NBDE Diagnosis and Treatment Planning 2 — Questions and Answers
Question 1: A 45-year-old patient presents with a painless, slow-growing swelling on the posterior mandible. Radiograph shows a well-defined unilocular radiolucency with scalloped borders around the crowns of impacted third molars. What is the most likely diagnosis?
- Dentigerous cyst
- Ameloblastoma
- Odontogenic keratocyst (Correct answer)
- Central giant cell granuloma
Correct answer: Odontogenic keratocyst
Odontogenic keratocysts (OKC) characteristically show scalloped borders and a tendency to grow along the medullary space with minimal cortical expansion.
Question 2: A patient's periodontal chart shows generalized probing depths of 5-7 mm with bleeding on probing, bone loss on radiographs, and Class II furcation involvement on maxillary molars. How should this periodontitis be classified?
- Stage I, Grade A
- Stage II, Grade B
- Stage III, Grade B (Correct answer)
- Stage IV, Grade C
Correct answer: Stage III, Grade B
Stage III periodontitis is characterized by tooth loss potential due to severe bone loss and furcation involvement (Class II or III), without masticatory dysfunction.
Question 3: Which finding on a panoramic radiograph would most indicate the need for immediate referral to an oral surgeon before initiating orthodontic treatment?
- Mild root resorption of maxillary incisors
- Unerupted maxillary canine with dilaceration
- Multilocular radiolucency in the posterior mandible (Correct answer)
- Impacted mandibular third molars with no associated pathology
Correct answer: Multilocular radiolucency in the posterior mandible
A multilocular radiolucency in the posterior mandible raises concern for ameloblastoma or other aggressive jaw lesions requiring biopsy before any elective dental treatment.
Question 4: A 60-year-old patient taking bisphosphonates for osteoporosis requires extraction of a non-restorable mandibular molar. Which is the most critical consideration in the treatment plan?
- Prescribe prophylactic antibiotics for 2 weeks post-extraction
- Consult with the prescribing physician regarding risk of MRONJ (Correct answer)
- Delay extraction until bisphosphonate therapy is completed
- Place an immediate implant to minimize socket exposure time
Correct answer: Consult with the prescribing physician regarding risk of MRONJ
Medication-related osteonecrosis of the jaw (MRONJ) risk must be assessed by consulting the prescribing physician before any dentoalveolar surgery in bisphosphonate patients.
Question 5: A 7-year-old child presents with a maxillary central incisor that was avulsed 2 hours ago and stored dry. What is the most appropriate management?
- Reimplant immediately after cleaning with saline
- Do not reimplant; space maintenance and prosthetic replacement (Correct answer)
- Reimplant after soaking in fluoride solution for 20 minutes
- Extract the contralateral tooth to maintain symmetry
Correct answer: Do not reimplant; space maintenance and prosthetic replacement
Dry storage for more than 60 minutes results in non-vital periodontal ligament cells, making reimplantation of primary teeth contraindicated; in permanent teeth, reimplantation is still considered but with poor prognosis.
Question 6: When evaluating occlusion as part of treatment planning, which finding most strongly indicates the need for an occlusal splint before restorative work?
- Class II Division 1 malocclusion
- Fremitus detected on maxillary anterior teeth
- Signs and symptoms of bruxism with wear facets (Correct answer)
- Deep overbite with no muscle tenderness
Correct answer: Signs and symptoms of bruxism with wear facets
Active bruxism with wear facets indicates parafunctional forces that can destroy restorations; stabilization with an occlusal splint is indicated before placing definitive restorations.
Question 7: A 55-year-old smoker presents with a 3-week-old non-healing ulcer on the lateral border of the tongue. What is the most appropriate next step?
- Prescribe antifungal therapy and review in 2 weeks
- Recommend smoking cessation and schedule 3-month recall
- Perform incisional biopsy or immediate referral for biopsy (Correct answer)
- Prescribe a 2-week course of chlorhexidine rinse
Correct answer: Perform incisional biopsy or immediate referral for biopsy
Any oral ulcer persisting more than 2 weeks in a tobacco user must be considered potentially malignant until proven otherwise, requiring urgent biopsy.
NBDE Diagnosis and Treatment Planning 2
A 45-year-old patient presents with a painless, slow-growing swelling on the posterior mandible.
Radiograph shows a well-defined unilocular radiolucency with scalloped borders around the crowns of impacted third molars.
What is the most likely diagnosis?