What is the stage and grade for the 62-year-old female with probing depths of 7-8 mm and five teeth lost?

• A. Stage III, Grade A
• B. Stage IV, Grade B
• C. Stage IV, Grade C
• D. Stage II, Grade B

Answer: (B)

The key idea here is distinguishing how we measure current disease impact versus how fast it’s progressing. Staging looks at how severe and widespread the damage is and how it affects function, while grading estimates how quickly the disease is advancing over time.

Deep probing depths of 7–8 mm indicate severe periodontal destruction, and losing five teeth due to periodontitis shows extensive impact on the dentition. Together these findings place the patient in Stage IV, which reflects advanced disease with significant tooth loss and functional considerations.

For the grade, we assess the rate of progression. In the absence of systemic risk factors like uncontrolled diabetes or smoking, a moderate rate of progression fits best. That corresponds to Grade B, indicating progression roughly in the 0.5–1.0 mm per year range. Stage IV with Grade B is the best match because the disease is clearly advanced, but the information given doesn’t suggest a rapid (Grade C) or very slow (Grade A) progression.

So, the combination of severe destruction with substantial tooth loss points to Stage IV, and the estimated moderate pace of progression fits Grade B.