Dentoskeletal effects of the bitejumping appliance and the twin-block appliance in the treatment of skeletal class ii malocclusion: A retrospective controlled clinical trial

The current retrospective controlled trial aimed to compare the dentoskeletal effects of the Bite-Jumping (BJ) and the Twin- Block Appliance (TB) in the treatment of skeletal Class II malocclusion. The sample was screened for eligibility criteria including skeletal and dental Class II malocclusion; Cervical Vertebral Maturation at Stage 3 at treatment start, and Func- tional orthopedic treatment with either a TB or BJ appliances. Twenty-three patients treated with TB, and twenty-three treated with BJ were included. Cephalometric data were compared with a control group of 15 untreated subjects retrieved from the American Association of Orthodontists Foundation Craniofacial Growth Legacy Collection. Baseline character- istics were similar between groups. A significant increase for the AO-BO dimension, and a significant decrease in the over- jet, were registered for both study groups respect to controls. TB was more effective than BJ in increasing the mandibu- lar length (Co-Gn), in reducing the ANB angle and changing the SNB angle. The resulting differences between the two groups could be attributed to the different appliances. In conclusion, both appliances demonstrated a clinical efficacy in treating Class II. TB seems therefore better indicated, respect to BJ, in Class II cases with a predominant component of mandibular hypoplasia.