Despite not implying a causative relationship, public health and clinical findings suggest that secondhand smoke could be associated with dental carries. Scientists in Japan performed a study recently to evaluate the efficacy of such a hypothesis.
The Problem Of Dental Carries
The extent of dental carries in baby teeth in developed countries continues to increase – 20.5 percent in children aged 2 to 5 years in the US, and 25 percent in children aged 3 years in Japan. Certified methods to prevent the development of carries include restriction of sugar intake, use of fluoride supplementation and varnish.
Recently, certain studies have indicated that secondhand smoke could be related to dental carries. However, it remains uncertain whether reducing exposure to secondhand smoke among children would be a viable preventive strategy.
Scientifically Evaluating A Concept
A group of researchers based in Japan investigated whether smoking during pregnancy, and exposure of fourth month old infants to secondhand smoke could be risk factors in causing carries. Data was analyzed for 76,920 children born between 2004 and 2010. They had routine health check-ups at zero, four, nine, 18 months and at three years of age.
Mothers were asked to fill questionnaires for assessing the extent of exposure to secondhand smoke during their pregnancy and till their child was three years old. Also, lifestyle factors such as oral health and dietary habits were also analyzed.
The incidence of carries in baby teeth was defined as at least one decayed, filled or missing tooth, ascertained by qualified dentists. The prevalence of exposure to household smoking was 55.3 percent, and 6.8 percent of the children had been exposed to tobacco. A total of 12,729 incidents of dental carries were identified, including a majority of decayed teeth.
Compared with no exposure, being exposed to tobacco smoke at four months was associated with an almost two-fold increase in the risk of developing carries. Also, this risk increased to those exposed to secondhand smoke, while the effect of maternal smoking during pregnancy was not significant.
Despite the study not establishing a causative relation, the researchers conclude:
“Exposure to secondhand smoke at four months of age – experienced by half of all children of that age in Kobe City, Japan – is associated with an increase in the risk of carries in baby teeth. Although these findings cannot establish causality, they support the need of developing extensive public health and clinical interventions to reduce exposure to secondhand smoke”.