Radiology · patient case question
All of the following are reasonable radiolucent differentials associated with an impacted tooth EXCEPT:
Patient case: Radiographic Differential — Impacted Canine
demo: 19-year-old male
chief: Referred for evaluation of a retained primary canine.
history: Non-contributory.
meds: None
findings: Panoramic radiograph shows tooth #6 impacted high in the maxilla with an associated well-defined radiolucency surrounding the crown. Images below illustrate two of the entities under consideration.
Show answer and explanation
Correct answer: D. Radicular cyst
- A. OKC frequently presents around impacted teeth and can mimic a dentigerous cyst radiographically.
- B. A dentigerous cyst attaches at the CEJ of an unerupted crown and is the single most common cyst associated with an impaction.
- C. AOT is classically associated with an impacted canine in a young patient, which is exactly this scenario.
- D. Correct — this is the exception. A radicular cyst arises from the rests of Malassez following pulpal necrosis of an erupted tooth. An impacted, unerupted tooth has an intact pulp and cannot generate one.