Patients with periodontitis have a significantly increased risk of stroke before age 50

Periodontitis, inflammation of the structures that support teeth, significantly increases the risk of stroke in people under 50 years of age with no known predisposing causes. A study in the Journal of Dental Research shows that the further the inflammation in the mouth progresses, the more severe the stroke.

Periodontitis is an inflammatory disease of the oral cavity that destroys the supporting structures of the teeth. The study, led by the Department of Oral and Jaw Diseases at the University of Helsinki, examined inflammatory changes associated with periodontitis, as well as recent dental procedures, in young stroke patients. The focus was on stroke survivors aged 20 to 50 years without known stroke predisposing factors.

“The incidence of such strokes has been increasing in recent decades,” says associate professor and neurology specialist Jukka Putaala from Helsinki University Hospital (HUS).

“Previous studies have established that periodontitis increases the risk of ischemic stroke, but there was no definitive information on the significance of oral inflammation in young patients who had a stroke without traditional causes,” says university researcher Susanna Paju from the University of Helsinki.

The study found that periodontitis was significantly more common among stroke patients than among healthy control subjects. And not only did periodontitis increase the risk of stroke, but its severity also influenced the severity of the stroke.

Microbes from the mouth can increase blood clotting

Dental procedures performed in the previous three months, such as tooth extraction or root canal treatment, and acutely symptomatic inflamed teeth that had not yet been extracted increased the risk of stroke, according to the study.

“Microbes from the mouth enter the bloodstream in connection with low-grade inflammation, but also in the short term in connection with dental procedures, especially if there is pre-inflammation in the mouth,” says Payu.

"The body usually removes these bacteria from the bloodstream," she adds.

Dental procedures and symptomatic bad teeth posed a particular risk for people with a hole known as the patent interatrial foramen in the interatrial septum of the heart. According to the researchers, this foramen ovale could contribute to the formation of blood clots that lead to strokes, as well as bacteria entering the bloodstream from the mouth.

This foramen ovale is common and usually does not require treatment. However, its association with cerebral infarction has been observed in other studies, and closure procedures have been performed to prevent further infarctions.

The microbiome is important

The mouth contains the body's second largest microbiome, or community of microbes, such as bacteria, yeast and viruses - only the intestines are more abundant. A healthy oral cavity has a balanced microbiome, but with periodontitis it changes and harmful bacteria have an advantage.

“A vicious circle is born where bacteria feed on tissues destroyed by inflammation. Their proliferation, in turn, increases inflammation,” says professor of translational dentistry Pirkko Pussinen from the University of Eastern Finland.

It is therefore important to respond promptly to symptoms associated with periodontitis.

“Bad teeth must be removed and inflammation treated, and the teeth must be checked regularly,” confirms Payu.