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 131: All of the following lesions of the oral cavity are premalignant except?

A. Erythroplakia
B. Hyperplastic candidiasis
C. Sideropenia
D. Aphthous ulcer (Correct Answer)

Explanation: **Explanation:** The correct answer is **Aphthous ulcer**. Aphthous ulcers (canker sores) are common, painful, inflammatory ulcers of the oral mucosa. They are **not** premalignant; they are self-limiting, do not show cellular atypia, and do not progress to squamous cell carcinoma. **Why the other options are Premalignant Lesions/Conditions:** * **Erythroplakia:** This is the most dangerous premalignant lesion of the oral cavity. It presents as a red velvety patch. Histologically, it shows severe dysplasia or carcinoma-in-situ in over 90% of cases, carrying a much higher risk of malignancy than leukoplakia. * **Hyperplastic Candidiasis:** Also known as Candidal Leukoplakia, this is a chronic fungal infection. It is considered premalignant because the chronic inflammation and fungal metabolites can induce epithelial dysplasia. * **Sideropenia (Plummer-Vinson Syndrome):** Chronic iron deficiency (sideropenia) leads to mucosal atrophy of the upper gastrointestinal tract. This atrophic epithelium is highly susceptible to carcinogens, significantly increasing the risk of post-cricoid carcinoma and oral cancer. **High-Yield Clinical Pearls for NEET-PG:** * **Potentially Malignant Disorders (PMDs):** Include Leukoplakia (most common), Erythroplakia (highest risk), Oral Submucous Fibrosis (OSMF), and Lichen Planus (erosive type). * **OSMF:** Characterized by "juxta-epithelial hyalinization" and restricted mouth opening; strongly associated with betel nut chewing. * **Speckled Leukoplakia:** A mix of red and white patches (Erythroleukoplakia) which has a higher malignant transformation rate than homogenous leukoplakia. * **Site Risk:** The floor of the mouth and the ventrolateral tongue are the highest-risk sites for malignant transformation in the oral cavity.

Question 132: True ankyloglossia occurs as a result of which of the following?

A. Union between the tongue and floor of the mouth or the ventral surface of the tongue (Correct Answer)
B. Absence of the lingual frenum
C. Lingual frenum attached to the tip of the tongue
D. A short lingual frenum

Explanation: **Explanation:** **Ankyloglossia (Tongue-tie)** is a congenital anomaly characterized by an abnormally short or thick lingual frenum that restricts the displacement of the tongue. However, it is clinically categorized into two types: **Partial** and **True (Complete)** ankyloglossia. 1. **Why Option A is Correct:** **True (Complete) Ankyloglossia** is a rare condition where the tongue is physically fused to the floor of the mouth. This occurs due to the failure of the primary tongue bud to separate from the floor of the mouth during embryogenesis. This extensive **union between the ventral surface of the tongue and the floor of the mouth** results in total restriction of tongue movement, severely affecting speech and deglutition. 2. **Why Other Options are Incorrect:** * **Option B:** Absence of the lingual frenum is not a feature of ankyloglossia; rather, it is the abnormal presence or attachment of the frenum that causes the condition. * **Option C & D:** These describe **Partial Ankyloglossia**, which is the more common clinical presentation. In these cases, the lingual frenum is either too short or attached too far anteriorly (near the tip), causing a "heart-shaped" notch upon protrusion. **High-Yield Clinical Pearls for NEET-PG:** * **Clinical Feature:** Difficulty in protruding the tongue beyond the lower incisors and impaired articulation of sibilants and lingual sounds (e.g., t, d, z, s, n, l). * **Treatment:** The procedure of choice for partial ankyloglossia is **Frenuloplasty** or **Frenectomy** (Z-plasty is often preferred to gain length). * **Complications:** If left untreated, it can lead to breastfeeding difficulties in infants and orthodontic issues (e.g., open bite) in children.

