Single- or multiple-session viscosupplementation protocols for temporomandibular joint degenerative disorders: A randomized clinical trial

Objectives. The aim of this investigation was to assess the association of magnetic resonance imaging (MRI)-diagnosed temporomandibular joint (TMJ) disorders [i.e., disc displacement with reduction, disc isplacement without reduction (DDNR), osseous changes (OC), joint effusion] on the same side as well as in the joints of the two sides of the same individual. Materials and methods A total of 199 patients undergoing bilateral MRI of the TMJs were included in the study. A single variable correlation matrix was created to assess the within- and between-side correlation of single diagnoses. Then, based on 12 possible combinations of diagnoses per each side, a contingency table was created to assess the chisquare values of the differences between the observed and expected frequencies of the different cross-combinations. Multiple variable permutation test was performed to assess the null hypothesis that the diagnoses in the right and left joints are not related.