Radiology · patient case question
Which imaging modality best determines the three-dimensional position of a mesiodens before surgical removal?
Patient case: Reading the panoramic film
demo: Series of radiographic interpretation items
chief: Assorted radiographic findings and technique errors from a single clinic session.
history: Several patients imaged the same morning; the films are reviewed together at the end of the day.
meds: Not applicable.
findings: One panoramic film shows the right ramus and posterior teeth appreciably wider than the left. Another shows two ring-shaped radiopacities superimposed over one maxillary sinus and three over the other, in a patient wearing earrings. A third shows a curved radiopacity in the lower field. An occlusal film shows a soft tissue shadow over the incisal edges of the anterior teeth.
Show answer and explanation
Correct answer: D. Cone beam computed tomography
- A. A single periapical film is two-dimensional and cannot resolve buccal from palatal without a second angled exposure.
- B. Panoramic imaging has substantial distortion in the anterior midline and considerable superimposition in that region.
- C. An occlusal film adds a second plane and, paired with a periapical using the tube shift rule, can localise reasonably. But when precise three-dimensional relationships matter, CBCT is superior.
- D. Correct. CBCT gives true three-dimensional localisation, showing the mesiodens in relation to the incisor roots, the nasopalatine canal and the cortical plates, which determines the surgical approach and reduces the risk of damaging adjacent structures.