ADEX Radiographic Interpretation 5 — Questions and Answers
Question 1: Which radiographic feature helps differentiate a lateral periodontal cyst from a periapical lesion?
- The lateral periodontal cyst is ill-defined and associated with non-vital teeth
- The lateral periodontal cyst is located lateral to the root of a vital tooth with no periapical involvement (Correct answer)
- The lateral periodontal cyst always shows root resorption
- The periapical lesion is well-corticated while the lateral cyst is not
Correct answer: The lateral periodontal cyst is located lateral to the root of a vital tooth with no periapical involvement
A lateral periodontal cyst appears as a well-defined radiolucency on the lateral aspect of a vital tooth root, distinguishing it from periapical pathology associated with non-vital teeth.
Question 2: A patient's periapical radiograph shows a 'sunburst' or 'sunray' pattern of bone destruction extending from the jaw. This pattern is most suggestive of:
- Osteosarcoma or other malignant bone tumor (Correct answer)
- Fibrous dysplasia
- Central giant cell granuloma
- Ameloblastoma
Correct answer: Osteosarcoma or other malignant bone tumor
A sunburst or sunray pattern of periosteal new bone formation radiating from the cortex is highly characteristic of osteosarcoma.
Question 3: What term describes a radiographic error where the image appears elongated?
- Foreshortening due to excessive vertical angulation
- Elongation due to insufficient vertical angulation (Correct answer)
- Overlapping due to incorrect horizontal angulation
- Cone cutting due to misalignment of the beam
Correct answer: Elongation due to insufficient vertical angulation
Elongation occurs when the vertical angulation is too flat (insufficient), causing the image to appear longer than the actual tooth.
Question 4: On a periapical radiograph, a widened periodontal ligament space that is uniform around the entire root most likely indicates:
- Localized periodontal disease attacking one surface
- Occlusal trauma or systemic disease causing generalized PDL widening (Correct answer)
- Periapical abscess formation
- External root resorption at the apex only
Correct answer: Occlusal trauma or systemic disease causing generalized PDL widening
Uniform widening of the PDL space around the entire root is associated with occlusal trauma, systemic diseases like scleroderma, or early malignant infiltration.
Question 5: A simple bone cyst (traumatic bone cyst) most commonly appears radiographically as:
- A multilocular radiolucency with sclerotic borders
- A unilocular radiolucency with scalloping between tooth roots and no cortical expansion (Correct answer)
- A mixed radiolucent-radiopaque lesion in the posterior mandible
- A diffuse radiopacity replacing cancellous bone
Correct answer: A unilocular radiolucency with scalloping between tooth roots and no cortical expansion
Simple bone cysts present as unilocular radiolucencies that classically scallop upward between tooth roots; they are empty cavities and teeth test vital.
Question 6: Which of the following describes the radiographic appearance of enamel pearls (enamelomas)?
- Radiolucent droplets at the CEJ of molars
- Small, discrete radiopaque nodules located in the furcation area of molar roots (Correct answer)
- Radiopaque lines running parallel to the root surface
- Calcified pulp stones visible within the pulp chamber
Correct answer: Small, discrete radiopaque nodules located in the furcation area of molar roots
Enamel pearls are small deposits of ectopic enamel that appear as discrete radiopaque nodules, usually found in the furcation area of maxillary molars.
Question 7: Which radiograph is most appropriate for evaluating the extent of a large cyst or pathology involving the entire mandible?
- Full-mouth series of periapical radiographs
- Panoramic radiograph (Correct answer)
- Cross-sectional occlusal radiograph
- Bitewing series
Correct answer: Panoramic radiograph
A panoramic radiograph provides the broadest field of view of the entire mandible and maxilla in a single image, making it ideal for evaluating large jaw lesions.
ADEX Radiographic Interpretation 5
Which radiographic feature helps differentiate a lateral periodontal cyst from a periapical lesion?