Diseases of the Oral Cavity and Salivary Glands — MCQs

A 19-year-old woman has swelling in the back of her mouth for 2 months. Examination reveals swelling in the area of the left third molar. Radiographs show a radiolucent unilocular, well-circumscribed cyst surrounding the crown of the unerupted third mandibular molar. Histopathology shows the cyst is lined by stratified squamous epithelium and surrounded by a chronic inflammatory infiltrate. What is the most likely diagnosis?

Q198Easy

Diagnosis of dry socket is done by?

Q199Easy

What is the most common organism causing fungal infection of the oral cavity?

Q200Easy

What is the treatment for submandibular salivary gland duct calculi?

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

Question 191: Aphthous ulcers are also known as which of the following?

A. Canker sores (Correct Answer)
B. Marjolin's ulcer
C. Curling's ulcer
D. Cushing ulcers

Explanation: **Explanation:** **Aphthous ulcers**, commonly referred to as **canker sores**, are the most frequent cause of recurrent oral ulceration. They are painful, shallow, non-contagious ulcers characterized by a yellow-gray necrotic base surrounded by an erythematous "halo." They typically occur on non-keratinized mucosa (buccal and labial mucosa, floor of the mouth). **Analysis of Options:** * **A. Canker sores (Correct):** This is the synonymous term for Recurrent Aphthous Stomatitis (RAS). * **B. Marjolin's ulcer:** This refers to a squamous cell carcinoma arising in a site of chronic inflammation, most commonly a long-standing burn scar or chronic osteomyelitis. * **C. Curling's ulcer:** An acute gastric erosion/ulcer resulting as a complication of **severe burns** (due to reduced plasma volume and mucosal ischemia). * **D. Cushing ulcers:** An acute gastric ulcer associated with **elevated intracranial pressure** (due to overstimulation of the vagus nerve leading to increased gastric acid secretion). **High-Yield Clinical Pearls for NEET-PG:** * **Types:** 1. **Minor (Mikulicz’s):** Most common (<1cm), heal without scarring in 7–10 days. 2. **Major (Sutton’s):** Large (>1cm), deep, very painful, and heal **with scarring**. 3. **Herpetiform:** Multiple crops of tiny ulcers; not related to the Herpes virus. * **Associations:** Often linked to stress, trauma, Vitamin B12/Folic acid deficiency, and systemic conditions like **Behçet’s disease** (triad of oral ulcers, genital ulcers, and uveitis) or Celiac disease. * **Management:** Topical corticosteroids (e.g., Triamcinolone acetonide) and topical analgesics are the mainstays of treatment.

Question 192: Vincent's angina is also known as?

A. Trench mouth (Correct Answer)
B. Dry mouth
C. Foot and mouth disease
D. Red mouth

Explanation: **Explanation:** **Vincent’s Angina**, also known as **Acute Necrotizing Ulcerative Gingivitis (ANUG)** or **Trench Mouth**, is a painful, non-contagious infection of the gums. The term "Trench Mouth" originated during World War I, as soldiers in the trenches frequently developed the condition due to poor oral hygiene, extreme psychological stress, and malnutrition. The disease is characterized by a **fusospirochetal infection**, primarily caused by a symbiotic combination of *Borrelia vincentii* (a spirochete) and *Fusobacterium nucleatum*. Clinically, it presents with "punched-out" ulcerations of the interdental papillae, a greyish pseudomembrane, halitosis (fetid breath), and metallic taste. **Analysis of Options:** * **Option A (Trench Mouth):** Correct. This is the historical and common synonym for Vincent’s Angina. * **Option B (Dry Mouth):** Incorrect. This is medically termed **Xerostomia**, often caused by Sjögren's syndrome, radiotherapy, or drugs (anticholinergics). * **Option C (Foot and Mouth Disease):** Incorrect. This is a highly contagious viral disease of cattle (Coxsackievirus) that rarely affects humans; it is distinct from Hand-Foot-and-Mouth disease. * **Option D (Red Mouth):** Incorrect. This is not a standard medical term for Vincent’s Angina; redness (erythema) is a general sign of inflammation but not a synonym for this specific necrotizing condition. **High-Yield Clinical Pearls for NEET-PG:** * **Microbiology:** Look for the "Fusospirochetal complex" in clinical vignettes. * **Risk Factors:** Smoking, stress (increased cortisol), and HIV/AIDS. * **Treatment:** Debridement, hydrogen peroxide mouthwashes, and antibiotics (Metronidazole is the drug of choice as it targets anaerobes). * **Complication:** If untreated, it can spread to the cheeks and face, leading to **Cancrum Oris (Noma)**, especially in malnourished children.

