Fight Back! Proactively Addressing the Caries Process

The Oral Systemic Connection
The premise that oral health may influence systemic health is not new but it has undergone a number of modifications throughout the years. In 400 BC, Hippocrates reported that a patient was cured of arthritis after the extraction of an ill tooth. More recently, the theory that poor dental health can cause several systemic diseases has been called the Theory of Focal Infection. Focal infection can be traced back to the late 19th century when Dr. Willoughby Miller, an oral microbiologist, claimed that cavities played a role in the etiology of gastric problems, lung and brain abscesses, and other medical conditions.

In 1900, Dr. William Hunter, a prominent British physician, drew wide attention to these theories by presenting them in a lecture to the medical students of McGill University in Canada.

Dr. Frank Billings formally introduced the focal infection theory to American physicians. His lectures at Stanford University Medical School were published in 1916 in the book, Focal Infections. Dr. Billings went a step further than Dr. Hunter and promoted tonsillectomies and dental extractions as remedies for focal infections. Even prominent doctors like Dr. Charles Mayo (founder of the prestigious Mayo Clinic) promoted focal infection.

In 1923, Dr. Weston Price, chairman of the Research Section of the ADA, published Dental Infections, Oral and Systemic. Despite Dr. Price himself saying that more research was needed and care should be used in applying focal infection theory, Dental Infections, Oral and Systemic was used as a reference in textbooks and diagnosis guides of the early to mid 1930s.

The focal theory began to lose steam as scientists and physicians began to embrace modern “evidence-based” theories of disease. Perhaps a turning point in the popularity of focal infection was offered in an article published in the Annals of Internal Medicine in 1938. A former proponent of the theory, Dr. Russell Cecil stated that “focal infection is a splendid example of a plausible medical theory which is in danger of being converted by its enthusiastic supporters into the status of an accepted fact.” His study of 200 cases of rheumatoid arthritis documented no curative benefit of tonsillectomies or dental extractions. The final demise of the focal theory can probably be traced to a 1940 paper published in the Journal of the American Medical Association entitled, “Focal Infection and Systemic Disease: A Critical Appraisal,” by Drs. Hobart Reimann and Paul Havens. The authors showed that the theory was completely unproven.

A special 1951 issue of the Journal of the American Dental Association stated: “Many authorities, who formally felt that focal infection was an important etiologic factor in systemic disease, have become skeptical and now recommend less radical procedures in the treatment of such disorder.”

Toward the end of the 20th century, researchers began to view gingivitis and periodontal disease as an infection and chronic inflammatory condition. Like other chronic inflammatory diseases, the results can become widespread. The bacteria and their toxins can enter the bloodstream and reach distant sites, causing havoc and disease in organs throughout the body.

Beginning in the 1980s, a series of journal articles describing the association between periodontal disease and coronary heart disease (CHD), stroke and preterm birth/low-birthweight caught the attention of the medical and dental professions. While in some sense this can be construed as a return to the theory of focal infection, the response from the dental and medical professions has been more conservative. Modern investigative science uses greater sophistication in assaying data. There is a better understanding of the limits of epidemiologic studies in establishing causality and greater appreciation of the etiology of periodontal diseases and associated systemic diseases. In short, we have come to understand that the major killer diseases—cardiovascular disease (CVD) and cancer—have multiple causes and multiple risk factors.

There is no single cause for heart attacks. It is not smoking, not high blood pressure, not obesity, not high cholesterol, not stress, not lack of exercise, not genetics; and no, it is not periodontal disease. Rather it is a combination of these, and other risk factors that add layer upon layer of increased risk of suffering a heart attack. Modern science has come to understand that many chronic diseases such as CVD and cancer are multifactorial in nature, and anything that we can do to eliminate risk factors can go a long way to lengthening our lives.

In the past 2 decades there have been hundreds of studies published in the peer-reviewed medical journals that show periodontal disease is a risk factor for heart attacks. Several thousand more have been published in dental journals. Upon further investigation, it appears clear that brushing your teeth and avoiding periodontal disease really can save your life.

The modern connection between periodontal disease and CVD lies in the chronic, inflammatory nature of gum disease. Periodontal disease, simply put, is a bacterial infection of the gums and structures supporting the teeth. As with most infections throughout the entire body, gum infection leads to inflammation.