Radiology · patient case question
What is the most likely explanation for this radiolucency?
Patient case: Radiolucency between #9 and #10
Scenario: A radiolucency is seen between teeth #9 and #10. The periapical radiograph was not very clear.
Show answer and explanation
Correct answer: C. Nares / nasal fossa — a normal anatomic radiolucency superimposed on the region
- A. A periapical (radicular) cyst requires a NON-VITAL tooth and is centred on the apex. No pulp-testing information is given.
- B. A mesiodens is a supernumerary TOOTH and would appear RADIOPAQUE, not radiolucent.
- C. Keyed per the source. In the anterior maxilla, superimposed anatomic radiolucencies (nasal fossa, nasopalatine canal, incisive foramen) are common and are the first thing to exclude — particularly when the film is described as 'not very clear'. If the adjacent teeth test VITAL, the lucency is anatomic or a non-endodontic entity rather than a periapical lesion.
- D. A periapical granuloma also requires a non-vital tooth, and — importantly — a granuloma CANNOT be distinguished from a radicular cyst radiographically. Definitive differentiation is histologic.
Note: ⚠️ AMBIGUOUS ITEM. The recall did not record a highlighted key. The decisive clinical information is PULP VITALITY: vital teeth point to an anatomic or non-endodontic lucency (nares, lateral periodontal cyst); non-vital teeth point to granuloma/cyst — and those two cannot be separated on a radiograph. Worth discussing as a group.