NBDE Oral Surgery 2 — Questions and Answers
Question 1: Which classification system is most commonly used to assess the predicted difficulty of impacted mandibular third molar removal?
- Kennedy classification
- Pell and Gregory classification (Correct answer)
- Angle classification
- Black's classification
Correct answer: Pell and Gregory classification
The Pell and Gregory classification evaluates the depth of impaction relative to the occlusal plane and the space between the second molar and ramus, predicting surgical difficulty.
Question 2: During extraction of the maxillary first molar, oroantral communication is a recognized risk primarily because:
- The roots are unusually long and curved
- The apices of the roots are in close proximity to the floor of the maxillary sinus (Correct answer)
- The tooth frequently has five separate roots
- The periodontal ligament is atypically thin in this region
Correct answer: The apices of the roots are in close proximity to the floor of the maxillary sinus
The roots of the maxillary first molar have a close anatomical relationship with the floor of the maxillary sinus, making inadvertent sinus perforation a risk during extraction.
Question 3: The Caldwell-Luc procedure is a surgical approach primarily used to access which anatomical structure?
- Submandibular space
- Maxillary sinus (Correct answer)
- Infratemporal fossa
- Pterygomaxillary fissure
Correct answer: Maxillary sinus
The Caldwell-Luc approach creates an opening into the maxillary sinus through the canine fossa (anterior wall) to treat chronic sinusitis, remove foreign bodies, or repair oroantral fistulae.
Question 4: The correct target landmark for the standard inferior alveolar nerve block is approximately:
- 10 mm above the mandibular occlusal plane, medial to the pterygomandibular raphe (Correct answer)
- At the level of the occlusal plane, lateral to the pterygomandibular raphe
- Within the body of the medial pterygoid muscle
- At the posterior border of the ramus near the condyle
Correct answer: 10 mm above the mandibular occlusal plane, medial to the pterygomandibular raphe
The needle is directed approximately 10 mm above the mandibular occlusal plane, medial to the pterygomandibular raphe, aiming at the mandibular foramen on the lingual aspect of the ramus.
Question 5: A patient develops trismus and dysphagia 2 days after mandibular molar extraction. Which space infection is most likely responsible?
- Buccal space abscess
- Parotid space abscess
- Pterygomandibular space abscess (Correct answer)
- Submental space abscess
Correct answer: Pterygomandibular space abscess
Pterygomandibular space infection causes trismus (due to medial pterygoid muscle involvement) and dysphagia (due to proximity to the lateral pharyngeal wall), and typically follows lower molar infections.
Question 6: What is the most appropriate immediate management when a small oroantral communication is discovered directly after extraction?
- Pack with gauze and prescribe antibiotics only
- Attempt primary closure with a buccal advancement flap (Correct answer)
- Leave open to drain and schedule follow-up in 2 weeks
- Place a PTFE membrane and suture over it
Correct answer: Attempt primary closure with a buccal advancement flap
A small oroantral communication found immediately post-extraction is best managed by primary closure using a buccal advancement flap to prevent development of a chronic oroantral fistula.
Question 7: Which of the following represents an absolute contraindication to elective tooth extraction?
- Oral bisphosphonate therapy for osteoporosis
- Warfarin therapy with INR of 2.5
- Myocardial infarction within the previous 30 days (Correct answer)
- Controlled type 2 diabetes with HbA1c of 7%
Correct answer: Myocardial infarction within the previous 30 days
A recent myocardial infarction within 30 days is an absolute contraindication to elective extraction due to unacceptable cardiac risk, ongoing antiplatelet/anticoagulant therapy, and hemodynamic instability.
NBDE Oral Surgery 2
Which classification system is most commonly used to assess the predicted difficulty of impacted mandibular third molar removal?