Use of SUS2 appliance in orthodontic treatment of Angle II malocclusion at early stage of permanent dentition

Objective To analyze the curative effect and characteristics of SUS2 appliance in the orthodontic treatment of Angle II malocclusion at early stage of permanent dentition.Methods 20 cases of skeletal Angle II with mandibular deficiency,aged 12 to 15 years old,were selected.All the patients were treated with the combination of SUS2 appliance and bracket fixed appliance.Lateral cephalogram measurement was carried out before and after treatment,and the results were statistically analyzed.Results 20 patients achieved remarkable improvement in the profiles,normal overbite and overjet in teeth and Class I in molar relationship after treatment.The cephalometric analysis showed that ANB,U1/SN,U1-NA,U6-PP,L1-MP,UL-E,OB,OJ were decreased,while SNB,L1/MP,L1-NB,Co-Go,Co-Gn,Go-Po,U1-PP,L6-MP,LL-B'-Pos were increased after treatment,both with significant statistical difference.There was no significant change in MP-SN and Y-axis before and after treatment.Conclusion The combination use of SUS2 appliance and fixed appliance can be used efficiently in the orthodontic treatment of Angle II malocclusion at an early stage of permanent dentition because it can reduce overbite and overjet,correct molar relationship and improve the patients' facial outline.