Cephalometric changes of orthodontic treatment for Angle ClassIIdivision 1 malocclusion in adult patients

Objective To investigate the changes of hard tissue before and after orthodontic treatment for Angle ClassⅡdivision 1 malocclusion adult patients with the first maxillary premolars extracted.Methods Twenty adult patients of Angle ClassⅡdivision 1 malocclusion received orthodontic treatment with extraction of two maxillary first premolars.Cephalometric analysis was carried out and compared before and after treatment.Results There was a clockwise rotation in mandible.The overjet was reduced maily by upper incisors retraction,which had no significant relation to lower incisor inclination.Conclusion The treatment of Angle ClassⅡdivision 1 malocclusion in adult patients by extraction of two first maxillary premolars is satisfactory.The deep overjet can be corrected,good occlusion relationship achieved and treatment time shortened.