Question 133: Frey's syndrome is due to faulty regeneration of damaged nerve fibers. The source of that injured nerve is:

A. hypoglossal nerve
B. trigeminal nerve (Correct Answer)
C. vagus nerve
D. glossopharyngeal nerve

Explanation: **Explanation:** **Frey’s Syndrome** (also known as Auriculotemporal Syndrome) is a common complication following parotidectomy. It occurs due to the aberrant regeneration of damaged nerve fibers. **Why the Correct Answer is Right:** The nerve involved is the **Auriculotemporal nerve**, which is a branch of the **Mandibular division (V3) of the Trigeminal nerve**. * **Normal Physiology:** The auriculotemporal nerve carries parasympathetic fibers (from the otic ganglion) to the parotid gland for salivation and sympathetic fibers to the sweat glands of the overlying skin. * **Pathophysiology:** After parotid surgery, the parasympathetic fibers are severed. During regeneration, they "misfire" and grow into the empty neurilemmal sheaths of the sympathetic fibers. * **Result:** Stimuli that normally cause salivation (like seeing or smelling food) now cause localized sweating and flushing in the preauricular area (Gustatory Sweating). **Why Other Options are Wrong:** * **Hypoglossal Nerve (CN XII):** Supplies motor innervation to the tongue muscles; injury leads to tongue deviation, not gustatory sweating. * **Vagus Nerve (CN X):** Involved in the gag reflex and parasympathetic supply to thoracic/abdominal viscera; not related to parotid innervation. * **Glossopharyngeal Nerve (CN IX):** While the preganglionic parasympathetic fibers originate here (Jacobson’s nerve), the *injured* nerve fiber that regenerates incorrectly at the surgical site is the postganglionic **Auriculotemporal nerve (Trigeminal branch)**. **High-Yield Clinical Pearls:** * **Diagnostic Test:** **Minor’s Starch-Iodine Test** (the area turns blue-black upon sweating). * **Treatment:** Topical anticholinergics (Glycopyrrolate) or **Botulinum toxin** injection (most effective). * **Prevention:** Interposition of a barrier (e.g., SMAS flap or Sternocleidomastoid flap) during surgery.

Question 134: A subperiosteal abscess that penetrates deeply is most commonly seen after the extraction of which tooth?

A. Maxillary third molar
B. Mandibular third molar (Correct Answer)
C. Maxillary first molar
D. Mandibular first molar

Explanation: ### Explanation The correct answer is **Mandibular third molar (Option B)**. **Why it is correct:** The anatomical relationship between the tooth roots and the **mylohyoid muscle** attachment is the key factor. The roots of the mandibular third molar (wisdom tooth) often extend below the level of the mylohyoid line on the internal surface of the mandible. When an infection or subperiosteal abscess occurs following extraction, it can easily penetrate the thin lingual plate. Because the root tips are situated inferior to the mylohyoid muscle, the infection bypasses the oral cavity and spreads directly into the **submandibular space** or the **parapharyngeal space**, leading to deep neck infections like **Ludwig’s Angina**. **Why the other options are incorrect:** * **Maxillary third molar (A):** Infections here typically spread to the infratemporal space or the buccal space, but they do not commonly lead to the deep, life-threatening subperiosteal abscesses seen in the mandible. * **Maxillary first molar (C):** Infections usually spread to the maxillary sinus (odontogenic sinusitis) or the buccal space. * **Mandibular first molar (D):** The roots of the first molar are generally located *above* the mylohyoid line. Therefore, an abscess here is more likely to drain into the **sublingual space** (above the muscle) rather than penetrating deeply into the submandibular space. **High-Yield Clinical Pearls for NEET-PG:** * **Ludwig’s Angina:** A rapidly spreading cellulitis of the submandibular, sublingual, and submental spaces. The most common cause is the **mandibular second or third molar**. * **Danger Space:** Located between the alar fascia and prevertebral fascia; infections here can spread from the pharynx to the mediastinum. * **Quinsy (Peritonsillar Abscess):** Most common deep neck infection in young adults, usually following tonsillitis, not tooth extraction.

Question 135: A 15-year-old boy shows an inverted pear-shaped radiolucency between the upper lateral incisor and cuspid. The teeth are normal in all aspects. What is the most likely diagnosis?

