Exposure to second-hand smoke at four months of age is associated with an increased risk of tooth decay at age three years, concludes a study published recently in The British Medical Journal.
While caries prevention in young children generally focuses on sugar restriction, oral fluoride supplementation and fluoride varnish, some studies have suggested that second-hand smoke plays a role. Second-hand smoke may directly affect teeth and microorganisms in a number of ways, including inflammation of the oral membrane, damage to the salivary gland function and a decrease in serum vitamin C levels, as well as immune dysfunction.
A team of researchers in Japan wanted to know whether maternal smoking during pregnancy and exposure of infants to tobacco smoke at the age of four months would increase the risk of caries in deciduous teeth.
The team analysed data for 76,920 children born between 2004 and 2010, who attended routine health check-ups at 0, four, nine and 18 months, and at three years of age, at healthcare centres in Kobe City, Japan. Mothers completed questionnaires about second-hand smoke exposure from pregnancy to three years of age, and other lifestyle factors, such as dietary habits and oral care.
Incidence of caries in deciduous teeth was defined as at least one decayed, missing or filled tooth assessed by qualified dentists.
Compared with having no smokers in the family, exposure to tobacco smoke at four months of age was associated with an approximately twofold increase in the risk of caries.