mandibular Occlusal View is Correct:** Wharton’s duct (the submandibular duct) runs along the floor of the mouth. Stones (sialoliths) in the **distal portion** of this duct are positioned horizontally above the mylohyoid muscle. The **Standard Mandibular Occlusal View** is the gold standard for visualizing these stones because the X-ray beam is directed perpendicular to the floor of the mouth. This prevents the radiopaque stone from being "masked" or superimposed by the dense cortical bone of the mandible, providing a clear view of the soft tissues in the floor of the mouth. **2. Why the Other Options are Incorrect:** * **Lateral Oblique View of the Mandible:** This is better suited for visualizing stones in the **proximal portion** (near the hilum) of the submandibular gland or stones within the gland parenchyma itself. * **Panoramic Film (OPG):** While useful for a general survey, OPG often results in the superimposition of the hyoid bone or the mandibular body over the floor of the mouth, making small distal stones difficult to identify. * **Intraoral Periapical Radiograph (IOPA):** The film size is too small and the angle is designed to visualize teeth and periapical structures, not the soft tissues of the floor of the mouth. **3. Clinical Pearls for NEET-PG:** * **80% Rule:** 80% of all salivary stones occur in the **Submandibular gland** (due to alkaline pH, high calcium/mucin content, and the upward, tortuous course of Wharton’s duct). * **Radiopacity:** 80% of submandibular stones are radiopaque (visible on X-ray), whereas 80% of parotid stones are radiolucent. * **Bimanual Palpation:** Distal Wharton’s duct stones can often be felt manually in the floor of the mouth. * **Sialography:** This is contraindicated during acute infection.

Question 233: Ectopic sebaceous glands in the mouth are called:

A. Linea alba buccalis
B. Heck's disease
C. Lingual varices
D. Fordyce spots (Correct Answer)

Explanation: **Explanation:** **Fordyce spots** (Option D) are the correct answer. These are **ectopic sebaceous glands** that occur in the oral mucosa or vermilion border of the lips. Unlike normal sebaceous glands, they are not associated with hair follicles. Clinically, they appear as asymptomatic, small (1–3 mm), yellowish-white granules or clusters. They are considered a normal anatomical variation rather than a pathology and require no treatment. **Analysis of Incorrect Options:** * **A. Linea alba buccalis:** This is a horizontal white line on the buccal mucosa at the level of the occlusal plane. It is caused by friction or pressure from the teeth (hyperkeratosis) and is not glandular. * **B. Heck’s disease:** Also known as Focal Epithelial Hyperplasia, this is caused by **HPV types 13 and 32**. It presents as multiple soft, pinkish papules in the oral cavity, primarily in children and specific ethnic groups. * **C. Lingual varices:** These are dilated, tortuous veins typically found on the ventral surface of the tongue in elderly patients. They appear bluish-purple and are vascular, not glandular. **High-Yield Clinical Pearls for NEET-PG:** * **Prevalence:** Fordyce spots are present in approximately 80% of adults; they become more prominent after puberty due to hormonal influence on sebaceous activity. * **Common Sites:** Most frequently seen on the buccal mucosa (opposite the molars) and the vermilion border of the upper lip. * **Histology:** They are identical to normal sebaceous glands found in the skin but lack an associated hair follicle (hence "ectopic"). * **Differential Diagnosis:** Must be distinguished from Milia (keratin cysts) or small Candida albicans colonies.

Question 234: Which statement is not true regarding carcinoma of the tongue?

A. Lateral border is commonly involved.
B. Cervical lymph node involvement is frequent.
C. It is commonly an adenocarcinoma. (Correct Answer)
D. Tobacco chewing is a significant risk factor.

Explanation: **Explanation:** **1. Why Option C is the correct answer (The False Statement):** The oral cavity, including the tongue, is lined by stratified squamous epithelium. Therefore, the most common histological type of tongue cancer (accounting for >90% of cases) is **Squamous Cell Carcinoma (SCC)**, not adenocarcinoma. Adenocarcinomas are rare in the tongue and usually arise from minor salivary glands located in the base of the tongue. **2. Analysis of Incorrect Options (True Statements):** * **Option A:** The **lateral border** of the anterior two-thirds of the tongue is indeed the most common site for carcinoma, often due to chronic irritation from sharp teeth or tobacco contact. * **Option B:** The tongue has a very rich lymphatic drainage that crosses the midline. **Cervical lymph node metastasis** is frequent and often occurs early (especially to Level II/Jugulodigastric nodes), which significantly impacts the prognosis. * **Option D:** Chronic irritation from **tobacco chewing**, smoking, and betel nut (paan) are the primary etiological factors for oral malignancies in the Indian subcontinent. **3. High-Yield Clinical Pearls for NEET-PG:** * **Premalignant Lesions:** Erythroplakia (highest risk) and Leukoplakia are significant precursors. * **Staging:** The "T" in TNM staging for the oral cavity is determined by the maximum diameter of the tumor and the **Depth of Invasion (DOI)**. * **Plummer-Vinson Syndrome:** Associated with an increased risk of post-cricoid and tongue base carcinoma. * **Field Cancerization:** This concept explains why patients with one oral primary are at high risk for developing a second primary tumor in the upper aerodigestive tract.

Question 235: In a pericoronal abscess related to a distoangularly impacted lower third molar, to which space may the infection spread?

A. Submasseteric space (Correct Answer)
B. Sublingual space
C. Submental space
D. Buccal space

Explanation: ### Explanation The spread of odontogenic infections is determined by the relationship of the tooth apex to the surrounding muscle attachments and the path of least resistance through the bone. **1. Why Submasseteric Space is Correct:** The **submasseteric space** is a potential space located between the lateral surface of the mandibular ramus and the medial surface of the masseter muscle. In the case of a **distoangularly impacted lower third molar**, the infection (pericoronitis or abscess) is positioned posteriorly. When the infection erodes through the lateral cortex of the mandible posterior to the attachment of the buccinator muscle, it tracks directly into the submasseteric space. This is a classic site for "trismus" because the inflammation directly involves the masseter muscle. **2. Why Other Options are Incorrect:** * **Sublingual space:** This is located superior to the mylohyoid muscle. Infections spread here if the tooth apex (usually premolars or the first molar) lies above the mylohyoid attachment on the lingual side. * **Submental space:** This space is located between the anterior bellies of the digastric muscles. It typically involves infections from the **mandibular incisors**. * **Buccal space:** Infection spreads here if it perforates the bone lateral to the **buccinator muscle**. While possible for molars, a distoangular impaction is positioned further back, making the submasseteric space the more specific and likely destination. **3. Clinical Pearls for NEET-PG:** * **Mylohyoid Line Rule:** This is the most high-yield concept. Infections from teeth with apices **above** the mylohyoid line (2nd molar and forward) go to the **Sublingual space**. Infections from apices **below** the line (2nd and 3rd molars) go to the **Submandibular space**. * **Ludwig’s Angina:** A cellulitis involving the submandibular, sublingual, and submental spaces bilaterally. * **Trismus:** Severe "lockjaw" in a patient with a wisdom tooth infection strongly suggests **submasseteric space** involvement.

Question 236: Sjogren's syndrome is primarily a disease of which glands?

A. Parotid glands (Correct Answer)
B. Thyroid gland
C. Parathyroid glands
D. Multiple endocrine neoplasia

Explanation: **Explanation:** Sjogren’s syndrome is a chronic, systemic autoimmune disorder characterized by lymphocytic infiltration of the **exocrine glands**, primarily the lacrimal and salivary glands. **Why Parotid glands is correct:** The hallmark of Sjogren’s syndrome is the destruction of moisture-producing glands. The **parotid glands** are the most commonly affected major salivary glands, often presenting with bilateral, painless, and intermittent or chronic swelling. This leads to **xerostomia** (dry mouth) and **keratoconjunctivitis sicca** (dry eyes), collectively known as the "Sicca complex." **Why other options are incorrect:** * **Thyroid and Parathyroid glands:** These are **endocrine glands** (secreting hormones directly into the blood). Sjogren’s specifically targets exocrine glands (secreting via ducts). While patients with Sjogren’s may have associated autoimmune thyroiditis, the primary pathology of the syndrome itself does not involve these glands. * **Multiple Endocrine Neoplasia (MEN):** This refers to a group of genetic syndromes characterized by tumors in at least two endocrine glands (e.g., pituitary, parathyroid, pancreas). It is a neoplastic condition, not an autoimmune exocrine disorder. **NEET-PG High-Yield Pearls:** * **Diagnosis:** The most accurate diagnostic test is a **Minor Salivary Gland Biopsy** (usually from the lower lip), showing lymphocytic aggregates (Focus score >1). * **Serology:** Positive for **Anti-Ro (SS-A)** and **Anti-La (SS-B)** antibodies. * **Schirmer’s Test:** Used to quantify decreased tear production (<5mm in 5 minutes is positive). * **Malignancy Risk:** Patients have a 40-fold increased risk of developing **B-cell Non-Hodgkin Lymphoma** (MALToma). * **Classification:** Primary (Sicca alone) vs. Secondary (associated with Rheumatoid Arthritis or SLE).

Question 237: 'Canker sore' is otherwise commonly known as?

A. Recurrent aphthous ulcer (Correct Answer)
B. Recurrent herpetic gingivitis
C. Acute necrotizing ulcerative gingivitis
D. Recurrent herpes labialis

Explanation: **Explanation:** **Recurrent Aphthous Ulcers (RAU)**, commonly known as **'Canker sores'**, are the most frequent cause of recurrent oral ulcerations. They are characterized by painful, shallow, necrotizing ulcers with a gray-white pseudomembranous center and a surrounding erythematous "halo." Unlike viral infections, they occur exclusively on **non-keratinized mucosa** (e.g., buccal mucosa, floor of the mouth) and are not preceded by vesicles. **Analysis of Incorrect Options:** * **Recurrent herpetic gingivitis/labialis:** Caused by the Herpes Simplex Virus (HSV). Unlike canker sores, these begin as **vesicles** and typically involve **keratinized mucosa** (e.g., hard palate, gingiva, or the vermilion border of the lips). * **Acute Necrotizing Ulcerative Gingivitis (ANUG):** Also known as "Vincent’s Angina" or "Trench Mouth," this is a severe bacterial infection characterized by "punched-out" interdental papillae, a foul odor (halitosis), and a gray pseudomembrane. It is not a simple canker sore. **High-Yield Clinical Pearls for NEET-PG:** * **Etiology:** Likely T-cell mediated immune response; often triggered by stress, trauma, or nutritional deficiencies (B12, Folate, Iron). * **Types:** 1. **Minor (Mikulicz’s):** Most common (<10mm), heals without scarring (7-10 days). 2. **Major (Sutton’s):** Large (>10mm), deep, painful, and **heals with scarring**. 3. **Herpetiform:** Multiple crops of tiny ulcers; not related to the Herpes virus. * **Systemic Association:** Recurrent oral ulcers are a hallmark of **Behçet’s Disease** (along with genital ulcers and uveitis). * **Treatment:** Topical corticosteroids (e.g., Triamcinolone) and analgesics.

Question 238: What is the condition involved with an unerupted or impacted tooth?

A. Dentigerous cyst
B. Mural ameloblastoma
C. Adenomatoid odontogenic tumor
D. All of the above (Correct Answer)

Explanation: The correct answer is **D. All of the above.** ### **Explanation and Medical Concept** The common denominator in these three conditions is their **odontogenic origin**, specifically their association with the **dental follicle** of an unerupted or impacted tooth (most commonly the mandibular third molar or maxillary canine). 1. **Dentigerous Cyst (Follicular Cyst):** This is the most common developmental odontogenic cyst. It originates from the separation of the follicle from around the crown of an **unerupted tooth**. Radiographically, it appears as a well-defined unilocular lucency attached to the cemento-enamel junction (CEJ). 2. **Mural Ameloblastoma:** This is a variant of Unicystic Ameloblastoma (Type 3). In many cases, these tumors arise from the epithelial lining of a pre-existing dentigerous cyst. Therefore, they are frequently found in association with an **impacted tooth**. 3. **Adenomatoid Odontogenic Tumor (AOT):** Often called the "Two-Thirds Tumor," it occurs in the maxilla (2/3 cases), in young females (2/3 cases), and is associated with an **impacted tooth** (2/3 cases, usually the maxillary canine). ### **Clinical Pearls for NEET-PG** * **Dentigerous Cyst:** If the follicular space around an unerupted tooth is **>3mm**, suspect a dentigerous cyst. * **AOT (Adenomatoid Odontogenic Tumor):** Look for "snowflake" calcifications within the radiolucency on X-ray. It typically involves the crown and part of the root, unlike a dentigerous cyst which stops at the CEJ. * **Ameloblastoma:** While the multicystic type shows a "soap bubble" or "honeycomb" appearance, the **Unicystic** type (associated with impacted teeth) mimics a cyst and has a better prognosis. * **Pindborg Tumor (CEOT):** Another differential for impacted teeth, characterized by "driven snow" calcifications.

