NBDE General Practice 3 — Questions and Answers
Question 1: A patient presents with a 2-week-old, non-healing ulcer on the lateral border of the tongue. What is the most important next step?
- Prescribe chlorhexidine rinse and reassess in 2 weeks
- Prescribe antifungal therapy
- Perform an incisional biopsy (Correct answer)
- Recommend warm salt water rinses
Correct answer: Perform an incisional biopsy
Any non-healing oral ulcer persisting more than 2 weeks requires an incisional biopsy to rule out squamous cell carcinoma.
Question 2: Which of the following is the MOST common cause of postoperative hemorrhage after a tooth extraction?
- Factor VIII deficiency
- Local factors such as trauma and infection (Correct answer)
- Thrombocytopenia
- Vitamin K deficiency
Correct answer: Local factors such as trauma and infection
Most postoperative bleeding after extraction is due to local factors including excessive trauma, infection, or failure to form a stable clot rather than systemic coagulopathies.
Question 3: A dentist places a composite restoration and the patient returns 1 week later with sensitivity to cold. The most likely cause is:
- Pulp necrosis
- Inadequate polymerization of the composite (Correct answer)
- Carious lesion at the margin
- Occlusal hypercontact
Correct answer: Inadequate polymerization of the composite
Inadequate curing of composite leaves unpolymerized resin monomers that cause pulpal irritation and sensitivity to cold stimuli.
Question 4: When taking a panoramic radiograph, a patient's chin is not sufficiently elevated. What artifact results?
- Reverse smile curve of the occlusal plane (Correct answer)
- Blurring of the condyles
- Ghosting of the cervical spine
- Magnification of the anterior teeth
Correct answer: Reverse smile curve of the occlusal plane
If the chin is too low (patient tipping head down), the Frankfort plane is below horizontal and the occlusal plane curves upward, producing a reverse (frowning) smile curve.
Question 5: A patient presents with xerostomia, bilateral parotid enlargement, and keratoconjunctivitis sicca. Which condition should be suspected?
- Sjögren's syndrome (Correct answer)
- Sarcoidosis
- Diabetes mellitus
- Hyperparathyroidism
Correct answer: Sjögren's syndrome
The classic triad of dry mouth, dry eyes (keratoconjunctivitis sicca), and salivary gland enlargement is characteristic of Sjögren's syndrome, an autoimmune exocrinopathy.
Question 6: Which radiographic sign on a periapical film is MOST indicative of a periapical abscess rather than a granuloma?
- Well-defined radiolucency with a distinct corticated border
- Ill-defined radiolucency with loss of lamina dura (Correct answer)
- Diffuse sclerosis around the apex
- Widening of the periodontal ligament space only
Correct answer: Ill-defined radiolucency with loss of lamina dura
An abscess typically presents as an ill-defined radiolucency with loss of lamina dura, while a granuloma or cyst tends to have a well-defined, corticated border.
Question 7: A patient has a fully impacted mandibular third molar with a follicular space greater than 5 mm on panoramic radiograph. What is the most likely diagnosis?
- Periapical cyst
- Dentigerous cyst (Correct answer)
- Odontogenic keratocyst
- Ameloblastoma
Correct answer: Dentigerous cyst
A pericoronal radiolucency greater than 3–5 mm surrounding an impacted tooth crown is the hallmark of a dentigerous (follicular) cyst.
NBDE General Practice 3
A patient presents with a 2-week-old, non-healing ulcer on the lateral border of the tongue.
What is the most important next step?