Diseases of the Oral Cavity and Salivary Glands — MCQs

A 45-year-old man presents with a small mass in his oral cavity. Physical examination reveals left facial nerve palsy and a firm, mobile, painless mass in the left parapharyngeal space. Biopsy of the oral cavity mass shows chondromyxoid stroma and epithelium. Which of the following best explains this mass?

Q66Easy

Which of the following is not a true cyst?

Q67Medium

Which jaw cyst is premalignant?

Q68Easy

A white persistent patch in the mouth most commonly indicates which of the following?

Q69Medium

Which of the following statements about salivary gland tumors is false?

Q70Easy

Frey's syndrome is due to involvement of which nerve?

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

Question 61: Which of the following drug classes is essential in the management of dry socket?

A. Analgesics (Correct Answer)
B. Antibiotics
C. Antihistaminics
D. Antacids

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 from the socket. This exposes the underlying bone and nerve endings to the oral environment. **Why Analgesics are the Correct Answer:** The primary clinical feature of dry socket is **intense, radiating pain** that typically begins 3–5 days post-extraction. Since the condition is an **inflammatory process** rather than a primary infection, the mainstay of management is symptomatic relief. Treatment involves irrigation of the socket with saline and the placement of a medicated dressing (e.g., Zinc Oxide Eugenol), supplemented by systemic **Analgesics** (NSAIDs) to manage the severe pain until the socket heals by secondary intention. **Why Other Options are Incorrect:** * **Antibiotics:** Dry socket is not a primary bacterial infection; it is a failure of clot formation/retention. Routine use of systemic antibiotics is not indicated unless there is evidence of spreading cellulitis or the patient is immunocompromised. * **Antihistaminics:** These have no role in managing alveolar osteitis as the pathophysiology does not involve an allergic or histamine-mediated response. * **Antacids:** These are unrelated to the localized inflammatory process of a dental socket. **High-Yield Clinical Pearls for NEET-PG:** * **Risk Factors:** Smoking, oral contraceptives (estrogen increases fibrinolysis), traumatic extraction, and mandibular third molar extractions. * **Pathophysiology:** Increased **fibrinolytic activity** (plasminogen to plasmin conversion) leads to the dissolution of the blood clot. * **Clinical Presentation:** Empty-looking socket, "halitosis" (foul odor), and severe pain radiating to the ear. * **Management Gold Standard:** Local debridement and **Obtundent dressing** (Alvogyl).

Question 62: Pericoronitis is most commonly seen in relation to which of the following dental conditions?

A. Impacted third molars
B. Around an incompletely erupted crown (Correct Answer)
C. Completely erupted crowns
D. None of the above

Explanation: **Explanation:** **Pericoronitis** is the inflammation of the soft tissues (the gingival flap or operculum) surrounding the crown of a tooth. **Why Option B is correct:** The condition occurs most frequently **around an incompletely erupted crown**. When a tooth has only partially broken through the gum line, a pocket of soft tissue called an **operculum** remains over the occlusal surface. This space acts as a "food trap," accumulating bacterial plaque and debris that are nearly impossible to clean. The resulting infection leads to pain, swelling, and sometimes trismus (lockjaw). **Analysis of Incorrect Options:** * **Option A (Impacted third molars):** While pericoronitis is most commonly associated with mandibular third molars (wisdom teeth), the *state* of eruption is the defining factor. A completely impacted tooth (buried under bone/soft tissue) does not communicate with the oral cavity and thus cannot develop pericoronitis. It is only when the tooth is **partially erupted** that the infection occurs. * **Option C (Completely erupted crowns):** Once a tooth is fully erupted, the gingival attachment is firm around the neck of the tooth, eliminating the operculum and the space for debris entrapment. **Clinical Pearls for NEET-PG:** * **Most Common Site:** Mandibular third molars (lower wisdom teeth). * **Microbiology:** Usually a mixed infection (aerobes and anaerobes like *Prevotella*). * **Complications:** Can lead to peritonsillar abscess, Ludwig’s angina, or parapharyngeal space infection if left untreated. * **Management:** Saline irrigation and antibiotics for acute phases; **Operculectomy** (removal of the flap) or extraction of the tooth for definitive treatment.

