Classification according to 1999 and 2018 classification system
| 1999 classification system | N (%) | 2018 classification system | N (%) | 2018 classification system | |
|---|---|---|---|---|---|
| Sum | N (%) | ||||
| Aggressive periodontitis | 15 (30) | Stage III Grade C | 8 (53.3) | Stage II Grade A | 2 (4) |
| Chronic periodontitis | 35 (70.0) | Stage IV Grade C | 7 (46.7) | Stage II Grade B | 3 (6) |
| Moderate | 5 (14.3) | Stage II Grade A | 2 (5.7) | Stage III Grade B | 3 (6) |
| Severe | 30 (85.7) | Stage II Grade B | 3 (8.6) | Stage III Grade C | 30 (60) |
| Stage III Grade B | 3 (8.6) | Stage IV Grade C | 12 (24) | ||
| Stage III Grade C | 22 (62.9) | ||||
| Stage IV Grade C | 5 (14.2) | ||||