NBDHE NBDHE Dental Radiography and Interpretation 5 — Questions and Answers
Question 1: Which of the following is a characteristic radiographic feature of condensing osteitis?
- Radiolucency at the apex with loss of lamina dura
- Well-defined radiopaque mass at the apex of a tooth with pulpal pathology (Correct answer)
- Multilocular radiolucency with scalloped borders
- Generalized decrease in bone density around multiple teeth
Correct answer: Well-defined radiopaque mass at the apex of a tooth with pulpal pathology
Condensing osteitis presents as a focal sclerotic bone reaction appearing as a well-defined radiopaque area at the apex of a tooth with chronic low-grade pulpal inflammation.
Question 2: The geometric factor that most affects image sharpness is the:
- Kilovoltage peak (kVp)
- Source-to-object distance (Correct answer)
- Milliamperage (mA)
- Exposure time
Correct answer: Source-to-object distance
Increasing the source-to-object distance (focal spot to tooth distance) reduces penumbra and improves image sharpness.
Question 3: Which radiographic technique minimizes the overlap of proximal surfaces on a bitewing radiograph?
- Increasing vertical angulation
- Directing the central ray through the contact points using correct horizontal angulation (Correct answer)
- Placing the receptor closer to the tongue
- Using a longer exposure time
Correct answer: Directing the central ray through the contact points using correct horizontal angulation
Correct horizontal angulation directs the X-ray beam through the interproximal contacts, preventing overlapping of adjacent tooth surfaces.
Question 4: On a panoramic radiograph, which artifact results from the patient's tongue not being in contact with the palate during exposure?
- A radiopaque band across the lower third of the maxilla
- A radiolucent band across the roots of the maxillary teeth (Correct answer)
- A ghost image of the mandible
- Blurring of the anterior teeth
Correct answer: A radiolucent band across the roots of the maxillary teeth
When the tongue is not positioned against the palate, an air space creates a dark radiolucent shadow (shadow of the air space) across the roots of the maxillary teeth.
Question 5: The latent image on conventional radiographic film is formed by:
- Direct exposure of the film emulsion to visible light
- Interaction of X-ray photons with silver halide crystals in the emulsion (Correct answer)
- Chemical development of the gelatin base
- Ionization of the polyester film base
Correct answer: Interaction of X-ray photons with silver halide crystals in the emulsion
X-ray photons interact with silver halide crystals in the film emulsion, liberating electrons that reduce silver ions and form a latent (invisible) image.
Question 6: A radiograph showing a widened periodontal ligament (PDL) space around the entire tooth is most consistent with:
- Periapical abscess
- Occlusal trauma or bruxism (Correct answer)
- Hypercementosis
- Ankylosis
Correct answer: Occlusal trauma or bruxism
Uniform widening of the PDL space around the entire root is a classic radiographic sign of occlusal trauma or bruxism causing increased tooth mobility.
Question 7: Which of the following best describes the recommended position for a patient's head during a panoramic radiograph to ensure proper positioning in the focal trough?
- Head tilted back 20 degrees with chin raised
- Frankfort plane parallel to the floor with the midsagittal plane perpendicular to the floor (Correct answer)
- Head rotated 10 degrees to the right for right-side detail
- Chin resting on the chin rest with the head tilted forward 15 degrees
Correct answer: Frankfort plane parallel to the floor with the midsagittal plane perpendicular to the floor
Proper panoramic positioning requires the Frankfort plane (ala-tragus line) to be parallel to the floor and the midsagittal plane to be perpendicular to the floor to ensure symmetrical positioning within the focal trough.
NBDHE NBDHE Dental Radiography and Interpretation 5
Which of the following is a characteristic radiographic feature of condensing osteitis?