NBDE General Practice 2 — Questions and Answers
Question 1: A patient on warfarin requires a routine extraction. The INR is 2.8. What is the most appropriate management?
- Proceed with extraction without alteration
- Discontinue warfarin 5 days before the procedure
- Use local hemostatic measures and proceed (Correct answer)
- Refer to the patient's physician to reverse anticoagulation completely
Correct answer: Use local hemostatic measures and proceed
For INR values up to 3.5, dental extractions can proceed safely with local hemostatic measures such as suturing, oxidized cellulose, and pressure packs.
Question 2: Which organism is most commonly associated with Ludwig's angina?
- Staphylococcus aureus
- Streptococcus viridans (Correct answer)
- Candida albicans
- Actinomyces israelii
Correct answer: Streptococcus viridans
Streptococcus viridans is the most frequently isolated organism in Ludwig's angina, a life-threatening bilateral submandibular and sublingual space infection.
Question 3: A 45-year-old patient presents with trismus, fever, and swelling in the pterygomandibular space. What is the most likely diagnosis?
- Parotitis
- Pericoronitis
- Pterygomandibular space abscess (Correct answer)
- Masseteric space abscess
Correct answer: Pterygomandibular space abscess
Trismus combined with pterygomandibular space swelling and systemic signs indicates a pterygomandibular space abscess, typically arising from a lower molar.
Question 4: Which local anesthetic has the longest duration of action for pulpal anesthesia?
- Lidocaine 2%
- Mepivacaine 3%
- Bupivacaine 0.5% (Correct answer)
- Prilocaine 4%
Correct answer: Bupivacaine 0.5%
Bupivacaine 0.5% provides the longest pulpal anesthesia duration (up to 90 minutes) due to its high lipid solubility and protein binding.
Question 5: A patient taking bisphosphonates for osteoporosis requires an extraction. Which complication is of greatest concern?
- Dry socket
- Medication-related osteonecrosis of the jaw (MRONJ) (Correct answer)
- Hemorrhage
- Nerve paresthesia
Correct answer: Medication-related osteonecrosis of the jaw (MRONJ)
Bisphosphonates impair osteoclast activity and bone remodeling, leading to MRONJ, characterized by exposed necrotic bone that fails to heal after 8 weeks.
Question 6: During inferior alveolar nerve block, the needle is inadvertently inserted into the parotid gland and anesthetic is deposited. What complication would most likely result?
- Hematoma formation
- Transient facial nerve paralysis (Correct answer)
- Permanent trismus
- Cavernous sinus thrombosis
Correct answer: Transient facial nerve paralysis
Injection into the parotid gland anesthetizes branches of the facial nerve traversing the gland, causing transient facial paralysis that resolves as the anesthetic wears off.
Question 7: Which of the following best describes the mechanism of action of epinephrine in local anesthetic solutions?
- Directly blocks sodium channels at the nerve membrane
- Causes vasoconstriction, reducing systemic absorption and prolonging anesthesia (Correct answer)
- Increases the pH of the solution for faster onset
- Acts as a preservative to extend shelf life
Correct answer: Causes vasoconstriction, reducing systemic absorption and prolonging anesthesia
Epinephrine causes local vasoconstriction, which slows systemic absorption of the anesthetic, prolongs duration of action, and reduces bleeding in the field.
NBDE General Practice 2
A patient on warfarin requires a routine extraction.
The INR is 2.8.
What is the most appropriate management?