Question 193: A 40-year-old tobacco chewer presents for a routine oral examination. A non-scrapable white patch is noticed on the left buccal mucosa. What is the provisional diagnosis for this white lesion?

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

Explanation: **Explanation:** The provisional diagnosis for a non-scrapable white patch in the oral cavity, especially in a patient with a history of tobacco use, is **Leukoplakia**. **1. Why Leukoplakia is correct:** By definition (WHO), Leukoplakia is a clinical term for a white patch or plaque that **cannot be rubbed off** and cannot be characterized clinically or pathologically as any other disease. It is a **premalignant condition** strongly associated with tobacco (smoking/chewing) and alcohol. The "non-scrapable" nature distinguishes it from Oral Candidiasis (which rubs off, leaving a raw base). **2. Why other options are incorrect:** * **Lichen Planus:** Typically presents as bilateral, symmetrical, lace-like white lines known as **Wickham’s striae**. It is an inflammatory condition, not primarily triggered by tobacco. * **Erythroplakia:** This refers to a **red** velvety patch. While it has a much higher malignant transformation rate than leukoplakia, it does not present as a white lesion. * **Submucous Fibrosis (OSMF):** Characterized by mucosal rigidity, vertical fibrous bands, and **trismus** (restricted mouth opening). While the mucosa may appear pale/blanched, it is a generalized condition rather than a localized "patch." **High-Yield Clinical Pearls for NEET-PG:** * **Most common site:** Buccal mucosa and commissures. * **Highest malignant potential:** Proliferative Verrucous Leukoplakia (PVL) and Speckled Leukoplakia (Erythroleukoplakia). * **Biopsy:** Mandatory to rule out dysplasia or invasive carcinoma. * **Management:** Cessation of habits is the first step; surgical excision or laser ablation is preferred for dysplastic lesions.

Question 194: What is lingua nigra?

A. Familial dysautonomia.
B. Hairy tongue. (Correct Answer)
C. Migratory glossitis.
D. Median rhomboid glossitis.

Explanation: **Lingua Nigra**, commonly known as **Black Hairy Tongue**, is a benign condition characterized by the hypertrophy and elongation of the **filiform papillae** on the dorsal surface of the tongue. ### Why the Correct Answer is Right: The "hairy" appearance is not due to actual hair but results from the failure of keratinized filiform papillae to desquamate normally. These elongated papillae (which can reach up to 15mm) trap debris, bacteria, and fungi. The characteristic black or brown discoloration is caused by **porphyrin-producing chromogenic bacteria** or staining from food, tobacco, and medications. ### Explanation of Incorrect Options: * **A. Familial Dysautonomia (Riley-Day Syndrome):** This is a genetic disorder characterized by the **absence of vallate and fungiform papillae**, leading to a smooth tongue and loss of taste sensation. * **C. Migratory Glossitis (Geographic Tongue):** This presents as multiple, well-demarcated erythematous areas (due to atrophy of filiform papillae) surrounded by a raised white border. The patterns "migrate" over time. * **D. Median Rhomboid Glossitis:** This is a central, diamond-shaped erythematous area located in the midline of the posterior dorsal tongue, typically associated with a chronic **Candidal infection**. ### NEET-PG High-Yield Pearls: * **Risk Factors:** Poor oral hygiene, heavy smoking, excessive coffee/tea intake, and use of broad-spectrum antibiotics (which alter oral flora). * **Clinical Feature:** Usually asymptomatic, but patients may complain of halitosis or a gagging sensation. * **Management:** Primarily involves tongue scraping/brushing and cessation of predisposing habits. * **Note:** Do not confuse this with **Oral Hairy Leukoplakia**, which occurs on the lateral borders of the tongue and is caused by **EBV** in immunocompromised (HIV) patients.