A. Globulomaxillary cyst (Correct Answer)
B. Nasopalatine cyst
C. Aneurysmal bone cyst
D. Dentigerous cyst

Explanation: ### Explanation **Correct Option: A. Globulomaxillary cyst** The **Globulomaxillary cyst** is a classic "non-odontogenic" developmental cyst (though now often considered odontogenic in origin) characterized by a pathognomonic **inverted pear-shaped radiolucency** found between the **maxillary lateral incisor and the canine (cuspid)**. A key diagnostic feature is that it causes the roots of these teeth to diverge, but the **teeth themselves remain vital** and normal in appearance. **Why the other options are incorrect:** * **B. Nasopalatine cyst:** Also known as an Incisive Canal Cyst, it presents as a **heart-shaped radiolucency** located in the midline of the anterior maxilla, between the central incisors. * **C. Aneurysmal bone cyst:** This is a reactive lesion, not a developmental cyst. It typically presents as a "soap-bubble" or multilocular radiolucency and is more common in the mandible than the maxilla. * **D. Dentigerous cyst:** This is an odontogenic cyst that always encloses the **crown of an unerupted tooth** (most commonly the third molar or maxillary canine). In this clinical scenario, the teeth are described as normal and erupted. **High-Yield Clinical Pearls for NEET-PG:** * **Radiographic Shapes:** * *Inverted Pear:* Globulomaxillary Cyst. * *Heart-shaped:* Nasopalatine Duct Cyst. * *Scalloped border around roots:* Traumatic/Simple Bone Cyst. * **Vitality Testing:** In Globulomaxillary cysts, the involved teeth are **vital**. If the teeth are non-vital, the diagnosis shifts toward a Radicular (periapical) cyst. * **Modern Classification:** Many pathologists now classify "Globulomaxillary" lesions as Lateral Periodontal Cysts or Keratocystic Odontogenic Tumors (OKC) based on histology, but the "inverted pear" description remains a classic exam trigger for Globulomaxillary cyst.

Question 136: Saroj, a 32-year-old female from a rural background, presented with a history of chronic tobacco chewing since 14 years of age. She now has difficulty in opening her mouth. On oral examination, no ulcers are seen. What is the most probable diagnosis?

A. Submucous oral fibrosis (Correct Answer)
B. Carcinoma of buccal mucosa
C. TM joint arthritis
D. Trigeminal nerve paralysis

Explanation: ### Explanation **Correct Answer: A. Submucous Oral Fibrosis (OSMF)** **Why it is correct:** Oral Submucous Fibrosis is a chronic, insidious, premalignant condition characterized by juxta-epithelial inflammatory reaction followed by **progressive fibrosis of the lamina propria and deeper connective tissues**. * **Etiology:** It is strongly associated with areca nut and tobacco chewing (common in rural India). * **Clinical Presentation:** The hallmark is **trismus (difficulty in opening the mouth)** due to the formation of vertical fibrous bands in the buccal mucosa, soft palate, and faucial pillars. * **Key Finding:** The absence of ulcers and the presence of a blanched, "marble-like" appearance of the mucosa with restricted tongue mobility are classic features. **Why incorrect options are wrong:** * **B. Carcinoma of buccal mucosa:** While tobacco is a risk factor, malignancy typically presents as a non-healing ulcer or an exophytic growth. Trismus in malignancy usually indicates advanced stage (invasion of masticatory muscles). * **C. TM joint arthritis:** This would present with joint pain, clicking sounds, and tenderness over the pre-auricular region, rather than a history of tobacco-induced mucosal changes. * **D. Trigeminal nerve paralysis:** The trigeminal nerve (CN V) provides motor supply to the muscles of mastication. Paralysis would cause weakness in jaw closure or deviation of the jaw, not progressive mechanical restriction (fibrosis). **High-Yield Pearls for NEET-PG:** * **Pathogenesis:** Areca nut alkaloids (e.g., Arecoline) stimulate fibroblasts to produce collagen, while flavonoids inhibit collagenase, leading to excessive collagen deposition. * **Pre-malignant potential:** OSMF has a high malignant transformation rate (approx. 7–13%). * **Clinical Sign:** "Burning sensation" in the mouth on eating spicy food is often the earliest symptom. * **Treatment:** Cessation of habit, intralesional steroids (Hyaluronidase/Dexamethasone), and surgical release of bands in severe cases.

Question 137: Which of the following, if left untreated, is most likely to result in a periapical lesion?

