A prospective study concerning with the transmission of mutans streptococci from mother to infant

我们试图澄清变形链球菌何时在日本婴儿口腔中定植，并分析哪些因素与30月龄婴儿龋齿的发生有关。在日本岩手县的一个小镇对71名年龄分别为12个月、18个月和30个月的婴儿进行了调查。在每个调查点，我们检查了他们的牙列，并获得了他们的牙菌斑和菌丝样本。在检查前，他们的母亲填写了一份调查问卷，其中包含了当时儿童的日常饮食行为习惯和口腔卫生问题，我们在检查当天回收了问卷。为了了解母亲龋齿的经历和变形链球菌的水平，我们在研究开始时对她们进行了牙齿检查，并收集了她们的唾液样本。在21.1%的12月龄婴儿中发现了变形链球菌的定植。之后，定植率在18月龄增加到35.2%，在30月龄增加到54.9%。21.1%的婴儿在30月龄时出现一颗或多颗蛀牙。logistic回归分析显示，与30月龄龋齿发生相关的因素有统计学意义。这些婴儿用奶瓶喝含糖饮料，父母和孩子共用餐具，以及12个月大时变形链球菌的定植。此外，在18月龄时，变形链球菌的定植即使在年龄上也是显著的因素，并且发现母亲每天刷牙可以减少蛀牙的发生。

We attempted to clarify when mutans streptococci were colonized in Japanese infants' oral cavities, and to analyze what factors related to the occasion of dental caries in 30 months old infants. 71 infants were surveyed at the age of 12 months, 18 months and 30 months, in a town of Iwate prefecture, Japan. In each point of survey, we examined their dentitions, and obtained their dental plaque and sliva samples. Prior to the examination, their mothers had completed a questionnaire containing the questions about daily habits of dietary behavior and oral hygiene in the child care at the time, and we recovered it on the day of examination. To know the mother's experience of dental caries and level of mutans streptococci, we carried out the dental examinations for them and collected their sliva samples at the start of this study. The colonization of mutans streptococci was found in 21.1% of 12 months old infants. Afterwards, the colonization rate increased to 35.2% at the age of 18 months, and 54.9% at the age of 30 months. And 21.1% of the infants had one or more tooth suffering from dental caries at the age of 30 months. A logistic regression analysis showed the significant factors relating to the occurrence of dental caries at the age of 30 months. Those were taking sugar contained drinks with feeding bottle, sharing the tableware in parent and child, and the colonization of mutans streptococci in the age of 12 months. Further, in the age of 18 months, the colonization of mutans streptococci was significant factors even in the age, and daily toothbrushing by the mother was found as a factor could reduce the occasion of dental caries.