How is CAL calculated when there is gingival recession?

• A. PD - GM-CEJ distance
• B. PD + CEJ distance
• C. PD
• D. PD + GM-CEJ distance

Answer: (D)

The essential idea is that CAL (Clinical Attachment Level) is the distance from the cementoenamel junction to the base of the pocket. When gingival recession is present, the gingival margin sits apical to the CEJ, so you must add the amount of recession to the probing depth to get CAL. In other words, CAL = probing depth plus the distance from the CEJ to the gingival margin (the recession distance).

If the gingival margin has receded 2 mm apically from the CEJ and the probing depth is 5 mm, CAL would be 7 mm.

This approach is better than just using probing depth, which would miss recession, and it aligns with using the recession distance (GM-CEJ) as the added component.