Question 239: What is the most common site for salivary gland tumors?

A. Submandibular gland
B. Parotid gland (Correct Answer)
C. Minor salivary glands
D. Sublingual gland

Explanation: **Explanation:** The distribution of salivary gland tumors follows a specific pattern based on the size and location of the gland. The **Parotid gland** is the correct answer because it accounts for approximately **80% of all salivary gland tumors**. **Breakdown of Options:** * **Parotid Gland (Correct):** It is the largest salivary gland and the most frequent site for both benign and malignant neoplasms. A useful rule of thumb is the "80% Rule": 80% of tumors occur in the parotid, and 80% of those are benign (most commonly Pleomorphic Adenoma). * **Submandibular Gland:** This is the second most common site, accounting for about 10-15% of tumors. Unlike the parotid, nearly 40-50% of tumors here are malignant. * **Minor Salivary Glands:** These are scattered throughout the oral cavity (most commonly the palate). While they account for only 5-10% of all tumors, they have a much higher malignancy rate (approx. 50-80%). * **Sublingual Gland:** This is the rarest site for tumors (<1%). However, if a tumor is found here, there is an 80% chance it is malignant. **NEET-PG High-Yield Pearls:** 1. **Most common benign tumor (overall):** Pleomorphic Adenoma (most common in the Parotid). 2. **Most common malignant tumor (overall):** Mucoepidermoid Carcinoma. 3. **Warthin’s Tumor:** Almost exclusively found in the Parotid gland; associated with smoking and often bilateral. 4. **The "Size-Malignancy Inverse Rule":** The smaller the gland, the higher the probability that a tumor found there is malignant.

Question 240: A 95-year-old man has noted swelling of his lower lip for the past month. On examination, there is a fluctuant, 1-cm nodule with a blue, translucent hue just beneath the oral mucosa on the inside of his lip. The lesion is excised, and microscopic examination shows granulation tissue. What is the most likely etiology for this lesion?

A. Eating chili peppers
B. French kissing
C. HIV infection
D. Local trauma (Correct Answer)

Explanation: **Explanation:** The clinical presentation describes a classic case of a **Mucocele** (Mucous extravasation cyst). This is the most common minor salivary gland lesion, typically occurring on the **lower lip**. **Why Local Trauma is Correct:** The underlying pathophysiology involves **local trauma** (such as accidental biting of the lip) that causes rupture of a minor salivary gland duct. This leads to the leakage (extravasation) of mucus into the surrounding submucosal soft tissues. The body responds by forming a wall of **granulation tissue** (pseudocyst) around the mucus, which explains the microscopic findings and the characteristic fluctuant, blue, translucent appearance. **Why Other Options are Incorrect:** * **A & B (Chili peppers/French kissing):** While these involve the oral cavity, they do not typically cause the specific ductal rupture required to form a mucocele. * **C (HIV infection):** HIV is associated with salivary gland issues like Benign Lymphoepithelial Lesions (BLEL), particularly in the parotid gland, but it is not a primary cause of lower lip mucoceles. **NEET-PG High-Yield Pearls:** * **Most common site:** Lower lip (due to frequent trauma). * **Pathology:** It is a **pseudocyst** because it lacks an epithelial lining (lined by granulation tissue). * **Ranula:** A mucocele occurring on the floor of the mouth, usually arising from the **sublingual gland**. A "Plunging Ranula" extends below the mylohyoid muscle into the neck. * **Treatment:** Complete surgical excision along with the involved minor salivary gland to prevent recurrence.

Practice by Chapter

Stomatitis

Practice Questions

Oral Ulcers

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Oral Leukoplakia

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Oral Cancers

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Sialadenitis

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Sialolithiasis

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Salivary Gland Tumors

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Ranula

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Xerostomia

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Sjögren's Syndrome

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Oral Manifestations of Systemic Diseases

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Temporomandibular Joint Disorders

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