Interrater Reliability of Tender Points Using Different RDC for TMD

Introduction:TMDs comprise a number of painful conditions affecting the muscles of mastication and TMJ. Research Diagnostic Criteria for TMDs(RDCV1, 1992) formed a model diagnostic algorithm based on clinical history and physical ex­amination. Myofascial pain(MFP) is particularly dependent on physical examination, requiring standardized palpation across masticatory muscle sites. Recently, revised RDC-TMD(RDCV2) diagnostic algorithms have been recommended to improve validity and reliability, with several changes in the diagnostic algorithm of MFP.

Objectives :1)To determine interrater reliability of RDCV1 MFP diagnosis.2)To determine whether the 12 muscles sites retained for MFP diagnosis in RDCV2 showed better interrater reliability than the 8 muscle sites removed in RDCV2.3)To compare overall interrater reliability for MFP in RDCV1 and V2.

Methods :Diagnostic reliability data were drawn from an ongoing case-control study exploring possible mechanisms underlying MFP. Subjects were palpated by 2 clinical examiners across 20 muscle sites. Diagnosis of MFP using RDCV1 included pain upon palpation at ³3 of twenty muscle sites, while the diagnosis of MFP using RDCV2 included pain at ³1 of twelve muscle sites. Percent agreement and Kappa were calculated. Facial exams were preceded by questions relating to subjects' past and present pain severity on a scale of 0(no pain) to 10(worst pain imaginable). Independent sample t-tests were used to compare mean spontaneous pain ratings between subjects for whom there was diagnostic discor­dance and concordance.

Results: Percent agreement showed no difference between interrater reliability of muscle sites specific to RDCV1 and those retained in RDCV2. Diagnostic reliability for the purposes of the case-control study from which these data were drawn was found to be acceptable. 

Conclusions: Among the few instances of diagnostic discor­dance, a pattern of relatively low mean spontaneous pain ratings suggested difficulty in establishing diag­nostic reliability in individuals with milder symptoms. The high base rate of TMDs among subjects likely contributed to the low kappa values seen.