Diseases of the Oral Cavity and Salivary Glands Practice Questions

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.

Q: What is the treatment for a child with cherubism?

Cosmetic surgery after puberty. **Explanation:** **Cherubism** is a rare, autosomal dominant fibro-osseous disorder characterized by symmetrical, non-neoplastic enlargement of the mandible and maxilla. It is caused by a mutation in the **SH3BP2 gene**. **Why Option B is Correct:** The natural history of cherubism is unique: the lesions typically appear in early childhood (2–7 years), progress until puberty, and then undergo **spontaneous regression** or stabilization as the fibrous tissue undergoes remodeling into normal bone. Therefore, the standard management is **observation**. Surgical intervention is deferred until after puberty to allow for natural regression. If significant deformity persists after skeletal maturity, **cosmetic contouring** (recontouring of the bone) is performed. **Why Other Options are Incorrect:** * **A & D (Surgical excision/En bloc dissection):** Aggressive surgery during the active growth phase is contraindicated as it can trigger rapid regrowth or cause severe dental and facial developmental issues. Surgery is only indicated earlier if there is functional impairment (e.g., airway obstruction or severe visual loss). * **C (Radiation):** Radiation therapy is strictly contraindicated due to the high risk of secondary osteosarcoma and interference with facial growth. **NEET-PG High-Yield Pearls:** * **Radiology:** Characterized by **bilateral, symmetrical multilocular radiolucencies** (soap-bubble appearance) at the angles of the mandible. * **Clinical Feature:** "Eyes upturned to heaven" sign (due to maxillary involvement stretching the skin and exposing the lower sclera). * **Histology:** Features giant cells similar to Giant Cell Granuloma. * **Inheritance:** Autosomal Dominant (SH3BP2 gene on chromosome 4p16).

Q: A businessman notices a lump in front of his ear while shaving. His wife thinks it has been present for several months. What is the most likely cause of a mass in the parotid gland in this patient?

Benign mixed tumor. **Explanation:** The most likely diagnosis for a slow-growing, painless lump in the parotid gland of an adult is a **Pleomorphic Adenoma**, also known as a **Benign Mixed Tumor**. **1. Why Benign Mixed Tumor is correct:** Pleomorphic adenoma is the **most common salivary gland tumor**, accounting for approximately 80% of all parotid neoplasms. It typically presents as a slow-growing, painless, firm, and mobile mass, often discovered incidentally (e.g., while shaving). The term "mixed tumor" refers to its histological composition of both epithelial and mesenchymal elements. **2. Why other options are incorrect:** * **Lymphoma (A):** While the parotid contains intra-nodal lymph nodes, primary salivary lymphoma is rare. It usually presents in patients with underlying autoimmune conditions like Sjögren’s syndrome. * **Squamous Cell Carcinoma (B):** Primary SCC of the parotid is rare. Malignancies usually present with rapid growth, pain, skin fixation, or facial nerve palsy—none of which are mentioned here. * **Metastatic Skin Cancer (C):** The parotid can be a site for metastasis from scalp or facial skin cancers (e.g., melanoma or SCC), but this is statistically less common than a primary benign tumor. **Clinical Pearls for NEET-PG:** * **Rule of 80s for Parotid:** 80% are in the parotid; 80% of parotid tumors are benign; 80% of those are Pleomorphic Adenomas. * **Most common site:** Superficial lobe of the parotid gland. * **Treatment of choice:** Superficial parotidectomy (Enucleation is avoided due to the risk of recurrence from pseudopod extensions). * **Malignant transformation:** If left for years, it can transform into *Carcinoma ex-pleomorphic adenoma*. * **Warthin’s Tumor:** The second most common benign tumor; typically occurs in older males, often bilateral, and associated with smoking.

Q: A painless, fluid-filled retention cyst appearing in an area of recent dental treatment may be the result of which of the following?

