Health and Oral Health

By Dr. Alison Adams, Contributor

One Radio Network

Periodontal disease is the most common disease in the world with 90% of the adult population affected to some lesser or greater extent.The microorganisms that can be found in the mouth would be considered a serious threat to health if found elsewhere in the body and yet most dental and health professionals still consider oral infection to be a localised issue.

“The incidence of periodontal infection exceeds 70% in the 30 – 44 age groups and 90% in the 55 – 64 age group. The prevalence and severity of periodontal infection will increase as the life expectancy of the population and retention of teeth increase.”

US National Institute of Health

However, a growing body of research evidenceover the last couple of decades has linkedperiodontal (gum) diseaseto a wide variety of systemic diseases. In fact, The Research, Science and Therapy Committee of The American Academy of Periodontology lists over 40 such diseases including:

• Infective endocarditis (damaged heart valves)
• Cardiovascular diseases includingcoronary thrombosis,arteriosclerosis, ischaemic heart disease and strokes
• Diabetes and obesity
• Respiratory problems including pneumonia
• Pancreatic cancer
• Osteoporosis
• Rheumatoid arthritis and
• Some behavioural issues.

Such is the link that a study conducted by the University Of Michigan School Of Dentistry has found an association betweenpoor dental health andpremature death from all causes.This is significant too because the pathogens involved in periodontal disease are communicable and can potentially be passed between family members and down through the generations.

It is accepted that oral microorganisms can be launched into the circulation in appreciable numbers during some dental procedures and for this reason patients deemed to be ‘at risk’ are required to have prophylactic antibiotics (‘antibiotic cover’) for some kinds of dental treatment. Further, it is widely accepted that considerable numbers of bacteria enter the circulation during everyday activities including chewing and tooth brushing and that this too may pose a health risk in some vulnerable people.

Individuals considered to be ‘at risk’ from systemic bacteraemia include those with a history of infective endocarditis, heart valve disorders, congenital heart diseases and cardiac myopathy. Experts differ as to whether people who have had an intra-synovial joint replacement should receive antibiotic prophylaxis to prevent infection affecting established prostheses with the American Association of OrthopaedicSurgeons in favour and other professional bodies considering it unnecessary.

So the fact that oral microbes enter the circulation posing a threat to general health is well established and yet still overlooked by many. The following explores just some of the research evidence linking periodontal disease to systemic illness and the possible mechanisms by which this occurs.

Gum health and heart disease

There is growing evidence that the presence of periodontal disease can be linked to the incidence of coronary heart disease. Gums infected with periodontal disease are toxic reservoirs of disease-causing bacteria. The bacteria are able to live and reproduce in periodontal pockets adjacent to the teeth, where the healthy tight contact between the supporting tissues and the tooth has been lost.

The lining of such pockets is inflamed and provides an easy entry point for any microbes present to enter the general circulation as recently demonstrated byDr Mark Herzberg and fellow researchersat the University of Minnesota in Minneapolis. In particular the bacteria, Streptococcus sanguis, can enter the circulation causing blood clots that can block arteries and trigger heart attacks. The researchers found that rabbits injected with plaque demonstrated reduced blood flow to the heart within as little as 30 minutes.

“Severe periodontitis is the equivalent of about nine square inches of chronic wound around the teeth. It offers considerable opportunity over time for these bacteria to enter the blood.”

Professor Mark Herzberg DDS PhD, director of the study

In astudy of veteransconducted by Dr. Walter Loesche of the University of Michigan, older men with heart disease were found to have more active periodontal disease and more missing teeth, and those with severe periodontal disease were 4.5 times more likely to have coronary heart disease than those with healthy gums. In the same study, the researchers also showed an inverse relationship between regular dental appointment attendance and the likelihood of having a stroke.

Analysis of the fatty plaquesassociated with heart attacks and strokes at theState University of New York at Buffalofound that these deposits contained the DNA of several periodontal microorganisms, and that total bacterial numbers appeared to be more important than any specific species.

Another studyof 10,000 adults found that people with periodontal disease also have elevated blood levels of the blood-clotting factor fibrinogen which may lead to blocked coronary or cerebral arteries (heart attacks and strokes respectively).

In asix-year prospective studyof over44,000 male health professionals (many of whom were dentists) those who had a history of tooth loss and/or periodontal disease at the start of the study demonstrated an increased risk of coronary heart disease.

