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

我们试图弄清变形链球菌何时在日本婴儿的口腔中定植，并分析哪些因素与30个月大婴儿的龋齿发生有关。在日本岩手县的一个小镇，71名婴儿在12个月、18个月和30个月大的时候接受了调查。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Sliva样本。在检查前，他们的母亲已经完成了一份调查问卷，其中包含了当时托儿所的日常饮食行为和口腔卫生问题，我们在检查当天收回了这份问卷。为了了解这位母亲的龋病经历和变形链球菌的水平，我们在研究开始时为她们进行了牙齿检查，并收集了她们的Sliva样本。变形链球菌在12月龄婴儿中的定植发生率为21.1%。18月龄定殖率为35.2%，30月龄为54.9%。21.1%的婴儿在30个月时有一颗或多颗牙齿患龋齿。Logistic回归分析显示，与30个月龄龋齿发生有关的显著因素。含糖饮料和奶瓶进食，亲子共用餐具，12个月龄变形链球菌定植情况。此外，在18个月大的婴儿中，变形链球菌的定植即使在这个年龄也是重要的因素，母亲每天刷牙被发现是减少龋齿的一个因素。

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.