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 171: A dentigerous cyst is associated with which of the following conditions?

A. Impacted 3rd molar
B. Impacted supernumerary tooth
C. Odontome
D. All the above (Correct Answer)

Explanation: **Explanation:** A **dentigerous cyst** (also known as a follicular cyst) is the most common type of non-inflammatory odontogenic cyst. It originates from the separation of the follicle from around the crown of an **unerupted tooth**. The pathogenesis involves the accumulation of fluid between the reduced enamel epithelium and the tooth crown. Because the cyst is fundamentally linked to any tooth that fails to erupt, it can be associated with: * **Impacted 3rd molars:** The most common site (especially mandibular). * **Impacted supernumerary teeth:** Such as a mesiodens. * **Odontomes:** These are dental hamartomas that can act as physical barriers, preventing eruption and triggering cyst formation around the crown. Therefore, **Option D** is correct as all three conditions involve unerupted dental structures. **Clinical Pearls for NEET-PG:** * **Radiological Appearance:** Characteristically presents as a well-defined, unilocular radiolucency attached to the **cemento-enamel junction (CEJ)** of an unerupted tooth. * **Most Common Site:** Mandibular 3rd molar > Maxillary canine > Maxillary 3rd molar. * **Potential Complications:** If left untreated, it may lead to pathological fractures, or rarely, transform into **Ameloblastoma**, Squamous Cell Carcinoma, or Mucoepidermoid Carcinoma. * **Treatment:** Enucleation and removal of the associated tooth.

Question 172: Which of the following is NOT true regarding sialadenitis in AIDS?

A. May present as Sjogren's syndrome
B. Unilateral parotid enlargement is common (Correct Answer)
C. Non-tender enlargement of salivary gland
D. May present as xerostomia

Explanation: **Explanation:** The correct answer is **B (Unilateral parotid enlargement is common)** because HIV-associated salivary gland disease typically presents as **bilateral**, painless, and persistent parotid enlargement. **1. Why Option B is the correct answer (False statement):** In patients with AIDS, salivary gland involvement is often part of **DILS (Diffuse Infiltrative Lymphocytosis Syndrome)**. This condition is characterized by CD8+ T-lymphocyte infiltration of the glands. The hallmark clinical presentation is **bilateral (not unilateral)**, non-tender parotid swelling. Unilateral enlargement in an HIV patient should instead raise suspicion for an abscess, obstructive stone, or neoplasm (like Kaposi sarcoma or B-cell lymphoma). **2. Analysis of Incorrect Options (True statements):** * **Option A:** HIV-associated salivary gland disease is often referred to as a **"Sjogren’s-like syndrome"** because it presents with similar symptoms (glandular enlargement and dryness). However, it differs immunologically (CD8+ infiltration in HIV vs. CD4+ in Sjogren’s) and lacks the typical autoantibodies (SS-A/SS-B). * **Option C:** The enlargement is characteristically **non-tender** and soft-to-firm because it is caused by lymphocytic infiltration and the formation of multiple **benign lymphoepithelial cysts (BLEC)**, rather than an acute bacterial infection. * **Option D:** **Xerostomia** (dry mouth) is a common complaint due to the replacement of functional acinar tissue by lymphoid infiltrates and cysts, leading to decreased salivary flow. **Clinical Pearls for NEET-PG:** * **Pathognomonic Finding:** Multiple **Benign Lymphoepithelial Cysts (BLEC)** seen on CT/MRI as "Swiss cheese" appearance in the parotid glands is highly suggestive of HIV. * **DILS Triad:** Bilateral parotid swelling, xerostomia, and generalized lymphadenopathy. * **Treatment:** Highly Active Antiretroviral Therapy (HAART) often reduces the size of the glands; aspiration or surgery is rarely required unless for cosmetic reasons or secondary infection.

Question 173: What is the most common cyst found in the oral region?

