[Comparison of temporomandibular joint changes in adolescent Class II devision 1 malocclusion patients with mandibular retrusion treated with Twin-block and Class II elastics].

OBJECTIVE: To compare the temporomandibular joint changes in adolescent Class II division 1 malocclusion patients with mandibular retrusion treated with Twin- block and Class II elastics. METHODS: Sixty Class II division 1 malocclusion patients with mandibular retrusion were divided into 3 groups (Twin- block group, Class II elastic group and control group, 20 patients in each group) randomly. Differences of condylar process morphology were compared using cone- beam CT (CBCT) before and after treatment. RESULTS: Condylar largest anteroposterior diameter and upper condylar height increased after treatment in both Twin-block group and Class II elastic group. The condylar largest anteroposterior diameter and upper condylar height were longer in both Twin- block group [(8.51 ± 1.48) and (7.39 ± 1.42) mm] and Class II elastic group [(8.44 ± 1.03) and (7.24 ± 0.89) mm] than those in the control group [(7.47 ± 1.27) and (6.47 ± 1.56) mm] (P<0.05). No significant difference was found in other measurements (P>0.05). CONCLUSIONS: Condylar largest anteroposterior diameter and upper condylar height in Class II division 1 malocclusion patients increased after treatment using Twin- block and Class II elastics. There was no significant difference between two groups.