Injury to a salivary gland. **Explanation:** The clinical presentation described is characteristic of a **Mucocele** (Mucous extravasation cyst). **1. Why the correct answer is right:** A mucocele is a common lesion of the oral mucosa caused by the **traumatic injury to a minor salivary gland duct**. In the context of dental treatment, accidental biting, surgical trauma, or instrumentation can lacerate a duct. This leads to the leakage (extravasation) of mucus into the surrounding subepithelial connective tissue. Since the mucus is not lined by epithelium but rather by granulation tissue, it forms a painless, bluish, fluctuant, fluid-filled swelling. The lower lip is the most common site. **2. Why incorrect options are wrong:** * **Option A:** Local anesthetics are rapidly absorbed into the systemic circulation. Failure of absorption would lead to prolonged anesthesia or localized toxicity, not a fluid-filled retention cyst. * **Option B:** Allergic reactions (Type I hypersensitivity) typically present as diffuse swelling (angioedema), erythema, or itching immediately after exposure, rather than a localized, persistent cyst. * **Option C:** Post-treatment infections usually present with the classic signs of inflammation: pain, warmth, redness, and potentially purulent discharge (abscess), which contradicts the "painless" nature of this lesion. **3. NEET-PG High-Yield Pearls:** * **Ranula:** A mucocele specifically located on the floor of the mouth, arising from the **sublingual gland**. A "Plunging Ranula" extends below the mylohyoid muscle into the neck. * **Treatment:** Simple incision often leads to recurrence. The definitive treatment is **surgical excision** of the cyst along with the involved minor salivary gland. * **Most common site:** Lower lip (due to frequent trauma). It rarely occurs on the upper lip.

Q: Which of the following statements is false regarding plunging ranula?

Diagnosis is made by CT scan. ### Explanation A **Plunging Ranula** is a mucus extravasation cyst that arises from the sublingual gland and herniates through or around the **mylohyoid muscle** into the submandibular space. **Why Option B is the correct (False) statement:** While a CT scan or MRI can help visualize the extent of the lesion (showing the characteristic "tail sign"), the **diagnosis of a plunging ranula is primarily clinical**. In doubtful cases, the most definitive and cost-effective diagnostic tool is **Fine Needle Aspiration Cytology (FNAC)**. The aspirate typically shows high amylase and protein content, confirming its origin from salivary tissue. Therefore, stating that the diagnosis is "made by CT scan" is technically false in a clinical examination context. **Analysis of other options:** * **Option A (True):** It originates from the **sublingual gland** but presents as a swelling in the **submandibular** region, involving both anatomical spaces. * **Option C (True):** The definitive treatment is **surgical excision**. This must include the removal of the offending **sublingual gland** along with the cyst to prevent recurrence. Simple aspiration or marsupialization has a high failure rate. * **Option D (True):** It often presents as a **dumb-bell shaped mass**, with one portion above the mylohyoid (intraoral) and the larger "plunging" portion below it in the neck. **High-Yield Clinical Pearls for NEET-PG:** * **Anatomical Landmark:** The **mylohyoid muscle** is the key structure that a plunging ranula "perforates" or wraps around. * **Radiological Sign:** The **"Tail Sign"** on CT/MRI is pathognomonic, representing the extension of the cyst from the sublingual space into the submandibular space. * **Most Common Source:** Always the **sublingual gland**, never the submandibular gland itself. * **Differential Diagnosis:** Often confused with a cystic hygroma or dermoid cyst.

Q: A palatal abscess most commonly results from an infection of which of the following teeth?

