Validation of the clinical diagnostic criteria for temporomandibular disorders for the diagnostic subgroup - disc derangement with reduction.

Research is needed to assess the validity of the clinical diagnostic criteria for temporomandibular disorders (CDC/TMD). The purpose of this study was to test the reliability of the clinical diagnosis of temporomandibular joint (TMJ) internal derangement type (ID)-I as compared with the magnetic resonance imaging (MRI) 'gold standard'. The study comprised 168 TMJs in 84 patients, who were assigned a clinical TMJ-related diagnosis of ID-I (disc displacement with reduction) in at least one TMJ. Bilateral sagittal and coronal MR images were obtained subsequently to establish the corresponding diagnosis of the disc-condyle relationship. For the CDC/TMD interpretations, the positive predictive value (PPV) of ID-I for disc displacement with reduction (DDR) was 44%, and for the presence of an ID 69%. The overall diagnostic agreement for ID-I was 47.6% with a corresponding K-value of 0.05. Most of the disagreement was the result of the false-positive interpretations of ID-I, and false-negative interpretations of an 'absence of ID'. The results suggest CDC/TMD for ID-I to be insufficient reliable for determination of ID and/or DDR. Patients assigned a clinical TMJ-related diagnosis of ID-I may need to be supplemented by evidence from MRI to determine the functional 'disc-condyle relationship'.