NBDE Diagnosis and Treatment Planning 4 — Questions and Answers
Question 1: A 70-year-old complete denture wearer presents with an erythematous, velvety red lesion under the maxillary denture that has been present for several months. She denies pain. What is the most appropriate first step?
- Adjust the denture and reappoint in 3 months
- Prescribe antifungal therapy and remove the denture at night
- Perform biopsy to rule out erythroplakia (Correct answer)
- Reline the denture and schedule a 1-year recall
Correct answer: Perform biopsy to rule out erythroplakia
Persistent red lesions (erythroplakia) carry a high risk of malignant transformation and must be biopsied regardless of apparent denture-related cause.
Question 2: A patient requires extraction of maxillary third molars. Preoperative CBCT shows the roots closely approximating the maxillary sinus. What complication must be specifically discussed during informed consent?
- Inferior alveolar nerve paresthesia
- Oroantral communication with risk of oroantral fistula (Correct answer)
- Trismus lasting more than 6 months
- Dry socket of the adjacent second molar
Correct answer: Oroantral communication with risk of oroantral fistula
Proximity of maxillary molar roots to the sinus floor creates risk of oroantral communication during extraction, which may lead to a persistent oroantral fistula if not managed.
Question 3: In developing a treatment plan for a patient with generalized aggressive periodontitis, which adjunct to mechanical therapy has the strongest evidence for improving outcomes?
- Chlorhexidine irrigation subgingivally at each visit
- Systemic amoxicillin and metronidazole combined with scaling and root planing (Correct answer)
- Local delivery of doxycycline hyclate into pockets ≥5 mm
- Laser-assisted new attachment procedure (LANAP)
Correct answer: Systemic amoxicillin and metronidazole combined with scaling and root planing
Systemic amoxicillin plus metronidazole as an adjunct to scaling and root planing has the strongest evidence base for treating generalized aggressive periodontitis.
Question 4: A 35-year-old patient presents with sudden onset facial swelling, limited mouth opening, and difficulty swallowing. Intraoral exam shows an infected lower third molar. Which space infection is most life-threatening?
- Buccal space abscess
- Submasseteric space abscess
- Ludwig's angina (bilateral submandibular/sublingual space) (Correct answer)
- Pterygomandibular space abscess
Correct answer: Ludwig's angina (bilateral submandibular/sublingual space)
Ludwig's angina involves bilateral submandibular and sublingual spaces and can rapidly progress to airway obstruction, making it a true dental emergency requiring hospitalization.
Question 5: When planning crown lengthening surgery to expose adequate tooth structure, what minimum biological width must be re-established between the restorative margin and the alveolar crest?
- 0.5 mm
- 1.0 mm
- 2.0–3.0 mm (Correct answer)
- 4.0–5.0 mm
Correct answer: 2.0–3.0 mm
The biologic width (junctional epithelium + connective tissue attachment) averages approximately 2 mm; a restorative margin must maintain at least 2–3 mm from the bone crest to avoid violation.
Question 6: A patient presents with asymptomatic white patches on the buccal mucosa that cannot be rubbed off with a gauze pad. Biopsy reveals epithelial dysplasia. What does dysplasia indicate in the treatment plan?
- Routine follow-up with no treatment needed
- Immediate surgical excision and close surveillance (Correct answer)
- Antifungal therapy to address candidal leukoplakia
- Corticosteroid therapy to reduce inflammation
Correct answer: Immediate surgical excision and close surveillance
Epithelial dysplasia in an oral white lesion indicates pre-malignant change requiring surgical removal and regular surveillance for recurrence or malignant transformation.
Question 7: A patient declines the recommended treatment and opts for a less invasive alternative. The dentist disagrees with this choice but the patient is competent and informed. What is the ethical obligation?
- Override patient preference and provide the recommended treatment
- Dismiss the patient from the practice immediately
- Respect patient autonomy and document informed refusal (Correct answer)
- Consult the state dental board before proceeding
Correct answer: Respect patient autonomy and document informed refusal
Respect for patient autonomy requires that informed, competent patients have the right to refuse recommended treatment; the dentist must document the discussion and refusal.
NBDE Diagnosis and Treatment Planning 4
A 70-year-old complete denture wearer presents with an erythematous, velvety red lesion under the maxillary denture that has been present for several months.
She denies pain.
What is the most appropriate first step?