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 181: A 40-year-old male patient presents with a painless swelling causing fullness of the upper lip and elevation of the nostril on the left side. The only positive radiographic finding is unilateral elevation of the floor of the nasal cavity. What is the probable diagnosis?

A. Globulomaxillary cyst
B. Polyp in the nasal cavity
C. Radicular cyst
D. Nasolabial cyst (Correct Answer)

Explanation: ### Explanation **Correct Answer: D. Nasolabial cyst** The **Nasolabial cyst** (also known as Klestadt’s cyst) is a rare, non-odontogenic, soft-tissue cyst. It typically presents as a slow-growing, painless swelling in the nasolabial fold area. **Key Diagnostic Features:** 1. **Clinical Presentation:** It causes fullness of the upper lip, flaring of the ala of the nose, and elevation of the nostril. 2. **Radiographic Finding:** Since it is a soft-tissue cyst, it does not usually show bone changes on X-ray. However, it can cause **pressure erosion** of the underlying bone, leading to the classic sign: **unilateral elevation of the floor of the nasal cavity** (convexity of the nasal floor). 3. **Bimanual Palpation:** It can be felt between a finger in the labial sulcus and another in the floor of the nasal vestibule. --- ### Why the other options are incorrect: * **Globulomaxillary cyst:** This is an intraosseous cyst located between the maxillary lateral incisor and canine. Radiographically, it appears as a **well-defined, inverted pear-shaped radiolucency** between the roots of these teeth. * **Polyp in the nasal cavity:** While it can cause nasal obstruction, a simple polyp does not typically cause external swelling of the upper lip or elevation of the nasal floor on radiographs. * **Radicular cyst:** This is an odontogenic cyst associated with the apex of a **non-vital (carious) tooth**. It presents as a radiolucency at the root apex, not as a soft-tissue swelling elevating the nasal floor. --- ### NEET-PG High-Yield Pearls: * **Origin:** Derived from remnants of the nasolacrimal duct or trapped epithelium at the junction of the globular, lateral nasal, and maxillary processes. * **Gender:** More common in females (approx. 3:1 ratio). * **Treatment:** Surgical excision via a **sublabial approach**. * **Classic Sign:** Look for the triad of **ala flaring, fullness of the gingivolabial sulcus, and elevation of the nasal floor.**

Question 182: What is the earliest sign of Oral Submucous Fibrosis (OSMF)?

A. Burning sensation
B. Blanching (Correct Answer)
C. Restricted mouth opening
D. Circumoral bands

Explanation: **Explanation:** **Oral Submucous Fibrosis (OSMF)** is a chronic, progressive, premalignant condition primarily associated with the habit of chewing areca nut (betel nut). **1. Why Blanching is the Correct Answer:** **Blanching** of the oral mucosa is considered the **earliest clinical sign** of OSMF. It occurs due to subepithelial inflammatory changes and early collagen deposition, which leads to a decrease in vascularity. The mucosa loses its normal pink appearance and becomes pale, marble-like, or "chalky white." This may be localized or generalized and is often first noticed on the buccal mucosa or soft palate. **2. Analysis of Incorrect Options:** * **Burning Sensation (Option A):** This is the **earliest symptom** (subjective) reported by the patient, especially when consuming spicy food. However, the question asks for the earliest **sign** (objective finding), which is blanching. * **Restricted Mouth Opening (Option C):** This is a **late feature** of the disease caused by the formation of dense fibrous bands in the cheeks and pterygomandibular raphe. It is the most common reason patients seek medical attention. * **Circumoral Bands (Option D):** These are palpable fibrous bands that develop as the disease progresses. While characteristic of OSMF, they appear after the initial blanching phase. **Clinical Pearls for NEET-PG:** * **Etiology:** Areca nut (alkaloids like arecoline) increases collagen synthesis and decreases degradation. * **Pathognomonic Sign:** Palpable vertical fibrous bands. * **Uvula Appearance:** Often described as **"Bud-shaped"** or shrunken due to fibrosis. * **Malignant Transformation:** OSMF has a high transformation rate (approx. 7–13%) to Oral Squamous Cell Carcinoma. * **Treatment:** Cessation of habit, intralesional steroids (Hyaluronidase), and in advanced cases, surgical release of bands.