Question 195: A 45-year-old male patient complains of a non-healing oral ulcer present for one month on the lateral border of the tongue. Histologic examination reveals abnormal keratinization. What is the possible diagnosis?

A. Basal cell carcinoma
B. Squamous cell carcinoma (Correct Answer)
C. Keratoacanthoma
D. Erythroplakia

Explanation: **Explanation:** **1. Why Squamous Cell Carcinoma (SCC) is correct:** Squamous cell carcinoma is the most common malignancy of the oral cavity, accounting for over 90% of cases. The **lateral border of the tongue** is the most frequent site for oral SCC. The clinical presentation of a **non-healing ulcer** (persisting for more than 3 weeks) in an adult is a classic "red flag" for malignancy. Histologically, SCC is characterized by the invasion of malignant epithelial cells into the subepithelial tissue and **abnormal keratinization**, often manifesting as "keratin pearls" or "epithelial pearls" in well-differentiated tumors. **2. Why other options are incorrect:** * **Basal Cell Carcinoma (BCC):** BCC typically affects the skin of the face (above the line joining the tragus to the angle of the mouth). It almost **never** occurs primarily within the oral cavity or on the tongue. * **Keratoacanthoma:** This is a rapidly growing skin tumor that often regresses spontaneously. While it shows keratinization, it typically occurs on sun-exposed skin and is rare on the mucous membranes of the tongue. * **Erythroplakia:** This is a clinical term for a red, velvety patch. While it is a high-risk **premalignant condition** (more likely to harbor dysplasia than leukoplakia), it is a clinical description rather than a histological diagnosis of an invasive ulcer. **Clinical Pearls for NEET-PG:** * **Most common site of Oral SCC:** Lower lip (overall), but **Tongue** (specifically lateral border) is the most common intra-oral site. * **Premalignant conditions:** Erythroplakia has a much higher transformation rate to SCC than Leukoplakia. * **Lymphatic spread:** Tongue SCC often spreads to Level II (upper deep cervical) lymph nodes. * **Field Cancerization:** This concept explains why patients with one oral SCC are at high risk for developing a second primary tumor in the upper aerodigestive tract.

Question 196: A cyst occurs under the tongue, caused by obstruction of a salivary gland. What is this condition called?

A. Mucocele
B. Ranula (Correct Answer)
C. Dermoid cyst
D. Dentigerous cyst

Explanation: **Explanation:** **Ranula** is a clinical term for a mucocele that occurs specifically in the **floor of the mouth**. It is a bluish, translucent, fluctuant swelling caused by the leakage of mucus from a ruptured or obstructed salivary gland duct—most commonly the **sublingual gland**. The name is derived from the Latin word *Rana* (frog), as the swelling resembles a frog’s belly. **Analysis of Options:** * **Mucocele (Option A):** While a ranula is technically a type of mucocele, the term "mucocele" usually refers to similar lesions found on the **lower lip** or buccal mucosa. "Ranula" is the specific anatomical term for this condition when it occurs under the tongue. * **Dermoid Cyst (Option C):** This is a developmental cyst that occurs in the midline of the floor of the mouth. Unlike a ranula, it is usually **opaque, doughy to touch**, and located in the midline rather than being lateral and translucent. * **Dentigerous Cyst (Option D):** This is an odontogenic cyst associated with the **crown of an unerupted tooth** (most commonly the mandibular third molar). It is an intraosseous (bone) lesion, not a soft tissue salivary cyst. **High-Yield Clinical Pearls for NEET-PG:** * **Plunging Ranula:** This occurs when the mucus extravasates through or around the **mylohyoid muscle**, presenting as a swelling in the submandibular region of the neck. * **Treatment:** The treatment of choice for a ranula is **Marsupialization** or complete excision of the cyst along with the offending sublingual gland to prevent recurrence. * **Histology:** Most ranulas are "extravasation pseudocysts," meaning they lack a true epithelial lining.

