Dental Radiography and Interpretation Flashcards

Which radiographic technique uses a horizontal angulation of 0° and a vertical angulation of +8° to +10° for mandibular premolars in the paralleling technique?

Answer: The beam is directed perpendicular to the long axis of the teeth and the film/sensor, with specific vertical angulation per region

The paralleling technique directs the central beam perpendicular to both the long axis of the teeth and the image receptor, with regional vertical angulations (mandibular premolars ~+8° to +10°).

A periapical radiograph showing a well-defined radiolucency with a sclerotic border at the apex of a vital tooth is MOST likely:

Answer: Periapical cemento-osseous dysplasia (early stage)

Early-stage cemento-osseous dysplasia around the apices of vital anterior teeth appears as a well-defined radiolucency; vitality testing differentiates it from endodontically involved lesions.

The maximum permissible dose (MPD) of ionizing radiation for an occupationally exposed dental worker per year in the U.S. is:

Answer: 50 mSv (5 rem) per year

The National Council on Radiation Protection sets the MPD for occupationally exposed persons at 50 mSv (5 rem) per year, with a cumulative lifetime limit of 10 mSv × age.

Elongation on a periapical radiograph using the bisecting angle technique is caused by:

Answer: Insufficient vertical angulation (too flat/shallow)

Elongation occurs when the vertical angulation is too shallow (not enough) — the beam does not bisect the angle properly and the image appears stretched/lengthened.

On a panoramic radiograph, the 'ghost image' artifact is caused by:

Answer: A radiopaque structure on the contralateral side projecting across the midline at a higher and more blurred level

Ghost images in panoramic radiography are reversed, magnified, blurred secondary images of radiopaque structures located on the opposite side of the beam path that appear above and blurred compared to the primary image.

Which type of dental radiograph is BEST for evaluating the crestal bone height in a periodontal patient?

Answer: Vertical bitewing radiograph

Vertical bitewing radiographs show both the maxillary and mandibular alveolar crests on the same image with minimal distortion, making them ideal for assessing crestal bone levels in periodontally involved patients.