Which statement best differentiates Stage II from Stage III disease under the 2018 classification?

Which statement best differentiates Stage II from Stage III disease under the 2018 classification?

• A. Bleeding on probing
• B. Diet and fluoride exposure
• C. Probing depth, bone loss, mobility, and furcation involvement
• D. Patient age

Answer: (C)

In this 2018 staging system, what sets Stage II apart from Stage III is the level of disease complexity tied to how much supporting bone is lost and what that loss brings in terms of tooth stability and root area involvement. Stage II reflects moderate bone loss, with probing depths typically in the 4–5 mm range and no major structural complications. Stage III, however, involves more extensive bone loss (generally greater than about 30%), deeper pockets, and additional signs of complexity such as tooth mobility and furcation involvement. These features—more bone loss together with mobility and furcation issues—are what move a case from Stage II into Stage III. Bleeding on probing helps gauge inflammation but doesn’t define the stage, and age or diet/fluoride exposure aren’t used to differentiate these stages.

In this 2018 staging system, what sets Stage II apart from Stage III is the level of disease complexity tied to how much supporting bone is lost and what that loss brings in terms of tooth stability and root area involvement. Stage II reflects moderate bone loss, with probing depths typically in the 4–5 mm range and no major structural complications. Stage III, however, involves more extensive bone loss (generally greater than about 30%), deeper pockets, and additional signs of complexity such as tooth mobility and furcation involvement. These features—more bone loss together with mobility and furcation issues—are what move a case from Stage II into Stage III. Bleeding on probing helps gauge inflammation but doesn’t define the stage, and age or diet/fluoride exposure aren’t used to differentiate these stages.