Comparison of sonography and MRI in cases of intra-articular temporomandibular (TMJ) dysfunction: a cross-sectional study

Background information and objective: The objective of this cross-sectional study was to compare diagnoses obtained by sonographic findings, with the results of magnetic resonance imaging (MRI), in the case of displacement of the articular disc and degenerative alterations of the temporomandibular joint (TMJ). Material and methods: A total of 22 test subjects (44 temporomandibular joints; 16 women and 6 men aged between 20 and 70 years) were subjected to sonographic and MRI examination and the results were then compared. Results: Agreement with regard to the position of the articular disc can be considered as good, with a value of κ = 0.62 (sensitivity: P = 1.0; specificity: P = 0.63). Agreement with the degenerative alterations can be regarded as poor, due to inadequacies, with κ = 0.24 (sensitivity: P = 0.83; specificity: P = 0.25). It was significant that all examinations were characterized by a high rate of false positive findings. Conclusion: The sonographic findings of the TMJ with regard to the diagnosis of articular disc displacement were viable in comparison to the MRI findings. Sonography is suitable for the rough depiction of intra-articular structural changes. The greatest disadvantage is the fact that transversal and rotatory discrepancies of the articular disc can only be insufficiently depicted. A detailed medical case history and functional examination still remain indispensable. Keywords: craniomandibular dysfunction, magnetic resonance imaging (MRI), sonography, temporomandibular joint