Dental Radiology Flashcards

What does a 'ghost image' artifact on a panoramic radiograph represent?

Answer: A magnified mirror-image of a structure on the opposite side

Ghost images on panoramic radiographs are blurred, magnified images of radiopaque structures (e.g., earrings, spine) that appear on the opposite side of the film.

The mental foramen on a periapical radiograph most commonly appears adjacent to which tooth?

Answer: Mandibular second premolar

The mental foramen, which transmits the mental nerve and vessels, most commonly appears near the apex of the mandibular second premolar.

Which property makes digital radiography preferable to conventional film in terms of radiation safety?

Answer: It requires up to 80% less radiation than conventional film

Digital sensors are significantly more sensitive to X-rays than conventional film, allowing diagnostic images to be captured with substantially lower radiation doses.

What is the function of the intensifying screen in traditional dental radiography cassettes?

Answer: To convert X-ray energy into visible light to expose the film

Intensifying screens contain phosphor crystals that fluoresce (emit light) when struck by X-rays, amplifying the effect on the film and reducing required radiation dose.

Elongation of teeth on a periapical radiograph is caused by which error in the bisecting angle technique?

Answer: Directing the beam too shallowly (insufficient vertical angulation)

When the vertical angulation of the X-ray beam is too flat (too little downward angle), the tooth image appears longer (elongated) on the film.

Which radiograph is specifically used to assess impacted third molars and the relationship of tooth roots to the inferior alveolar canal?

Answer: Panoramic

Panoramic radiographs are routinely used to evaluate third molar impactions and their proximity to the inferior alveolar nerve canal before extraction.