How can internal or external root resorption best be differentiated?

Differentiating between internal and external root resorption is critical in endodontics and preventive dentistry. The best approach involves understanding the behavior of the resorption in relation to the canal space, which is appropriately captured in the context of B.

External root resorption typically originates from factors outside the tooth, such as trauma or periodontal disease, and presents itself as a lesion that extends from the root surface inward toward the pulp canal. By taking additional periapical (PA) radiographs while also noting the movement of the resorptive defect in relation to the canal, clinicians can observe that external resorption will move or change in context to the canal configuration due to its external origin.

On the other hand, internal resorption begins from within the pulp chamber and typically leads to a more symmetrical, balloon-shaped enlargement of the canal system. It does not shift relative to the canal space because its source is internal.

While panoramic radiography could provide some information about the overall structure of the roots, it lacks the detail needed to distinguish the nuanced changes between internal and external resorption effectively. Evaluating occlusal views can help locate resorption but may not be definitive in distinguishing between the two types. An electric pulp tester can assess pulpal vitality but does not