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 141: What are the three stages in the progression of acute odontogenic infection?

A. Periapical osteitis, cellulitis, abscess (Correct Answer)
B. Abscess, cellulitis, periapical osteitis
C. Cellulitis, abscess, periapical osteitis
D. Periapical osteitis, abscess, cellulitis

Explanation: ### Explanation: Progression of Acute Odontogenic Infection The progression of an acute odontogenic infection follows a predictable anatomical and pathological sequence based on the spread of bacteria from the tooth pulp into the surrounding tissues. **1. Why Option A is Correct:** The infection follows three distinct stages: * **Periapical Osteitis:** The process begins when dental caries reach the pulp (pulpitis), leading to necrosis. Bacteria then exit the apical foramen, causing an inflammatory response in the bone surrounding the root tip (periapical osteitis). * **Cellulitis:** As the infection breaches the cortical plate of the jaw, it spreads into the loose connective tissue and fascial planes. This stage is characterized by diffuse, non-fluctuant, painful swelling (cellulitis). * **Abscess:** If the body’s defenses or medical intervention do not halt the cellulitis, the tissue undergoes liquefactive necrosis, leading to the formation of a localized collection of pus (abscess). **2. Why Other Options are Incorrect:** * **Options B & C:** These suggest that an abscess or cellulitis precedes the bone involvement. Pathologically, the infection must originate at the tooth root (osteitis) before spreading to soft tissues. * **Option D:** This suggests an abscess occurs before cellulitis. In the natural history of odontogenic spread, diffuse inflammatory edema (cellulitis) almost always precedes the localization of pus (abscess). **3. NEET-PG High-Yield Pearls:** * **Ludwig’s Angina:** A life-threatening cellulitis involving the submandibular, sublingual, and submental spaces, usually originating from the 2nd or 3rd mandibular molars. * **Microbiology:** Odontogenic infections are typically **polymicrobial**, involving a mix of aerobic (Streptococcus viridans) and anaerobic (Bacteroides, Peptostreptococcus) bacteria. * **Management:** The definitive treatment for an odontogenic abscess is **Incision and Drainage (I&D)** plus extraction of the offending tooth or root canal therapy.

Question 142: The "cherry blossom appearance" is a characteristic feature of which of the following conditions?

A. Normal salivary gland
B. Sjogren's syndrome (Correct Answer)
C. Ptyalism
D. Sialolithiasis

Explanation: **Explanation:** The **"cherry blossom appearance"** (or "snowstorm appearance") is a classic sialographic finding characteristic of **Sjogren’s Syndrome**. **1. Why Sjogren’s Syndrome is Correct:** Sjogren’s syndrome is a chronic autoimmune disorder characterized by lymphocytic infiltration of the exocrine glands (primarily salivary and lacrimal). This leads to the destruction of the glandular acini. On sialography (imaging of the salivary ducts using contrast), the contrast material leaks out of the damaged intralobular ducts and collects in small, globular inflammatory pockets. These multiple punctate collections of contrast resemble flowers on a tree branch, leading to the descriptive term "cherry blossom appearance." **2. Why the other options are incorrect:** * **Normal salivary gland:** A normal sialogram shows a "leafless tree" appearance, where the main duct and its branches are clearly defined without any leakage or globular collections. * **Ptyalism:** This refers to excessive salivation (often seen in pregnancy or GERD). It is a functional symptom rather than a structural disease and does not produce specific sialographic patterns. * **Sialolithiasis:** Salivary stones typically present with a "sausage-string" appearance (due to strictures and dilatations) or a filling defect where the stone obstructs the duct. **Clinical Pearls for NEET-PG:** * **Sjogren’s Triad:** Xerostomia (dry mouth), Keratoconjunctivitis sicca (dry eyes), and a connective tissue disorder (most commonly Rheumatoid Arthritis). * **Schirmer’s Test:** Used to quantify tear production (Positive if <5mm in 5 minutes). * **Diagnostic Gold Standard:** Minor salivary gland biopsy (usually from the lower lip) showing lymphocytic aggregates (Focus score ≥1). * **Malignancy Risk:** Patients with Sjogren’s have a 40-fold increased risk of developing **B-cell MALT Lymphoma**.

