A Comparison Of Correlation And Stability Study Between Soft And Hard Tissues Changes In Patients With Skeletal Angle ClassⅢ Malocclusion After Orthodontic And Surgical Treatments

Objective:The purpose of this study was to analyze the changes of soft and hard tissues at each treatment stage in patients with Skeletal Angle Classâ…¢malocclusion following orthodontic-orthognathic surgery,and to discuss the change of angles in hard and soft tissues and the long-sterm stability after treatment,so as to get some guidelines for clinical work.Methods:The authors selected twenty-four Skeletal Angle Classâ…¢malocclusion patients from 19 to 25 years old(22.4±3.6 on average)in Orthodontic Department,College of Shandong University.Each patient was taken standardized lateral cephalograms at the following stages:T₀:before treatmentT₁:3 months after surgeryT₂:1 year after surgeryT₃:3 years after surgery A total of 28 hard and soft tissues landmarks were selected and evaluated between the different stages.All data were analyzed by SPSS 12.0 software to study the correlation of the changes in hard and soft tissues and the long-term stability after treatment.Results:(1)The comparison of the angle's change between the stage of T₀ and T₁:only 11 ones have significant diversity in those 16 hard tissue angles.Except N-S-Ar,N-S-Ba,N-S-Go,N-Ba-Pt-Gn and Y,others all have statistical significance.In those 16 soft tissue angles,except A'UL-B'LL and FH-B'LL,others have significant diversity.(2)The comparison of the angle's change between the stage of T₁ and T₂:compared with the stage of T₁,16 hard tissue angles have a light tendency to recur at the stage of T₂.Only SNPo,U1-SN have significant diversity.In those soft tissue angles,except S-N'-B,G-Sn-Pos,Ns-Sn-Pos,FH-SnPos and Z,other 11 ones all have a light tendency to recur.(3)The comparison of the angle's change between the stage of T₁ and T₃:In those 16 hard tissue angles,only U1-SN has an obvious change.Others have a light recrudescence.But this recrudescence has no statistical meaning.We can get a conclusion that the change of hard issue after orthognathic surgery is stable.In those 16 soft tissue angles, except S-N'-B',G-Sn-Pos,Ns-Sn-Pos,FH-SnPos,Z and Ns-Prn-Pos,others have a light recrudescence,and have no statistical significance. (4)The comparison of the angle's change between the stage of T₂ and T₃:the changes after one year and three years are slight,and all hard issue angles' changes have no statistical significance.In the items of soft issue,except G-Sn-Pos,others have no obvious diversity.(5)The comparison of the angle's change between the stage of T₀ and T₂,T₃:in one year and three years after surgery,although those 16 hard issue angles have varying degrees of recrudescence,the recrudescence is similar to 3 months after surgery.In one year and three years after surgery,except FH-A'UL,other soft issue angles are similar to 3 months after surgery.Conclusion:To Skeletal Angle Classâ…¢malocclusion patients,Orthodontic-Orthognathic surgery treatment can improve the soft profile.After Orthodontic-Orthognathic surgery,the measured angles in hard issue have a slight recrudescence in the period of three months and one year.But this recrudescence has no essential influence to surgery effect.Compared with hard issue,soft issue's recrudescence is obvious.Those measured angles related to Pos have visible tendency to recur.From one year to three years after surgery,patients' hard issue is relative stability.As a whole,the long-term effect of Orthodontic-Orthognathic surgery treatment is stable.