Which radiographic finding is most characteristic of external root resorption?

Which radiographic finding is most characteristic of external root resorption?

• A. Symmetrical enlargement of the pulp chamber
• B. Internal radiolucent defect within the root canal
• C. Irregular or discontinuous root outline with loss of root structure adjacent to the PDL
• D. Uniform widening of the lamina dura

Answer: (C)

External root resorption shows up on radiographs as irregularities on the outer surface of the tooth root. The root outline becomes irregular or discontinuous with areas where root structure is lost on the side next to the periodontal ligament space. This outward, jagged loss of tooth structure is the hallmark, and you may see the lamina dura in that area appear interrupted as well. This differs from internal resorption, which creates a radiolucent defect inside the root canal while the external outline stays relatively intact. Uniform widening of the lamina dura isn’t specific to resorption, and symmetrical enlargement of the pulp chamber points to internal resorption rather than external.

External root resorption shows up on radiographs as irregularities on the outer surface of the tooth root. The root outline becomes irregular or discontinuous with areas where root structure is lost on the side next to the periodontal ligament space. This outward, jagged loss of tooth structure is the hallmark, and you may see the lamina dura in that area appear interrupted as well. This differs from internal resorption, which creates a radiolucent defect inside the root canal while the external outline stays relatively intact. Uniform widening of the lamina dura isn’t specific to resorption, and symmetrical enlargement of the pulp chamber points to internal resorption rather than external.