by D. Walter Cohen, D.D.S.
Dean Emeritus, University of Pennsylvania School of Dental Medicine,
Chancellor Emeritus, Drexel University College of Medicine

Diabetes mellitus is a devastating disease that affects 17 million Americans and kills 210,000 people each year, making it the sixth leading cause of death in the United States. According to the American Diabetes Association, approximately one-third of the millions affected by the disease, or nearly six million people, are not aware that they have it, while at least another 16 million people are at increased risk for type 2 diabetes. In New York City alone, 8 percent of adults are affected—double the rate of eight years ago.

Each year research yields more information on the links between oral and systemic health. Indeed, over the past decade, researchers have noted that in addition to such traditional complications of diabetes as retinopathy, nephropathy, neuropathy, cardiovascular disease, and obstetrical complications, there may be oral manifestations associated with diabetes, especially if the glycemic regulation is not well controlled (table 1). But even as far back as the 1930s, Isadore Hirschfeld described a triad of periodontal manifestations associated with diabetes, which consisted of multiple periodontal abscesses, advanced alveolar bone destruction, and fungating masses of granulomatous tissue growing out of periodontal pockets. Michael Cohen showed similar oral changes in young patients and Cheraskin later suggested that gingival tenderness, dry mouth, and burning tongue may also be associated with hyperglycemia. As similar reports appeared, dental researchers began to suggest that periodontal changes may be a sixth major complication of diabetes. Most recently, a conference supported by the National Institute of Dental and Craniofacial Research and the American Academy of Periodontology reached the conclusion that dentists and physicians need to work more collaboratively in light of increasing evidence connecting oral diseases with preterm, low birth-weight infants, cardiovascular diseases, and diabetes mellitus. Such findings place a great responsibility on the dental team to recognize oral problems that may have important relationships to systemic manifestations, and on the physician to increase his or her knowledge of oral diseases. Indeed, we can expect to see an end to the era when the physician took a tongue blade and looked past the oral structures into the pharynx of his or her patient and the beginning of a new era when physicians and dentists are united in their care of patients with systemic diseases, such as diabetes.

Types of Diabetes
Type 1 diabetes constitutes about 10 percent of all diabetic cases and is most common in Caucasians. Since it frequently occurs before age 30, it was once known as “juvenile” diabetes. Type 1 diabetes is caused by cell-mediated autoimmune destruction of the insulin- producing BETA cell in the pancreas. Individuals with type 1 diabetes are highly susceptible to ketoacidosis. Diabetic ketoacidosis frequently results from accumulation of ketones in body fluids, increased loss of electrolytes in the urine, and subsequent alteration in the bicarbonate buffer system. Ketoacidosis usually occurs in a type 1 diabetic who has not been diagnosed, or in a known diabetic who is poorly controlled for his or her glycemic state. If not recognized and treated properly, severe cases of acidosis may lead to coma and death (tables 2 and 3).

Type 2 diabetes is the much more common form of the disease, accounting
for 90 percent of all cases. Type 2 is not characterized by autoimmune destruction of the BETA cells, but it does demonstrate peripheral resistance to insulin in muscle, also impaired pancreatic insulin secretion, and increased glucose production by the liver. It is frequently referred to as “insulin resistance syndrome” and results in hyperglycemia, which is similar to type 1 diabetes.

The Dental Team’s Responsibility in Treating the Diabetic Patient
In taking a patient’s medical history, the dental team needs to know which patients are insulin dependent, what type of insulin they are taking, and when it is being administered. It is also important to ask what medications the type 2 diabetic patient is receiving. It is advisable as well for dental offices to be equipped with glucose-monitoring devices, which can give a reading in less than 30 seconds after a drop of blood from a finger prick is placed on a strip and then entered into the glucometer. Recently the health insurer Ameri-Choice began encouraging dentists to use the hemoglobin A1C device, which also utilizes a drop of blood, but takes about nine minutes to indicate the level of glucose control during the preceding 60 to 90 days (figure 1). Less than a 7 percent reading is desirable, and the test can be performed by the dental team with minimum inconvenience to the patient (table 4). The HbA1C reading is much more informative, since it provides a broader time perspective on glucose control in contrast to a glucometer, which measures only the instant of the finger prick. If diabetes is suspected based on oral findings or history given by the patient, or HbA1C data, the dental team has an obligation to tell the physician that the oral status of the patient suggests the possibility of an underlying undiagnosed or poorly controlled diabetic condition, but the diagnosis is ultimately the physician’s responsibility.

The Impact of Periodontal Research on the Health of Society
While some of the early studies on diabetes and periodontal diseases indicate that reducing or eliminating oral infections can result in reduced insulin requirement in diabetic patients, the means of eliminating the oral infection in most cases were to extract the involved teeth. Today, all that has changed and we have evidence dating from the studies of Hirschfeld and Wasserman in 1978 and others, that periodontal therapy is effective in allowing Americans, who are living longer than ever before, to retain their natural dentition as they grow older.

