NBDHE NBDHE Dental Radiography and Interpretation 2 — Questions and Answers
Question 1: Which type of dental radiograph is most useful for evaluating the entire tooth including the apex and surrounding bone?
- Bitewing
- Periapical (Correct answer)
- Occlusal
- Panoramic
Correct answer: Periapical
Periapical radiographs capture the entire tooth from crown to apex along with surrounding alveolar bone.
Question 2: On a periapical radiograph, a radiolucent halo around the apex of a non-vital tooth most likely represents:
- External root resorption
- Periapical cemento-osseous dysplasia
- Periapical abscess or granuloma (Correct answer)
- Condensing osteitis
Correct answer: Periapical abscess or granuloma
A periapical radiolucency around a non-vital tooth typically indicates a periapical abscess, granuloma, or cyst.
Question 3: The paralleling technique for periapical radiographs requires the film or sensor to be placed:
- Against the lingual surface of the teeth
- Parallel to the long axis of the teeth with the central ray perpendicular (Correct answer)
- At a 45-degree angle to the occlusal plane
- As close to the teeth as possible
Correct answer: Parallel to the long axis of the teeth with the central ray perpendicular
The paralleling technique positions the receptor parallel to the tooth's long axis with the X-ray beam directed perpendicular to both.
Question 4: Elongation of a tooth image on a periapical radiograph is caused by:
- Excessive vertical angulation
- Insufficient vertical angulation (Correct answer)
- Excessive horizontal angulation
- Film/sensor placed too far from the teeth
Correct answer: Insufficient vertical angulation
Insufficient (too little) vertical angulation causes elongation because the X-ray beam is directed too flat relative to the tooth.
Question 5: Which radiographic landmark appears as a radiopaque Y-shaped structure in the maxillary premolar region?
- Median palatine suture
- Inverted Y (junction of nasal fossa and maxillary sinus) (Correct answer)
- Incisive foramen
- Zygomaticotemporal suture
Correct answer: Inverted Y (junction of nasal fossa and maxillary sinus)
The inverted Y is formed by the junction of the floor of the nasal fossa and the anterior wall of the maxillary sinus, visible in the maxillary premolar area.
Question 6: A 'double lamina dura' appearance on a periapical radiograph may be associated with:
- Periapical abscess
- Hyperparathyroidism (Correct answer)
- Paget's disease
- Osteomyelitis
Correct answer: Hyperparathyroidism
Hyperparathyroidism can cause altered bone metabolism that produces a double lamina dura appearance around teeth.
Question 7: When using the bisecting angle technique, the central ray should be directed:
- Perpendicular to the long axis of the tooth
- Perpendicular to the bisector of the angle formed by the tooth and the receptor (Correct answer)
- Parallel to the occlusal plane
- Perpendicular to the receptor
Correct answer: Perpendicular to the bisector of the angle formed by the tooth and the receptor
In the bisecting angle technique, the X-ray beam is directed perpendicular to an imaginary line that bisects the angle between the tooth and the receptor.
NBDHE NBDHE Dental Radiography and Interpretation 2
Which type of dental radiograph is most useful for evaluating the entire tooth including the apex and surrounding bone?