Question 63: Denture sore mouth is caused by which of the following microorganisms?

A. Actinomyces
B. Candida albicans (Correct Answer)
C. Blastomyces
D. None of the above

Explanation: **Explanation:** **Denture Sore Mouth**, also known as **Chronic Atrophic Candidiasis**, is a common form of oral candidiasis. It is primarily caused by an overgrowth of **Candida albicans** (Option B). The condition typically occurs under ill-fitting or poorly cleaned dentures. The space between the denture base and the palatal mucosa creates a warm, moist, and anaerobic environment with low pH, which promotes the proliferation of Candida. Clinically, it presents as diffuse erythema and edema of the mucosa covered by the denture, often without the typical white "curd-like" patches seen in pseudomembranous candidiasis. **Analysis of Incorrect Options:** * **Option A (Actinomyces):** These are Gram-positive anaerobic bacteria responsible for Actinomycosis ("Lumpy Jaw"). They cause chronic granulomatous lesions with sulfur granules, not generalized mucosal soreness under dentures. * **Option C (Blastomyces):** This is a systemic fungal infection (Blastomycosis) that primarily affects the lungs. While it can have oral manifestations, they usually present as chronic non-healing ulcers or verrucous lesions, not as denture-related stomatitis. **Clinical Pearls for NEET-PG:** * **Newton’s Classification:** Used to grade Denture Stomatitis (Type I: Localized inflammation; Type II: Diffuse erythema; Type III: Papillary hyperplasia). * **Predisposing Factors:** Poor oral hygiene, continuous denture wear (not removing them at night), and xerostomia. * **Management:** Improving denture hygiene, soaking dentures in antifungal solutions (e.g., Nystatin), and ensuring a proper fit. * **Key Association:** Often associated with **Angular Cheilitis** (Perleche), which is also frequently caused by *C. albicans*.

Question 64: True regarding Warthin's tumor?

A. Shows a hot spot on technetium-99m scan (Correct Answer)
B. Most common tumor of minor salivary glands
C. Most common malignant tumor
D. Common in females

Explanation: **Explanation:** **Warthin’s Tumor (Papillary Cystadenoma Lymphomatosum)** is the second most common benign tumor of the parotid gland. **Why Option A is Correct:** Warthin’s tumor is unique because it is an **oncocytic tumor**. The cells contain a high density of mitochondria which actively take up and retain **Technetium-99m pertechnetate**. Unlike most other salivary tumors which appear as "cold" (non-functional) areas, Warthin’s tumor (and Oncocytoma) shows up as a **"hot spot"** on a radionuclide scan. **Analysis of Incorrect Options:** * **Option B:** The most common tumor of the minor salivary glands is **Pleomorphic Adenoma** (benign) or **Adenoid Cystic Carcinoma** (malignant). Warthin’s tumor almost exclusively occurs in the parotid gland (specifically the tail). * **Option C:** Warthin’s tumor is a **benign** neoplasm. The most common malignant tumor of the salivary glands is **Mucoepidermoid Carcinoma**. * **Option D:** Warthin’s tumor is significantly more **common in males** (though the gap is narrowing) and is strongly associated with **smoking**. **High-Yield Clinical Pearls for NEET-PG:** * **Location:** Most common tumor to occur **bilaterally** (10%) or multicentrically. * **Origin:** Arises from salivary gland tissue entrapped in parotid lymph nodes during embryogenesis. * **Histology:** Characterized by a **double layer of oncocytic epithelium** and a dense **lymphoid stroma** with germinal centers. * **Risk Factor:** Smoking is the most significant risk factor. * **Treatment:** Superficial parotidectomy or Enucleation (low recurrence rate).

Question 65: A 45-year-old man presents with a small mass in his oral cavity. Physical examination reveals left facial nerve palsy and a firm, mobile, painless mass in the left parapharyngeal space. Biopsy of the oral cavity mass shows chondromyxoid stroma and epithelium. Which of the following best explains this mass?

