The concept that there is a connection between oral infections and systemic (body) health is not new. As early as 1891, Dr. Willoughby Miller recognized and outlined the concept in a book called "The Dental Cosmos". Miller described the mouth as a "focus of infection where microorganisms or their waste products obtain entrance to parts of the body adjacent to or remote from the mouth". The need to find better tooth filling materials and tooth replacement methods overshadowed this concern and it was disregarded.
Recent research has once again identified an "oral-systemic link" and it is changing the way dentists, doctors and patients view oral health. An increasing amount of research indicates that oral infections can play a role in a variety of systemic health problems as wide ranging as diabetes, respiratory illness, pregnancy complications, and heart disease.
New information on the oral-systemic link emerges almost daily. For example, in May 2006 it was announced at an American Society for Microbiology meeting that researchers have identified genes in certain oral bacteria that allow the organisms to invade and infect human arterial cells predisposing the aorta to form clogging plaques. In July, 2009, the following statement was published in The American Journal of Cardiology: “Patients with moderate to severe periodontitis should be informed that there may be an increased risk for atherosclerotic cardiovascular disease associated with periodontitis.”
Physicians and dentists are becoming more aware that even mild oral infections can trigger adverse changes in other areas of the body. Clearly the mouth is the "gateway" to the rest of the body.