A smile is the most universally recognized nonverbal signal of happiness. It has enormous power. It can diffuse anger, embolden us, provide comfort, and communicate safety. It is also a luxury many of us take for granted, something to consider as we mark World Oral Health Day this month.
In the 1970’s, I was a young teenager accompanying my mother, a children’s dentist, on a dental health service project to Jamaica. We set up camps in the rural villages where people routinely had to cauterize their toothaches with hot wires because of the lack of dental care. The contrast in access when we returned home was stark. I saw how easily my mother could partner with local authorities through mobile dental vans traveling among Los Angeles schools to give oral hygiene visits and education to elementary students, along with free toothbrush and toothpaste kits.
As an adult, I chose the medical field of emergency medicine, drawn to its in-the-moment demands and requirement to be familiar with multiple areas of the body and how different biological systems interact. Commonly, we may tend to imbue oral health with cosmetic associations and values. These do matter, and the lack of confidence that often comes from having an unhealthy mouth can have serious repercussions. But there are other effects, too, including the effects of oral health policies implemented by governments.
When I was working in South Africa, the country boasted of having one of the lowest periodontal disease, or gum disease rates in the world. Yet, the achievement was much less impressive up close. The South African government was using extraction – pulling teeth – to prevent gum disease in low-income communities and townships. Children were losing permanent teeth, but it saved money in the long run. It was an acceptable collateral consequence of the policy that this population would grow up missing many, if not all, of its permanent teeth. Side effects included hindered speech, limitations on the types of food a person could eat, the self-esteem and self-image problems arising from missing teeth, and reduced ability to compete in the workforce.
A growing body of scientific evidence is finding more repercussions of poor oral health and correlations between unhealthy mouth and serious health conditions like diabetes, cardiovascular disease, chronic obstructive pulmonary disease and chronic kidney disease.
Periodontitis (oral bacterial infection), the sixth most common human disease worldwide, is also shaping up to be a factor in preterm labor and birth.
This is significant because preterm labor (birth before 37 weeks) is a leading cause of neonatal disease and death. In the United States, African American women are disproportionately affected, with a 50% higher rate of preterm birth than white or Hispanic women, and it is the leading cause of death among Black infants.
Babies born prematurely may suffer any number of serious complications including acute respiratory, gastrointestinal, immunologic, central nervous system, hearing and vision problems. They are also more likely to have learning and behavioral problems throughout childhood although these may not appear until elementary or middle school. In addition to premature births, 8% of babies in the U.S. weigh less than 2.5 kilograms at birth, or about 5.5 pounds, and low birth weight alone carries additional health and developmental risks.
The financial cost of premature birth is also enormous. A review by the Institute of Medicine at the National Academies put the cost associated with premature birth in the United States at $26.2 billion in 2005. A 2019 study in the Journal of Perinatology showed average medical costs of $76,153 for preterm babies and $114,437 for low birth-weight babies.
But the price in dollars is far exceeded by the emotional toll on families, particularly if their child requires longer term care or special services during school years, as about one in three children born prematurely does.
Though we have long known of a close correlation between maternal oral health and pre-term birth, the relationship is not well understood. Several randomized trials testing the efficacy of expensive dental procedures, such as scaling or planing, have not demonstrated improved pregnancy outcomes. At the same time, a recent, rather surprising study showed that simply chewing sugar-free gum—yes, gum—can significantly reduce the risk of preterm births.
How did the idea for the study come up? Researchers have known that xylitol, commonly used in sugar-free gum, can reduce tooth decay by increasing the flow of saliva, which protects tooth enamel and neutralizes dental plaque and acids. It also supports tooth remineralization, one of the reasons dentists recommend it in addition to brushing. But the effects of sugar-free gum on preterm births were unknown.
A group of doctors set out to discover whether such a small intervention can really make such a big difference. To test whether chewing xylitol gum reduces the incidence of preterm births, they looked for an answer in a rural area of Malawi, a country in central Africa with the world’s highest known proportion of preterm births at nearly 20%.
The study, conducted over a six-year period, included approximately 10,000 pregnant women in 8 different health clinics in Malawi. All women received education on oral health care and healthy pregnancy practices. One group was also asked to chew xylitol-sweetened gum for 10 minutes 1 -2 times a day throughout pregnancy. The group that chewed gum experienced a 24% reduction in the rate of pre-term delivery compared to the control.
Chewing gum alone isn’t a sufficient solution, but it does represent a small breakthrough in our understanding of what can help reduce preterm birth, particularly in low resource communities. And if reducing inflammation in the body is one reason for gum’s efficacy, perhaps other advances can be made in understanding why common mouth disease contributes to serious health conditions.
Everyone needs a healthy mouth, and there is more than smiles at stake. If some of us are not affected by limited access to care, lifestyle factors, habits, or genetic predispositions that increase the chances of gum disease, we are still all linked in our responsibility for education, access, and treatment for the less fortunate.
World Oral Health Day offers an opportunity to pause and consider how we can increase equal access to healthy smiles for the whole-body health benefit of all.