DMD DMD - Doctor of Medicine in Dentistry Dental Radiology and Imaging Questions and Answers 2

Question 1

Cone beam computed tomography (CBCT) provides what primary advantage over conventional 2D radiography in dentistry?

Accepted Answer

Three-dimensional imaging with reduced radiation compared to medical CT

Answer

Lower cost than periapical X-rays

Answer

No radiation exposure

Answer

Better soft tissue contrast than MRI

Question 2

On a periapical radiograph, condensing osteitis appears as which radiographic finding?

Accepted Answer

Radiopaque (dense) area around the apex of a tooth

Answer

Radiolucent area around the apex

Answer

Mixed radiolucent-radiopaque lesion

Answer

Loss of lamina dura only

Question 3

The bisecting angle technique uses which geometric rule to determine beam angulation?

Accepted Answer

The central ray is directed perpendicular to the bisector of the angle formed by the tooth and the film

Answer

The central ray is directed parallel to the long axis of the tooth

Answer

The film is placed parallel to the occlusal plane

Answer

The beam is angled at exactly 45° regardless of tooth position

Question 4

Which radiographic landmark appears as a radiopaque bow-shaped line above the roots of the maxillary posterior teeth on a periapical radiograph?

Accepted Answer

Floor of the maxillary sinus

Answer

Zygomatic process of the maxilla

Answer

Nasal floor

Answer

Hamular process

Question 5

What is the primary purpose of using a long-cone (PID) technique in periapical radiography?

Accepted Answer

To reduce image magnification and increase sharpness by increasing the source-to-film distance

Answer

To decrease exposure time

Answer

To widen the beam for broader coverage

Answer

To eliminate the need for a film holder

Question 6

A 'ghost image' artifact on a panoramic radiograph most commonly results from which error?

Accepted Answer

Patient jewelry or metallic object left in place during exposure

Answer

Incorrect patient positioning only

Answer

Overexposure of the film

Answer

Using a rectangular collimator