In a study published in The BMJ, researchers found that exposure to secondhand smoke as an infant as young as 4 months is associated with increased risk of tooth decay at age 3, according to Medical News Today.
Preventing tooth decay in young children tends to focus on restricting sugar, supplementing with oral fluoride and fluoride varnish. However, studies suggest that secondhand smoke plays a part in the development of cavities, which can result from a number of factors that include physical, biological, and environmental and lifestyle.
A big part of oral health is the acquisition of Streptococcus mutans (S. mutans), that produce acids from the sugar one consumes, dissolving the hard enamel coating on teeth. The age of highest risk for these bacteria is at 19-31 months.
Looking at smoking during pregnancy and exposure to household smoke in infants at 4 months of age as risk factors, Japanese researchers looked to see if these led to tooth decay among children exposed.
Focused on health care centers in Kobe City, Japan, they analyzed data for 76,920 children born between 2004 and 2010. These children attended routine health checkups at 0, 4, 9 and 18 months, and at 3 years of age. Their mothers answered questions, offering information about secondhand smoke exposure from pregnancy to 3 years of age and other lifestyle factors, such as dietary habits and oral care.
Tooth decay in youth teeth included at least one decayed, missing or filled tooth assessed by qualified dentists.
The researchers found 55.3 percent prevalence of smoking in the home among children studied, and 6.8 percent showed evidence of tobacco exposure. A total of 12,729 cases of dental cavities, mostly decayed teeth, were identified.
When looking at those who had no smokers in the family, exposure to tobacco smoke at 4 months of age, the increase in the risk of cavities jumped twofold. The effect of maternal smoking during pregnancy was not statistically significant.