Classification
Stage I
Initial periodontitis
- • CAL 1–2mm
- • Bone loss coronal third <15%
- • Max probing depth ≤4mm
- • No tooth loss due to periodontitis
Stage II
Moderate periodontitis
- • CAL 3–4mm
- • Bone loss coronal third 15–33%
- • Max probing depth ≤5mm
- • No tooth loss due to periodontitis
Stage III
Severe — potential for tooth loss
- • CAL ≥5mm
- • Bone loss extending to middle/apical third
- • Vertical bone loss ≥3mm, furcation II–III
- • Tooth loss ≤4 due to periodontitis
Stage IV
Severe — potential for dentition loss
- • Same as Stage III
- • Masticatory dysfunction
- • Secondary occlusal trauma
- • Tooth loss ≥5 due to periodontitis