A Cephalometric Study Of Soft And Hard Tissue Changes In Angle Class Ⅱ Division 1 Malocclusion Treated Orthodontics With Extraction

Objectives:The aims of this study were to determine the changes in the dentofacial structures of ClassⅡdivision 1 patients after orthodontics treatment with extraction of four first premolars,and to compare pre- with post-treatment values. Methods:The ClassⅡdivision 1 subjects included 11 males and 14 females(mean age: 12.08±2.03 years).All received comprehensive orthodontic treatment with extraction of four first premolars,including using a fixed appliance and classⅡelastics.Lateral cephalograms were taken at the beginning and end of treatment.Twenty-five(12 linear and 13 angular)measurements were measured on each radiograph.All data were analyzed by SPSS 12.0 software.Results:Compared with pre- and post-treatment measurements,statistically significant differences were found for ten of 25 measurements.They are:SNA,ANB,N-Me,U1-SN,U1-NA°,U1-NA,Ns-Sn-Pg,Cm-Sn-UL,UL-E plane,UL-UI.Conclusions:The findings demonstrates that camouflage treatment in ClassⅡ~1 subjects has characteristic skeletal,dental and soft tissue effects on the dentofacial complex.(1)Through orthodontics treatment with tooth extraction,the teeth is moved and some skeletal changes,the soft facial tape and lip form are improved significantly;(2)Orthodontic treatment can improve the soft profile,but it has a limit.(3)To ClassⅡdivision 1 patients,the upper incisor should not be so excessively retracted that the upper lip appears to be over upright.(4)some skeletal changes slightly,while soft tissue and tooth change obviously.