Question 143: A periapical cyst is usually preceded by which of the following conditions?

A. Periapical granuloma (Correct Answer)
B. Periodontal abscess
C. Periapical abscess
D. All of the above

Explanation: ### Explanation **Correct Answer: A. Periapical granuloma** **Pathophysiology and Mechanism:** A **periapical cyst** (also known as a Radicular Cyst) is the most common inflammatory cyst of the jaws. It originates from the **Malassez epithelial rests** (remnants of Hertwig’s epithelial root sheath) found in the periodontal ligament. The sequence of progression is typically: 1. **Dental Caries** leads to pulpitis and subsequent **pulp necrosis**. 2. Infection spreads to the apex, forming a **Periapical Granuloma** (a mass of chronically inflamed granulation tissue). 3. Inflammation stimulates the Malassez epithelial rests within the granuloma to proliferate. 4. As the epithelial mass grows, the central cells become deprived of nutrients, undergo liquefaction necrosis, and form a fluid-filled cavity—the **Periapical Cyst**. **Why other options are incorrect:** * **B. Periodontal abscess:** This is a localized purulent infection involving the supporting structures of the teeth (gingiva/alveolar bone), usually associated with periodontal pockets rather than the root apex or pulp necrosis. * **C. Periapical abscess:** While an abscess is an acute inflammatory response, a cyst specifically requires the chronic, proliferative environment of a granuloma to trigger epithelial growth. An abscess may follow a granuloma (as an acute exacerbation), but it is not the direct histological precursor to a cyst. **High-Yield Clinical Pearls for NEET-PG:** * **Most common odontogenic cyst:** Radicular (Periapical) cyst. * **Radiological feature:** A well-defined unilocular radiolucency at the apex of a **non-vital (dead) tooth**. * **Histology:** Characterized by **Rushton bodies** (eosinophilic linear/curved inclusions in the epithelial lining) and cholesterol clefts. * **Treatment:** Root canal treatment (RCT) or extraction with apical curettage.

Question 144: Bacterial pyogenic parotitis is most commonly found in which of the following conditions?

A. Mumps
B. Debilitation after major surgery (Correct Answer)
C. Drug reaction (iodine mumps)
D. Uveoparotid fever

Explanation: **Explanation:** **Acute Bacterial Pyogenic Parotitis** (also known as "Surgical Mumps") is a bacterial infection of the parotid gland, most commonly caused by *Staphylococcus aureus*. **Why Option B is Correct:** The primary pathophysiology involves **stasis of salivary flow**. In patients who are debilitated, dehydrated, or recovering from major surgery, there is often a combination of reduced oral intake, dehydration, and poor oral hygiene. This leads to decreased salivary production and thickening of secretions. The lack of "flushing" action allows oral commensals to migrate retrogradely through Stensen’s duct into the gland, leading to acute suppuration. **Analysis of Incorrect Options:** * **A. Mumps:** This is a **viral** infection caused by the Paramyxovirus. It is the most common cause of parotitis in children but is not a "pyogenic" (pus-forming) bacterial condition. * **C. Drug reaction (Iodine mumps):** This is a non-inflammatory, painless swelling of the parotid glands following the administration of iodinated contrast media. It is an idiosyncratic reaction, not an infection. * **D. Uveoparotid fever (Heerfordt’s syndrome):** This is a specific manifestation of **Sarcoidosis** characterized by the triad of parotid enlargement, uveitis, and facial nerve palsy. It is a granulomatous condition, not pyogenic. **High-Yield Clinical Pearls for NEET-PG:** * **Most common organism:** *Staphylococcus aureus*. * **Risk Factors:** Dehydration (most common), anticholinergic drugs (which dry secretions), and poor oral hygiene. * **Clinical Presentation:** Sudden onset of firm, painful swelling at the angle of the jaw, often with pus exuding from Stensen’s duct upon massage. * **Management:** Rehydration, intravenous antibiotics (anti-staphylococcal), and warm compresses. If an abscess forms, surgical drainage via a **Blair’s incision** is required.