Question 197: A 19-year-old woman has swelling in the back of her mouth for 2 months. Examination reveals swelling in the area of the left third molar. Radiographs show a radiolucent unilocular, well-circumscribed cyst surrounding the crown of the unerupted third mandibular molar. Histopathology shows the cyst is lined by stratified squamous epithelium and surrounded by a chronic inflammatory infiltrate. What is the most likely diagnosis?

A. Ameloblastoma
B. Dentigerous cyst (Correct Answer)
C. Odontogenic keratocyst
D. Odontoma

Explanation: **Explanation:** The clinical and radiological presentation is classic for a **Dentigerous Cyst** (also known as a Follicular Cyst). **Why it is correct:** A dentigerous cyst is the most common developmental odontogenic cyst. It originates from the separation of the follicle from around the crown of an **unerupted tooth**. The pathognomonic radiological feature is a **well-circumscribed, unilocular radiolucency** attached to the **cemento-enamel junction (CEJ)**, typically involving the mandibular third molars or maxillary canines. Histologically, it is lined by thin, non-keratinized stratified squamous epithelium. **Why other options are incorrect:** * **Ameloblastoma:** While it commonly occurs in the molar-ramus area, it usually presents as a "soap-bubble" or "honeycomb" multilocular radiolucency and is an aggressive neoplasm rather than a simple cyst. * **Odontogenic Keratocyst (OKC):** These often show a characteristic "picket-fence" or "tombstone" appearance of the basal layer on histology and have a high recurrence rate. They typically grow along the length of the bone without causing significant expansion initially. * **Odontoma:** These are dental hamartomas rather than cysts. They appear as radiopaque masses (resembling small teeth in "compound" type or a calcified mass in "complex" type) rather than a clear radiolucency. **High-Yield Clinical Pearls for NEET-PG:** * **Most common site:** Mandibular 3rd molar > Maxillary canine. * **Radiological hallmark:** Radiolucency attached to the neck of an unerupted tooth. * **Potential complication:** If left untreated, it can transform into Ameloblastoma or Squamous Cell Carcinoma. * **Treatment:** Enucleation and extraction of the involved tooth.

Question 198: Diagnosis of dry socket is done by?

A. History (Correct Answer)
B. Clinical examination
C. Radiographs
D. None of the above

Explanation: **Explanation:** **Dry Socket (Alveolar Osteitis)** is a painful dental condition that occurs after tooth extraction when the blood clot fails to form or is prematurely dislodged, leaving the underlying bone and nerves exposed. **Why History is the Correct Answer:** The diagnosis of dry socket is primarily **clinical**, and the **history** is the most critical diagnostic tool. The hallmark of dry socket is the **timing and nature of the pain**. A patient typically reports a relatively painless first 24–48 hours post-extraction, followed by the sudden onset of severe, throbbing pain radiating to the ear or temple on the **3rd to 5th postoperative day**. This specific temporal pattern in the patient's history is pathognomonic for the condition. **Analysis of Incorrect Options:** * **Clinical Examination:** While an empty socket filled with food debris or a "grayish" appearance may be seen, these findings are not always definitive. Many sockets look "empty" during normal healing; it is the characteristic history of delayed, severe pain that confirms the diagnosis. * **Radiographs:** X-rays are generally useless for diagnosing dry socket as there are no specific radiographic changes in the bone during the acute phase. They are only used to rule out other complications like retained root fragments or sequestrum. **High-Yield Clinical Pearls for NEET-PG:** * **Most Common Site:** Mandibular third molar (wisdom tooth) extraction sites. * **Risk Factors:** Smoking, oral contraceptives (estrogen), poor oral hygiene, and excessive trauma during surgery. * **Pathophysiology:** Increased **fibrinolysis** (plasminogen to plasmin conversion) leading to the dissolution of the blood clot. * **Management:** Irrigation with saline and placement of a medicated dressing (e.g., **Zinc Oxide Eugenol** or Alveogyl). Antibiotics are usually not required unless systemic infection is present.