A. Medial cyst
B. Radicular cyst (Correct Answer)
C. Follicular cyst
D. Nasolabial cyst

Explanation: **Explanation:** The **Radicular cyst** (also known as a Periapical cyst) is the most common cyst of the oral cavity, accounting for approximately 50-75% of all jaw cysts. It is an **inflammatory odontogenic cyst** that arises from the epithelial rests of Malassez in the periodontal ligament. It typically develops at the apex of a non-vital (necrotic) tooth due to dental caries or trauma. **Analysis of Options:** * **Radicular Cyst (Correct):** Its high prevalence is due to the high incidence of dental caries leading to pulp necrosis and subsequent periapical inflammation. * **Follicular Cyst (Dentigerous Cyst):** This is the second most common odontogenic cyst. It originates from the reduced enamel epithelium around the crown of an **unerupted tooth** (most commonly the mandibular 3rd molar). * **Nasolabial Cyst:** A rare, non-odontogenic, soft-tissue cyst located in the nasolabial fold area. It does not involve the bone. * **Medial Cyst:** This is a non-specific term; however, "Median palatal cysts" are rare developmental cysts located in the midline of the hard palate. **High-Yield Clinical Pearls for NEET-PG:** * **Most common odontogenic cyst:** Radicular cyst. * **Most common developmental odontogenic cyst:** Follicular (Dentigerous) cyst. * **Radiological feature of Radicular cyst:** A well-defined unilocular radiolucency at the apex of a **non-vital tooth**. * **Keratocystic Odontogenic Tumor (OKC):** Known for a high recurrence rate and association with **Gorlin-Goltz Syndrome**. * **Stafne’s Bone Cavity:** A "pseudocyst" (not a true cyst) caused by an indentation of the mandible by the submandibular gland; it is always located below the inferior alveolar canal.

Question 174: What is true about Ludwig's angina?

A. Rapidly spreading cellulitis of the neck
B. H. influenzae is the most common organism
C. Edema of the floor of the mouth
D. Sublingual and submandibular spaces are involved (Correct Answer)

Explanation: **Ludwig’s Angina** is a life-threatening, rapidly spreading cellulitis (not an abscess) involving the submandibular, sublingual, and submental spaces bilaterally. ### **Explanation of Options** * **Correct Answer (D):** The hallmark of Ludwig’s Angina is the involvement of the **submandibular and sublingual spaces**. These spaces are divided by the mylohyoid muscle but communicate posteriorly. Infection typically starts in the submandibular space (often from the 2nd or 3rd molar teeth) and spreads to the sublingual space. * **Option A:** While it is a rapidly spreading cellulitis, it specifically involves the **submandibular region** rather than the general "neck." It is a "woody" or "brawny" edema that does not involve the lymph nodes. * **Option B:** The most common organisms are **Streptococcus viridans** and **Staphylococcus aureus**, often in a polymicrobial mix with anaerobes (Peptostreptococcus, Bacteroides). *H. influenzae* is more commonly associated with acute epiglottitis. * **Option C:** While edema of the floor of the mouth occurs, it is a **clinical sign**, not the defining anatomical characteristic. The involvement of the specific fascial spaces (Option D) is the definitive anatomical description. ### **High-Yield Clinical Pearls for NEET-PG** * **Source of Infection:** Dental infections (80%), specifically the **lower 2nd and 3rd molars**, as their roots lie below the mylohyoid line. * **Clinical Presentation:** "Brawny" or "Woody" induration of the neck, **tongue protrusion** (due to floor of mouth elevation), and "Hot potato voice." * **Primary Risk:** Airway obstruction is the most common cause of death. * **Management:** 1. **Airway maintenance** (Tracheostomy if needed). 2. Intravenous antibiotics. 3. **Incision and Drainage:** Indicated if there is no improvement or if fluctuation occurs (though it is primarily a cellulitis).

