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†152534
 2500–2999(n=16 159)7182636
 3000–3499(n=19 411)7182837
 ≥3500(n=5582)9203039
Sex
 Female(n=21 010)7182736
 Male(n=22 373)7182737
Parity
 1(n=19 875)6152433
 2(n=14 639)9202838
 3(n=4729)10233545
 ≥4(n=1000)11233445
Maternal age at delivery
 <25(n=5861)8203040
 25–29.9(n=16 848)7172635
 30–34.9(n=15 200)7182736
 ≥35(n=5474)8203039
Socioeconomic factors
Maternal educational attainment
 High school or less(n=18 023)8203040
 Two-year college or vocational school(n=16 715)7172636
 Four-year college or higher(n=5615)6132230
Maternal smoking status
 Non-smoker(n=35 623)7182636
 Light smoker(n=4817)8203039
 Heavy smoker(n=2622)9223244
Marital status
 Married(n=42 827)7182736
 Not married(n=556)9203042
Region of birth
 Hokkaido(n=1674)8182737
 Tohoku(n=3244)9213241
 Kanto(n=13 828)7162433
 Chubu(n=7874)7182837
 Kinki(n=7935)7182737
 Chugoku(n=2601)7182737
 Shikoku(n=1276)7202940
 Kyushu/Okinawa(n=4951)9213142
Family income*
 <250(n=3265)9†213040
 250–499(n=15 256)8192938
 500–749(n=14 235)7182736
 ≥750(n=7860)6152433
  • *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).