Question 199: What is the most common organism causing fungal infection of the oral cavity?

A. Candida (Correct Answer)
B. Blastomycosis
C. Aspergillosis
D. Cryptococcus

Explanation: **Explanation:** **1. Why Candida is the correct answer:** *Candida albicans* is the most common fungal pathogen affecting the oral cavity. It is a commensal organism found in the normal oral flora of approximately 30–50% of the population. Infection (Candidiasis or "Thrush") occurs when there is an overgrowth due to an opportunistic environment, such as immunosuppression (HIV/AIDS), prolonged antibiotic use, inhaled corticosteroids, diabetes mellitus, or xerostomia. **2. Why the other options are incorrect:** * **Blastomycosis:** This is a systemic pyogranulomatous infection caused by *Blastomyces dermatitidis*. While it can manifest with oral lesions, these are rare and usually secondary to primary pulmonary involvement. * **Aspergillosis:** While *Aspergillus* is a common fungal pathogen in the paranasal sinuses (Fungal Ball or Invasive Aspergillosis), it rarely affects the oral cavity unless the patient is severely neutropenic. * **Cryptococcus:** Caused by *Cryptococcus neoformans*, this primarily presents as meningitis or pulmonary infection in immunocompromised hosts. Oral manifestations are extremely rare. **3. Clinical Pearls for NEET-PG:** * **Most common type:** Pseudomembranous candidiasis (Thrush), characterized by "curd-like" white patches that **can be scraped off**, leaving an erythematous/bleeding base. * **Erythematous Candidiasis:** Often seen in HIV patients or under dentures (Denture Stomatitis). * **Median Rhomboid Glossitis:** Now considered a form of chronic atrophic candidiasis. * **Drug of Choice:** Topical Nystatin or Clotrimazole for mild cases; systemic Fluconazole for moderate-to-severe or immunocompromised cases. * **Diagnosis:** KOH mount showing budding yeast cells and pseudohyphae.

Question 200: What is the treatment for submandibular salivary gland duct calculi?

A. Excision of the submandibular gland
B. Opening the duct at the frenulum
C. Opening the duct and removal of the calculus (Correct Answer)
D. Excision of the gland and duct

Explanation: **Explanation:** The primary goal in managing submandibular sialolithiasis (calculi) is to preserve the gland's function while removing the obstruction. **1. Why Option C is Correct:** Most submandibular stones (80%) are located in the **Wharton’s duct**. If the stone is palpable intraorally, the treatment of choice is **Sialolithotomy**. This involves making a longitudinal incision over the duct directly above the stone, removing the calculus, and leaving the duct open (marsupialization) to allow for drainage and prevent stricture. This procedure is conservative and avoids the risks associated with major surgery. **2. Why Other Options are Incorrect:** * **Option A & D:** Excision of the submandibular gland (Sialadenectomy) is reserved for stones located within the **gland parenchyma** (hilar stones) or cases where the gland has become chronically infected and non-functional (atrophic) due to recurrent obstruction. It is not the first-line treatment for ductal stones. * **Option B:** Opening the duct specifically at the frenulum is incorrect because the incision must be made **directly over the stone** to ensure successful retrieval. Opening only at the distal end may fail to reach stones located in the middle or posterior segments of the duct. **Clinical Pearls for NEET-PG:** * **Wharton’s Duct:** The most common site for salivary stones because the duct is long, the flow is against gravity, and the saliva is more alkaline and rich in calcium/mucin. * **Diagnosis:** 80% of submandibular stones are **radiopaque** (visible on X-ray/Occlusal views), whereas 80% of parotid stones are radiolucent. * **Sialendoscopy:** This is the modern "Gold Standard" for managing small, non-palpable ductal stones. * **Bimanual Palpation:** Always perform this to locate the stone before surgery.

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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