Radiology & IRMER Flashcards

What clinical indication justifies taking a CBCT for assessment of an impacted upper canine?

Answer: When conventional 2D radiographs are inconclusive about root relationship to adjacent teeth, dilacerations, or root resorption — CBCT provides 3D localisation

CBCT is justified for impacted canines when 2D views show signs suggesting resorption of adjacent incisors, unusual root morphology, or equivocal localisation, providing 3D information that changes clinical management.

What is the appearance of periapical cemental dysplasia (cemento-osseous dysplasia) on a radiograph?

Answer: Early: periapical radiolucency (florid stage: mixed radio-opaque and radiolucent lesions); mature: radiopaque mass with radiolucent rim — in vital teeth

Periapical cemento-osseous dysplasia evolves through three stages: osteolytic (radiolucent), cementoblastic (mixed), and mature (radiopaque with thin radiolucent rim) — always associated with vital teeth.

What is the recommended radiographic monitoring interval for an ameloblastoma after surgical resection?

Answer: Annual or biannual radiographic review for at least 5–10 years due to high recurrence rate

Ameloblastoma has a significant recurrence rate (especially follicular type); annual or biannual radiographic monitoring for at least 5–10 years post-resection is recommended to detect recurrence early.

What is the significance of the 'snowstorm' appearance on a panoramic radiograph?

Answer: Multiple small calcifications scattered throughout the salivary glands or jaw — suggests phleboliths, calcified nodes, or calcifying lesions

Multiple small radiopaque foci ('snowstorm') scattered in the jaw or soft tissues may indicate phleboliths (in haemangiomas), calcified lymph nodes, calcifying odontogenic cysts, or other calcifying lesions.

What is the radiographic appearance of a dentigerous cyst?

Answer: Well-defined corticated unilocular radiolucency enclosing the crown of an unerupted tooth, attached at the CEJ

A dentigerous (follicular) cyst appears as a well-defined, corticated, radiolucent space surrounding the crown of an unerupted tooth from the CEJ; a normal follicular space is 3–5 mm.

When is a bitewing radiograph preferred over a periapical for caries detection?

Answer: When detecting early interproximal and occlusal caries in asymptomatic patients — bitewings show contact areas bilaterally without apical distortion

Bitewing radiographs position the film parallel to the contact areas of both arches simultaneously, making them superior for detecting early interproximal caries without the distortion of the periapical technique.