A. Internal resorption
B. Focal reversible pulpitis
C. Acute suppurative pulpitis (Correct Answer)
D. Chronic hyperplastic pulpitis

Explanation: **Explanation:** The progression of dental pathology typically follows a sequence: Dental caries → Pulpitis → Pulp Necrosis → **Periapical Lesion** (Abscess/Granuloma/Cyst). **Why Acute Suppurative Pulpitis is correct:** Acute suppurative pulpitis is a severe, irreversible inflammatory condition characterized by pus formation within the dental pulp. Because the pulp is encased in a rigid mineralized chamber, the increasing pressure from inflammatory exudate and suppuration rapidly compromises blood flow, leading to **pulp necrosis**. Once the pulp becomes necrotic, the infection travels through the apical foramen into the periapical tissues, resulting in a **periapical abscess or lesion**. **Analysis of Incorrect Options:** * **Focal Reversible Pulpitis:** This is the earliest stage of inflammation. If the stimulus (like a small cavity) is removed, the pulp heals. It does not progress to the apex unless it becomes irreversible. * **Internal Resorption:** This is an idiopathic vascular phenomenon where dentin is resorbed from within the pulp chamber (often seen as a "pink spot"). While it can lead to perforation, it is not primarily an infectious process leading to periapical pathology. * **Chronic Hyperplastic Pulpitis (Pulp Polyp):** This occurs in young teeth with open apices and large carious exposures. The pulp proliferates into a "polyp" rather than undergoing necrosis. Because it is an open system, pressure does not build up, making periapical involvement less common than in acute suppurative forms. **NEET-PG High-Yield Pearls:** * **Definition:** A periapical lesion is the body's defense response to microbes exiting the root canal system. * **Clinical Sign:** The hallmark of acute suppurative pulpitis is intense, throbbing pain that is **exacerbated by heat and relieved by cold** (due to contraction of gases/exudate). * **Sequelae:** If an acute periapical abscess is not drained, it may lead to **Ludwig’s Angina** (if involving mandibular molars) or **Maxillary Sinusitis** (if involving maxillary premolars/molars).

Question 138: A 60-year-old male patient presents with a parotid lump and facial weakness (House Brackmann grade 6). A fine needle aspiration biopsy is arranged under ultrasound guidance. What is the likely cytology report?

A. Pleomorphic adenoma (Correct Answer)
B. Warthin's tumor
C. Mucoepidermoid carcinoma
D. Oncocytic adenoma

Explanation: ### Explanation The correct answer is **Pleomorphic Adenoma**. **1. Why Pleomorphic Adenoma is correct:** In NEET-PG, this question tests your knowledge of the **"Statistical Probability vs. Clinical Presentation"** rule. * **Pleomorphic Adenoma** is the most common salivary gland tumor (80% of all parotid tumors). * While facial nerve palsy (HB Grade 6) is a classic sign of malignancy (suggesting infiltration), Pleomorphic Adenoma can occasionally cause facial weakness due to its size, pressure effect, or secondary infection. * However, the most critical point for examiners is that even if a tumor presents with malignant features, the **most common tumor overall** remains the most likely finding on cytology unless a specific malignant cell type is described. **2. Why other options are incorrect:** * **Warthin’s Tumor:** The second most common benign tumor. It is typically found in elderly males (smokers) and is often bilateral or multicentric, but it rarely ever causes facial nerve palsy. * **Mucoepidermoid Carcinoma:** This is the most common **malignant** salivary gland tumor. While it is more likely to cause facial nerve palsy than a benign tumor, it is statistically less common than Pleomorphic Adenoma. * **Oncocytic Adenoma:** A rare benign tumor composed of oncocytes; it does not typically present with facial nerve involvement. **3. Clinical Pearls for NEET-PG:** * **Most common parotid tumor:** Pleomorphic Adenoma (Benign Mixed Tumor). * **Most common site for minor salivary gland tumors:** Palate. * **Malignancy Rule:** The smaller the salivary gland, the higher the chance of malignancy (Sublingual > Submandibular > Parotid). * **Facial Nerve Palsy:** In a parotid mass, this is a "Red Flag" sign strongly suggestive of malignancy (usually Adenoid Cystic Carcinoma or Mucoepidermoid Carcinoma), but for MCQ purposes, always prioritize the most frequent pathology unless cytology confirms malignancy.

