The clinical investigation of magnetic Twin-block appliance for Angle's class II division 1 malocclusion

Objective To evaluate the skeletal changes of Angle's class Ⅱ division 1 malocclusion patients after treatment with magnetic Twin-block appliance.Methods Fifteen Angle's class Ⅱ division 1 malocclusion patients(late mixed dentition or early permanent dentition) with the overjet more than 10 mm were treated using the magnetic twin-block appliance and fixed appliance.Before and after the treatment,the cephalometric radiographs were taken to observe the structure changes of the jaw and the teeth.The results were statistically analysed.Results Before and after the treatment with magnetic twin-block,SNB is increased by(1.97 ± 1.01)°,ANB is decreased by(1.94 ± 0.72)°,MP-FH is increased by(4.80 ± 1.37)°(P 0.001).The sagittal and vertical effection on the mandible is obvious,and the difference was statistically significant.Conclusions Using magnetic Twin-block appliance on Angle's class Ⅱ division 1 malocclusion patients in late mixed dentition or early permanent dentition phase,can improve the bone remodeling of jaw(especially the mandible) and facial profile esthetics.