Skeletal Effect of Modified Twin Block with Clear Plates Versus Conventional Twin Block in Class II Malocclusions – a Randomized Controlled Trial of Functional Appliances

Purpose: The aim of this in-vivo study was to evaluate the skeletal changes of a modified Twin Block with clear plates versus a conventional Twin Block appliance in skeletal class II patients. Methods and Materials: A total of 32 patients with skeletal class II malocclusion contributing to mandibular retrognathism were involved. The sample was divided into two groups: group A: 16 patients will undergo to orthodontic treatment with modified Twin Block with clear plates; group B: 16 patients will undergo to orthodontic treatment with conventional Twin Block appliance. After 12 months of treatment a cephalometric radiograph was taken in central occlusion to study skeletal changes. Independent sample T-test was used for studying significance between groups. Results: There were significant differences in MP-SN; MP-SPP and SN-NPG values. While there were no statistically significant differences in SNA, SNB and ANB values. A significant difference was observed after 12 months of treatment for each group (P<0.05). Conclusion: Modified Twin Block with clear plates is an effective alternative device to treat skeletal class II malocclusion with vertical growth pattern.