Anatomical Mimics Periapical Lesion — ORE Part 1 MCQ

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ModerateRadiology & ImagingAnatomical Mimics Periapical LesionORE Part 1

A periapical radiograph shows a well-defined round radiolucency apparently associated with the apex of an upper right canine. The tooth is caries-free, unrestored and responds normally to pulp sensibility testing. Which is the most likely explanation?

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Correct answer: B — Superimposition of the canalis sinuosus

The best explanation is superimposition of the canalis sinuosus, an anatomical canal in the anterior maxilla that may project near the roots of anterior teeth and simulate apical disease on a two-dimensional radiograph. The intact, caries-free tooth and normal sensibility response make an endodontic inflammatory lesion unlikely. A periapical granuloma, radicular cyst and periapical abscess are ordinarily consequences of pulpal infection and would not fit this clinical picture. Periapical cemento-osseous dysplasia can occur adjacent to vital teeth, but it is classically associated with the mandibular anterior region and usually develops from a radiolucent to mixed or radiopaque appearance rather than representing this specific maxillary canine anatomical mimic. If uncertainty remained clinically, additional angled radiographs or justified CBCT assessment could clarify the relationship.

Reference: Lowe LG, Peters E, Persaud A. Canalis Sinuosus Mimicking Periapical Pathology on Radiographic Assessment. Journal of Endodontics. 2024. https://pubmed.ncbi.nlm.nih.gov/23322846/