Question 175: All of the following are true about a ranula except:

A. Mucous extravasation cyst arising from sublingual gland
B. Treated by marsupialization
C. Most common structure injured during ranula surgery is submandibular duct
D. Diagnosed by MRI (Correct Answer)

Explanation: **Explanation:** A **ranula** is a clinical term for a pseudocyst (mucous extravasation cyst) that occurs in the floor of the mouth, typically arising from the **sublingual gland**. **Why Option D is the correct answer (False statement):** Diagnosis of a ranula is primarily **clinical**. While imaging like MRI or CT can be used to assess the extent of a "plunging ranula" (one that extends into the neck through the mylohyoid muscle), it is not the standard or required method for diagnosing a simple ranula. The diagnosis is usually made by the characteristic "frog’s belly" appearance—a translucent, bluish, fluctuant swelling in the floor of the mouth. **Analysis of other options:** * **Option A:** True. It is most commonly a **mucous extravasation cyst** caused by trauma or obstruction of the ducts of the sublingual gland (Ducts of Rivinus). * **Option B:** True. **Marsupialization** is a standard surgical treatment where the cyst is opened and the edges are sutured to the oral mucosa to allow continuous drainage. However, for recurrent cases, excision of the sublingual gland is the definitive treatment. * **Option C:** True. The **submandibular duct (Wharton’s duct)** runs in close proximity to the sublingual gland in the floor of the mouth, making it the most vulnerable structure during surgical excision or marsupialization. **Clinical Pearls for NEET-PG:** * **Plunging Ranula:** Occurs when mucus extravasates below the **mylohyoid muscle**, presenting as a neck swelling in the submandibular space. * **Treatment of Choice:** For simple ranula, marsupialization; for plunging or recurrent ranula, **excision of the sublingual gland**. * **Aspiration:** Typically reveals thick, straw-colored fluid with high amylase content.

Question 176: Inflammation of the dorsal root ganglion and vesicular eruption of the skin and mucous membrane in the area supplied by an affected sensory nerve is characteristic of what condition?

A. Herpes zoster (Correct Answer)
B. Herpes simplex
C. Uveoparotid fever
D. Aphthous stomatitis

Explanation: ### Explanation **Correct Option: A. Herpes zoster** Herpes zoster (Shingles) is caused by the reactivation of the **Varicella-Zoster Virus (VZV)**, which remains latent in the **dorsal root ganglia** or cranial nerve ganglia after a primary chickenpox infection. When the virus reactivates, it travels down the sensory nerve, causing intense inflammation of the ganglion and a characteristic **vesicular eruption** strictly following the **dermatomal distribution** of that nerve. In the head and neck, the trigeminal nerve (especially the ophthalmic division) is frequently involved. **Why other options are incorrect:** * **B. Herpes simplex:** While it causes vesicular eruptions, it typically presents as recurrent localized lesions (like cold sores) and does not typically involve the widespread inflammation of the dorsal root ganglion or a strict dermatomal pattern characteristic of Zoster. * **C. Uveoparotid fever (Heerfordt's syndrome):** This is a manifestation of **Sarcoidosis** characterized by the triad of parotid enlargement, uveitis, and facial nerve palsy. It is a granulomatous disease, not a viral vesicular eruption. * **D. Aphthous stomatitis:** These are common, painful, non-infectious **ulcers** (not vesicles) found on non-keratinized oral mucosa. They do not involve sensory ganglia or skin eruptions. **NEET-PG Clinical Pearls:** * **Ramsay Hunt Syndrome (Herpes Zoster Oticus):** Reactivation involving the **geniculate ganglion** of the Facial Nerve (CN VII). Clinical triad: Facial palsy, vesicles in the external auditory canal/auricle, and vestibulocochlear symptoms (tinnitus/vertigo). * **Tzanck Smear:** Used for diagnosis; shows **multinucleated giant cells** and Cowdry Type A inclusion bodies. * **Hutchinson’s Sign:** Vesicles on the tip of the nose indicating involvement of the nasociliary nerve, predicting a high risk of ocular complications.

