By Michael Glick, DMD

Professor of Oral Medicine, Arizona School of Dentistry and Oral Health Associate Dean for Oral–Medical Sciences, College of Osteopathic Medicine, Mesa Editor, Journal of the American Dental Association

Oral healthcare professionals (OHCPs) today find themselves in a privileged position to influence general health and well being. Because oral infections may be linked to the risk for development and exacerbation of various systemic conditions outside of the oral cavity, opportunities exist for OHCPs to play a larger role in influencing healthcare services beyond safe and appropriate dental care. OHCPs also have an opportunity proactively to screen for and monitor a range of non–oral diseases, including such devastating maladies as hypertension and diabetes mellitus. This essay aims to highlight some of the options available to practicing dentists to significantly impact the overall health and well being of their patients, and hopefully to motivate them to exercise these options.

It may be too early to come to any definitive conclusions based on the existing literature, but the likelihood is that an infection any place in the body, including the oral cavity, will have some effect on other structures or bodily systems. A known example is the development of infective endocarditis secondary to viridans group streptococci, ostensibly originating in the oral cavity.¹ The problem with most studies exploring the relationship between oral and non–oral disease is the paucity of intervention studies, which are the gold standard for establishing causality. During the past decade, numerous articles have been published describing the affect of periodontal diseases on various non–oral illnesses and conditions, including cardiovascular disease, diabetes mellitus, preterm birth and low birth weight, stroke, lung, and pancreatic cancers, among others. Although some randomized, controlled intervention trials have been published on the influence of periodontitis and/or periodontal pathogen on non–oral disease, questions still remain to be answered. Two studies published recently in the prestigious New England Journal of Medicine look specifically at the effect of periodontal interventions on preterm birth and low birth weight, and at endothelial function as a marker for cardiovascular disease.^{2, 3}

On the one hand, although treatment of periodontitis improved periodontal disease, no significant differences were seen regarding the risk for preterm birth or low birth weight babies when comparing a periodontal treatment group of pregnant women to a non–treatment group of pregnant women with a similar gestational age.² On the other hand, the second study showed that intensive periodontal therapy can improve endothelial function, which would suggest that this type of treatment may contribute to the prevention of atherosclerosis and cardiovascular events.³ An important question that has yet to be answered is whether the results from these and similar studies can be applied to a general population.

Studies looking at the association between diabetes mellitus and periodontal disease suggest a bidirectional relationship, where the presence of periodontal infection may influence glycemic control and where uncontrolled diabetes may exacerbate periodontal diseases. However, a recent meta–analysis looking at long–term glycemic control did not find a clinically significant improvement after periodontal therapy.⁴ It is not clear if the result of this meta–analysis could be applied to an individual patient.

Opportunities currently exist for dentists to provide expanded healthcare services in the areas of oral detection of systemic disease, oral fluid diagnostics, risk screening for cardiovascular disease and other potentially deadly conditions, and the treatment of medically complex patients.

Except for otolaryngologists and some plastic surgeons, very few medical residents have an opportunity to learn how to examine the oral cavity. As experts in oral pathologies, OHCPs are therefore often the first to see changes in the mouth. Some of these changes may be the earliest manifestation of systemic diseases, signs of immune suppression or exacerbation of a systemic condition.⁵ This has never been more evident than in patients infected with HIV disease.⁶

The use of oral fluids and tissues as diagnostics is discussed elsewhere in this issue of Global Health Nexus in an article by Dr. Daniel Malamud (see page 20). However, I would be remiss in not pointing out the importance of OHCPs proactively taking on this emerging technology and establishing "ownership" of saliva.⁷ The ease of use and non–invasive nature of this technology lend themselves very well to utilization by non–physicians in non–traditional settings.

Another area in which dentists have a potentially significant role to play is that of diseases with high morbidity and mortality, including cardiovascular disease and type 2 diabetes mellitus, which are preventable if detected early. The first step in any prevention program is the identification of individuals at risk. More than 60 percent of adults visited a dental office last year, while less than 40 percent saw a physician. An important difference between seeking medical care and dental care is that patients usually seek out a physician when they have signs and symptoms of a systemic disease, but show up for recall appointments with a dentist when they feel well. This would suggest that OHCPs are in an excellent position to identify asymptomatic patients who are not aware of being ill. This has been shown both in a statistical analysis and in an actual study of patients seeking care at a dental school.^{8, 9} Both of these studies suggest that OHCPs could identify individuals with a high risk (<20%) for developing an angina or myocardial infarction within the next ten years. However, to do so OHCPs would have to offer patients tests for measuring blood cholesterol or plasma glucose.

Lastly, OHCPs need to care for medically complex patients. Our patient population is graying, yet patients retain their dentition. Eighty percent of patients over age 65 have at least one chronic disease, while 50% have at least two or more chronic conditions and take at least three prescription medications. If we do not start to include more medicine into our dental curricula¹⁰ and increase the number of continuing education courses designed to teach dentists how to care for patients with multiple and sometimes complex medical conditions, we will soon not be able to provide appropriate dental care for more than half of our patient population.

So what is the role of OHCPs today and in the near future? We need to continue to explore the association between oral infections and non–oral diseases and conditions. We need to be aware that treatment of oral conditions may influence conditions beyond the oral cavity. We need to acknowledge that treatment of non–oral diseases may affect oral health. We need to realize that oral signs may be associated with onset and exacerbation of non–oral diseases. We need to embrace and incorporate the use of oral fluid diagnostics within the scope of health care in a dental setting. We need to shoulder the responsibility to screen and monitor for non–oral diseases and conditions. And we need to start to learn how to provide dental care to medically complex patients.

This is a tall order, and I am not sure all OHCPs will be able to accomplish all of these tasks. In the meantime, it is essential that we make sure that students graduating from our dental schools are exposed to and are capable of taking on these challenges.