NBDE Oral Pathology and Radiology 4 — Questions and Answers
Question 1: Oral submucous fibrosis, a potentially malignant disorder, is strongly associated with the habit of:
- Cigarette smoking
- Areca nut (betel quid) chewing (Correct answer)
- Alcohol consumption
- Khat chewing
Correct answer: Areca nut (betel quid) chewing
Areca nut (betel quid) contains arecoline, which stimulates fibroblasts to produce excess collagen, causing progressive submucosal fibrosis and trismus.
Question 2: Stafne bone cavity (static bone cyst) characteristically appears on a panoramic radiograph as:
- Multilocular radiolucency above the inferior alveolar canal
- Well-defined unilocular radiolucency below the inferior alveolar canal near the mandibular angle (Correct answer)
- Periapical radiolucency at a non-vital molar
- Corticated cyst in the anterior maxilla
Correct answer: Well-defined unilocular radiolucency below the inferior alveolar canal near the mandibular angle
Stafne bone cavity is a developmental corticated depression in the posterior mandible lingual cortex below the inferior alveolar canal, filled with submandibular gland tissue.
Question 3: A Wickham's striae pattern on buccal mucosa with white lace-like striations is pathognomonic of:
- Lichen planus (Correct answer)
- Leukoedema
- Nicotine stomatitis
- White sponge nevus
Correct answer: Lichen planus
Wickham's striae — interlacing white lines on a violaceous background — are the hallmark of oral lichen planus, representing saw-tooth rete pegs and band-like lymphocytic infiltrate.
Question 4: On a periapical radiograph, which structure appears as a radiopaque line at the midline of the palate just superior to the anterior teeth?
- Incisive foramen
- Nasal septum
- Anterior nasal spine
- Median palatal suture (Correct answer)
Correct answer: Median palatal suture
The median palatal suture appears as a thin radiopaque midline line between the two palatine processes of the maxilla, superior to the central incisors.
Question 5: Which of the following salivary gland tumors is most likely to undergo malignant transformation?
- Warthin tumor
- Pleomorphic adenoma (Correct answer)
- Oncocytoma
- Basal cell adenoma
Correct answer: Pleomorphic adenoma
Pleomorphic adenoma (mixed tumor) has a 1-5% risk of malignant transformation to carcinoma ex pleomorphic adenoma, especially with long-standing or recurrent lesions.
Question 6: Fordyce granules of the oral cavity represent:
- Ectopic sebaceous glands in the oral mucosa (Correct answer)
- Retained keratin cysts in the buccal mucosa
- Minor salivary gland hyperplasia
- Lymphoid aggregates below the mucosa
Correct answer: Ectopic sebaceous glands in the oral mucosa
Fordyce granules are ectopic sebaceous glands without hair follicles, appearing as multiple small yellow-white papules on the buccal mucosa and vermilion border.
Question 7: A 'sunburst' periosteal reaction on a jaw radiograph in a child is most alarming for:
- Ameloblastoma
- Osteosarcoma (Correct answer)
- Fibrous dysplasia
- Ewing sarcoma
Correct answer: Osteosarcoma
A sunburst periosteal reaction (perpendicular bone spicules radiating from the cortex) is a classic sign of osteosarcoma, reflecting aggressive periosteal bone formation.
NBDE Oral Pathology and Radiology 4
Oral submucous fibrosis, a potentially malignant disorder, is strongly associated with the habit of: