Mothers’ oral bacteria pose health risk for children

An affectionate kiss on the lips, sharing a spoon over ice cream—without giving it a second thought parents expose their children to potentially harmful oral bacteria every day. Surprisingly, they do so against their better knowledge, a Finnish study has found.

The transmission of oral bacteria, together with diet and oral hygiene, has proven to be important in the aetiology of dental caries in toddlers in various studies. Since certain health behaviours play a major role in the prevention of most common oral diseases, researchers from the University of Oulu have aimed to investigate the variety and complexity of such habits in a group of Finnish mothers.

In the study, the health knowledge and behaviour of 313 mothers of toddlers under the age of 3 were evaluated. Information on oral health-related routines, such as sharing a spoon with the child, cleaning its dummy with the mouth and kissing on the lips, was collected via questionnaires. Background data on the mothers’ toothbrushing and smoking habits, age, and education level was also obtained.

The most common health practice related to bacterial transmission from the mother’s mouth to the child’s mouth was kissing the child on the lips, which was reported by 38 per cent of the participants. Another 14 per cent said that they shared a spoon when feeding their child. In contrast, virtually none of the mothers reported cleaning the child’s dummy in their own mouth, while a minority of 11 per cent believed that oral bacteria cannot be transmitted from mother to child at all.

The findings further showed that general health behaviour was primarily related to the age and education level of the mothers. Older age and a higher level of education appeared to be associated with behaviours considered optimal, such as twice-daily toothbrushing and not smoking, in the group.

Surprisingly, behaviours related to potential bacterial transmission, such as sharing a spoon with the child or kissing the child on the lips, only had a weak or no link to the age and education level of the mothers. According to the scientists, this suggests that physical contact and shared pleasure in early mother–child interaction appears to be of greater significance to the mothers surveyed than existing oral health knowledge.

As various studies have shown, children acquire infectious agents that are most strongly associated with dental caries, such as Streptococcus mutans, primarily from their mothers. Consequently, reducing the transmission of mothers’ oral bacteria during the emergence of children’s primary teeth at the age of about 6 to 12 months could help prevent or delay colonisation by these bacteria for a prolonged period and decrease the children’s risk of caries.

With that in mind, the Finnish scientists suggested that health education should put more emphasis on how to avoid bacterial transmission from caregivers to children during feeding in the future.