Studies have shown associations between oral conditions, particularly periodontal disease, and systemic ailments, some of them life-threatening and all affecting quality of life.
What does the condition of your teeth, gums, and jaws have to do with your heart, brain, and guts? More than you might realize.
The public perception of the mouth as separate from the body—a sort of self-sustaining city within a larger country—has held sway for decades. Yet “more and more research is showing the impact of oral disease on general health, and it is much greater than it was once thought to be,” says Athanasios Zavras, who leads the Department of Public Health and Community Service at Tufts University School of Dental Medicine.
Significant data exist on the association between various oral conditions, particularly periodontal disease, and systemic ailments, some of them life-threatening and all affecting quality of life. And the relationship is reciprocal. Just ask anyone with diabetes whose disease was first flagged through their swollen, bleeding gums.
“I think we are in a good position to address these issues, and prevent and treat oral disease, which will eventually benefit all of human health,” says Jake Jinkun Chen, professor of basic and clinical translations sciences at the School of Dental Medicine. In his lab, Chen and his team are searching not just to find common underlying mechanisms that connect oral and systemic diseases, but to find strategies that could prevent or treat them, including Type 2 diabetes, osteoporosis, Alzheimer’s, and autoimmune diseases like Sjorgen’s and rheumatoid arthritis.
In the meantime, what can we do to protect our oral, and thus overall, health? In a word, prevention. “Pay very meticulous attention to oral health,” says Zavras, the Delta Dental of Massachusetts Professor in Public Health and Community Service. “It should require some minutes of someone’s time twice a day.”
And that attention should encompass the whole mouth. For too long, Zavras says, the focus has been solely on our pearly whites. “It’s the teeth and gums,” he stresses.
The Vital but Messy Microbiome
Why does what happens in the mouth not stay in the mouth? The answer is the oral microbiome, which is basically “all the germs we have in our mouths and how they travel to distant sites in the body,” says Zavras.
The mouth is the point of entry for numerous bacteria and viruses, and the immune cells that live there can become the first to fight off those pathogens. For example, Hend Alqaderi, an assistant professor in the Department of Public Health and Community Service, has found people who developed severe cases of COVID-19 had considerably different oral bacteria than those with milder symptoms.
Infections that begin in the mouth can also spread through the bloodstream to other parts of the body. Zavras refers to the dramatic case of a Maryland preteen who died in 2007 after he was unable to get timely treatment for a dental abscess and the infection eventually attacked his brain. Similarly, pathogens that are inhaled through the mouth can contribute to respiratory conditions like pneumonia.
Why aren’t these connections better known? Talking about microbes in the mouth can be off-putting for the public, says Yau-Hua Yu, an associate professor of periodontology who has examined the association between self-reported poor oral health and negative long-term systemic health outcomes.
When oral care is presented as being all about smiles, that’s very appealing, she says. “But when we start to think about other things in the oral cavity”—say, saliva, bacteria, and mucous membranes—“that can be a little messy,” and people become less receptive to oral health messages.
Yu sees hope in the recent popular emphasis on gut health. “The microbiome has become very trendy,” she says. “But the microbiome starts at the oral cavity.”
A Drop in the Bucket
Approximately 47% of people over age 30 in the U.S. have some form of periodontal disease: essentially, inflammation and infection of the tissues that support the teeth. It can range from mild recession to gingivitis to severe periodontitis, and eventually endanger the teeth and jawbone.
“Numerous studies show periodontal disease may increase risk of cardiovascular disease, heart attack, stroke, and hardening of the arteries,” says Natalie Jeong, professor and chair of the Department of Periodontology.
Jeong stresses that a direct causal relationship has not been definitively established between these cardiovascular conditions and periodontal disease. “But both share common risk factors: smoking, diabetes, age, even lifestyle factors like poor diet, lack of exercise, and obesity,” she says.
There is also a strong correlation between periodontal disease and diabetes—both Type 1 and Type 2—and it goes in both directions, Jeong says. “If blood glucose is well-controlled, the state of periodontal disease improves; when periodontal disease is treated, glycemic control tends to improve.” Oftentimes, she says, when a newly diagnosed periodontal patient, particularly a younger person, does not respond to initial treatment, that’s a sign that undiagnosed diabetes is also likely in the mix, Jeong says.
Oral disease is just one of many conditions that promote systemic inflammation, says Nadeem Karimbux, dean of the School of Dental Medicine and a professor of periodontology. But that doesn’t mean it should be minimized, either.
He uses the metaphor of several taps—various risk factors—dripping into a bucket, the collected stresses on the body’s health. Eventually, the bucket spills over into heart disease or other ailments, “The drip from the oral health condition may just be one more contributing factor that pushes you over the edge,” Karimbux says.
