Diseases of the Oral Cavity and Salivary Glands Practice Questions

Q: Mucooceles are rarely seen in which of the following locations?

Upper lip. **Explanation:** A **mucocele** is a common clinical condition involving the accumulation of mucus due to the rupture of a minor salivary gland duct (extravasation cyst) or, less commonly, the blockage of the duct (retention cyst). **Why the Upper Lip is the Correct Answer:** Mucooceles occur most frequently in areas prone to minor trauma, which leads to ductal rupture. The **lower lip** is the most common site (approx. 70–80%) because it is frequently bitten or traumatized against the teeth. In contrast, the **upper lip** is rarely traumatized in this manner. Clinically, a minor salivary gland swelling on the upper lip is statistically more likely to be a **salivary gland neoplasm** (like a Pleomorphic Adenoma or Canalicular Adenoma) rather than a mucocele. **Analysis of Incorrect Options:** * **Lower Lip:** This is the **most common** site for mucoceles. It is a high-yield fact that any cystic swelling on the lower lip is a mucocele until proven otherwise. * **Buccal Mucosa:** This is a relatively common site, often occurring along the line of occlusion due to accidental biting. * **Floor of the Mouth:** A mucocele in this location is specifically called a **Ranula** (usually arising from the sublingual gland). While less common than the lower lip, it is still more frequent than upper lip mucoceles. **High-Yield Clinical Pearls for NEET-PG:** * **Most common site:** Lower lip (lateral to midline). * **Ranula:** A mucocele on the floor of the mouth; "Plunging Ranula" occurs when it herniates through the mylohyoid muscle into the neck. * **Histology:** Most mucoceles are **Extravasation cysts** (lacking an epithelial lining, surrounded by granulation tissue). * **Differential Diagnosis:** If you see a swelling on the **upper lip**, always suspect a **salivary gland tumor** first.

Q: What is the treatment of choice for pleomorphic adenoma?

Superficial parotidectomy. **Explanation:** **Pleomorphic Adenoma** (Mixed Tumor) is the most common benign tumor of the salivary glands, most frequently involving the superficial lobe of the parotid gland. **Why Superficial Parotidectomy is the Correct Choice:** The treatment of choice for a pleomorphic adenoma located in the superficial lobe is **superficial parotidectomy** (removal of the gland superficial to the facial nerve). This approach is preferred because pleomorphic adenomas possess a **false capsule** with microscopic finger-like projections (pseudopods) extending into the surrounding tissue. A wide margin of healthy tissue must be removed to ensure these projections are cleared, preventing recurrence. **Why Other Options are Incorrect:** * **Excision of tumor (Enucleation):** Simple enucleation is contraindicated. Because of the pseudopods mentioned above, "shelling out" the tumor leaves behind microscopic disease, leading to a very high recurrence rate (up to 45%). * **Radical Parotidectomy:** This involves the sacrifice of the facial nerve. It is reserved for malignant tumors showing clinical evidence of nerve involvement. Since pleomorphic adenoma is benign, the facial nerve must be preserved. * **Radiotherapy:** Pleomorphic adenoma is **radioresistant**. Radiation is generally avoided due to the risk of inducing malignant transformation (Carcinoma ex-pleomorphic adenoma). **Clinical Pearls for NEET-PG:** * **Most common site:** Parotid gland (Tail of the gland). * **Recurrence:** If it recurs, it often presents as multiple "satellite" nodules, making subsequent surgery difficult. * **Malignant Transformation:** Occurs in about 3–5% of cases; suspected if a long-standing painless lump suddenly grows rapidly or causes facial nerve palsy. * **Deep Lobe Involvement:** If the tumor involves the deep lobe, **Total Conservative Parotidectomy** (preserving the facial nerve) is performed.

Q: What is the most common cause of clicking in the temporomandibular joint?