A. Once excised, no recurrence occurs.
B. The mass represents a benign cystic tumor with germinal centers.
C. The mass represents the most common malignant tumor in the salivary glands.
D. The mass represents the most common salivary gland tumor. (Correct Answer)

Explanation: ### Explanation The clinical presentation and histopathology point toward **Pleomorphic Adenoma** (Benign Mixed Tumor). **1. Why the Correct Answer is Right:** The biopsy finding of **chondromyxoid stroma** (mesenchymal component) and **epithelium** (epithelial component) is pathognomonic for Pleomorphic Adenoma. It is the **most common salivary gland tumor** overall, accounting for approximately 80% of parotid tumors. While typically found in the superficial lobe of the parotid, it can arise from the deep lobe, presenting as a **parapharyngeal space mass** that bulges into the oral cavity/oropharynx. Although benign, deep lobe tumors can occasionally compress the facial nerve, though frank palsy is more common in malignancy. **2. Why the Incorrect Options are Wrong:** * **Option A:** Pleomorphic adenomas have a high rate of **recurrence** if simple enucleation is performed. This is due to "pseudopods" (finger-like projections) and a friable capsule that can rupture, seeding the surgical field. * **Option B:** This describes **Warthin’s Tumor** (Adenolymphoma), which is characterized by a double layer of oncocytic epithelium and a dense lymphoid stroma with germinal centers. * **Option C:** The most common malignant salivary gland tumor is **Mucoepidermoid Carcinoma**. While Pleomorphic Adenoma is the most common tumor overall, it is histologically benign. **3. High-Yield Clinical Pearls for NEET-PG:** * **Most common site:** Parotid gland (Superficial lobe). * **Most common minor salivary gland site:** Palate. * **Carcinoma ex-pleomorphic adenoma:** A malignant transformation (usually into an adenocarcinoma) that should be suspected if a long-standing stable mass suddenly grows rapidly or causes nerve palsy. * **Treatment of choice:** Superficial parotidectomy (with nerve preservation). Never perform an incisional biopsy; use FNAC instead.

Question 66: Which of the following is not a true cyst?

A. Hemorrhagic cyst (Correct Answer)
B. Median palatal cyst
C. Globulomaxillary cyst
D. Nasolabial cyst

Explanation: ### Explanation The fundamental distinction between a "true" cyst and a "pseudocyst" lies in the presence of an **epithelial lining**. A true cyst is a pathological cavity lined by epithelium, whereas a pseudocyst lacks this lining. **1. Why Hemorrhagic Cyst is the correct answer:** The **Hemorrhagic cyst** (also known as a Simple Bone Cyst or Traumatic Bone Cyst) is a **pseudocyst**. It is an empty or fluid-filled cavity within the bone that lacks an epithelial lining. Pathologically, it is often just a space surrounded by bony walls, sometimes containing a thin connective tissue membrane or blood remnants. Since it lacks epithelium, it is not a "true" cyst. **2. Analysis of Incorrect Options:** * **Median Palatal Cyst:** A true developmental odontogenic cyst located in the midline of the hard palate. It is lined by stratified squamous or respiratory epithelium. * **Globulomaxillary Cyst:** Historically described as a true non-odontogenic cyst appearing as an inverted pear-shaped radiolucency between the maxillary lateral incisor and canine. It is lined by epithelium. * **Nasolabial Cyst:** A true soft tissue cyst (extraosseous) located in the nasolabial fold area, lined by pseudostratified columnar epithelium. **3. NEET-PG High-Yield Pearls:** * **Other Pseudocysts to remember:** Stafne’s bone cavity, Aneurysmal bone cyst (ABC), and Mucous extravasation cysts (Mucocele). * **Radiological Sign:** Hemorrhagic cysts often show **scalloping** between the roots of teeth on an X-ray, but the teeth remain vital. * **Dermoid Cyst:** This is a true cyst and is a common differential for swellings in the floor of the mouth (midline). * **Ranula:** A mucous extravasation pseudocyst in the floor of the mouth arising from the sublingual gland.