Question 183: Oral lesions are rarely seen in which of the following conditions?

A. AIDS
B. Tuberculosis (Correct Answer)
C. Syphilis
D. Leukemia

Explanation: **Explanation:** The correct answer is **Tuberculosis (B)**. While tuberculosis (TB) is a systemic infection, oral manifestations are considered **rare**, occurring in only 0.05% to 5% of all TB cases. The oral cavity is relatively resistant to *Mycobacterium tuberculosis* due to the protective nature of saliva (which has antibacterial properties), the presence of saprophytic organisms, and the thickness of the oral epithelium. When it does occur, it is usually secondary to pulmonary TB (via infected sputum) and typically presents as a **painless, undermined ulcer** on the dorsum of the tongue. **Why other options are incorrect:** * **AIDS:** Oral lesions are a hallmark of HIV/AIDS. Common manifestations include Oral Candidiasis (most common), Oral Hairy Leukoplakia (caused by EBV), and Kaposi Sarcoma. * **Syphilis:** Oral lesions occur in all three stages: Primary (Chancre on lips/tongue), Secondary (Mucous patches and Snail-track ulcers), and Tertiary (Gumma of the hard palate). * **Leukemia:** Oral manifestations are frequently the first sign of leukemia, especially in Acute Myeloid Leukemia (AML). Common signs include gingival hyperplasia, petechiae, and mucosal bleeding. **High-Yield Clinical Pearls for NEET-PG:** * **TB Ulcer:** Classically described as a **painless ulcer with undermined edges** and a pale, granulating base. * **Syphilitic Ulcer:** Secondary syphilis presents with **"Snail-track ulcers"** (multiple, superficial, coalescing ulcers). * **Vincent’s Angina:** A painful, pseudomembranous ulceration of the gums and tonsils caused by *Borrelia vincentii* and *Fusobacterium*. * **Behçet’s Syndrome:** Characterized by the triad of recurrent oral ulcers, genital ulcers, and uveitis.

Question 184: A 60-year-old man presents with an ulcer on the lateral border of the tongue. What is the probable diagnosis?

A. Dental ulcer
B. Carcinomatous ulcer (Correct Answer)
C. Tuberculosis ulcer
D. Syphilitic ulcer

Explanation: **Explanation:** The most probable diagnosis for a chronic ulcer on the lateral border of the tongue in an elderly patient is a **Carcinomatous ulcer (Squamous Cell Carcinoma)**. **Why Carcinomatous Ulcer is correct:** The lateral border of the tongue is the most common site for intraoral Squamous Cell Carcinoma (SCC). In a 60-year-old patient, any non-healing ulcer persisting for more than 2–3 weeks must be considered malignant until proven otherwise. These ulcers typically present with **everted (rolled-out) edges** and a **特征性 (characteristic) indurated base** due to tissue infiltration. **Analysis of Incorrect Options:** * **Dental Ulcer:** Usually caused by a sharp or jagged tooth. While it also occurs on the lateral border, it typically heals rapidly once the offending tooth is filed or extracted. In an elderly patient, a "dental ulcer" that doesn't heal is often a precursor to or a misdiagnosed malignancy. * **Tuberculosis Ulcer:** Classically presents as a **shallow, painful ulcer with undermined edges** and a pale, granulating base. It is usually secondary to pulmonary TB and most commonly affects the dorsum of the tongue. * **Syphilitic Ulcer:** Primary syphilis (chancre) is usually painless and occurs on the tip or dorsum. Tertiary syphilis presents as a **Gumma**, which is a "punched-out" ulcer, typically located on the midline of the dorsum of the tongue. **NEET-PG High-Yield Pearls:** * **Most common site of Oral Cavity Cancer:** Lower lip (Global), but in India, it is the **Buccal Mucosa** (due to tobacco chewing). * **Most common site of Tongue Cancer:** Lateral border (Middle third). * **Lymphatic Spread:** Tongue tip drains to Submental nodes (Level Ia); Lateral borders drain to Submandibular (Level Ib) or Deep Cervical nodes. * **Premalignant conditions:** Erythroplakia carries a much higher risk of transformation than Leukoplakia.

