Diseases of the Oral Cavity and Salivary Glands Practice Questions

Q: Which of the following conditions may necessitate emergency tracheostomy to prevent suffocation?

Ludwig's angina. **Explanation:** **Ludwig’s Angina** is a rapidly spreading, life-threatening cellulitis of the submandibular, submental, and sublingual spaces (bilaterally). The primary danger lies in the **posterior and superior displacement of the tongue** caused by the swelling of the floor of the mouth. This leads to acute upper airway obstruction. While initial management involves aggressive antibiotics and airway monitoring, a rapidly progressing case may necessitate an **emergency tracheostomy** (or cricothyroidotomy) to bypass the mechanical obstruction and prevent suffocation. **Analysis of Incorrect Options:** * **Cellulitis (A):** General skin cellulitis (e.g., of the limb) does not involve the airway. Even facial cellulitis rarely causes the rapid, deep-space mechanical obstruction seen in Ludwig’s Angina. * **Cavernous Sinus Thrombosis (C):** This is a late complication of facial infections (danger triangle of the face). It presents with proptosis, chemosis, and cranial nerve palsies (III, IV, V1, V2, VI), but it does not cause airway obstruction. * **Maxillary Sinusitis (D):** This is an inflammation of the paranasal sinuses. While it causes pain and nasal discharge, it does not compromise the oropharyngeal or laryngeal airway. **High-Yield Clinical Pearls for NEET-PG:** * **Source:** Most commonly arises from an odontogenic infection (usually the **2nd or 3rd mandibular molar**). * **Clinical Sign:** "Woody" or "brawny" edema of the neck; patients often present with drooling and a "hot potato" voice. * **Microbiology:** Usually polymicrobial (Streptococci, Staphylococci, and anaerobes). * **Management Priority:** Airway maintenance is the #1 priority, followed by IV antibiotics and surgical drainage if pus is present.

Q: What is the management for an established Frey's syndrome?

Tympanic neurectomy. ### Explanation **Frey’s Syndrome (Auriculotemporal Syndrome)** occurs due to the aberrant regeneration of parasympathetic fibers of the **auriculotemporal nerve** after parotid surgery. These fibers, which normally stimulate salivary secretion, mistakenly grow to innervate the sweat glands of the overlying skin, leading to gustatory sweating and flushing. **Why Tympanic Neurectomy is Correct:** The parasympathetic pathway for salivation begins in the inferior salivatory nucleus and travels via the **Jacobson’s nerve (tympanic branch of the glossopharyngeal nerve)** through the middle ear plexus. **Tympanic neurectomy** involves sectioning these fibers as they pass over the promontory of the middle ear. By interrupting the preganglionic parasympathetic supply before it reaches the otic ganglion and auriculotemporal nerve, the stimulus for gustatory sweating is abolished. **Analysis of Incorrect Options:** * **A. Facial nerve stimulation:** This is used intraoperatively to identify the nerve or postoperatively to assess nerve integrity; it has no role in treating autonomic dysfunction. * **B. Physiotherapy:** While useful for facial nerve palsy (re-education), it cannot redirect misdirected autonomic nerve fibers. * **C. Antidepressants:** These have no physiological basis for treating localized gustatory sweating. **High-Yield Clinical Pearls for NEET-PG:** * **Diagnosis:** Confirmed by the **Minor’s Starch-Iodine Test** (affected area turns blue-black upon eating). * **Prophylaxis:** Interposition of barriers (e.g., SMAS flap, acellular dermis, or Temporalis fascia) during parotidectomy. * **Medical Management:** Topical 2% glycopyrrolate or **Botulinum toxin A** (currently the most effective non-surgical treatment). * **Nerve involved:** Auriculotemporal nerve (branch of the Mandibular nerve, V3).

Q: Hairy leukoplakia is characterized by?

EBV infection. **Explanation:** **Hairy Leukoplakia (HL)** is a distinctive white lesion of the oral mucosa, primarily affecting the lateral borders of the tongue. 1. **Why Option B is correct:** The condition is caused by the **Epstein-Barr Virus (EBV)**. In immunocompromised states, EBV undergoes productive replication in the squamous epithelium of the tongue, leading to the characteristic corrugated or "hairy" appearance. It is considered an opportunistic infection. 2. **Why other options are incorrect:** * **Option A:** HL is typically **asymptomatic (painless)**. Patients usually discover it incidentally or due to its texture. * **Option C:** There is a **strong association with HIV**. It is one of the most common oral manifestations of HIV/AIDS and often serves as an early clinical sign of progression to AIDS or a declining CD4 count. * **Option D:** Unlike "Oral Leukoplakia," Hairy Leukoplakia has **no malignant potential**. It is not a pre-cancerous lesion and does not require aggressive surgical excision. **High-Yield Clinical Pearls for NEET-PG:** * **Appearance:** White, non-scrapable, vertical ridges (corrugated) on the lateral margins of the tongue. * **Diagnosis:** Usually clinical; biopsy shows hyperkeratosis, acanthosis, and "balloon cells" in the upper stratum spinosum. * **Treatment:** Generally not required unless for cosmetic reasons (Acyclovir or Podophyllin can be used), but its presence mandates an immediate workup for HIV/immunodeficiency. * **Differentiating Feature:** Unlike Oral Candidiasis, Hairy Leukoplakia **cannot** be scraped off.