Question 67: Which jaw cyst is premalignant?

A. Radicular cyst
B. Dental cyst
C. Odontogenic keratocyst (Correct Answer)
D. Dentigerous cyst

Explanation: **Explanation:** **Odontogenic Keratocyst (OKC)**, recently also known as Keratocystic Odontogenic Tumor (KCOT), is considered premalignant because of its aggressive clinical behavior, high recurrence rate, and its potential to undergo neoplastic transformation into Squamous Cell Carcinoma. Unlike other cysts, its lining is derived from the **dental lamina** and possesses an innate growth potential similar to a benign tumor. Histologically, it is characterized by a thin, friable wall and a parakeratinized stratified squamous epithelium. **Why other options are incorrect:** * **Radicular Cyst (Option A) & Dental Cyst (Option B):** These are synonymous. They are the most common inflammatory odontogenic cysts, usually occurring at the apex of a non-vital tooth. They are inflammatory in origin, not neoplastic, and have a very low potential for malignant change. * **Dentigerous Cyst (Option D):** This is a follicular cyst that surrounds the crown of an unerupted tooth (most commonly the mandibular 3rd molar). While it can occasionally transform into an Ameloblastoma or Mucoepidermoid carcinoma, it is primarily considered a developmental cyst rather than a classic premalignant lesion like OKC. **High-Yield Clinical Pearls for NEET-PG:** * **Gorlin-Goltz Syndrome:** Multiple OKCs are a hallmark of this syndrome (along with Basal Cell Carcinomas and bifid ribs). * **Aspiration:** OKC often contains a "cheesy" or "creamy" white material (keratin) with low soluble protein levels (<4g/dL). * **Radiology:** Typically appears as a well-defined multilocular or unilocular radiolucency, often in the **posterior body or ramus of the mandible**. * **Treatment:** Due to high recurrence, treatment often involves enucleation with **Carnoy’s solution** application or marsupialization.

Question 68: A white persistent patch in the mouth most commonly indicates which of the following?

A. Mucormycosis
B. Streptococcal infection (Correct Answer)
C. Erythroplakia
D. None of the above

Explanation: The correct answer is **B. Streptococcal infection**. ### **Explanation** A persistent white patch in the oral cavity is clinically defined as **Leukoplakia**. However, in the context of acute infections, a white patch or exudate on the tonsils or oropharynx is most commonly associated with **Group A Beta-Hemolytic Streptococcus (GABHS)**. In the clinical setting of a "white patch" appearing as a pseudomembrane or exudative coating, streptococcal pharyngitis/tonsillitis is the most frequent bacterial cause encountered in general practice. ### **Analysis of Options** * **A. Mucormycosis:** This is a fulminant fungal infection typically seen in immunocompromised or uncontrolled diabetic patients. It is characterized by **black eschar** (necrosis) due to angioinvasion, rather than a simple white patch. * **C. Erythroplakia:** This refers to a persistent **red patch** in the oral cavity. While it is a significant premalignant condition, it does not present as a white lesion. (Note: Leukoplakia is the term for a white patch). * **D. None of the above:** Incorrect, as Streptococcal infection is a recognized cause of white exudative patches. ### **NEET-PG High-Yield Pearls** * **Leukoplakia:** Defined by WHO as a "white patch or plaque that cannot be characterized clinically or pathologically as any other disease." It is the most common **premalignant** lesion of the oral cavity. * **Erythroplakia:** Has a much higher risk of malignancy (up to 90% show dysplasia or carcinoma) compared to leukoplakia. * **Membranous Tonsillitis:** Differential diagnosis for a white/greyish membrane includes **Diphtheria** (bleeds on removal), **Infectious Mononucleosis** (Epstein-Barr Virus), and **Vincent’s Angina**. * **Oral Candidiasis (Thrush):** A white patch that **can be scraped off**, leaving an erythematous base.

Question 69: Which of the following statements about salivary gland tumors is false?

A. Mucoepidermoid carcinoma is the most common malignant tumor of salivary glands.
B. The most common neoplasm of salivary glands in children is pleomorphic adenoma. (Correct Answer)
C. MRI is the best imaging investigation for salivary gland neoplasms.
D. FNAC is the best diagnostic modality for parotid swelling.

