Real-time MRI as a new technique for the functional assessment of the temporomandibular joint

For the diagnostics of the temporomandibular joint, the dental treatment provider has a series of procedures at his/ her disposal. In addition to the recording of the case history and the clinical functional analysis, magnetic resonance imaging (MRI) plays an important part as the so-called "gold standard". To this purpose, both the osseous and the connective tissue structures are depicted in high resolution. For technical reasons, however, it was only possible to produce static images to date, although the dynamic examination of the temporomandibular joint and the use of corresponding imaging procedures during splint therapy are certainly considered advantageous. The technique presented here makes it possible to record a real-time MRI movies of arbitrary length with a frame rate of 3 images per second. This means that a dynamic depiction of the temporomandibular joint function is possible. In this article, 30 test subjects were examined clinically according to the RDC/TMD, and the temporomandibular joint movement recorded using real-time magnetic resonance imaging. The goal of this task was the comparison of the clinical examination results with those of real-time MRI in order to ascertain the potential additional value of real-time MRI with regard to diagnostic information. This resulted in Cohen's kappa values of 0.88 to 0.849. In the second examination, the study results showed a 99.95% rate of agreement. Furthermore, this resulted in a sensitivity value of 0.67 and specificity values ranging between 0.88 and 0.98. On the one hand, the results reflect the high image quality and good anatomical accessibility, and on the other hand seem to offer more valuable information for diagnostic purposes. The insights gained give the first indication that real-time MRI appears to be superior to static MRI. Keywords: TMD, real-time MRI, RDC/TMD, sensitivity, specificity