Question 145: What is the best diagnostic modality for parotid swelling?

A. Enucleation
B. FNAC (Correct Answer)
C. Superficial parotidectomy
D. Excisional biopsy

Explanation: **Explanation:** The correct answer is **FNAC (Fine Needle Aspiration Cytology)**. **Why FNAC is the best diagnostic modality:** FNAC is the initial investigation of choice for any salivary gland swelling. It is a safe, minimally invasive, and cost-effective procedure with high sensitivity (85-95%) and specificity (95-100%) for distinguishing between benign and malignant lesions. It helps the surgeon plan the extent of surgery (e.g., whether to preserve or sacrifice the facial nerve) without the risk of seeding tumor cells, which is a major concern in the parotid region. **Why other options are incorrect:** * **Enucleation:** This involves "shelling out" the tumor. It is strictly contraindicated in parotid masses (especially Pleomorphic Adenoma) because the tumor often has pseudopods that breach the capsule. Enucleation leads to a very high recurrence rate. * **Excisional Biopsy:** Taking a piece of the tumor or the whole tumor without proper anatomical dissection is contraindicated in the parotid gland. It risks damaging the facial nerve and can lead to tumor spillage, causing "seeding" and multifocal recurrence. * **Superficial Parotidectomy:** This is a **therapeutic** procedure (the treatment of choice for most benign parotid tumors), not a primary diagnostic modality. Diagnosis should ideally be established via FNAC before proceeding to surgery. **High-Yield Clinical Pearls for NEET-PG:** * **Gold Standard for Diagnosis:** FNAC. * **Incisional Biopsy:** Absolutely contraindicated in parotid tumors due to the risk of **Frey’s Syndrome** and tumor seeding. * **Most common parotid tumor:** Pleomorphic Adenoma (Benign Mixed Tumor). * **Most common malignant parotid tumor:** Mucoepidermoid Carcinoma. * **Imaging:** MRI is the preferred imaging modality to assess soft tissue extent and nerve involvement, but FNAC remains the primary diagnostic tool for pathology.

Question 146: In which of the following conditions is sialography contraindicated?

A. Ductal calculus
B. Chronic parotitis
C. Parotid obstruction
D. Acute sialadenitis (Correct Answer)

Explanation: **Explanation:** **Sialography** is a radiographic technique where a radio-opaque contrast medium is injected into the salivary ductal system. **Why Acute Sialadenitis is the Correct Answer:** Sialography is strictly **contraindicated** in acute sialadenitis (acute inflammation of the salivary gland) for two primary reasons: 1. **Exacerbation of Infection:** The retrograde injection of contrast under pressure can force bacteria and inflammatory debris deeper into the glandular parenchyma, potentially leading to abscess formation or systemic spread (septicaemia). 2. **Severe Pain:** The procedure involves ductal dilatation and pressure, which is excruciatingly painful for a patient with an already inflamed and tender gland. **Analysis of Incorrect Options:** * **A. Ductal Calculus:** Sialography is often used to identify radiolucent stones or to map the ductal anatomy distal to a stone, though it has largely been replaced by USG or CT. * **B. Chronic Parotitis:** This is a classic indication. Sialography helps visualize characteristic patterns like "sialectasis" (punctate, globular, or cavitary) seen in chronic inflammatory conditions. * **C. Parotid Obstruction:** Sialography is indicated here to identify the site and nature of the obstruction (e.g., strictures or mucous plugs). **High-Yield Clinical Pearls for NEET-PG:** * **Contraindications:** Acute infection and **known allergy to iodine** (contrast medium). * **Sialographic Patterns:** * **Sjögren’s Syndrome:** "Snowstorm" or "Cherry blossom" appearance (punctate sialectasis). * **Chronic Sialadenitis:** "Sausage-string" appearance (due to segments of dilatation and stenosis). * **Benign Tumors:** "Ball-in-hand" appearance (displacement of ducts around a mass). * **Gold Standard:** For visualizing salivary stones, **Non-Contrast CT (NCCT)** is highly sensitive, while **Sialendoscopy** is the modern interventional gold standard.

