Intra- and inter-examiner reliability for diagnostic criteria of temporomandibular disorders (DC/TMD) - axis 1: assessment in a sample of students

ABSTRACT

Objective: The aim of this study was to analyze the intra- and inter-examiner reliability when using the DC/TMD axis 1 and verify the replicability and validity of the data obtained.Methods: The sample comprised 30 volunteers (students) of the Instituto Universitário de Ciências da Saúde Norte (Portugal). The calibration process consisted of a volunteer selection, theoretical and practical training, data collection, and agreement calculation. Examiners received proper previous training. Three dental practitioners applied the questionnaire (T1) and re-examined all the participants one week later (T2). To measure the degree of inter and intra-examiner agreement, multiple Kappa coefficients were obtained when nominal or ordinal variables were involved. When the correspondence between quantifiable variables was assessed, Pearson correlation coefficients and their statistical significance were replicated.Results: Regarding opening patterns, a strong overall agreement was obtained, only showing discrepancies in left-assisted and unassisted maximum openings (from -0.034 to -0.370 and -0.630 to -0.933, respectively). A high level of inter-examiner agreement during TMJ noise during the opening assessment was obtained, only displaying variations in clicks (Kappa -0.423 to 0.757). Protrusion movement showed negative kappa and weaker agreement of all measurements (Kappa between -0.034 and -0037). Small discrepancies were obtained from palpation assessment (left lateral pole- Kappa -0.034).Conclusion: There was no discernible and persistent difference in the amount of agreement among the three examiners, demonstrating that all three examiners were capable of participating in data collecting by employing the DC/TMD questionnaire. The findings indicated nearly perfect intra- and inter-examiner concordance scores.