Added value of dynamic 3T-MRI to conventional static MRI in evaluation of internal derangement of tempromandibular joint.

PURPOSE: This prospective study aimed at comparing dynamic T1W fast field echo sequence to the standard static sequences in the evaluation of TMJ disorders using 3T MRI. METHODS: 8 patients, 14 with bilateral symptomatic internal derangement of TMJ and 4 with unilateral symptoms (32 TMJs) were examined, including 17 females and one male. Static T1W, T2W and PD turbo spin-echo sequences in closed and open mouth positions as well as dynamic T1W-FFE sequence were acquired on 3T MRI unit and images were assessed for the articular disc position, morphological disc changes, condylar morphology and translation. Marginal homogeneity test was used to analyze difference between dynamic and static imaging findings and significant results were considered at p </= 0.05. RESULTS: The study shows statistically significant difference between static and dynamic MRI in the evaluation of condylar position (p < 0.005). Out of the examined 32 joints, 28 joints (87.5%) had normal condylar position and 4 joints (12.5%) had a subluxated condyle. Dynamic MRI showed 24 joints (75%) had normal condylar position and 8 joints (25%) had a subluxated condyle. Regarding disc morphology and position, dynamic MRI added no significant superior information compared to standard static images. CONCLUSION: Static MRI of TMJ provides proper accurate assessment of pathological changes in TMJ disorders and considered the gold standard. Dynamic MRI added superior information regarding joint biomechanics even in normal static MRI cases and valuable findings regarding the movement patterns of the condyle and disc in different types of TMJ internal derangement.