In an attempt to better our understanding of temporomandibular joint disorders, the research department, under the leadership of Dr. Mark A. Piper, has developed the Piper Research Database. This has been in use since 1994, and was originally in Microsoft Access, a relational database useful for generating descriptive statistics. With the expansion of the research department to include an epidemiologist and biostatistician, the database was converted to a statistical software package, SPSS (Statistical Package for the Social Sciences) version 7.5 for Windows, which is a comprehensive spreadsheet and data analysis package. It can take data from almost any type of file and use them to generate tabulated reports, charts, and plots and distributions of trends, descriptive statistics, and complex statistical analyses. The Piper Research Database currently contains demographic and medical history, as well as the results of pain and psychological questionnaires on over 700 TMD patients. From this database, much knowledge has been gained in the field of temporomandibular disorders. The topics studied include the prevalence of avascular necrosis and condylar edema by Piper stages, the condyle to fossa ratio by Piper stages, the relationship between oral parafunctions and trauma in individuals treated for TMD, the efficacy of radiation therapy for the treatment of bony ankylosis, and the evaluation of pain, psychological, and range of motion testing as diagnostic of severity of TMD. Also in progress is a long-term follow-up study of the efficacy of surgical and conservative therapies in the treatment of various stages of TMD.

Frequently Asked Questions About Research

Q: What is epidemiology? A: Epidemiology is the study of the distribution of a disease in human populations and of the factors that influence this distribution. Some well-known epidemiologic findings include discovering the relationship between cholera and certain water supplies in London in 1849, the relationship between fluoride and a decrease in dental caries in the 1930's, and smoking habits and lung cancer in the 1950's. Maybe we will be able to determine the risk factors for the onset and progression of temporomandibular disease! Q: What is biostatistics? A: Epidemiology and biostatistics are closely related. While epidemiology will determine the increased chance that a group has of getting an illness, biostatistics determines what the probability is that this has occurred by chance. This is indicated by the "p-value." The number indicated by the p-value is the probability that the difference observed has occurred by chance. For example, the normally accepted p-value, which is p<.05, indicates that there is less than a 5% chance that the result was observed by chance. Likewise a p-value of p<.1 or p<.01 indicates that there is a 10% or 1% chance, respectively. Q: Why is epidemiologic research important for TMD? A: Considerable controversy has plagued the research and treatment of temporomandibular disorder. Because the NIH consensus document asserted that temporomandibular disorder is psychological, and that it does not have a clinical progression, it is important to contribute this type of research to the literature to clarify these misunderstandings. Epidemiologic research is often considered the gold standard of health research, because its results are applicable to populations. The three primary goals of research should therefore be to determine the biologic processes and risk factors contributing to the disorder, the most effective treatments for TMD, and to describe the natural course of the disease in the general population of TMD patients.