Table 2.
Proportion of children with dental caries by biological and socioeconomic factors at each survey from the third to the sixth (nbaseline=43 383)
| 30 Months (n=39 404) (%) | 42 Months (n=38 258) (%) | 54 Months (n=36 673) (%) | 66 Months (n=35 547) (%) | ||
|---|---|---|---|---|---|
| Biological factors | |||||
| Birth weight*, g | |||||
| <2500 | (n=2231) | 6† | 15 | 25 | 34 |
| 2500–2999 | (n=16 159) | 7 | 18 | 26 | 36 |
| 3000–3499 | (n=19 411) | 7 | 18 | 28 | 37 |
| ≥3500 | (n=5582) | 9 | 20 | 30 | 39 |
| Sex | |||||
| Female | (n=21 010) | 7 | 18 | 27 | 36 |
| Male | (n=22 373) | 7 | 18 | 27 | 37 |
| Parity | |||||
| 1 | (n=19 875) | 6 | 15 | 24 | 33 |
| 2 | (n=14 639) | 9 | 20 | 28 | 38 |
| 3 | (n=4729) | 10 | 23 | 35 | 45 |
| ≥4 | (n=1000) | 11 | 23 | 34 | 45 |
| Maternal age at delivery | |||||
| <25 | (n=5861) | 8 | 20 | 30 | 40 |
| 25–29.9 | (n=16 848) | 7 | 17 | 26 | 35 |
| 30–34.9 | (n=15 200) | 7 | 18 | 27 | 36 |
| ≥35 | (n=5474) | 8 | 20 | 30 | 39 |
| Socioeconomic factors | |||||
| Maternal educational attainment | |||||
| High school or less | (n=18 023) | 8 | 20 | 30 | 40 |
| Two-year college or vocational school | (n=16 715) | 7 | 17 | 26 | 36 |
| Four-year college or higher | (n=5615) | 6 | 13 | 22 | 30 |
| Maternal smoking status | |||||
| Non-smoker | (n=35 623) | 7 | 18 | 26 | 36 |
| Light smoker | (n=4817) | 8 | 20 | 30 | 39 |
| Heavy smoker | (n=2622) | 9 | 22 | 32 | 44 |
| Marital status | |||||
| Married | (n=42 827) | 7 | 18 | 27 | 36 |
| Not married | (n=556) | 9 | 20 | 30 | 42 |
| Region of birth | |||||
| Hokkaido | (n=1674) | 8 | 18 | 27 | 37 |
| Tohoku | (n=3244) | 9 | 21 | 32 | 41 |
| Kanto | (n=13 828) | 7 | 16 | 24 | 33 |
| Chubu | (n=7874) | 7 | 18 | 28 | 37 |
| Kinki | (n=7935) | 7 | 18 | 27 | 37 |
| Chugoku | (n=2601) | 7 | 18 | 27 | 37 |
| Shikoku | (n=1276) | 7 | 20 | 29 | 40 |
| Kyushu/Okinawa | (n=4951) | 9 | 21 | 31 | 42 |
| Family income* | |||||
| <250 | (n=3265) | 9† | 21 | 30 | 40 |
| 250–499 | (n=15 256) | 8 | 19 | 29 | 38 |
| 500–749 | (n=14 235) | 7 | 18 | 27 | 36 |
| ≥750 | (n=7860) | 6 | 15 | 24 | 33 |
*Treated as continuous in the statistical analyses.
†The percentage describes the proportion of children with dental caries (versus without) within each category in the left column at each age (eg, the proportion of children with dental caries in the <2500 g category at 30 months).