Birth order is associated with caries development in young children: a register-based cohort study

Abstract

Background: Birth order has been shown to affect the health of the child; less is known, however, about how birth order affects caries development in children. Thus, the present study investigated the association between birth order and dental caries development in young children. Methods: This retrospective registry-based cohort study included all children born in 2000–2003 who were residing in Stockholm County, Sweden, at age 3 years (n = 83,147). The study followed the cohort until subjects reached 7 years of age. Children with registry data on dental examinations and sociodemographic characteristics at ages 3- and 7 years constituted the final study cohort (n = 65,259). The outcome variable was “caries increment from age 3- to 7 years” (Δdeft > 0) and the key exposure, “birth order”, was divided into five groups. A forward stepwise logistic binary regression was done for the multivariate analysis with adjustments for sociodemographic factors. Results: At age 3 years, 94% had no fillings or manifest caries lesions. During the study period, 22.5% (n = 14,711) developed dental caries. The final logistic regression analysis found a statistically significant positive association between birth order and caries increment. Further, excess risk increased with higher birth order; with the mother’s first-born child as reference, risk for the second-born child was OR 1.17, 95% CI=1.12–1.23; for the third-born child, OR 1.47, 95% CI=1.38–1.56; for the fourth-born child, OR 1.69, 95% CI=1.52–1.88; and for the fifth-born or higher birth-order child, OR 1.84, 95% CI=1.58–2.14. Conclusions: These findings show that birth order influences caries development in siblings, suggesting that birth order can be regarded as a predictor for caries development in young children. This factor may be helpful in assessing caries risk in preschool children and should be considered in caries prevention work in young children with older siblings.

Impact of an extended postnatal home visiting programme on oral health among children in a disadvantaged area of Stockholm, Sweden

“…Birth order has recently been associated with caries development in young children. 32 Furthermore, the study sample was small, and several children were lost to follow-up due to the high mobility of the families. These limitations in the findings urge further research through randomised controlled trials to find causal links between the parental support programme and positive oral health outcomes.…”

Salivary cystatin S levels in children with early childhood caries in comparison with caries-free children; statistical analysis and machine learning

“…Considering the high level of cystatin S in CF children, a statistically significant relationship between cystatin S and caries risk factors is anticipated. Julihn suggested that birth order is associated with caries increment in young children [ 45 ]. Compared with first-born children, the highest risk of caries increment occurred in fifth- or later-born [ 45 – 47 ].…”

“…Julihn suggested that birth order is associated with caries increment in young children [ 45 ]. Compared with first-born children, the highest risk of caries increment occurred in fifth- or later-born [ 45 – 47 ]. In our study, there was a statistically significant inverse relationship between expression of salivary cystatin S and birth order.…”

Is grandparents' social class associated with adult grandchildren's oral health? Analysis of two British cohorts

“…The following variables were included in the analysis as putative confounders based on previous studies 6‐11 and data availability: cohort member's gender and ethnicity (White vs non‐White), country (England, Wales and Scotland) and area of residence (urban vs rural) at birth, and maternal age (years) and marital status (cohabiting vs not cohabiting) at birth. Birth order was not considered as a confounder because there is inconclusive evidence of its association with oral health 31,32 …”