Q: Areas of carcinoma of the oral mucosa can be identified by staining with which of the following?

2% toluidine blue. **Explanation:** **1. Why 2% Toluidine Blue is Correct:** Toluidine blue (also known as tolonium chloride) is a **vital acidophilic dye** that has a high affinity for nucleic acids. Malignant and dysplastic cells have a significantly higher DNA/RNA content and increased nuclear-to-cytoplasmic ratios compared to normal cells. When applied to the oral mucosa, the dye selectively stains these areas of high nucleic acid concentration, highlighting suspicious lesions (carcinoma in situ or invasive squamous cell carcinoma) as dark blue. This is a common chair-side screening tool used to demarcate biopsy sites. **2. Why the Other Options are Incorrect:** * **1% Zinc Chloride:** This is primarily used as an astringent or in certain chemical cautery pastes (like Mohs paste), but it has no diagnostic staining properties for malignancy. * **2% Silver Nitrate:** This is a caustic agent used for chemical cauterization of aphthous ulcers or to control minor bleeding (hemostasis). It stains tissues black but is not selective for cancer cells. * **Gentian Violet:** This is an antifungal and antiseptic dye used to treat oral candidiasis (thrush). While it stains the mucosa purple, it does not differentiate between normal and malignant cells. **3. High-Yield Clinical Pearls for NEET-PG:** * **False Positives:** Toluidine blue can also stain inflammatory lesions (like ulcers) because of the high cellular turnover; therefore, a "re-stain" after 10–14 days of anti-inflammatory treatment is often recommended. * **Lugol’s Iodine:** Another vital stain used in the oral cavity and esophagus. Normal squamous epithelium (rich in glycogen) stains brown, while **malignant cells (glycogen-poor) remain unstained.** * **Gold Standard:** Remember that while toluidine blue helps in identifying the site, the definitive diagnosis of oral cancer always requires a **histopathological examination (biopsy).**

Q: A patient presents with a history of recurrent episodes of pain and swelling in the mandibular posterior region and is diagnosed with pericoronitis. The partially erupted 3rd molar was vital. Radiographical examination revealed a well-defined radiolucency on the distal aspect of the affected tooth. What is the most likely diagnosis?

Paradental cyst.. ### Explanation The correct diagnosis is **Paradental Cyst** (also known as Craig’s cyst). **1. Why Paradental Cyst is correct:** A paradental cyst is an inflammatory odontogenic cyst that typically occurs on the **distal or buccal aspect** of a **partially erupted mandibular third molar** with a history of **pericoronitis**. * **Key Diagnostic Feature:** The tooth involved is **vital**. * **Pathogenesis:** Inflammation (pericoronitis) stimulates the epithelial rests of Malassez or the reduced enamel epithelium, leading to cyst formation. Radiographically, it appears as a well-defined radiolucency distal to the tooth. **2. Why other options are incorrect:** * **Dentigerous Cyst:** This is a developmental cyst that attaches to the **cemento-enamel junction (CEJ)** and encloses the crown of an **unerupted** tooth. In this case, the tooth is partially erupted and the radiolucency is specifically distal. * **Eruption Cyst:** This is essentially a soft-tissue analog of a dentigerous cyst. It presents as a bluish, fluctuant swelling on the alveolar ridge over an erupting tooth, rather than a deep distal radiolucency. * **Periapical (Radicular) Cyst:** This is the most common inflammatory cyst, but it occurs at the **apex** of a **non-vital** tooth due to pulp necrosis. The question specifies the tooth is vital. **Clinical Pearls for NEET-PG:** * **Location:** Most common in the mandibular 3rd molar (distal) or mandibular 1st/2nd molars (buccal—where it is called a **Buccal Bifurcation Cyst**). * **Vitality:** Always check tooth vitality; if the tooth is vital and there is a history of pericoronitis, think Paradental Cyst. * **Treatment:** Enucleation of the cyst; extraction of the involved third molar is usually necessary.

Q: What is the recommended treatment for a mucocele on the lower lip?

