Comparison of the effects of the monoblock appliance and the skeletal anchorage-supported class II elastics application in patients with class II division 1 malocclusion caused BY mandibular retrognathia

Objective: The aim of this study is to compare the skeletal, dental and soft tissue effects of Monoblock appliance and Miniplate Anchored Class II Elastics treatment in the Skeletal Class II patients with retrognathic mandible in the pubertal period. Method: The individuals included in the prospective clinical study were divided into two groups randomly as skeletal anchoraged Class II elastics and monoblock appliance groups. The first group consisted of 15 patients (mean age:12.74 ± 1.01) who were treated with miniplate anchored Class II elastics. Mini plates were performed bilaterally apertura priformis area in maxilla and anterior part of ramus in mandible. The second group consisted of 15 patients (mean age:13.00 ± 1.26) who were treated with conventional monoblock appliance. Treatment duration of skeletal anchorage group was 0.80 ± 0.11 years, monoblock appliance was 0.76 ± 0.12 years. Lateral cephalograms were taken at the beginning and end of the treatment in both 2 groups. Changes in both groups were assessed with paired-t test, changes between the two groups were assessed with Student-t test on cephalometric masurements. Results: In cephalometric evaluation, Co-Gn (mm), B-VRD (mm) and Pog-VRD (mm) lengths were higher in the IA group compared to the MA group and the difference between the two groups was statistically significant (p<0.01). When changes in lower incisors were examined, significant changes were observed in both groups in IMPAo, L1-NBo angular and L1-NB (mm), L1-VRL (mm) linear measurements. While there was a significant increase in these values in the MA group, the difference between the groups was statistically significant as a result of the significant decrease in the IA group (p<0.001). Conclusion: Mandibular sagittal stimulation is higher in the Class II elastic application compared to the monobloc group. Dentoalveolar effects are minimalized in IA group. Key Words : mandibular retrognathia, monoblock, skeletal anchorage