This is pretty amazing, considering that one of the first departments of periodontics at a U.S. dental school was established at NYU in 1924, only 79 years ago, and that most dental schools did not start to teach the subject until after World War II. We have made great progress in a relatively short time, but it took a major revision in the way dental education was taught. For many decades, most dental school curricula addressed only one disease—dental caries. Today, the other major dental disease, periodontitis, has taken its rightful place in the dental curriculum.

We now know that the antimicrobial therapy involved in periodontal treatment is no longer exclusively mechanical. Although scaling and root planing have long been the cornerstone of periodontal treatment, chemotherapeutics, recently coined “periceutics,” are beginning to play a role in therapy. Pharmacology is becoming a much more important part of the dental curriculum and the use of drugs to detoxify the periodontal lesion will become even more prevalent. This is another development that requires close collaboration between the dentist and the physician, especially since certain cardiologists are prohibiting scaling and root planing procedures on patients who are at risk for coronary heart disease.

We may also see an increase in oral microbiology testing for patients with
periodontal disease because one of the advantages of using this testing, in addition to the identification of the flora, is learning which drugs they are sensitive to. And now that a drop of blood from a finger prick will provide results in 9 to 10 minutes, more dentists will be doing glucose testing and hemoglobin A1C evaluations in their practices. With physicians and dentists working more closely together, more patients with systemic disease will be managed more successfully and will retain their dentition longer. As though
in anticipation of the new emphasis on the role of medicine in dental
education, numerous dental institutions have elected to change the degree they offer from D.D.S. to D.M.D.

A Retrospective Case Study
The case of a patient with diabetes mellitus whom I treated over a period of 39 years illustrates the success of periodontal therapy and also supports the conclusion that periodontal disease should be viewed as a sixth major complication of diabetes mellitus.

This 18-year-old juvenile diabetic presented in 1955 with several of the periodontal manifestations of diabetes described by Hirschfeld in the 1930s. The patient had advanced alveolar bone loss in the maxillary right lateral
incisor region along with a fungating mass of granulomatous tissue emerging from a 10 mm suprabony pocket. Her diabetologist was concerned about her being extremely brittle and suggested prophylactic use of penicillin in association with each periodontic visit (figure 2). Initial treatment consisted of
scaling and root planing and instruction in personal hygiene. Her mouth responded well and occlusal adjustment was followed by the use of a removable maxillary appliance to close the diastema in the maxillary lateral incisor areas. In 1957, at age 20, the patient was delighted with the cosmetic appearance of her mouth and was extremely diligent with her oral hygiene (figure 3).

During the period 1957 through 1994, the patient was seen quarterly on a maintenance program and continued to be conscientious about her personal care. During these three decades, she developed the major complications of diabetes, including nephropathy, neuropathy retinopathy, and cardiovascular disease. She had a kidney transplant, which was rejected in 1984. Tragically, she died from kidney failure in 1995 at age 58. The clinical photos taken one year before her death show that despite taking the immunosuppressant drug cyclosporine she was maintaining her oral health extremely well (figure 4).

It is interesting, as well as unusual, to follow a patient for more than 39 years with this type of systemic involvement and to note that the periodontal destruction was arrested (figure 5) despite the deterioration of other organ systems as a result of the diabetes. The patient was extremely careful, using self-monitoring glucose extract devices to help her keep her blood sugar as close to the normal range as possible.

This story illustrates that when well informed of a patient’s medical history and possible oral symptoms at each maintenance visit, the dental team of dentist, dental hygienist, dental assistant, and other staff may be in a position to identify undiagnosed diabetes in their patients and, ultimately, help to reduce the figure of six million undiagnosed diabetics in the U.S. Another important reason for the dental team to be knowledgeable about the management of known diabetics is to reduce possible hyper- and hypoglycemic reactions
during dental treatment (table 5).

How does the team keep current in the area of diagnosis and therapy of
diabetics? The dental literature is one method. Other opportunities include study clubs that frequently review significant articles and lectures and postdoctoral continuing education courses.

Understanding the role of nutrition in the care of diabetics is also important, and the dental team needs to interact more frequently with diabetologists, endocrinologists, and internists who treat diabetics, so that the quality of care provided to the diabetic patient continues to improve. The results of information sharing among dentists and physicians will benefit both patients and the dental profession, which will achieve yet another advance in the area of prevention.

Acknowledgments
Tables 1 through 5, courtesy of Dr. Brian Mealey, Periodontal Medicine, B.C. Decker, publisher.

Figures 2 through 5, courtesy of Dr. D.W. Cohen, in Compendium of Continuing Education in Dentistry, Dental Learning Systems, Publisher.