Another study found that young adults who had some periodontal bone loss were 50% more likely to have a coronary heart problem and that fatal heart disease was twice as common in those with gum disease.

The Department of Oral Biology,University of Florida at Gainesvillelooked at the ability ofthree periodontal pathogens to invade the endothelial cells lining the blood vessels and the smooth muscle of the coronary artery. They found that specific species demonstrated the ability to invade the coronary artery cells at significant levels. In particular,Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans were found to be two of the most aggressive offenders associated with periodontal disease.

“Our finding is important because it has proved there are live periodontal bacteria in human atherosclerotic tissue. Now we can begin to understand how these bacteria contribute to the disease process.”

Professor Ann Progulske-Fox, Oral Biology, University of Florida College of Dentistry

And Finnish research conducted byPussinen et alat the Helsinki University Central Hospital which followed nearly 10,000 patients over 14 years showed that those with the worst periodontal disease at the outset of the study had a 25% increased risk of developing coronary heart disease, especially the younger men.

There are several mechanisms by which oral and systemic diseases may be related. One is that during the immune response to chronic periodontal infection, there are elevated quantities of white blood cells and apseudo-hormone called C-reactive protein (CRP) is produced by the liver. It is this protein that causes inflammation of artery walls causing compromised blood flow in certain vulnerable organs and systems. In addition, pre-existing conditions can also be made worse by the inflammatory and infective agents produced in chronic periodontal disease.

Research at the University of North Carolina found elevated levels of C-reactive protein inheart-attack survivors with advanced periodontal disease. And further studies found that CRP levels were directly related to the severity of the periodontal disease.

A recent study published in The New England Journal of Medicine identified elevated CRP levels as a stronger predictor of heart attacks than elevated cholesterol levels, and recommended CRP screening be included for an accurate risk assessment of cardiovascular disease.

Oral health and strokes

The first USNational Health and Nutrition Examination Survey(NHANES) and its follow-up studies of nearly 10,000 adults have conclusively found that having gum disease doubles the risk of having a stroke.

AndDr Arnin Grau, M.D., of the Department of Neurology at the University of Heidelberg, Germany found that chronic periodontal disease increased the risk of a stroke two and a half times over patients with no periodontal disease. His research team also found that stroke patients were three times more likely to have periodontal disease and that this was the only significant causative factor.

Diabetes and gum health

Historically, the presence of periodontal disease in the mouths of diabetics has been assumed to have been associated with reduced immunity and to have been asymptomof diabetes.This is because the peripheral circulation is compromised in diabetics leading to reduced oxygenation and toxin removal and the teeth and supporting tissues are end organs.

The research ofDr. Robert Genco and his teamat the Oral Biology Department at State University of New York at Buffalo has shown that treating periodontal disease stabilises blood sugar levels in diabetics.

In anotherstudy conducted in Swedenof insulin-dependent diabetics who were followed over 11 years, the incidence of stroke, angina and heart failure was four times higher in those rated as having severe periodontal disease when compared to those who had mild gum disease at the outset.

Another study testing the causative role of periodontal disease in type II diabetics found that the dysregulation of blood sugar was directly proportionate to the severity of the periodontal disease.

The relationship between periodontal disease and diabetes is thought to be a two-way relationship with the chronic inflammation associated with periodontal infection causing metabolic disruption.On a pragmatic level, addressing periodontal disease has also been shown to be cost-effective in reducing the quantities of medication required for diabetics which may see its widespread acceptance. It is also suggested that patients with advanced periodontal disease should be screened for diabetes in the absence of other risk factors.

The link between poor gum health, stomach problems and obesity

Further to the studies into diabetes, Dr Sara Grossi and researchers from the School of Dental Medicine at University of Buffalo, New York have found that the inability to lose weight is significantly related to periodontal disease through promoting insulin resistance.

“Infections are known to disrupt metabolic pathways and in this case, the bacteria associated with periodontal disease are thought tointerfere with fat metabolism, leading to elevated LDL cholesterol and total cholesterol.”

Dr. Sara Grossi, Clinical Assistant Professor of Oral Biology, SUNYAB

Statistics from the NHANES studies support a correlation between obesity and periodontal disease with overweight people with the highest levels of insulin resistance being 50% more likely to have severe periodontal disease compared to overweight people with low insulin resistance.

