How is CAL calculated for recession?

• A. Probe depth + gingival margin recession
• B. Probe depth - gingival margin recession
• C. CEJ to gingival margin distance
• D. Gingival recession minus probing depth

Answer: (A)

Clinical attachment level is the distance from the CEJ to the base of the pocket. When the gingival margin has receded apically, you must add the depth of the pocket to the amount of recession to get CAL. So CAL equals probing depth plus gingival recession. For example, if the probing depth is 3 mm and the recession is 2 mm, CAL is 5 mm. The other options either subtract recession, measure only the CEJ-to-margin distance, or don’t account for both the pocket depth and the recession, so they don’t reflect the true attachment loss.