Maxillary lateral incisors. ### Explanation The location of a dental abscess depends on the relationship between the tooth root apex and the surrounding muscle attachments. A **palatal abscess** occurs when the infection perforates the palatal cortical plate of the maxillary bone rather than the labial/buccal plate. **Why Maxillary Lateral Incisors are correct:** The roots of the **maxillary lateral incisors** are anatomically tilted distally and palatally. Their apices lie closer to the palatal cortical plate. Consequently, when an apical infection occurs, the pus follows the path of least resistance through the thinner palatal bone, resulting in a subperiosteal abscess on the hard palate. **Analysis of Incorrect Options:** * **Maxillary Central Incisors:** These teeth have roots that are generally positioned closer to the labial (front) cortical plate. Therefore, infections typically present as swelling in the labial vestibule or the upper lip. * **Maxillary Canines:** These have the longest roots in the maxillary arch. Their apices are usually covered by thick labial bone (the canine eminence). Infections here typically point labially, often involving the **canine space**, leading to swelling near the ala of the nose and lower eyelid. * **Maxillary Premolars:** While the palatal root of the first maxillary premolar can occasionally cause a palatal abscess, it is much more common for these teeth to drain into the maxillary sinus or the buccal vestibule. **Clinical Pearls for NEET-PG:** * **Palatal Abscess:** Most commonly associated with the **Maxillary Lateral Incisor** or the **Palatal root of Maxillary Molars**. * **Space Infections:** If an infection from a maxillary tooth spreads superiorly, it can lead to **Orbital Cellulitis** or **Cavernous Sinus Thrombosis** via the ophthalmic veins (retrograde spread). * **Rule of Thumb:** Most maxillary teeth drain labially/buccally; the lateral incisor is the classic exception favoring the palate.

Q: Leukoplakia with the worst prognosis is typically found on which of the following locations?

Floor of mouth. **Explanation:** Leukoplakia is a clinical term for a white patch or plaque that cannot be characterized clinically or pathologically as any other disease. While most leukoplakias are benign, the risk of malignant transformation varies significantly based on the anatomical site. **1. Why Floor of Mouth is Correct:** The **floor of the mouth** and the **ventrolateral surface of the tongue** are considered "high-risk" sites. Leukoplakia in these areas has the highest rate of malignant transformation (up to 40-50% in some studies). This is attributed to the thin, non-keratinized epithelium in these regions, which allows carcinogens (from tobacco and alcohol) dissolved in saliva to pool and penetrate the mucosal barrier more effectively. **2. Analysis of Incorrect Options:** * **Dorsum of tongue (A):** While the tongue is a common site for oral cancer, the dorsum is heavily keratinized and less susceptible to malignant change compared to the ventrolateral surface or the floor of the mouth. * **Buccal mucosa (C):** This is the most common site for leukoplakia (often associated with tobacco chewing), but it has a relatively lower rate of malignant transformation compared to the floor of the mouth. * **Palate (D):** Leukoplakia here is often associated with "reverse smoking" (Nicotina palati). While significant, it generally carries a lower risk profile than the sublingual region. **Clinical Pearls for NEET-PG:** * **Most common site for Leukoplakia:** Buccal mucosa. * **Site with highest malignant potential:** Floor of mouth > Ventrolateral tongue > Soft palate complex. * **Morphological risk:** **Speckled leukoplakia** (Erythroleukoplakia) has a much higher risk of malignancy than homogenous leukoplakia. * **Biopsy Rule:** Any leukoplakia persisting for more than 2-3 weeks after removing inciting factors must undergo biopsy to rule out dysplasia or CIS.

Q: A sialography report of a 46-year-old female is provided. Based on the findings, what is the most likely diagnosis?

Sjogren syndrome. ***Sjogren syndrome*** - Classic sialographic findings include **punctate** and **globular sialectasias** creating a characteristic **"snowstorm"** or **"cherry blossom"** pattern due to acinar destruction. - Typically affects **middle-aged females** and is associated with **autoimmune sicca syndrome** causing dry mouth and eyes. *Sialolithiasis* - Sialography would show a **filling defect** or **calculus shadow** within the ductal system, not the diffuse pattern seen in Sjögren syndrome. - Usually presents with **unilateral pain** and **swelling** during meals, particularly affecting the submandibular gland. *Normal parotid appearance* - Normal sialogram shows **smooth ductal outlines** with normal branching pattern and no evidence of sialectasias or strictures. - Would not demonstrate the **punctate** or **globular** changes characteristic of autoimmune salivary gland disease. *None of the above* - The sialographic findings described are pathognomonic for **Sjögren syndrome** in the appropriate clinical context. - The **punctate/globular sialectasias** pattern is a well-established diagnostic criterion for this **autoimmune condition**.

