DMD DMD - Doctor of Medicine in Dentistry Dental Radiology and Imaging Questions and Answers 1 — Questions and Answers
Question 1: Which radiographic technique uses a film or sensor placed parallel to the long axis of the tooth with a beam directed perpendicular to both?
- Paralleling technique (Correct answer)
- Bisecting angle technique
- Panoramic technique
- Occlusal technique
Correct answer: Paralleling technique
The paralleling technique places the receptor parallel to the tooth and directs the central ray at 90° to both, producing the most geometrically accurate periapical images.
Question 2: What is the ALARA principle in dental radiography?
- As Low As Reasonably Achievable (Correct answer)
- Automatic Lateral Angle Radiation Adjustment
- Adjusted Long Axis Radiographic Analysis
- Advanced Low-kV Radiation Alignment
Correct answer: As Low As Reasonably Achievable
ALARA stands for As Low As Reasonably Achievable and directs clinicians to minimize patient radiation exposure while still obtaining diagnostically adequate images.
Question 3: Which type of dental X-ray provides the most comprehensive single-image view of both dental arches, TMJ, and surrounding structures?
- Panoramic radiograph (Correct answer)
- Full mouth series
- Bitewing radiograph
- Cone beam CT (CBCT)
Correct answer: Panoramic radiograph
A panoramic radiograph (orthopantomogram) captures both arches, all teeth, sinuses, and temporomandibular joints in one extraoral projection.
Question 4: Bitewing radiographs are primarily used to detect which type of dental lesion?
- Interproximal caries and crestal alveolar bone loss (Correct answer)
- Periapical pathology and root fractures
- Impacted third molars
- Sinus abnormalities
Correct answer: Interproximal caries and crestal alveolar bone loss
Bitewing radiographs show the crowns and crestal bone of both arches simultaneously, making them ideal for detecting proximal caries and early periodontal bone changes.
Question 5: A radiolucent halo surrounding the apex of a non-vital tooth on a periapical radiograph is most consistent with which diagnosis?
- Periapical abscess or granuloma (Correct answer)
- Condensing osteitis
- Cementoblastoma
- Dentigerous cyst
Correct answer: Periapical abscess or granuloma
A periapical radiolucency associated with a non-vital tooth indicates inflammatory breakdown of periapical bone, consistent with a granuloma, abscess, or cyst.
Question 6: Which lead apron position is required when taking dental radiographs on a pregnant patient?
- Thyroid collar plus full-body lead apron covering abdomen (Correct answer)
- No lead apron needed with digital X-ray
- Thyroid collar only
- Full-body apron without thyroid collar
Correct answer: Thyroid collar plus full-body lead apron covering abdomen
Pregnant patients should wear both a thyroid collar and a full-body lead apron covering the abdomen to protect both the thyroid and the developing fetus.