Question 185: When adjacent tooth is used as a fulcrum instead of interdental bone, it is termed as:

A. Stobie's extraction (Correct Answer)
B. Balancing extraction
C. Both
D. Wilkinson extraction

Explanation: **Explanation:** **1. Why Stobie’s Extraction is Correct:** In conventional dental extractions using an elevator (like a Coupland or Cryer), the **interdental alveolar bone** is used as the fulcrum to luxate the tooth. However, **Stobie’s technique** is a specific modification where the **adjacent tooth** is used as the fulcrum. This technique is generally discouraged in modern dentistry because it risks damaging the periodontal ligament or luxating the healthy adjacent tooth. However, it may be intentionally employed when the adjacent tooth is also indicated for extraction or is a non-functional root piece. **2. Why Other Options are Incorrect:** * **Balancing Extraction:** This refers to the extraction of the same tooth on the opposite side of the same arch (e.g., extracting the left first premolar when the right first premolar is removed) to maintain the midline and prevent dental drifting during orthodontic treatment. * **Wilkinson’s Extraction:** This is a historical orthodontic concept involving the extraction of all four first permanent molars between the ages of 8.5 to 9.5 years to prevent crowding and reduce the incidence of third molar impaction. It has no relation to the choice of fulcrum. **3. High-Yield Clinical Pearls for NEET-PG:** * **Fulcrum Rule:** The golden rule of elevators is to **never** use an adjacent tooth as a fulcrum unless it is also slated for extraction. * **Elevator Principles:** Elevators work on three main principles: **Lever principle** (most common), **Wedge principle**, and **Wheel and Axle principle**. * **Compensation Extraction:** Extraction of the same tooth in the opposing arch (e.g., extracting the upper first premolar when the lower first premolar is removed) to prevent over-eruption.

Question 186: In a patient with reduced salivary flow, what is the carious incidence compared to a patient with normal salivary flow?

A. More than (Correct Answer)
B. Less than
C. Unaffected
D. None of the above

Explanation: **Explanation:** The correct answer is **More than (Option A)**. Saliva plays a critical role in maintaining oral health through several protective mechanisms. When salivary flow is reduced (Xerostomia), the incidence of dental caries increases significantly due to the loss of these functions: 1. **Buffering Action:** Saliva contains bicarbonate and phosphate ions that neutralize acids produced by plaque bacteria (like *Streptococcus mutans*), preventing the demineralization of enamel. 2. **Mechanical Cleansing:** The constant flow of saliva physically flushes away food debris and fermentable carbohydrates. 3. **Remineralization:** Saliva is supersaturated with calcium and phosphate ions, which help repair early carious lesions. 4. **Antimicrobial Properties:** It contains Lysozyme, Lactoferrin, and Secretory IgA, which inhibit bacterial growth. **Why other options are incorrect:** * **Less than (Option B):** This is incorrect because the absence of saliva creates an acidic, sugar-rich environment that promotes rapid tooth decay. * **Unaffected (Option C):** Saliva is the primary defense mechanism of the oral cavity; its reduction directly correlates with a spike in oral pathologies. **NEET-PG High-Yield Pearls:** * **Xerostomia Causes:** Most common causes include drugs (Anticholinergics, Antihistamines, Diuretics), Sjögren’s syndrome, and Post-Radiation therapy for Head and Neck cancers. * **Radiation Caries:** A rampant form of decay occurring after radiotherapy due to permanent damage to the acinar cells of the salivary glands. * **Sialometry:** Normal unstimulated flow is 0.3–0.4 ml/min. Xerostomia is clinically significant when the flow rate drops below 0.1 ml/min.

