Applying the NEW Periodontal Classification

What is the Three-Step Approach to Staging and Grading

Step 1: Establish Periodontitis Diagnosis
  1. Identify Interdental Clinical Attachment Loss (CAL):
    • ≥2 non-adjacent teeth with CAL ≥1 mm.
  2. Confirm Radiographic Bone Loss (RBL):
    • Correlate with CAL to confirm diagnosis.
  3. Rule Out Non-Periodontal Causes:
    • Examples: Trauma, gingival recession, root fractures, or dental caries.
Step 2: Determine Stage
  1. Base on Severity:
    • Key Measures:
      • Interdental CAL
      • RBL percentage
      • Tooth loss due to periodontitis
  2. Assess Complexity:
    • Consider probing depths, bone defects, furcation involvement, and restorative needs.
  3. Stages Summary:
    • Stage I: Initial (1-2 mm CAL, RBL <15%)
    • Stage II: Moderate (3-4 mm CAL, RBL 15-33%)
    • Stage III: Severe with potential for tooth loss (≥5 mm CAL, RBL mid-third or beyond)
    • Stage IV: Advanced with significant rehabilitation needs (≥5 mm CAL, RBL mid-third or beyond, ≥5 teeth lost).
Step 3: Determine Grade
  1. Assess Rate of Progression:
    • Use direct evidence of progression (e.g., bone loss/CAL over time).
    • Use indirect evidence (e.g., bone loss to age ratio).
  2. Consider Risk Factors:
    • Smoking and diabetes are the main systemic modifiers.
  3. Grades Summary:
    • Grade A: Slow progression (no CAL or RBL over 5 years, low systemic risk).
    • Grade B: Moderate progression (≤2 mm CAL or RBL over 5 years, moderate risk factors).
    • Grade C: Rapid progression (>2 mm CAL or RBL over 5 years, heavy smoking, or poorly controlled diabetes).
4. Practical Example Workflow
  • Patient Data Collection:
    • Interdental CAL: 5 mm
    • RBL: Extends to mid-third of root
    • Tooth loss: 3 teeth
    • Risk factors: Smokes 15 cigarettes/day
    • HbA1c: 8.5%
  • Stage: Stage III (based on severity and complexity).
  • Grade: Grade C (based on smoking and HbA1c levels).
5. Key Notes for Application
  • Systemic Health Integration:
    • Grading considers both local and systemic factors.
  • Reassess Regularly: Changes in clinical condition may require stage/grade updates.
  • Simplify Patient Communication:
    • Use staging and grading to explain disease severity and progression risk.

Radiographic Bone Loss (RBL) Calculation is critical to staging periodontitis. Here’s how to determine RBL:

Steps to Calculate RBL

  1. Identify the Total Root Length:
    • Measure from the cementoenamel junction (CEJ) to the root apex on a radiograph.
  2. Determine the Extent of Bone Loss:
    • Measure the distance from the CEJ to the current bone level on the radiograph. Focus on the worst-affected site.
  3. Calculate the Percentage of Bone Loss:
    • Use the formula

RBL Calculation Examples

Example 1:
  • Total Root Length (CEJ to Apex): 10 mm
  • Bone Loss (CEJ to Bone Level): 2 mm
  • RBL=(2/10)×100=20%
  • Stage: Based on this RBL, the patient would be Stage II (15-33% bone loss).
Example 2:
  • Total Root Length (CEJ to Apex): 13 mm
  • Bone Loss (CEJ to Bone Level): 7 mm
  • RBL=(7/13)×100=54%
  • Stage: Based on this RBL, the patient would be Stage III or IV (≥33% bone loss).

How to calculate the RBL-to-Age Ratio For Periodontal disease

To calculate Radiographic Bone Loss (RBL) relative to age, the formula is as follows:

RBL-to-Age Ratio=RBL (%) divided by the Age 

How to Use the Ratio

  1. Determine RBL (%): Use the method for calculating RBL as described above.
  2. Divide by the Patient’s Age.
  3. Compare the result to thresholds for grading.

Grading Based on RBL-to-Age Ratio

  • Grade A (Slow Progression): RBL-to-Age Ratio <0.25
  • Grade B (Moderate Progression): 0.25≤ RBL-to-Age Ratio ≤1.
  • Grade C (Rapid Progression): RBL-to-Age Ratio>1.0

Example Calculation of the RBL to Age Ratio

Example 1
  • RBL: 20%
  • Age: 40 years
  • RBL-to-Age Ratio=20/40=0.5
  • Grade: B (Moderate Progression).
Example 2:
  • RBL: 50%
  • Age: 25 years
  • RBL-to-Age Ratio=50/25=2.0
  • Grade: C (Rapid Progression).
Example 3:
  • RBL: 10%
  • Age: 50 years
  • RBL-to-Age Ratio=10/50=0.2
  • Grade: A (Slow Progression).

High Yield MCQS

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