The Hard Tissue Change before and after Orthodontic Treatment to the Adult Skeletal Class II Division 2 Malocclusion.

Objective: To investigate hard tissue changes and to evaluate the orthodontic effect induced by straight wire appliance for adult skeletal class Ⅱ division 2 malocclusion.Methods: 8 patients (3 males and 5 females, aged 19-27 years, mean age 23.6 years) were treated by straight wire appliance with upper two first premolars extracted. Pretreatment and post-treatment cephalometric radiograph were made and studied.Results: After treatment, SNA and SNB decreased, U1-SN and L1-MP increased,U1-L1 decreased. Root of upper incisors and base bone of maxilla palatally moved significantly. Crown of lower incisors labially moved, and mandibular retrusion was compensated.Conclusion: Obvious improvement of facial form can be achieved by orthodontic therapy in adult patient with skeletal class Ⅱ division 2 malocclusion.