Can dynamic magnetic resonance imaging replace static magnetic resonance sequences in evaluation of temporomandibular joint dysfunction?

Introduction Static MRI was used as an effective tool for diagnosis of temporomandibular joint dysfunction instead of invasive techniques such as arthroscopy and arthrography. The purpose of this study was to detect whether dynamic MRI can be used instead of static MRI in diagnosis of TMJ dysfunction or not. Methods This study was conducted on 40 patients clinically diagnosed as temporomandibular joint dysfunction. The age of the selected patients ranged from 18 to 66 years with a mean of 29.3 years. all patients were subjected to MRI. The static MRI images were acquired in the closed and open mouth positions. dynamic MRI was obtained as rapid acquisition of static images using a single shot fast spin echo (SSFSE proton density sequence) during slowly opening and closing of the mouth. Results According to disc displacement, anterior disc displacement was detected in 29 joints (36.25%) by both static and dynamic MRIs, and medial and lateral disc displacements were detected only by static MRI. Regarding disc mobility, dynamic MRI detects stuck disc in 4 joints versus 2 joints detected by static MRI (p value 0.008). Condylar translation was abnormal in 18 joints (22.5%) by static MRI and in 26 joints (32.5%) by dynamic MRI (p value < 0.001). The detection rate of articular disc for dynamic MRI was 87.5% versus static MRI 92.5% (p value 0.038), and the detection rate of condylar head for dynamic MRI was 97.5% versus static MRI 100% (p value 0.012). Conclusion Dynamic MRI cannot replace static MRI in evaluation of TMJ dysfunction; both of them support each other for accurate diagnosis and better image quality.