Helicobacter pylori is a type of bacteria found in the stomach lining of half of all people in the Western world that has been associated with causing stomach ulcers and stomach cancer. H. pylori has also been found in periodontal disease.

Dr. O. A’cbay and his team discovered that the presence of Helicobacter pylori in the stomach triggers the release of the hormone gastrin and that this in turn causes the pancreas to produce insulin. This can result in hyperinsulinaemia, which can lead to diabetes, obesity and heart disease.

Even when H. pylori infection is treated with antibiotic therapy, this has been shown to eliminate the infection from the mouth, but not from periodontal pockets which may re-infect the stomach. The contents of these pockets are technically outside the body and so are not accessible to the antibiotics or immune system.Studies have yet to show whether eliminating H. pylori in the stomach can help with weight reduction.

Oral health and respiratory disorders

There are several ways in which oral infection may affect the lungs, but one of the main routes is thought to be via aspiration of plaque microbes.Both pneumonia and lung abscesses can be caused by bacteria found in plaque. In fact, over half of all patients with pneumonia have periodontal disease.

Studies from the University of California andresearch published in the Journal of Periodontology,point to the link between poor oral health and respiratory disease, especially chronic respiratory disease and chronic obstructive pulmonary disease (COPD) respectively.

Gum health and pregnancy outcomes

Researchers at the University of North Carolina (UNC) have shown that the infectious agents and inflammatory messengers associated with periodontal disease may trigger the early onset of labour or premature rupture of membranes by placing undue stress on the immune system leading to the birth of pre-term, low birth weight babies (PTLBW). In particular, the study identified four organisms found in mature plaque to correlated with the probability of having a premature, low birth weight baby.

And in another study women were found to be seven times more likely to have a PTLBW if severe periodontal disease was present. This effect was noticed with as little as two areas of periodontal pocketing.

The periodontal and kidney disease link

Research at the University of California, San Francisco has documented a link between gum infections and kidney disease as well. This hassignificant implications for the prevention and treatment of kidney disease and collaborative longitudinal studies involved both nephrology and dental departments are under way.

Rheumatoid arthritis and oral health

Research recently published byDr Ted Mikuls of the University of Nebraska, showed that antibodies to Porphyromonas gingivalis were linked to the presence of rheumatoid arthritis autoantibodies This supports the hypothesis that infection with P. gingivalis may play a role in the loss of tolerance to self antigens that occurs in rheumatoid arthritis.

And in another study byScher et al at the Division of Rheumatology, New York Universitywhich profiled the microorganisms in the plaque of patients newly diagnosed with rheumatoid arthritis, patients were found to have a high prevalence of periodontal disease despite their young age and lack of smoking history.

The osteoporosis link to oral health

Research at the University of Buffalo, New Yorkhas revealed a connection between periodontal disease and osteoporosis. In a study involving just over 2,500 post-menopausal women, those with osteoporosis of the hip were twice as likely to have loose teeth as those with healthy hip bones.

And in research conducted byDr Howard Tenebbaum and team at the University of Toronto,Periodontic Department, periodontal pathogens such as Porphyromonas gingivalis were shown to not only stimulate bone resorption, but also to directly inhibit bone formation. Initial bone density studies suggest that hip bone and alveolar jaw bone density are both affected similarly.

Reflections on the oral and general health connection

It is possible that the whole way we have come to conceptualise the body by dividing it into parts and systems is part of the problem and is obscuring finding the answer(s). Then too we give all these ‘diseases’ names and regard them as separate and discrete entities and this too is fundamentally misleading.

Although periodontal disease has been shown to be associated with the conditions listed above, perhaps neither is causal. Like mould appearing in two spots on an apple or a lump of cheese, neither is causing the other disorder but rather both are signs of an underlying health issue.

The teeth all have energy meridians passing through them and their sockets which control the amount of vital energy reaching not only the associated tooth but also the organs and systems served by that meridian. If, for example, the processes of digestion are stressed, then the vitality and maintenance of the bone surrounding the posterior teeth will also be affected. This means that there is an underlying systems issue which needs addressing in addition to any symptomatic treatment provided in order to restore the entire system to health.

And finally, there are many who regard periodontal disease as fundamentally a vitamin deficiency (vitamin K2 and vitamin C primarily) and this will also produce symptoms in multiple organs and systems.