MRI evaluation of functional treatment in juvenile disk displacement with reduction.

PURPOSE: To evaluate the effect of functional treatment for disk displacement with reduction (DDWR) of the temporomandibular joint (TMJ). METHODS: Fifty-seven juvenile patients (78 joints) diagnosed as DDWR underwent functional treatment. MRIs were used before and after functional treatment. The disk position was judged according to the success criteria which included all sagittal planes after treatment. Those patients, whose disk of TMJ was in normal position with remarkable condylar remolding, were evaluated to be excellent. If normal disk-condyle relationship with no remarkable condylar remolding or mild disk displacement with disk-like structure of the bilaminar zone were found, the outcome was evaluated to be good. Compared with pre-treatment, if the disk position was the same or became worse, the outcome was evaluated to be poor. Cases evaluated as "excellent" and "good", were considered as successful. RESULTS: MRI for all joints confirmed that 73.08% (57/78) were excellent; 14.10% (11/78) were good, and only 12.82% (10/78) were poor. The total effective rate was 87.18% (68/78). The effective rate for anterior repositioning splint therapy was 84.09%, 87.50% for twin-block appliance, and up to 94.44% for the Herbst functional appliance. Arthroscopic surgery or open surgery was carried out for the joints which were evaluated as poor. CONCLUSION: This study indicates that functional appliance is effective in repositioning the DDWR confirmed by MRI examination, but long-time follow-up is necessary for the evaluation of its stability. Supported by Research Fund for Young College and University Teachers from Shanghai Municipal Education Commission (jdy11027). [ABSTRACT FROM AUTHOR]