Reliability of magnetic resonance imaging on detecting degenerative bone changes of the temporomandibular joint

To evaluate and describe the most frequent TMJ degenerative bone alterations on MRI and CT and to determine the accuracy, sensitivity, and specificity of MRI.

Images of 80 subjects were selected and evaluated from a database and 57 were selected. The subjects were submitted to CT and MRI exams (each subject on the same day). The joints were evaluated in the sagittal and coronal planes under closed mouth position. Each individual parameter was scored as absent or present. Absolute and relative frequencies were obtained and the Kappa concordance index test and equality of two proportions were used. To correlate the presence of bone alterations, the Chi-Square test was performed. A significance level of 0.05 (5%) was defined, with 95% of statistical confidence interval.

Of the 57 subjects, (47 female, 10 male), the ages ranged from 18-83 years (mean 43 years). The intra and inter-rater agreement tests demonstrated reliability among the examiners for all variables analyzed on MRI and CT.

MRI is a reliable and valid method for observing bone changes in the TMJ, with the advantage of non-exposure to radiation and cost-effectiveness due to the use of only one exam.