Disc displacement with reduction. **Explanation:** The temporomandibular joint (TMJ) is characterized by a fibrocartilaginous disc situated between the condyle and the glenoid fossa. **1. Why Option A is Correct:** **Disc displacement with reduction (DDWR)** is the most common cause of TMJ clicking. In this condition, the disc is displaced anteriorly when the mouth is closed. Upon opening, the condyle moves forward and "jumps" back onto the thick posterior band of the disc. This sudden realignment (reduction) creates the characteristic **audible click**. A second "reciprocal click" often occurs during closing when the disc slips anteriorly again. **2. Why the other options are incorrect:** * **Disc displacement without reduction:** Here, the disc remains permanently displaced anterior to the condyle. Because the disc never "reduces" or snaps back into place, there is **no clicking**. Instead, patients present with a limited mouth opening (closed lock) and a "thud" or crepitus. * **Hypermobility:** This refers to subluxation or dislocation where the condyle moves beyond the articular eminence. While it can cause a "clunk," it is less common than DDWR and involves a different mechanical failure. * **Loose articular bodies:** Also known as "joint mice" (often due to synovial chondromatosis), these cause mechanical interference or locking, but are rare compared to internal disc derangements. **Clinical Pearls for NEET-PG:** * **Most common TMJ disorder:** Myofascial Pain Dysfunction Syndrome (MPDS), which is psychogenic/muscular. * **Clicking vs. Crepitus:** Clicking suggests internal derangement (DDWR); **Crepitus** (grating sound) suggests bone-on-bone contact, typical of **Osteoarthritis**. * **Management:** Most cases of clicking are managed conservatively with NSAIDs, soft diet, and occlusal splints. Surgery is rarely indicated.

Q: What is the most common causative organism of acute suppurative parotitis?

Staphylococcus aureus. **Explanation:** **Acute Suppurative Parotitis** is a bacterial infection of the parotid gland, typically occurring in patients with dehydration, poor oral hygiene, or those in the postoperative period (traditionally called "Surgical Mumps"). **1. Why Staphylococcus aureus is correct:** *Staphylococcus aureus* is the most common causative organism isolated in acute suppurative parotitis. The pathogenesis involves the retrograde migration of oral flora into the Stensen’s duct, usually facilitated by reduced salivary flow (stasis). Since *S. aureus* is a prominent member of the oral flora and possesses virulence factors that allow it to thrive in the stagnant protein-rich saliva, it becomes the primary pathogen. **2. Why other options are incorrect:** * **Streptococcus pyogenes:** While Streptococci (including *S. viridans* and *S. pneumoniae*) can cause sialadenitis, they are significantly less common than *S. aureus*. * **Corynebacterium:** These are generally commensals of the skin and mucous membranes and are rarely implicated as primary pathogens in acute parotid infections. **High-Yield Clinical Pearls for NEET-PG:** * **Risk Factors:** Dehydration (most common), debilitation, use of anticholinergic drugs, and ductal obstruction (sialolithiasis). * **Clinical Presentation:** Sudden onset of firm, erythematous, and exquisitely tender swelling over the parotid region. Purulent discharge may be seen from the opening of the Stensen’s duct (opposite the upper second molar) upon massaging the gland. * **Management:** Rehydration, intravenous antibiotics (covering penicillinase-producing *S. aureus*), and sialogogues (to stimulate saliva flow). * **Complication:** If an abscess forms and medical management fails, **Hilton’s Method** (incision and drainage) is performed to avoid damaging the facial nerve.

Q: Ameloblastoma most frequently occurs in which anatomical region?

Mandibular molar region. **Explanation:** **Ameloblastoma** is the most common benign (but locally aggressive) odontogenic tumor. It arises from the dental epithelium (enamel organ, remnants of Malassez, or the lining of odontogenic cysts). 1. **Why Mandibular Molar Region is Correct:** Statistically, approximately **80% of ameloblastomas occur in the mandible**, while only 20% occur in the maxilla. Within the mandible, the **molar-ramus area** is the most frequent site of involvement (70-75%). This is attributed to the high concentration of odontogenic epithelial remnants in this region during tooth development. 2. **Analysis of Incorrect Options:** * **Maxillary Molar Region:** While the maxilla is the second most common site, it accounts for a significantly smaller percentage of cases. Maxillary tumors are often more dangerous as they can invade the maxillary sinus and skull base. * **Mandibular/Maxillary Premolar Regions:** Although these tumors can occur in the premolar or anterior regions (symphysis), they are far less frequent than the posterior mandibular involvement. **Clinical Pearls for NEET-PG:** * **Radiological Appearance:** Classically described as a **"Soap-bubble"** or **"Honey-comb"** multilocular radiolucency. * **Clinical Feature:** It causes painless, slow-growing expansion of the jaw, often leading to **bony thinning (Egg-shell crackling)** and root resorption of adjacent teeth. * **Histopathology:** The most common patterns are **Follicular** and **Plexiform**. * **Treatment:** It is locally invasive with a high recurrence rate; therefore, wide local excision with clear margins (segmental resection) is the treatment of choice rather than simple curettage.