Question 187: Which of the following predisposes to oral cancer?

A. Erythroplakia
B. Leukoplakia
C. Submucosal fibrosis
D. Lichen planus (Correct Answer)

Explanation: The question asks for a condition that **predisposes** to oral cancer. While all listed options are considered "potentially malignant disorders" (PMDs), the distinction lies in the **rate of malignant transformation**. ### **Explanation of the Correct Answer** **D. Lichen Planus:** This is a chronic inflammatory condition of the oral mucosa. While its malignant transformation rate is relatively low (approximately 0.5% to 2%), it is a well-recognized pre-malignant condition. In the context of this specific question (often sourced from standard textbooks like Dhingra), Lichen Planus is highlighted as a predisposing factor, particularly the **erosive and atrophic forms**, which carry a higher risk of developing Squamous Cell Carcinoma (SCC). ### **Analysis of Incorrect Options** * **A. Erythroplakia:** This is a red, velvety patch. It is not just a "predisposing" factor but has the **highest malignant potential** (over 50% transformation rate). It is often already "carcinoma in situ" at the time of biopsy. * **B. Leukoplakia:** A white patch that cannot be characterized clinically or pathologically as any other disease. It is the **most common** pre-malignant lesion, with a transformation rate of 3–5%. * **C. Submucous Fibrosis (OSMF):** Strongly associated with areca nut chewing. It has a high transformation rate (7–13%) and causes progressive trismus. *Note: In many competitive exams, if the question asks for the "highest risk," the answer is Erythroplakia. If it asks for "most common," it is Leukoplakia. Here, Lichen Planus is selected as a classic example of an inflammatory predisposing condition.* ### **High-Yield Clinical Pearls for NEET-PG** 1. **Highest Malignant Potential:** Erythroplakia > OSMF > Leukoplakia > Lichen Planus. 2. **Speckled Leukoplakia:** Also known as Erythroleukoplakia; it carries a higher risk than plain leukoplakia. 3. **Wickham Striae:** Pathognomonic white reticular patterns seen in Lichen Planus. 4. **Site Risk:** Oral cancer in the floor of the mouth or lateral tongue carries a worse prognosis than the buccal mucosa.

Question 188: Plunging ranula is a type of:

A. Retention cyst (Correct Answer)
B. Extravasation cyst
C. Implantation cyst
D. Malignant tumor

Explanation: **Explanation:** A **Ranula** is a clinical term for a mucocele that occurs in the floor of the mouth, typically arising from the **sublingual gland**. 1. **Why Option A is Correct:** A **Retention Cyst** occurs due to the partial obstruction of a salivary duct (usually the duct of Rivinus), leading to a fluid-filled lesion lined by **epithelium**. While many simple mucoceles are extravasation cysts, classic textbooks (and standard NEET-PG keys) classify the Ranula as a retention cyst of the sublingual gland. A **Plunging Ranula** specifically refers to a ranula that has herniated through or around the **mylohyoid muscle**, presenting as a soft, cystic swelling in the submandibular region of the neck. 2. **Why Other Options are Incorrect:** * **B. Extravasation cyst:** These occur due to ductal trauma leading to mucus leakage into surrounding tissues (lacks an epithelial lining). While common in minor salivary glands (lower lip), the plunging ranula is traditionally categorized under retention phenomena in standard ENT nomenclature. * **C. Implantation cyst:** These occur when surface epithelium is driven into deeper tissues due to trauma (e.g., dermoid cysts). * **D. Malignant tumor:** Ranulas are benign, fluid-filled cystic lesions, not neoplastic growths. **NEET-PG High-Yield Pearls:** * **Source:** Most commonly the **Sublingual gland**. * **Clinical Sign:** "Punsing" or "Plunging" refers to the extension into the neck. * **Appearance:** Classically described as a **"Blue translucent swelling"** in the floor of the mouth (resembling a frog's belly). * **Treatment of Choice:** Surgical excision of the cyst along with the **entire sublingual gland** to prevent recurrence. Simple aspiration or marsupialization has a high failure rate.

