Try it
Dentistry · Dental materials and radiology basics: panoramic ghost image
Sample itemA panoramic radiograph of a patient wearing a metal earring on the left shows a blurred radiopacity on the right ramus region, higher than the true object and enlarged. What is this artefact?
Original practice item, not a recalled exam question. Nothing here is recorded.
The answer and the reasoning
C. A ghost image on the opposite side
A ghost image forms when a dense object lies in the path of the beam, between the source and the rotation centre, and its image is projected on the opposite side. It appears higher, blurred and enlarged. Removing jewellery before exposure avoids it.
Option by option
A. Foreshortening of the mandibular ramus
Foreshortening shortens an object and does not create an extra shadow.
B. A cone-cutting error
Cone cutting is seen in intraoral films as an unexposed clear area.
C. A ghost image on the opposite side (correct)
Correct. The dense object projects a blurred opposite-side image higher than the object.
D. A double image of the right condyle
A double condyle image is not caused by an earring.
Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.
More Dentistry questions
- Tooth development: Hertwig's root sheathDuring tooth development, which structure induces odontoblast differentiation in the roo…
- Tooth eruption: first permanent toothA 6-year-old child has a new tooth behind the last deciduous molar, with no deciduous to…
- Tooth development: neonatal lineGround sections of deciduous teeth show an accentuated incremental line in enamel and de…
- Tooth development: cell rests of MalassezEpithelial cell rests of Malassez persist in the periodontal ligament. Which cyst most o…