Question 177: Which of the following is not a type of dental caries based on the senility of the lesion?

A. Rampant caries
B. Arrested caries
C. Recurrent caries (Correct Answer)
D. None of the above

Explanation: ### Explanation Dental caries are classified based on several criteria, including the **severity and rate of progression** (often referred to in clinical texts as the "senility" or chronicity of the lesion). **Why "Recurrent Caries" is the correct answer:** Recurrent caries (also known as secondary caries) is a classification based on the **location/site** of the lesion relative to a previous restoration. It occurs at the margins or underneath an existing filling or crown. It does not describe the speed or "age" of the disease process itself, but rather its anatomical recurrence. **Analysis of Incorrect Options:** * **Rampant Caries:** This is a classification based on **severity and rate**. It refers to a sudden, widespread, and rapidly progressing form of decay that involves multiple teeth, including those usually immune to caries (e.g., lower incisors). Examples include Nursing Bottle Caries or Radiation Caries. * **Arrested Caries:** This is also based on the **rate of progression**. It refers to a lesion that was once active but has become static or "dormant" due to changes in the oral environment (e.g., improved hygiene or remineralization). The dentin typically appears hard, polished, and dark brown. **High-Yield Clinical Pearls for NEET-PG:** * **Nursing Bottle Caries:** Typically affects the maxillary incisors first; the mandibular incisors are usually spared due to the protective action of the tongue and saliva. * **Radiation Caries:** A complication of radiotherapy for Head and Neck cancers, primarily caused by xerostomia (reduced salivary flow). * **Incipient Caries:** The earliest stage of a caries lesion, characterized by a "white spot" appearance, which is still reversible through remineralization. * **Classification Tip:** Always distinguish between classifications based on **Site** (G.V. Black’s), **Rate** (Acute/Rampant vs. Chronic/Arrested), and **Previous History** (Primary vs. Recurrent).

Question 178: A tumor arising from the crown of an unerupted tooth is called what?

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

Explanation: ### Explanation **Correct Answer: C. Dentigerous cyst** **1. Why it is correct:** A **Dentigerous cyst** (also known as a follicular cyst) is an odontogenic cyst that develops from the accumulation of fluid between the reduced enamel epithelium and the **crown of an unerupted (impacted) tooth**. It characteristically attaches to the **cemento-enamel junction (CEJ)**. Radiographically, it appears as a well-defined unilocular radiolucency surrounding the crown of a tooth, most commonly the mandibular third molar or maxillary canine. **2. Why the other options are incorrect:** * **Periapical cyst (Radicular cyst):** This is an inflammatory cyst that arises at the **apex (root tip)** of a non-vital, erupted tooth, usually due to dental caries or pulpitis. It does not involve the crown of an unerupted tooth. * **Odontogenic keratocyst (OKC):** Arises from the dental lamina. While it can sometimes involve an unerupted tooth, it is not defined by its attachment to the crown. It is known for its aggressive behavior, high recurrence rate, and association with **Gorlin-Goltz syndrome**. * **Ameloblastoma:** This is a true odontogenic neoplasm (tumor), not a simple cyst. While it can arise from the wall of a dentigerous cyst (mural ameloblastoma), it typically presents with a characteristic **"soap-bubble" or "honeycomb"** multilocular appearance on X-ray. **3. High-Yield NEET-PG Pearls:** * **Most common developmental odontogenic cyst:** Dentigerous cyst. * **Most common inflammatory odontogenic cyst:** Radicular (Periapical) cyst. * **Key Radiographic Sign:** A unilocular radiolucency larger than 3-4 mm surrounding an impacted tooth crown. * **Potential Complications:** If left untreated, a dentigerous cyst can transform into an Ameloblastoma or Squamous Cell Carcinoma. * **Treatment:** Enucleation and extraction of the associated tooth.

