Free drill · Clinical domain
Stage it. Grade it.
The 2017 classification turned perio into a system: stage for severity and complexity, grade for the rate and the risk. Read each case, tap the stage and the grade, and learn the logic the moment you commit.
- ✓Classify real cases. CAL, bone loss, tooth loss, age, and risk factors — the same inputs you'd chart.
- ✓Two axes, one call. Assign Stage I–IV and Grade A–C together; you only nail the case when both are right.
- ✓Feeds your dashboard. Your score rolls into your Clinical readiness.
10 items · about 12 minutes
Perio classification
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This run
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10 items
Flawless — every case, both axes.
Staged and graded ten cases without a single miss on the first look. That is exam-ready.
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Keep this · staging & grading at a glance
| Stage I | Interdental CAL 1–2 mm · bone loss in coronal third |
| Stage II | CAL 3–4 mm · bone loss coronal third |
| Stage III | CAL ≥5 mm · bone loss to mid-third or beyond · ≤4 teeth lost to perio |
| Stage IV | CAL ≥5 mm + complexity: ≥5 teeth lost, bite collapse, <20 teeth remaining |
| Grade A / B / C | % bone loss ÷ age <0.25 / 0.25–1.0 / >1.0 |
| Grade modifiers | Smoking ≥10/day and HbA1c ≥7.0% push the grade up (toward C) |
| Extent | Localized <30% of teeth · Generalized ≥30% · or molar–incisor |
This drill is a study aid based on the 2017 World Workshop (AAP/EFP) classification of periodontal and peri-implant diseases. Staging and grading here uses the worst-affected site and simplified thresholds for teaching; real diagnosis integrates the full clinical and radiographic picture and clinical judgment. The House of Hygiene is not affiliated with or endorsed by the JCNDE.