Explanation: ### **Explanation** **1. Why Option B is the Correct (False) Statement:** While **Pleomorphic Adenoma** is the most common *benign* tumor in children, it is not the most common neoplasm overall. In the pediatric population, the most common salivary gland neoplasm is actually **Hemangioma** (a non-epithelial benign tumor). If the question specifically refers to *malignant* neoplasms in children, **Mucoepidermoid Carcinoma** takes the top spot. Therefore, stating Pleomorphic Adenoma is the most common neoplasm is factually incorrect. **2. Analysis of Other Options:** * **Option A (True):** **Mucoepidermoid carcinoma** is indeed the most common malignant salivary gland tumor in both adults and children. It most frequently involves the parotid gland. * **Option C (True):** **MRI** is the gold standard for imaging salivary tumors because of its superior soft-tissue contrast. It helps in assessing nerve involvement (especially the Facial nerve), deep lobe extension, and perineural spread. * **Option D (True):** **FNAC** is the initial diagnostic modality of choice for parotid swellings. It has high sensitivity and specificity (approx. 90%) for differentiating benign from malignant lesions. *Note: Incisional biopsy is contraindicated in parotid tumors due to the risk of tumor seeding and facial nerve injury.* ### **High-Yield Clinical Pearls for NEET-PG:** * **80% Rule:** 80% of salivary tumors occur in the **Parotid**; 80% of parotid tumors are **Pleomorphic Adenoma**; 80% of these occur in the **superficial lobe**. * **Warthin’s Tumor:** Also known as Papillary Cystadenoma Lymphomatosum. It is the second most common benign tumor, often bilateral, associated with smoking, and shows "hot spots" on Technetium-99m scan. * **Adenoid Cystic Carcinoma:** Known for its **perineural invasion** (causing pain/palsy) and "Swiss-cheese" appearance on histology. * **Frey’s Syndrome:** A common post-parotidectomy complication diagnosed by the **Minor’s Starch-Iodine test**.

Question 70: Frey's syndrome is due to involvement of which nerve?

A. Lingual nerve
B. Inferior alveolar nerve
C. Auriculotemporal nerve (Correct Answer)
D. Nerve to mylohyoid

Explanation: **Explanation:** **Frey’s Syndrome (Gustatory Sweating)** is a common complication following parotidectomy or trauma to the parotid region. It occurs due to the **aberrant regeneration** of nerve fibers. **Why Auriculotemporal Nerve is Correct:** The auriculotemporal nerve (a branch of the mandibular nerve, V3) carries two types of fibers: 1. **Parasympathetic fibers:** Secretomotor to the parotid gland (via the otic ganglion). 2. **Sympathetic fibers:** To the sweat glands and blood vessels of the overlying skin. During surgery, these fibers are severed. During healing, the parasympathetic fibers mistakenly grow into the distal sheaths of the sympathetic fibers. Consequently, a stimulus intended for salivation (seeing or smelling food) results in localized **sweating and flushing** of the skin over the parotid area. **Why Other Options are Incorrect:** * **Lingual Nerve:** Provides sensory innervation to the anterior 2/3 of the tongue and carries taste (via chorda tympani). It is not involved in parotid innervation. * **Inferior Alveolar Nerve:** Supplies the mandibular teeth and the chin (mental nerve). It does not have a secretomotor role for the parotid. * **Nerve to Mylohyoid:** A branch of the inferior alveolar nerve that supplies the mylohyoid and the anterior belly of the digastric muscle. **Clinical Pearls for NEET-PG:** * **Diagnosis:** Confirmed by the **Minor’s Starch-Iodine Test** (the area turns blue-black upon sweating). * **Treatment:** Topical anticholinergics (Glycopyrrolate) or **Botulinum toxin** injections (most effective). * **Prevention:** Interposition of a barrier (e.g., SMAS flap or acellular dermal matrix) during parotidectomy.

Practice by Chapter

Stomatitis

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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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