Staging and Grading of Periodontitis (2017)
The 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions produced a multidimensional staging and grading system. Below is a concise extraction of the PDF content for use in teaching and clinical reference.
Periodontitis: Staging (concise)
Initial stage should be determined using clinical attachment loss (CAL). If CAL is not available, use radiographic bone loss (RBL). Tooth loss due to periodontitis may modify stage definition. Complexity factors may shift the stage higher.
| Stage | Key findings (CAL / RBL / Complexity) |
|---|---|
| Stage I | Interdental CAL 1–2 mm; RBL <15% (coronal third); PD ≤4 mm; mostly horizontal bone loss. |
| Stage II | Interdental CAL 3–4 mm; RBL 15–33% (coronal third); PD ≤5 mm; mostly horizontal bone loss. |
| Stage III | Interdental CAL ≥5 mm; RBL to middle third of root; ≤4 teeth lost due to periodontitis; complexity such as PD ≥6 mm, vertical bone loss ≥3 mm, furcation class II/III, moderate ridge defects. |
| Stage IV | Stage III features plus ≥5 teeth lost due to periodontitis and need for complex rehabilitation (masticatory dysfunction, secondary occlusal trauma, severe ridge defects, bite collapse, <20 10="" opposing="" pairs="" remaining="" td="" teeth=""> |
Extent/Distribution descriptor: For each stage describe as Localized (<30% of teeth), Generalized, or Molar/Incisor pattern.
Complexity factors (high level)
- Max probing depth >=6 mm
- Vertical bone loss ≥3 mm
- Furcation involvement Class II or III
- Moderate/severe ridge defects, bite collapse, drifting/flaring
- Masticatory dysfunction or secondary occlusal trauma (tooth mobility degree ≥2)
Periodontitis: Grading (concise)
Grading indicates rate of progression, responsiveness to therapy, and potential systemic impact. Assume Grade B initially unless evidence supports Grade A or C.
| Grade | Primary/Indirect criteria |
|---|---|
| Grade A (Slow) | No loss over 5 years; % bone loss / age <0.25; phenotype: heavy biofilm with low destruction. |
| Grade B (Moderate) |
|
| Grade C (Rapid) | ≥2 mm over 5 years or % bone loss / age >1.0; phenotype shows destruction exceeding expectations for biofilm level; presence of modifiers such as smoking ≥10 cigarettes/day or uncontrolled diabetes (HbA1c ≥7.0%). |
Grade modifiers (examples): Smoking — Non-smoker / <10 cigarettes/day / ≥10 cigarettes/day. Diabetes — normoglycemic / HbA1c <7.0% / HbA1c ≥7.0%.
Tables adapted from: Tonetti, Greenwell, Kornman. J Periodontol 2018;89 (Suppl 1): S159-S172. For the full reports and case definitions visit perio.org/2017wwdc.