Q: What is the characteristic ENT manifestation of Peutz-Jeghers syndrome with benign intestinal polyps?

Perioral and buccal mucosal pigmentation. **Explanation:** **Peutz-Jeghers Syndrome (PJS)** is an autosomal dominant disorder characterized by the mutation of the **STK11 (LKB1)** gene on chromosome 19. The hallmark of this condition is the association of gastrointestinal hamartomatous polyps with distinctive mucocutaneous pigmentation. **Why Option B is Correct:** The characteristic ENT manifestation is **melanocytic hyperpigmentation** (lentigines). These appear as dark brown to bluish-black macules typically located around the mouth (**perioral**), on the lips, and specifically on the **buccal mucosa**. While skin lesions may fade after puberty, the buccal mucosal pigmentation is pathognomonic as it tends to persist throughout life, serving as a vital clinical marker for diagnosis. **Why Other Options are Incorrect:** * **A. Vocal polyp:** These are usually related to vocal abuse or smoking and have no association with PJS. * **C. Nasal polyps:** While PJS involves intestinal polyps, it does not typically manifest with sinonasal polyposis (which is more common in Samter’s triad or Cystic Fibrosis). * **D. Sensorineural hearing loss:** This is not a feature of PJS; it is associated with syndromes like Alport, Usher, or Waardenburg. **High-Yield Clinical Pearls for NEET-PG:** * **Inheritance:** Autosomal Dominant (STK11 gene). * **Polyp Type:** Hamartomatous (most common in the small intestine/jejunum). * **Complications:** Intussusception (most common), GI bleeding, and a significantly increased risk of visceral malignancies (pancreas, breast, ovary, and colon). * **Mnemonic:** **P**igmentation, **P**olyps, **P**ancreatic cancer risk (**P**eutz-Jeghers).

Question 1

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 2

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

Question 3

What is the treatment for a child with cherubism?

Accepted Answer

Cosmetic surgery after puberty

Answer

Surgical excision

Answer

Radiation

Answer

En bloc dissection

Question 4

A businessman notices a lump in front of his ear while shaving. His wife thinks it has been present for several months. What is the most likely cause of a mass in the parotid gland in this patient?

Accepted Answer

Benign mixed tumor

Answer

Lymphoma

Answer

Squamous cell carcinoma

Answer

Metastatic skin cancer

Question 5

A painless, fluid-filled retention cyst appearing in an area of recent dental treatment may be the result of which of the following?

Accepted Answer

Injury to a salivary gland

Answer

Failure of absorption of the anesthetic

Answer

Allergic reaction to agents employed

Answer

Infection occurred during treatment

Question 6

Which of the following statements is false regarding plunging ranula?

Accepted Answer

Diagnosis is made by CT scan

Answer

Seen in submandibular and sublingual glands

Answer

Treatment is surgical excision

Answer

Presents as a dumb-bell shaped mass

Question 7

A palatal abscess most commonly results from an infection of which of the following teeth?

Accepted Answer

Maxillary lateral incisors

Answer

Maxillary central incisors

Answer

Maxillary canines

Answer

Maxillary premolars

Question 8

Leukoplakia with the worst prognosis is typically found on which of the following locations?

Accepted Answer

Floor of mouth

Answer

Dorsum of tongue

Answer

Buccal mucosa

Answer

Palate

Question 9

A sialography report of a 46-year-old female is provided. Based on the findings, what is the most likely diagnosis?

Accepted Answer

Sjogren syndrome

Answer

Sialolithiasis

Answer

Normal parotid appearance

Answer

None of the above

Question 10

What is the characteristic ENT manifestation of Peutz-Jeghers syndrome with benign intestinal polyps?

Accepted Answer

Perioral and buccal mucosal pigmentation

Answer

Vocal polyp

Answer

Nasal polyps

Answer

Sensorineural hearing loss

Diseases of the Oral Cavity and Salivary Glands — MCQs

Diseases of the Oral Cavity and Salivary Glands — MCQs

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