Question 147: Warthin tumor is characterized by which of the following?

A. Malignant neoplasm
B. Rapidly growing
C. Hot technetium scan (Correct Answer)
D. Cold technetium scan

Explanation: **Explanation:** **Warthin Tumor (Papillary Cystadenoma Lymphomatosum)** is the second most common benign salivary gland tumor, almost exclusively occurring in the **parotid gland**. **Why "Hot Technetium Scan" is correct:** Warthin tumors are unique because they contain a high density of **oncocytes** (mitochondria-rich cells) and lack an organized ductal system to drain secretions. When **Technetium-99m pertechnetate** is administered, it is actively taken up by these oncocytes. However, because the tumor lacks functional ducts to excrete the isotope, it accumulates within the cystic spaces. On a radionuclide scan, this results in increased uptake compared to the surrounding normal tissue, appearing as a **"Hot Spot."** **Analysis of Incorrect Options:** * **A. Malignant neoplasm:** Warthin tumor is a strictly **benign** neoplasm. Malignant transformation is extremely rare (<1%). * **B. Rapidly growing:** These tumors are typically **slow-growing**, painless, and mobile. Rapid growth in a parotid mass usually suggests malignancy or an abscess. * **D. Cold technetium scan:** Most other salivary gland tumors (like Pleomorphic Adenoma) and malignancies do not concentrate the isotope or lack the oncocytic density to retain it, thus appearing as "Cold" (areas of decreased uptake). **High-Yield NEET-PG Clinical Pearls:** * **Strongest Association:** Smoking (it is the only salivary tumor significantly linked to tobacco). * **Demographics:** Most common in elderly males (though female incidence is rising). * **Bilateralism:** It is the most common salivary tumor to present **bilaterally** (10%) or multicentrically. * **Location:** Usually found in the **tail/lower pole** of the parotid gland. * **Histology:** Characterized by a double layer of oncocytic epithelium forming papillary projections into cystic spaces, surrounded by a dense lymphoid stroma.

Question 148: Which of the following infections can cause multiple sites of osteomyelitis of the jaw?

A. Peritonsillar abscess
B. Local trauma
C. Hematogenous infection (Correct Answer)
D. Buccal space infection

Explanation: **Explanation:** **1. Why Hematogenous Infection is Correct:** Osteomyelitis of the jaw is typically a localized process resulting from odontogenic infections (e.g., dental caries or periodontal disease). However, when the infection is **hematogenous** (spread via the bloodstream), the pathogen can seed into the bone marrow at **multiple, non-contiguous sites** simultaneously. This is more common in pediatric populations or immunocompromised individuals where a primary focus (like a skin or respiratory infection) leads to bacteremia, allowing the bacteria to settle in the highly vascularized areas of the mandible or maxilla. **2. Why the Other Options are Incorrect:** * **Peritonsillar Abscess (Quinsy):** This is a localized collection of pus in the peritonsillar space. While it can spread to the parapharyngeal space, it rarely involves the bone and would be limited to a single anatomical region. * **Local Trauma:** Trauma (like a compound fracture) introduces bacteria directly into a specific site. The resulting osteomyelitis is strictly localized to the area of injury. * **Buccal Space Infection:** This is a soft tissue infection of the cheek. While it can occur secondary to an infected tooth, the spread is contiguous and localized to the adjacent bone, rather than causing multifocal involvement. **Clinical Pearls for NEET-PG:** * **Most Common Site:** The **mandible** is more frequently affected by osteomyelitis than the maxilla due to its poorer collateral blood supply and dense cortical bone. * **Microbiology:** *Staphylococcus aureus* is the most common organism in hematogenous spread; however, odontogenic cases are usually polymicrobial (anaerobes + streptococci). * **Garre’s Osteomyelitis:** A specific type of chronic osteomyelitis with proliferative periostitis, typically seen in children/young adults, presenting with a "layered" or "onion-skin" appearance on X-ray.

Question 149: Which of the following can cause a painless ulcer of the tongue?

