What's next in oral-systemics?

by Richard H. Nagelberg, DDS

We are still in the discovery phase of the degree to which risks for systemic diseases and conditions are impacted by the mouth and its microbial inhabitants. What will additional research reveal? Is there a realistic possibility that the existence of mouth/body connections are untrue? There is no possibility of that conclusion, because there is no separation between the two.

How is it that a foot infection can interfere with glycemic control, but not a gingival infection? Ask any podiatrist or orthopedist and he or she will tell you that any infection raises blood sugar levels significantly. He or she will tell you that even a small, ingrown toenail causes significant blood sugar swings. It is dogma for our medical colleagues. Periodontal disease is a serious bacterial infection. That is not disputed by anyone, including the biggest naysayers among us.

How is it that all contributors to the total inflammatory burden increase the risk for atherosclerosis and cardiovascular disease, but not periodontal disease? Periodontitis, especially moderate to severe cases, is accompanied by an overgrowth of capillaries, which means that the bloodstream is swimming in bacteria and inflammatory mediators and all manner of infectious agents. Is it possible that this has no effect on the body?

Live oral bacteria, including some periodontal pathogens, have been found in coronary blood vessels by DNA analysis. Their mere presence, regardless of how they got there, is cause for concern. More and more research is revealing the presence of oral bacteria in abdominal and coronary arteries, and now a study has detected periodontal pathogens in intracranial aneurysms, including Aa, Fn, and Td (J Neurol Neurosurg Psychiatry Jun 12, 2013). The authors of this study concluded, "This is the first report showing evidence that dental infection could be a part of pathophysiology in intracranial aneurysm disease." All of these bacteria are toxic and highly pathogenic. Fusobacterium nucleatum has the ability to break the cell-to-cell junctions of endothelial cells, allowing the bacteria and anything smaller to enter the arterial wall. Fn is now considered to be a facilitator of atherosclerosis by this mechanism.

How likely is it that these live bacteria will be inert while sitting inside various vascular structures? They are genetically programmed to survive by releasing enzymes that damage adjacent tissue, loosening up that tissue, facilitating their ability to move through that tissue, and expose more protein nutrient sources. They are programmed to release endotoxins, ingest proteins, and multiply. They are not programmed to just hang around and wait for a white blood cell to take them out. Research certainly needs to demonstrate exactly what they are doing while residing in arterial walls, among other places. Research does not need to tell us that it is highly likely that they are up to no good. Many people stopped smoking cigarettes before research indicated the link between smoking and cancer, heart disease, etc. The coughing, wheezing, and shortness of breath were sufficient evidence for them to quit.

Do the math regarding the number of bacteria in the oral cavity, the openings into the bloodstream via ulcerated gingival epithelium, and the capillary beds in the underlying connective tissue. In patients with moderate to severe periodontitis, it has been estimated that the surface area of the gum tissue involved in the infection is about the same surface area as the palm of the hand. Other researchers indicated the area of involved tissue is about the size of the forearm. In either case, it is a very large surface area of diseased, damaged tissue that does not offer a significant barrier to the rest of the body. The micro-ulcerations in the gingival epithelium are an open door to the circulatory system. Many millions of bacteria reside in the diseased periodontal pocket, perhaps as many as a billion in a particularly deep site, with access to the capillary beds in the connective tissue just below those ulcerations. A few pumps of the heart send them around the rest of the body.

We do not know what further research will reveal. We do know it is not going to indicate that nothing is going on here.

Richard Nagelberg, DDS, has practiced general dentistry in suburban Philadelphia for more than 30 years. He is a speaker, advisory board member, consultant, and key opinion leader for several dental companies and organizations, and he lectures on a variety of topics centered on understanding the impact dental professionals have beyond the oral cavity. Contact him at [email protected].