Radiographic Techniques and Errors Flashcards
7 cards from real RDA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Radiographic Techniques and Errors flashcards as text
A radiograph shows the apices of the maxillary molars superimposed over the zygomatic arch. Which error caused this?
Answer: Insufficient vertical angulation
Insufficient (flat) vertical angulation causes the zygomatic arch to overlap the apices of the maxillary molars.
Which receptor placement error results in a radiograph showing the roots of mandibular teeth appearing foreshortened?
Answer: Receptor tilted toward the tongue
When the receptor tilts toward the tongue (cupped), the effective vertical angulation increases, foreshortening the image.
During a bitewing series, the contact areas of posterior teeth are not open. The MOST likely cause is:
Answer: Incorrect horizontal angulation
Overlapping of proximal contacts on bitewings is caused by incorrect horizontal angulation, where the beam does not pass through the embrasures.
A periapical radiograph of the mandibular incisors shows a herringbone pattern on the image. What is the cause?
Answer: Film or receptor placed backward
The herringbone (tire-track) pattern results from X-rays passing through the lead foil backing when the receptor is placed backward in the mouth.
Which type of film fault produces a clear (unexposed) area on a processed radiograph shaped like a half-moon?
Answer: Crimping artifact
A crescent-shaped (half-moon) clear area results from crimping or bending the film sharply before exposure, which blocks X-rays from reaching that area.
When using the paralleling technique, the cone (PID) is directed perpendicular to the:
Answer: Both the long axis of the tooth and the receptor
In the paralleling technique, the receptor is placed parallel to the tooth's long axis and the PID is directed perpendicular to both.
A panoramic radiograph shows the anterior teeth appearing blurry and out of focus. The MOST likely cause is:
Answer: Patient positioned too far forward in the focal trough
When the patient is positioned too far forward, the anterior teeth are in front of the focal trough, causing them to appear blurry and narrowed.