Excision with removal of adjacent salivary glands. ### Explanation **Correct Answer: C. Excision with removal of adjacent salivary glands** **1. Why Option C is Correct:** A mucocele (specifically the **extravasation type**, which is most common on the lower lip) occurs due to the traumatic rupture of a minor salivary gland duct, leading to the accumulation of mucus in the surrounding submucosal tissue. The definitive treatment is **surgical excision of the cyst**. However, to prevent **recurrence**, it is mandatory to remove the **offending minor salivary gland** and any adjacent minor glands involved in the field. If the gland is left behind, it will continue to secrete mucus, leading to the formation of a new mucocele. **2. Why Other Options are Incorrect:** * **Incision (A):** Simply incising the lesion (I&D) will lead to temporary decompression, but the lesion will almost certainly recur as soon as the wound heals because the underlying secretory gland remains functional. * **Excision (B):** While excision of the cyst wall is necessary, "excision" alone (without addressing the minor salivary glands) is incomplete and carries a high risk of recurrence. * **Biopsy (D):** While a biopsy can confirm the diagnosis, it is not a "treatment." Since mucoceles are usually diagnosed clinically based on their characteristic bluish, translucent appearance and history of trauma, the primary goal is therapeutic excision. **3. NEET-PG High-Yield Pearls:** * **Most common site:** Lower lip (due to frequent trauma/biting). * **Ranula:** A mucocele occurring in the floor of the mouth, usually arising from the **sublingual gland**. * **Plunging Ranula:** A clinical variant that extends below the mylohyoid muscle into the neck, presenting as a soft cervical swelling. * **Histology:** Extravasation mucoceles lack a true epithelial lining (they are "pseudocysts" lined by granulation tissue).

Q: What is the most malignant tumor of the salivary glands?

Adenoid cystic carcinoma. **Explanation:** The correct answer is **Adenoid cystic carcinoma (C)**. While Mucoepidermoid carcinoma is the most *common* malignant salivary gland tumor, Adenoid cystic carcinoma is considered the most *malignant* or aggressive due to its unique biological behavior. It is characterized by **perineural invasion** (spreading along nerve sheaths), which leads to high rates of local recurrence and late distant metastasis, most commonly to the lungs. **Analysis of Options:** * **Pleomorphic adenoma (A):** This is the most common **benign** tumor of the salivary glands (usually the parotid). While it can undergo malignant transformation (*Carcinoma ex pleomorphic adenoma*), the tumor itself is benign. * **Warthin tumor (B):** Also known as Papillary Cystadenoma Lymphomatosum, this is a **benign** tumor almost exclusively found in the parotid gland. It is strongly associated with smoking and is frequently bilateral. * **Acinic cell tumor (D):** This is a low-grade malignancy. It has a much better prognosis compared to Adenoid cystic carcinoma and rarely exhibits aggressive perineural spread. **NEET-PG High-Yield Pearls:** * **Most common overall tumor:** Pleomorphic adenoma. * **Most common malignant tumor:** Mucoepidermoid carcinoma. * **Most common site for salivary tumors:** Parotid gland. * **Site with highest malignancy rate:** Sublingual gland (approx. 80% are malignant). * **Adenoid cystic carcinoma hallmark:** "Swiss-cheese" appearance (cribriform pattern) on histopathology and a high propensity for cranial nerve involvement (e.g., Facial nerve palsy).

Q: Mucous retention cysts are most commonly found on which anatomical location?

Lower lip. **Explanation:** **Mucous Retention Cysts** (often used interchangeably with **Mucocele**) are common lesions of the oral cavity caused by the accumulation of saliva due to trauma or obstruction of a minor salivary gland duct. 1. **Why Lower Lip is Correct:** The **lower lip** is the most common site for a mucocele (specifically the extravasation type), accounting for over **70-80% of cases**. This is primarily due to the high frequency of accidental trauma (biting the lip) which ruptures the minor salivary gland ducts, leading to the leakage of mucus into the surrounding subepithelial tissue. 2. **Analysis of Incorrect Options:** * **Floor of the mouth:** While common, a mucous cyst in this location is specifically termed a **Ranula** (arising from the sublingual gland). It is less frequent than the lower lip mucocele. * **Buccal mucosa:** Mucoceles can occur here, but the incidence is significantly lower than on the lip. * **All of the above:** While these cysts *can* occur in all these locations, the question asks for the **most common** site, making "Lower lip" the specific correct choice. **NEET-PG High-Yield Pearls:** * **Pathogenesis:** Most common type is **Extravasation mucocele** (lacks an epithelial lining; caused by trauma). The **Retention type** (true cyst with epithelial lining) is rarer and usually seen in older patients. * **Clinical Feature:** Presents as a painless, bluish, translucent, fluctuant swelling. * **Treatment of Choice:** Complete surgical excision along with the offending minor salivary gland to prevent recurrence. * **Ranula:** A "Plunging Ranula" occurs when the cyst herniates through the mylohyoid muscle into the neck.