Q: What is the first consideration in the differential diagnosis of a painless palatal perforation?

Syphilis. **Explanation:** The correct answer is **Syphilis (Option A)**. Palatal perforation is a classic manifestation of **Tertiary Syphilis**, specifically due to the formation of a **Gumma**. A gumma is a localized, chronic granulomatous lesion characterized by a "rubbery" consistency. When it involves the hard palate, it leads to endarteritis obliterans, resulting in tissue necrosis and eventual painless perforation. In the context of NEET-PG, any painless, destructive midline granuloma of the palate should first raise suspicion of Syphilis or Wegener’s Granulomatosis. **Analysis of Incorrect Options:** * **Histoplasmosis (Option B):** While it can cause oral ulcers (often painful) in immunocompromised patients, it typically presents as a proliferative or vegetative growth rather than a clean palatal perforation. * **Scrofuloderma (Option C):** This is a form of cutaneous tuberculosis resulting from the breakdown of skin over an underlying infected lymph node or bone. It typically involves the neck (cervical lymph nodes) and presents with "string of beads" ulcers and sinus tracts, not palatal perforation. * **Actinomycosis (Option D):** Known for "lumpy jaw," it presents with multiple draining sinuses and "sulfur granules" in the pus. It involves the mandible more commonly than the palate and is usually associated with painful swelling. **High-Yield Clinical Pearls for NEET-PG:** * **Gumma:** The hallmark of late benign syphilis; most common sites are the skin, bone (tibia/palate), and liver. * **Differential Diagnosis of Palatal Perforation:** Syphilis (Gumma), Wegener’s Granulomatosis (GPA), NK/T-cell lymphoma (Lethal Midline Granuloma), and chronic cocaine abuse. * **Treatment of Choice:** For Tertiary Syphilis (without neurosyphilis), the treatment is Benzathine Penicillin G, 2.4 million units IM weekly for 3 weeks.

Q: What is true about Ludwig's angina?

Sublingual and submandibular spaces are involved. **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 1

A 50-year-old male patient complains of restricted mouth opening following TMJ surgery three weeks prior. Arthrography revealed fibrous adhesions in the joint space. Which of the following is most likely to occur during the diagnostic procedure in this patient?

Accepted Answer

Resistance to injection of contrast agent

Answer

Free flow of contrast agent

Answer

No contrast agent can be injected

Answer

None of the above

Question 2

Mucooceles are rarely seen in which of the following locations?

Accepted Answer

Upper lip

Answer

Lower lip

Answer

Buccal mucosa

Answer

Floor of the mouth

Question 3

What is the treatment of choice for pleomorphic adenoma?

Accepted Answer

Superficial parotidectomy

Answer

Excision of tumor

Answer

Radical parotidectomy

Answer

Radiotherapy

Question 4

What is the most common reason for the removal of impacted mandibular third molars?

Accepted Answer

Recurrent pericoronitis

Answer

Referred pain

Answer

Orthodontic treatment

Answer

Chronic periodontal disease

Question 5

What is the most common cause of clicking in the temporomandibular joint?

Accepted Answer

Disc displacement with reduction

Answer

Disc displacement without reduction

Answer

Hypermobility

Answer

Loose articular bodies

Question 6

What is the most common causative organism of acute suppurative parotitis?

Accepted Answer

Staphylococcus aureus

Answer

Streptococcus pyogenes

Answer

Corynebacterium

Answer

None of the above

Question 7

Ameloblastoma most frequently occurs in which anatomical region?

Accepted Answer

Mandibular molar region

Answer

Maxillary molar region

Answer

Mandibular premolar region

Answer

Maxillary premolar region

Question 8

What is the first consideration in the differential diagnosis of a painless palatal perforation?

Accepted Answer

Syphilis

Answer

Histoplasmosis

Answer

Scrofuloderma

Answer

Actinomycosis

Question 9

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

Accepted Answer

Unilateral parotid enlargement is common

Answer

May present as Sjogren's syndrome

Answer

Non-tender enlargement of salivary gland

Answer

May present as xerostomia

Question 10

What is true about Ludwig's angina?

Accepted Answer

Sublingual and submandibular spaces are involved

Answer

Rapidly spreading cellulitis of the neck

Answer

H. influenzae is the most common organism

Answer

Edema of the floor of the mouth

Diseases of the Oral Cavity and Salivary Glands — MCQs

Diseases of the Oral Cavity and Salivary Glands — MCQs

On this page

Practice by Chapter

Want unlimited practice?