研究出生体重与7岁儿童龋病的关系。

2014年在上海市黄浦区某小学抽取498名7岁儿童，采用世界卫生组织的方法及标准，由经培训的口腔医生检查儿童口腔，记录龋失补情况，通过家长问卷调查获取儿童出生体重。排除67名未提供出生体重儿童，共431名儿童纳入分析。采用卡方检验比较两组或多组间患病率差异，t检验和Dunnett法检验两组或多组间龋失补牙数以及出生体重差异，Logistics回归法分析出生体重与重度龋病的关系。

研究对象患龋率为70.1%，龋失补牙数（dmft+DMFT）为3.44 ± 3.55，出生体重为（3.30 ± 0.51）kg。出生体重<2500、2500~ 2999、3000~ 3499、3500~ 3999和≥4000 g的7岁儿童龋失补牙数分别为4.09 ± 4.23、2.25 ± 2.48、3.42 ± 3.59、3.76 ± 3.56和4.11 ± 4.06，重度龋（dmft+DMFT≥5）患病率分别为40.9%、15.9%、35.0%、39.4%和41.7%。在出生体重≥2500 g儿童中，重度龋儿童的出生体重显著大于无龋儿童和轻中度龋儿童（出生体重均值差_{无龋-重度龋}=-0.12，P_{出生体重无龋-重度龋}=0.047；出生体重均值差_{轻中度龋-重度龋}=-0.14，P_{轻中度龋-重度龋}= 0.009）。用Logistic回归调整性别因素后，以出生体重2500~ 2999 g为参考组，<2500、3000~ 3499、3500~ 3999和≥4000 g的重度龋比值比（OR）及P值分别为OR_{<2500 g}= 3.37（95%可信区间1.13~ 10.05），P_{<2500 g}= 0.030；OR_{3000~ 3499 g}= 2.69（1.28~ 5.67），P_{3000~ 3499 g}= 0.009；OR_{3500~ 3999 g}= 3.16（1.46~ 6.84），P_{3500~ 3999 g}= 0.004；OR_{≥4000 g}= 3.45（1.33~ 8.98），P_{≥4000 g}= 0.011，差异均有统计学意义。

出生体重与7岁儿童龋失补牙数及重度龋患病率呈先降后升关系，出生体重过低或过高均可能是重度龋的危险因素。

To study the association between birth weight and dental caries in 7-years-old children.

All 498 children aged 7 were recruited from a primary school in Shanghai at 2014. Oral examinations were performed by calibrated dentists according to World Health Organization procedures and diagnostic criteria, which decayed, missing and filled teeth were recorded. Birth weight was collected through self-administrated questionnaires by children′s parents. After excluding 67 participants without reported birth weight, 431 children were recruited into analysis. Chi square test was applied to test the difference of caries prevalence in between respective groups as well as the t test and Dunnett test for the difference of decayed teeth and birth weight. The association between birth weight and severe caries was analyzed by Logistics regression.

The prevalence of dental caries was 70.1%, and the mean of decayed, missing and filled teeth (dmft+DMFT) were 3.44 with a standard deviation (SD) of 3.55. The average birth weight of participants was (3.30 ± 0.51) kg. For children with birth weight of<2500 g, 2500-2999 g, 3000-3499 g, 3500-3999 g and ≥4000 g groups, the dmft+DMFT were 4.09 ± 4.23, 2.25 ± 2.48, 3.42 ± 3.59, 3.76 ± 3.56 and 4.11 ± 4.06 respectively; and the prevalence of severe caries (dmft+DMFT≥5) were 40.9%, 15.9%, 35.0%, 39.4% and 41.7%, respectively. Among the children with birth weight ≥2500 g, children with severe caries had birth weight significantly higher than those without caries or with mild caries (mean-difference_{caries-free-severe-caries}=-0.12, P_{caries-free-severe-caries}= 0.047; mean-difference_{mild-caries-severe-caries}=-0.14, P_{mild-caries-severe-caries}= 0.009) . Compared to the children of with birth weight 2500-2999 g, the odds ratios (OR) of severe caries of groups with birth weight <2500 g, 3000-3499 g, 3500-3999 g and ≥4000 g were OR_<2500g= 3.37 (95% confidence interval 1.13~10.05) , P_<2500g=0.030; OR_3000~3499g= 2.69 (1.28-5.67) , P_{3000~ 3499 g}= 0.009; OR_{3500~ 3999 g}= 3.16 (1.46-6.84) , P_{3500~ 3999 g}= 0.004; OR_{≥4000 g}= 3.45 (1.33-8.98) , P_{≥4000 g}= 0.011.

A relationship was found between birth weight and dmft+DMFT or severe caries among children aged 7. Both Low and high birth weight were probably risk factors for severe caries.