A periodontitis patient with 5 teeth lost and HbA1c of 7% (well-controlled DM). What is the MOST appropriate AAP/EFP staging and grading?

Correct answer: B. Stage IV (complexity and tooth loss), Grade C (risk factor: DM, even if controlled)

• A. Stage III with 5 teeth lost doesn't meet Stage IV criteria — complexity (tooth loss ≥5) and potential for further tooth loss defines Stage IV.
• B. Correct. Stage IV = maximum severity with 5+ teeth lost due to periodontitis. Grade C (high risk/rapid progression) = evidence of rapid progression OR known risk factors such as DIABETES MELLITUS (HbA1c ≥7% or known DM). Even with an HbA1c of 7% (borderline), diabetes is a Grade C risk factor modifier. Additionally, heavy smokers (>10 cigarettes/day) → Grade C.
• C. Stage II with 5 lost teeth is incorrect — 5 lost teeth = Stage IV.
• D. Stage IV Grade A would apply to a young patient with extensive tooth loss but NO risk factors — DM pushes to Grade C.