乳幼児初期う蝕の予防における最適な歯磨き開始年齢と頻度：システマティックレビューとメタアナリシス

Early childhood caries (ECC) is a prevalent global public health concern. Although daily tooth brushing is a key preventive measure, uncertainty remains regarding the ideal age to initiate tooth brushing and the optimal brushing frequency to minimise ECC risk in preschool children. A systematic review and meta-analysis were conducted to explore the association between tooth brushing practices (initiation age and frequency) and the early childhood caries among children under 6 years of age.

We searched three databases (Proquest, Web of Science, and Scopus) for observational studies (2000-2024). Quality was assessed with the Newcastle-Ottawa Scale, and random-effects meta-analyses (DerSimonian-Laird) were conducted. Heterogeneity (I2), publication bias (Egger's test), and sensitivity analyses (outlier exclusion) were performed.

Thirty-two studies (27 cross-sectional, 5 longitudinal) out of 2833 initially identified records met inclusion criteria. 10 contributed to the brushing initiation meta-analysis and 8 to the frequency analysis. Including all 10 studies, late initiation showed a borderline nonsignificant pooled odds ratio (OR = 1.40, 95% CI: 0.91-2.16, p = 0.13) with I2 > 90%. Excluding one outlier yielded a significant OR = 1.75 (1.50-2.03, p < 0.0001). Brushing < 2 × /day was associated with 2.11-fold higher ECC odds (p = 0.0052), also with heterogeneity but no evidence of publication bias (Egger's p = 0.1161).

Despite considerable between-study variability, the overall evidence suggests that commencing tooth brushing by 12 months of age and brushing at least twice daily maybe protective against ECC, highlighting the importance of integrating these practices into early childhood health programs.