Table 1.
Distribution of selected characteristics of 3956 Japanese females
| Variable | Number (%) |
| Age (y) | 18.1 (0.4) |
| Cigarette smoking | |
| Never | 3828 (96.8) |
| Ever | 128 (3.2) |
| Toothbrushing frequency (times/day) | |
| 1 or less | 484 (12.2) |
| 2 | 2899 (73.3) |
| 3+ | 573 (14.5) |
| Region of residence | |
| Hokkaido and Tohoku | 332 (8.4) |
| Kanto | 1322 (33.4) |
| Hokuriku and Tokai | 637 (16.1) |
| Kinki | 837 (21.2) |
| Chugoku and Shikoku | 452 (11.4) |
| Kyushu | 376 (9.5) |
| Body Mass Index (kg/m2) | |
| < 18.5 | 582 (14.7) |
| 18.5–24.9 | 3078 (77.8) |
| 25.0–29.9 | 244 (6.2) |
| 30+ | 52 (1.3) |