Anyone who has visited a dentist has probably noticed something puzzling.
Some people seem to get very few cavities despite not always following perfect dental habits, while others develop tooth decay or gum disease even when they take excellent care of their teeth.
A major new study from Sweden suggests that part of the answer may lie in our genes.
Researchers from Umeå University have carried out the largest study ever conducted on the relationship between genetics and dental health. Their findings show that both inherited genes and everyday lifestyle factors influence a person’s risk of developing tooth decay and gum disease.
The study helps explain why some people appear naturally more vulnerable to dental problems than theirs and may eventually lead to more personalized approaches to dental care.
Tooth decay, often called cavities, and gum disease, known medically as periodontitis, are among the most common health conditions worldwide. They affect people of all ages and can have serious consequences if left untreated.
Cavities occur when bacteria in the mouth feed on sugars and produce acids that gradually damage the outer layers of teeth. Over time, this damage can create holes in the teeth, causing pain, sensitivity, and infection.
Gum disease begins when bacteria accumulate around the gums and trigger inflammation. In its early stages, gums may become red, swollen, or bleed during brushing. If the condition progresses, it can damage the tissues and bone that support the teeth, eventually leading to tooth loss.
Beyond oral health, growing evidence suggests that dental diseases may be linked to other health problems throughout the body, including heart disease, diabetes, and certain inflammatory conditions.
Scientists have suspected for many years that genetics plays a role in dental health. However, proving this has been difficult because so many other factors influence the condition of our teeth and gums. Diet, oral hygiene, smoking, access to dental care, education, income, and overall health can all affect a person’s risk.
To better understand the role of genetics, the Swedish researchers analyzed data from nine different studies involving approximately 62,000 individuals. They also used information from the UK Biobank, one of the world’s largest health databases, which contains genetic and health information from more than 460,000 people.
By combining data from such a large number of participants, the researchers were able to perform a detailed search across millions of locations in human DNA. Their goal was to identify genetic variations associated with tooth decay and gum disease.
The results revealed 47 previously unknown genes linked to tooth decay. The researchers also confirmed the importance of a key immune-system-related gene involved in gum disease.
These discoveries provide strong evidence that genetics can influence a person’s susceptibility to dental problems.
The newly identified genes perform many different functions within the body. Some help build and maintain teeth, jawbones, and other structures inside the mouth. Others influence the production and function of saliva.
Saliva plays a crucial role in protecting oral health. It helps wash away food particles and harmful bacteria, neutralizes acids that can damage tooth enamel, and contains substances that help fight infection.
If saliva production is reduced or its protective functions are weakened, the risk of cavities increases significantly. The study suggests that genetic differences affecting saliva may partly explain why some individuals develop tooth decay more easily than others.
The researchers also found that certain genes influence the types of bacteria that live in the mouth. The mouth contains hundreds of different bacterial species, forming a complex ecosystem known as the oral microbiome.
Some bacteria help maintain a healthy environment, while others contribute to tooth decay and gum disease. Genetic differences may affect which bacterial communities are more likely to thrive in an individual’s mouth.
For gum disease, the immune system appeared to be particularly important.
Because periodontitis is essentially a chronic infection, the body’s immune response plays a major role in determining how much damage occurs. If the immune system responds too weakly, harmful bacteria may multiply unchecked. If it responds too aggressively, inflammation can damage healthy tissues surrounding the teeth.
The study confirmed that genes involved in immune function significantly affect a person’s risk of developing gum disease.
One of the most interesting findings was the connection between dental health and broader health risks.
The researchers found links between tooth decay and several factors that are also associated with cardiovascular disease, including smoking and obesity. This supports the growing view that oral health and overall health are closely connected.
Poor oral health is increasingly being recognized as more than just a problem affecting the mouth. Inflammation and infection in the gums may influence other systems throughout the body, while general health conditions can also affect oral health.
Despite these important genetic discoveries, the researchers emphasize that lifestyle habits remain extremely important.
Having genes that increase the risk of cavities or gum disease does not mean that dental problems are inevitable. Regular brushing with fluoride toothpaste, daily flossing, routine dental check-ups, and limiting sugary foods and drinks remain among the most effective ways to protect teeth and gums.
Likewise, avoiding smoking and maintaining a healthy body weight can benefit both oral health and overall health.
The findings may eventually allow dentists to identify people who have a higher genetic risk of dental disease. In the future, these individuals could receive earlier monitoring, personalized prevention plans, or targeted treatments designed specifically for their risk profile.
This approach, often called personalized medicine, is already being explored in many areas of healthcare. The new study suggests that dentistry may also benefit from this strategy.
While genes influence the foundation of dental health, daily habits still play a major role in determining long-term outcomes. The research highlights that maintaining a healthy smile depends on both the biology we inherit and the choices we make every day.
If you care about tooth health, please read studies about an important causes of tooth decay and gum disease, and common tooth disease that may increase risks of dementia.
For more health information, please see recent studies about mouthwash that may increase your tooth damage, and results showing this diet could help treat gum disease.
The study was led by Ingegerd Johansson and published in Nature Communications.
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