Research of treatment effects of double parabolic lingual springs appliance and open vertical loops in combination with straight wire appliance therapy on skeletal classIII malocclusion in early permanent dentition

Abstract

Objective To evaluate the treatment effects of double parabolic lingual springs appliance and open vertical loops in combination with straight wire appliance therapy on skeletal classⅢmalocclusion in early permanent dentition. Methods 30 cases with skeletal classⅢ malocclusion in early permanent dentition were treated by double parabolic lingual springs appliance and open vertical loops in combination with straight wire appliance.Cephalometric tracing measurement was taken to analyze and compare between pretreatment and posttreatment. Results The comparison of before and after orthodontic treatment showed angle SNA increased (3.20±0.36)°,angle SNB decreased(-0.39±0.48)°,angle ANB decreased(4.69±1.34)°,Ls-E increased(3.50±1.14)mm(t=-4.65,2.73,-8.42,-4.32,all P< 0.01). Conclusion The above metioned technique could be a reliable way to treat mild and moderate skeletal classⅢ malocclusion. Key words: Tooth abnormalities; Orthodontic appliances; Orthotic devices