A. Dyspepsia
B. Syphilis (Correct Answer)
C. Tuberculosis
D. None of the above

Explanation: **Explanation:** The correct answer is **Syphilis**. In the context of the tongue, a painless ulcer is a classic presentation of **Primary Syphilis**, manifesting as a **Chancre**. 1. **Why Syphilis is correct:** The primary stage of syphilis, caused by *Treponema pallidum*, presents as a solitary, indurated, and characteristically **painless** ulcer (chancre) at the site of inoculation. While most common on genitalia, extragenital chancres frequently occur on the lips or tongue. Additionally, the **Gumma** of tertiary syphilis is also a painless, punched-out ulcer, typically involving the midline of the dorsum of the tongue. 2. **Why other options are incorrect:** * **Dyspepsia:** This is a symptom of indigestion, not a disease entity that causes tongue ulcers. However, associated conditions like Aphthous ulcers (canker sores) are exquisitely **painful**. * **Tuberculosis (TB):** A tubercular ulcer of the tongue is classically **extremely painful**. It typically presents as a shallow, undermined ulcer with a pale, granulating base, often secondary to pulmonary TB. **High-Yield Clinical Pearls for NEET-PG:** * **Painful Ulcers:** Aphthous ulcers, Vincent’s angina, and Tuberculosis. * **Painless Ulcers:** Syphilis (Chancre/Gumma) and early-stage Squamous Cell Carcinoma (though malignancy becomes painful as it infiltrates deeper tissues/nerves). * **Location Clue:** A midline ulcer on the tongue dorsum should strongly raise suspicion of a **Syphilitic Gumma**. * **Mnemonic:** "S" for Syphilis is "S" for Silent (Painless); "T" for TB is "T" for Terrible pain.

Question 150: Which of the following statements regarding premalignant oral lesions is true?

A. Biopsy is required to prove the diagnosis of leukoplakia.
B. Leukoplakia does not disappear after cessation of smoking.
C. Erythroplakia has a higher risk for malignancy than leukoplakia. (Correct Answer)
D. Oral submucous fibrosis is seen in all parts of the world.

Explanation: **Explanation:** **1. Why Option C is Correct:** Erythroplakia is defined as a fiery red patch that cannot be characterized clinically or pathologically as any other definable disease. It is considered the most severe premalignant lesion of the oral cavity. While leukoplakia has a malignant transformation rate of approximately **3–5%**, erythroplakia carries a significantly higher risk, with over **90%** of cases showing evidence of epithelial dysplasia, carcinoma in situ, or invasive squamous cell carcinoma at the time of biopsy. **2. Why Other Options are Incorrect:** * **Option A:** Leukoplakia is a **clinical diagnosis of exclusion**. It is defined as a white patch that cannot be characterized clinically or pathologically as any other disease and *cannot be scraped off*. While a biopsy is essential to check for dysplasia or malignancy, it is not required to "prove" the clinical label of leukoplakia itself. * **Option B:** Many cases of "Smoker’s Keratosis" (a form of leukoplakia) are reversible. If the causative irritant (smoking or tobacco chewing) is eliminated, the lesion may regress or disappear entirely within weeks. * **Option C:** Oral Submucous Fibrosis (OSMF) is a chronic, progressive condition primarily associated with **areca nut (betel nut) chewing**. Consequently, it is highly prevalent in **South Asia** and Southeast Asian populations but is rarely seen in the Western world except among immigrants from these regions. **High-Yield Clinical Pearls for NEET-PG:** * **Speckled Leukoplakia (Erythroleukoplakia):** A mix of white and red patches; it carries a higher risk of malignancy than pure leukoplakia. * **OSMF:** Characterized by "burning sensation" on eating spicy food and progressive "trismus" (lockjaw) due to vertical fibrous bands. * **Most common site for Leukoplakia:** Buccal mucosa and commissures. * **Most common site for Erythroplakia:** Floor of the mouth, retromolar trigone, and soft palate.

Practice by Chapter

Stomatitis

Practice Questions

Oral Ulcers

Practice Questions

Oral Leukoplakia

Practice Questions

Oral Cancers

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Sialadenitis

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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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