NBDE Diagnosis and Treatment Planning 4

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?

Accepted Answer

Perform biopsy to rule out erythroplakia

Answer

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?

Accepted Answer

Oroantral communication with risk of oroantral fistula

Answer

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?

Accepted Answer

Systemic amoxicillin and metronidazole combined with scaling and root planing

Answer

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?

Accepted Answer

Ludwig's angina (bilateral submandibular/sublingual space)

Answer

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?

Accepted Answer

2.0–3.0 mm

Answer

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.

NBDE - National Board Dental Examination Practice Test

NBDE - National Board Dental Examination Practice Test

NBDE Diagnosis and Treatment Planning 4