Tooth Decay Risk Doubles in Children Exposed to Secondhand Smoke

There is an alarmingly high rate of dental caries in deciduous teeth in developed countries, at a rate of about 20.5% in children aged 2-5 in the US. Dental caries can be caused by various biological, environmental, physical and lifestyle factors. In particular, one study has concluded that exposure to secondhand smoke at 4 months is associated with an increased risk of tooth decay at age 3.

In general, secondhand smoke can cause inflammation of the oral membrane and damage to the salivary gland function, as well as immune dysfunction. Children who have been exposed to passive smoking have lower salivary lgA levels and higher levels of sialic acid with higher activity. Sialic acid increases the accretion of Streptococcus mutans (S. mutans); this bacteria produces acids from sugar that is consumed which can dissolve the hard enamel coating of teeth, leading to the development of dental plaque and caries.

Japanese scientists looked more closely at how smoking during pregnancy and exposure to household smoke in 4-month-old infants influenced the probability of caries. After analyzing over 76,000 children, they found that children who have been exposed to tobacco smoke were twice as likely to develop dental caries when compared to children who had no smokers within the family. Surprisingly, the effect of maternal smoking during pregnancy was not statistically significant.