Question 189: Which is the most common salivary gland to develop stones?

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

Explanation: **Explanation:** Sialolithiasis (salivary stone formation) occurs most frequently in the **submandibular gland**, accounting for approximately **80%** of all cases. This high incidence is attributed to several anatomical and physiological factors: 1. **Wharton’s Duct Anatomy:** The duct is long and follows an upward, tortuous course, leading to stasis of saliva against gravity. 2. **Saliva Composition:** Submandibular saliva is more **alkaline** (higher pH) and has a higher concentration of **calcium and phosphate** salts compared to other glands. 3. **Mucin Content:** The saliva is more viscous due to high mucin content, which acts as a nidus for stone formation. 4. **Ductal Orifice:** The orifice is narrower than the duct itself, predisposing it to obstruction. **Analysis of Incorrect Options:** * **Parotid Gland (A):** Accounts for about 15-20% of stones. Parotid saliva is serous (thin) and acidic, which keeps calcium salts in solution. Stensen’s duct is also shorter and wider. * **Sublingual Gland (D) & Minor Salivary Glands (C):** These are rarely involved (1-5%) because their secretions are continuous and the ducts are short. **High-Yield Clinical Pearls for NEET-PG:** * **Radiopacity:** 80% of submandibular stones are **radiopaque** (visible on X-ray), whereas 80% of parotid stones are **radiolucent**. * **Clinical Presentation:** Post-prandial pain and swelling (Mealtime syndrome). * **Investigation of Choice:** Non-contrast CT (NCCT) is the gold standard; however, Intraoral Periapical (IOPA) or Occlusal views are often used for initial screening. * **Management:** Small stones may be milked out; larger stones require Sialendoscopy or surgical excision.

Question 190: Oral foci of Miller's are seen in which of the following conditions?

A. Herpes simplex
B. Lichen planus
C. Dental caries (Correct Answer)
D. Syphilis

Explanation: **Explanation:** **Oral foci of Miller** (also known as Miller’s foci) refer to the microscopic zones of liquefaction and tubular destruction seen in the **dentin** during the progression of **Dental caries**. 1. **Why Dental Caries is correct:** According to Miller’s Acidogenic Theory, dental caries is a chemico-parasitic process. When bacteria (primarily *Streptococcus mutans*) ferment carbohydrates, they produce acid that demineralizes the enamel. Once the process reaches the dentin, bacteria invade the dentinal tubules. The proteolytic enzymes produced by these bacteria lead to the liquefaction of the organic matrix, forming small, ovoid areas of destruction known as **Liquefaction foci of Miller**. These foci eventually coalesce, leading to the clinical cavitation of the tooth. 2. **Why other options are incorrect:** * **Herpes simplex:** Characterized by Tzanck cells (multinucleated giant cells) and Cowdry type A inclusion bodies in vesicular lesions. * **Lichen planus:** A chronic inflammatory condition characterized histologically by "saw-tooth" rete pegs and Wickham’s striae clinically. * **Syphilis:** Associated with Hutchinson’s teeth (notched incisors) and Mulberry molars in the congenital form, but not Miller’s foci. **High-Yield Clinical Pearls for NEET-PG:** * **Miller’s Theory:** The "Chemico-Parasitic Theory" is the most accepted theory for the etiology of dental caries. * **Dead Tracts:** These are empty dentinal tubules resulting from the death of odontoblasts, often seen beneath carious lesions. * **Sclerotic Dentin:** A protective mechanism where tubules are filled with mineral deposits to retard the progression of caries.

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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