ADEX Radiographic Interpretation 3 — Questions and Answers
Question 1: What is the primary purpose of using the paralleling technique in periapical radiography?
- To reduce patient exposure by using a shorter cone
- To minimize geometric distortion by aligning the film/sensor parallel to the long axis of the tooth (Correct answer)
- To allow imaging of the full arch on one film
- To improve visualization of soft tissue structures
Correct answer: To minimize geometric distortion by aligning the film/sensor parallel to the long axis of the tooth
The paralleling technique places the receptor parallel to the tooth's long axis and directs the central beam perpendicular to both, minimizing elongation and foreshortening.
Question 2: A radiopaque structure that appears to move in the same direction as the x-ray tube shift during SLOB technique is located:
- Buccally
- Lingually (Correct answer)
- At the same depth as the reference object
- Below the mandibular canal
Correct answer: Lingually
With the SLOB rule (Same = Lingual, Opposite = Buccal), an object moving with the tube shift is on the lingual side.
Question 3: Which radiographic finding is most consistent with a diagnosis of condensing osteitis?
- A well-defined radiolucency at the root apex of a non-vital tooth
- A diffuse radiopaque mass surrounding the apex of a tooth with a history of pulpitis (Correct answer)
- A radiolucent halo surrounding a sclerotic bone island
- Multiple small radiolucencies throughout the jaw
Correct answer: A diffuse radiopaque mass surrounding the apex of a tooth with a history of pulpitis
Condensing osteitis appears as a diffuse radiopacity at the apex of a tooth with pulpal inflammation, representing a bony reaction to low-grade infection.
Question 4: Furcation involvement in a maxillary molar is best evaluated radiographically using which projection?
- Standard occlusal view
- Bitewing radiograph with vertical angulation
- Periapical radiograph with correct horizontal angulation through the furcation (Correct answer)
- Panoramic radiograph only
Correct answer: Periapical radiograph with correct horizontal angulation through the furcation
A periapical radiograph with proper horizontal angulation directed through the furcation area provides the best view of furcation bone loss in maxillary molars.
Question 5: A patient presents with a large, multilocular radiolucency crossing the midline of the mandible with a 'soap bubble' appearance. What is the most likely diagnosis?
- Simple bone cyst
- Ameloblastoma (Correct answer)
- Central giant cell granuloma
- Odontogenic keratocyst
Correct answer: Ameloblastoma
A multilocular 'soap bubble' radiolucency in the mandible is a classic radiographic presentation of ameloblastoma.
Question 6: What does 'cervical burnout' refer to in radiographic interpretation?
- Overexposure of the cervical spine on a panoramic image
- A false radiolucency at the cervical margin of a tooth due to decreased x-ray absorption (Correct answer)
- Dark areas caused by developer contamination
- Radiation damage to enamel at the CEJ
Correct answer: A false radiolucency at the cervical margin of a tooth due to decreased x-ray absorption
Cervical burnout is a radiographic artifact appearing as a false radiolucency at the cervical region of a tooth due to the relative thinness of tooth structure there.
Question 7: On a panoramic radiograph, which anatomical landmark appears as a radiopaque band running horizontally across the maxillary sinus region?
- Coronoid process of the mandible
- Zygomatic arch (Correct answer)
- Nasal septum
- Infraorbital rim
Correct answer: Zygomatic arch
The zygomatic arch frequently appears as a horizontal radiopaque band superimposed over the maxillary sinus on panoramic radiographs.
ADEX Radiographic Interpretation 3
What is the primary purpose of using the paralleling technique in periapical radiography?