ADEX Radiographic Interpretation 4 — Questions and Answers
Question 1: A periapical radiograph shows a well-defined, corticated radiolucency at the apex of a tooth that tests vital on pulp testing. What is the most likely diagnosis?
- Periapical abscess
- Periapical cemento-osseous dysplasia (early stage) (Correct answer)
- Lateral periodontal cyst
- Periapical granuloma
Correct answer: Periapical cemento-osseous dysplasia (early stage)
Early-stage periapical cemento-osseous dysplasia appears as a well-defined radiolucency at the apex of a vital tooth, most commonly affecting mandibular incisors in middle-aged Black women.
Question 2: What radiographic change is associated with hypercementosis?
- Root shortening and blunting of the apex
- Bulbous thickening of the root with an intact PDL space and lamina dura (Correct answer)
- Loss of lamina dura and widened PDL space
- Irregular root surface with external resorption pits
Correct answer: Bulbous thickening of the root with an intact PDL space and lamina dura
Hypercementosis appears as a bulbous enlargement of the root due to excess cementum deposition, with the PDL space and lamina dura remaining intact.
Question 3: Which of the following best describes the radiographic appearance of a dentigerous (follicular) cyst?
- Multilocular radiolucency surrounding the root of an erupted tooth
- Well-defined unilocular radiolucency attached at the CEJ surrounding the crown of an impacted tooth (Correct answer)
- Diffuse radiopacity within the follicle of an unerupted tooth
- Ill-defined radiolucency with ragged borders at an impacted tooth apex
Correct answer: Well-defined unilocular radiolucency attached at the CEJ surrounding the crown of an impacted tooth
A dentigerous cyst presents as a well-defined, corticated unilocular radiolucency that attaches at the cemento-enamel junction surrounding the crown of an unerupted tooth.
Question 4: A bitewing radiograph shows a radiolucency confined to the enamel that does not reach the dentinoenamel junction. This represents which stage of caries?
- Incipient caries (early enamel caries) (Correct answer)
- Moderate caries extending into dentin
- Advanced caries approaching the pulp
- Arrested caries with remineralization
Correct answer: Incipient caries (early enamel caries)
Incipient caries is limited to the enamel and appears as a small radiolucency that has not penetrated the DEJ on a bitewing radiograph.
Question 5: What is the radiographic hallmark of a taurodont tooth?
- Excessively long, thin roots with small pulp chamber
- Enlarged pulp chamber extending apically with short roots and no constriction at the CEJ level (Correct answer)
- Multiple supernumerary roots on a single tooth
- Dilaceration of the root apex
Correct answer: Enlarged pulp chamber extending apically with short roots and no constriction at the CEJ level
Taurodontism is characterized by a vertically enlarged pulp chamber with roots that are shortened and positioned apically, lacking the normal horizontal constriction.
Question 6: Horizontal bone loss visible on a bitewing radiograph is measured from:
- The apex of the root to the crest of the alveolar bone
- The CEJ to the existing alveolar bone crest (Correct answer)
- The cusp tip to the midpoint of the root
- The base of the calculus deposit to the alveolar crest
Correct answer: The CEJ to the existing alveolar bone crest
Radiographic bone loss is measured from the CEJ to the existing alveolar bone crest; normal distance is 1.5–2 mm, and greater distances indicate bone loss.
Question 7: Ghost images on a panoramic radiograph appear on which side relative to the actual structure?
- On the same side as the actual structure but lower
- On the opposite side of the actual structure and higher (Correct answer)
- Directly over the actual structure making it appear doubled
- Below the mandibular border on the opposite side
Correct answer: On the opposite side of the actual structure and higher
Ghost images in panoramic radiography appear on the opposite side and higher than the actual structure due to the path of the x-ray beam.
ADEX Radiographic Interpretation 4
A periapical radiograph shows a well-defined, corticated radiolucency at the apex of a tooth that tests vital on pulp testing.
What is the most likely diagnosis?