Question 139: Which of the following increases the risk of salivary gland tumors?

A. Radiotherapy to head and neck
B. Exposure to silica dust
C. Early menarche and nulliparity
D. All of the above (Correct Answer)

Explanation: ### Explanation The etiology of salivary gland tumors is multifactorial, involving environmental, occupational, and hormonal influences. **1. Radiotherapy to Head and Neck (Option A):** Ionizing radiation is the most well-established risk factor for salivary gland neoplasms, particularly **Mucoepidermoid carcinoma**. Patients treated with radiotherapy for conditions like tinea capitis, acne, or lymphoid hyperplasia in the past show a significantly higher incidence of both benign and malignant salivary tumors after a latent period of 15–20 years. **2. Exposure to Silica Dust (Option B):** Occupational exposure to certain chemicals and dust is linked to salivary malignancies. Specifically, exposure to **silica dust** (common in mining and construction), rubber manufacturing, and certain woodworking chemicals has been shown to increase the risk of developing salivary gland cancer. **3. Early Menarche and Nulliparity (Option C):** Salivary glands are known to be sensitive to the hormonal environment. Epidemiological studies suggest that prolonged exposure to endogenous estrogen—characterized by **early menarche, late menopause, and nulliparity**—is associated with an increased risk of salivary gland tumors. This is similar to the hormonal risk profile seen in breast cancer. ### NEET-PG High-Yield Pearls: * **Most common salivary gland tumor:** Pleomorphic Adenoma (Parotid is the most common site). * **Most common malignant salivary tumor:** Mucoepidermoid Carcinoma (in both adults and children). * **Warthin’s Tumor (Adenolymphoma):** Strongly associated with **smoking** and typically occurs in the tail of the parotid in elderly males. * **Adenoid Cystic Carcinoma:** Known for **perineural invasion** and "Swiss-cheese" appearance on histology. * **Radiation sensitivity:** The parotid gland is the most sensitive salivary gland to radiation-induced oncogenesis.

Question 140: Death in Ludwig's angina occurs due to which of the following?

A. Sepsis
B. Respiratory obstruction (Correct Answer)
C. Cavernous sinus thrombosis
D. Carotid blow-out

Explanation: **Explanation:** **Ludwig’s Angina** is a rapidly spreading, life-threatening cellulitis involving the submandibular, sublingual, and submental spaces bilaterally. It is typically odontogenic in origin (usually the 2nd or 3rd mandibular molars). **1. Why Respiratory Obstruction is the Correct Answer:** The primary cause of death in Ludwig’s Angina is **acute airway obstruction**. As the sublingual space becomes involved, the floor of the mouth becomes edematous and firm (woody hard). This pushes the tongue **superiorly and posteriorly**, leading to mechanical blockage of the oropharynx. Rapidly progressing laryngeal edema further exacerbates the risk of asphyxia. **2. Analysis of Incorrect Options:** * **Sepsis (Option A):** While sepsis and septic shock can occur as the infection spreads to the mediastinum or bloodstream, they are secondary complications. Airway compromise occurs much faster and is the most immediate threat to life. * **Cavernous Sinus Thrombosis (Option C):** This is a classic complication of infections in the "danger area of the face" or ethmoid/sphenoid sinusitis, but it is not a typical feature of submandibular space infections. * **Carotid Blow-out (Option D):** This is a rare, terminal complication of deep neck space infections (like parapharyngeal abscess) involving erosion of the carotid artery, but it is not the characteristic cause of death in Ludwig’s Angina. **Clinical Pearls for NEET-PG:** * **Key Clinical Sign:** "Woody" or "Brawny" edema of the neck with a protruding tongue. * **Management Priority:** The first step is always **Airway Maintenance** (Tracheostomy is often preferred over intubation due to distorted anatomy). * **Microbiology:** Usually a polymicrobial infection (Streptococci, Staphylococci, and anaerobes). * **Radiology:** X-ray neck (lateral view) may show the "Steeple sign" or soft tissue swelling, but clinical diagnosis is paramount.

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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