Schiffman's TMD Research Recognized as Second Most Cited

Temporomandibular Pain

A paper authored by Eric Schiffman, DDS, MS, was the second most-cited article in dentistry in 2020, according to Scopus data (Asiri et al., Preprints, 202102002).

Schiffman is a professor and director of the School of Dentistry’s Oral Health Clinical Research Center and former director of the Division of TMD and Orofacial Pain. He is the first author of the article “Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) for Clinical and Research Applications: Recommendations of the International RDC/TMD Consortium Network and Orofacial Pain Special Interest Group,” published in Journal of Oral & Facial Pain and Headache in 2014. The paper was cited nearly 300 times in 2020, and has been cited 1,110 times since publication.

Schiffman and his 33 co-authors from around the world sought to provide a comprehensive, reliable, and valid diagnostic tool for identifying and assessing temporomandibular disorders (TMD) patients with simple to complex presentations. TMD affect 5 to 12% of the population. Because of the difficulties of properly diagnosing and finding a cause for different temporomandibular disorders, especially pain-related ones, a need existed at the time of publication to create a diagnostic tool that could be used both in research and in clinical practice.

Prior to 2014, the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) was the most widely used diagnostic protocol for TMD research. While the criteria were helpful, they were “only a beginning,” according to Schiffman. More research was needed to continue improving the criteria’s diagnostic accuracy and provide an assessment protocol for use in clinical settings.

The evidence-based DC/TMD presented by Schiffman includes a reliable and valid Axis I protocol for diagnosing for the most common TMD, including pain-related and temporomandibular joint (TMJ) intra-articular disorders. It also includes Axis II questionnaires that explore behavioral, psychological, and social factors that might contribute to TMD pain, in the hopes that a whole-person approach can provide insight into the kinds of treatments that might be right. Questionnaires explore the characteristics of pain, what makes it better and worse, psychological factors like habits and anxiety, and more comprehensive research-focused questions.

Eric Schiffman, DDS, MSEric Schiffman, DDS, MS

The authors of the new DC/TMD hope it will provide “a common language for clinicians, while providing the researcher with the methods for valid phenotyping of their subjects” (Schiffman et al.). NIH has since adapted DC/TMD as the official diagnostic criteria for use when researching TMD.

Since the original publication of the piece, Schiffman and his colleagues have continued exploring ways to make the tool better, including simplifying it even further for clinical use. “This tool isn’t the end,” Schiffman explained.

The Axis I diagnostic criteria is based on signs and symptoms. The next step is to create diagnostic criteria based on mechanism and etiology,” which would provide further insight into the causes of TMD, as well as more targeted treatments,” he continued.

Schiffman is proud of the criteria’s success and finds it to be a reminder of the importance of a research team. “I’m grateful for everyone who has supported me: the NIDCR, the people on the paper, and people in my research team who have worked with me on this directly and indirectly.”

He sees research like an orchestra, where he’s the director: “If I don’t have any players, there is no music. I can’t take the credit for this alone, but it makes me pleased that we’ve done some good work and have been able to advance the field.”

In looking to what can come next, Schiffman is reminded of his favorite quote from T.M. Tomlinson: “In months of travel, it is the horizon which the traveler cannot reach.”

Schiffman knows that he won’t reach the horizon of TMD alone. “I’m just a link in this continuation, and this research will go on for a long time,” he said.

“Someday, I’ll be a footnote. But I’ll be happy that what we did was able to move science ahead, and ultimately—I hope—allow patients with TMD to have a successful way of understanding and managing their condition and improving their quality of life.”