Which stage includes furcation involvement of stage 1 or less than 25% attachment loss?

• A. Stage 1
• B. Stage 2
• C. Stage 3
• D. Stage 4

Answer: (B)

In periodontal staging, the level of attachment loss and the presence of furcation involvement set the stage of disease. If furcation involvement is present and the attachment loss is limited to less than or equal to 25%, this pattern fits the second stage. That stage captures mild to early moderate destruction where you can start to see furcation changes (often Class I) but the overall attachment loss remains relatively low. Larger attachment loss and more advanced furcation involvement move into the higher stages, so the described combination is best described as the second stage.