Crown on tooth #30 with a tiny radiolucency on the mesial root (barely visible). What does the tooth show?

Correct answer: C. Apical resorption (root appears slightly shorter on mesial — barely perceptible)

• A. Loss of lamina dura would present as a discontinuity in the radiopaque line outlining the root, a different finding from this case's described root shortening.
• B. Uniform PDL widening would show an evenly thickened periodontal ligament space, not the localized finding of apical shortening described here.
• C. Correct, per the case description — subtle apical root resorption, evidenced by the root appearing slightly shortened on the mesial aspect.
• D. Internal resorption would appear as a radiolucent enlargement WITHIN the root canal space itself (ballooning), not external apical shortening.

Note: Treatment: Root canal treatment (RCT). Crown margins noted as OK, well-sealed.