A variant Research Diagnostic Criteria (vRDC) examination protocol for TMD

In clinical studies the Research Diagnostic Criteria (RDC) provides the gold standard for diagnosing temporomandibular disorders (TMD). Although the RDC is not widely used in routine clinical practice, its definitions are potentially useful to standardize clinical (Axis I) diagnosis. Accordingly, a streamlined examination protocol derived from the RDC, known as vRDC, has been developed. Objectives: to compare diagnoses made using the vRDC with the RDC and the time taken to reach them. Methods: 49 subjects (41 referred TMD patients and 8 symptom free subjects) were examined using both the RDC and vRDC (4 examinations per patient, order randomised). Three examiners, with varying levels of experience in diagnosing TMD, worked in pairs. Each member of a pair saw the same patient twice, once for the RDC and once for the vRDC examination. Examinations could yield single, multiple or no diagnosis. Comparisons (Cohen's kappa) between RDC and vRDC were made for each individual examiner but to provide overall comparisons between and within diagnostic systems all the examiners' results were combined. Results: There was substantial overall agreement between vRDC and RDC (kappa = 0.72). Within each diagnostic system there was also substantial overall agreement (RDC kappa = 0.64; vRDC kappa = 0.85).When comparing vRDC and RDC within the main diagnostic groups, the highest agreement was in group III, then group II and finally group I (kappa = 0.86, 0.60, and 0.43 respectively). Both diagnostic systems ascribed diagnoses to 80% of patients and identified all the asymptomatic controls. The mean time taken for examination and diagnosis was faster for vRDC than for RDC (7.5min c.f. 10.3; t-test, p < 0.001). Conclusion: The vRDC's diagnosis is comparable to the RDC thus providing a convenient and intuitive approach for dentists to physically diagnose TMD in clinical practice.