A chance meeting between dentistry professors that led to a career-long collaboration not only has revolutionized our understanding of gum diseases, but established the foundation for the modern field of periodontology.
Periodontitis is an infectious disease of the tissues surrounding the teeth. It is a major cause of tooth loss in human populations around the world. Prior to the 1970s, the causes of periodontitis were not fully understood. Investigators believed only one form of the disease existed, and approaches to prevention, diagnosis, and treatment were largely without any sort of scientific basis or rationale.
One day in 1970, UW dentistry professor Roy C. Page happened to meet Hubert E. Schroeder of the Dental Institute, University of Zurich, Switzerland. They met as strangers at a restaurant in the University Village shopping mall just east of the UW campus. But by the time lunch was over, the field of dentistry would never be the same.
The researchers struck up a collaboration that resulted in a landmark publication about periodontitis in the journal Laboratory Investigation in 1976, and a monograph published in 1982. Page and Schroeder demonstrated that periodontitis is not a homogeneous disease, but is rather a family of several related diseases, each of which behaves differently. They realized that while infection causes these diseases, bacteria alone are insufficient; the response of the patient can play an over-riding role in the development of these conditions.
Page and colleagues reanalyzed and reinterpreted existing data in this new framework, and discovered that previous concepts about gum disease were in error. For example, the researchers showed that, counter to conventional wisdom, the prevalence of periodontitis in adults was actually rather low. Their studies over the next ten years bore out this conclusion. They surmised that gingivitis was not a progressive lesion leading to gum tissue destruction, but rather a relatively stable, non-aggressive manifestation of a successful host defense against bacterial accumulation around the necks of the teeth. Their work showed that active tissue destruction was instead caused by acute inflammation.
Furthermore, Page and colleagues demonstrated that the host defense mechanisms are not only responsible for fending off periodontal infection, but are also the major participants in tissue destruction. They suggested that "an uncontrolled production of lymphokines, prostaglandins, and hydrolytic enzymes could induce damage of the type observed" in periodontitis. This, at a time when cytokines—molecules involved in cellular immune responses—were just beginning to be discovered, and the role of prostaglandins in destruction of the extracellular matrix and bone was just beginning to unfold. Their insights, which were at the cutting edge of biochemistry and molecular biology for the time, have continued to guide investigations over the past 25 years, consolidating what previously was a body of widely scattered observations and speculations, and establishing a scientific foundation for the field of periodontology.