Q: What is the most common cause of trismus due to infection in a muscle?

Medial pterygoid muscle. **Explanation:** **1. Why Medial Pterygoid is Correct:** Trismus (lockjaw) is the inability to open the mouth due to muscle spasms. In the context of infection, the **Medial Pterygoid muscle** is the most common culprit. This is primarily due to its anatomical proximity to the **parapharyngeal space** and the **pterygomandibular space**. Infections arising from the lower third molars (pericoronitis) or complications from an Inferior Alveolar Nerve Block (IANB) often lead to inflammation or abscess formation in these spaces. Because the medial pterygoid forms the medial boundary of the pterygomandibular space, it is the first muscle to undergo inflammatory irritation (myositis), leading to protective muscle guarding and severe trismus. **2. Why Other Options are Incorrect:** * **Masseter Muscle:** While the masseter is a powerful elevator of the mandible and is involved in trismus, it is located laterally on the ramus. It is more commonly involved in trismus due to external trauma or masseteric space infections, which are less frequent than pterygomandibular infections. * **Temporalis Muscle:** This muscle is involved in elevating and retracting the mandible. While it can be affected in deep temporal space infections, these are clinically rarer than infections affecting the medial pterygoid. * **All of the above:** While all these muscles are "muscles of mastication" that can cause trismus, the question asks for the *most common* cause due to infection, which specifically points to the medial pterygoid. **Clinical Pearls for NEET-PG:** * **Most common cause of trismus (overall):** Impacted third molar (pericoronitis). * **Most common muscle involved in trismus:** Medial Pterygoid. * **Quinsy (Peritonsillar Abscess):** A classic ENT cause of trismus due to irritation of the medial pterygoid muscle. * **Tetanus:** Causes "Risus Sardonicus" due to sustained spasms of facial and masticatory muscles.

Question 1

Which of the following conditions may necessitate emergency tracheostomy to prevent suffocation?

Accepted Answer

Ludwig's angina

Answer

Cellulitis

Answer

Cavernous sinus thrombosis

Answer

Maxillary sinusitis

Question 2

What is the management for an established Frey's syndrome?

Accepted Answer

Tympanic neurectomy

Answer

Facial nerve stimulation

Answer

Physiotherapy

Answer

Antidepressants

Question 3

Hairy leukoplakia is characterized by?

Accepted Answer

EBV infection

Answer

Pain

Answer

No association with HIV

Answer

Pre-cancerous

Question 4

Areas of carcinoma of the oral mucosa can be identified by staining with which of the following?

Accepted Answer

2% toluidine blue

Answer

1% zinc chloride

Answer

2% silver nitrate

Answer

Gentian violet

Question 5

A patient presents with a history of recurrent episodes of pain and swelling in the mandibular posterior region and is diagnosed with pericoronitis. The partially erupted 3rd molar was vital. Radiographical examination revealed a well-defined radiolucency on the distal aspect of the affected tooth. What is the most likely diagnosis?

Accepted Answer

Paradental cyst.

Answer

Dentigerous cyst.

Answer

Eruption cyst.

Answer

Periapical cyst.

Question 6

What is the recommended treatment for a mucocele on the lower lip?

Accepted Answer

Excision with removal of adjacent salivary glands

Answer

Incision

Answer

Excision

Answer

Biopsy

Question 7

Which statement with respect to mucoceles is false?

Accepted Answer

Preventing recurrence requires removal of associated major salivary gland.

Answer

Pseudocysts contain viscous saliva but lack a true epithelial lining.

Answer

Patients relate a history of filling, rupture and refilling.

Answer

Preventing recurrence requires removal of associated minor salivary gland.

Question 8

What is the most malignant tumor of the salivary glands?

Accepted Answer

Adenoid cystic carcinoma

Answer

Pleomorphic adenoma

Answer

Warthin tumor

Answer

Acinic cell tumor

Question 9

Mucous retention cysts are most commonly found on which anatomical location?

Accepted Answer

Lower lip

Answer

Floor of the mouth

Answer

Buccal mucosa

Answer

All of the above

Question 10

What is the most common cause of trismus due to infection in a muscle?

Accepted Answer

Medial pterygoid muscle

Answer

Masseter muscle

Answer

Temporalis muscle

Answer

All of the above

Diseases of the Oral Cavity and Salivary Glands — MCQs

Diseases of the Oral Cavity and Salivary Glands — MCQs

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