Question 179: Unilateral TMJ ankylosis is associated with the following features, except:

A. Multiple carious teeth
B. Facial asymmetry with fullness on the normal side of the mandible (Correct Answer)
C. Chin deviated towards the affected side
D. Prominent antegonial notch on the affected side

Explanation: ### Explanation **Concept:** Unilateral Temporomandibular Joint (TMJ) ankylosis, especially when occurring during the growth period, leads to significant craniofacial deformities due to the restriction of mandibular growth on the affected side. **1. Why Option B is the Correct Answer (The "Except" statement):** In unilateral TMJ ankylosis, the **affected side** appears full and rounded due to the crowding of soft tissues and a short, thick ramus. Conversely, the **normal (unaffected) side** appears flat and elongated. Therefore, the statement "fullness on the normal side" is clinically incorrect. **2. Analysis of Other Options:** * **Option A (Multiple carious teeth):** Due to the inability to open the mouth (trismus), oral hygiene is severely compromised, and dental procedures are difficult to perform, leading to rampant dental caries. * **Option C (Chin deviated towards the affected side):** The normal side of the mandible continues to grow, while the affected side is stunted. This differential growth "pushes" the chin toward the diseased/shorter side. * **Option D (Prominent antegonial notch):** This is a classic radiographic and clinical feature. It occurs due to the compensatory downward pull of the masseter and medial pterygoid muscles at the angle of the mandible in an attempt to open the mouth against the fused joint. **3. NEET-PG High-Yield Pearls:** * **Bird-Face Deformity:** Seen in **bilateral** TMJ ankylosis due to severe retrognathia (micrognathia). * **Most Common Cause:** Trauma (especially condylar fractures) is the #1 cause, followed by infections (Otitis media). * **Treatment of Choice:** Gap arthroplasty or Interpositional arthroplasty. * **Rule of Thumb:** In unilateral cases, "Deviation is towards the side of the lesion; Fullness is on the side of the lesion."

Question 180: Areca nut chewing is an etiological factor in which of the following conditions?

A. Leukoedema
B. Oral submucous fibrosis (Correct Answer)
C. Erythema multiforme
D. Oral lichen planus

Explanation: **Explanation:** **Oral Submucous Fibrosis (OSMF)** is a chronic, progressive, and premalignant condition of the oral cavity characterized by juxta-epithelial inflammatory reaction followed by fibroelastic change of the lamina propria. **Why Areca Nut is the Cause:** The primary etiological factor is the chewing of **areca nut** (betel nut). Areca nut contains alkaloids (such as **arecoline**) that stimulate fibroblasts to increase collagen synthesis. Simultaneously, it contains flavonoids (tannins) that inhibit collagenase activity, leading to a net accumulation of collagen in the oral mucosa. This results in the characteristic "vertical bands" and restricted mouth opening (trismus). **Analysis of Incorrect Options:** * **Leukoedema (A):** A benign anatomical variation of the oral mucosa (milky white appearance) that disappears on stretching. It is not related to areca nut; it is more common in smokers and dark-skinned individuals. * **Erythema Multiforme (C):** An acute, self-limiting hypersensitivity reaction (Type IV) often triggered by infections (HSV) or drugs (NSAIDs, Sulfonamides). It presents with "target lesions" on the skin and hemorrhagic crusting of lips. * **Oral Lichen Planus (D):** A chronic inflammatory T-cell mediated autoimmune condition. While it presents with Wickham’s striae, its etiology is idiopathic or related to stress/immune dysfunction, not areca nut. **High-Yield Clinical Pearls for NEET-PG:** * **Clinical Features:** Burning sensation on eating spicy food (earliest symptom), blanched/marble-like mucosa, and restricted tongue protrusion. * **Pre-malignant Potential:** OSMF has a high malignant transformation rate (approx. 7–13%) to Squamous Cell Carcinoma. * **Management:** Cessation of habit, intralesional steroids (to reduce inflammation), and Hyaluronidase (to break down collagen). Surgical release is reserved for severe trismus.

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

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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