The Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Validation Project has provided the first comprehensive assessment of reliability and validity of the original Axis I and II. In addition, Axis I of the RDC/TMD was revised with estimates of reliability and validity. These findings are reported in the five preceding articles in this series. The aim of this article is to present further revisions of Axis I and II for consideration by the TMD research and clinical communities. Potential Axis I revisions include addressing concerns with orofacial pain differential diagnosis and changes in nomenclature in an attempt to provide improved consistency with other musculoskeletal diagnostic systems. In addition, expansion of the RDC/TMD to include the less common TMD conditions and disorders would make it more comprehensive and clinically useful. The original standards for diagnostic sensitivity ( < or = 0.70) and specificity (< or = 0.95) should be reconsidered to reflect changes in the field since the RDC/TMD was published in 1992. Pertaining to Axis II, current recommendations for all chronic pain conditions include standardized instruments and expansion of the domains assessed. In addition, there is need for improved clinical efficiency of Axis II instruments and for exploring methods to better integrate Axis I and II in clinical settings.