The Comparison And Analysis Of The Two Different VTO

Objective:The purpose of the study was to predict soft tissue facial profile, hard tissuechanges and the tooth position after orthodontic treatment in patients with skeletalclass I using two kinds of visual treatment objectives (VTO), and to assess thedifferences and the availability between the two methods.Methods:1. The sample consisted of lateral cephalometric radiographs of40patients withskeletal class I who required extraction of4first premolars. Ricketts VTO and AyalaVTO was used to predict soft tissue facial profile, hard tissue and the tooth positionafter orthodontic treatment in the same patient. The differences between the twomethods was assess by the quantitative analysis.2. Comparisons were made between the two VTO methods and posttreatmenttracings, respectively, to assess the availability of the two methods.3. Get and trace the cephalometric radiographs before and after the treatment,and considering the above results, to confirm the conclusion of all the experimentsfurther.Results:1.Ricketts VTO and Ayala VTO’s prediction of U1-SN(°)、U1-PP(mm)、L1-MP(°) and the soft tissue had statistical significance, and the prediction ofL1-MP(mm) had no statistical significance.2.Ricketts VTO’s prediction of U1-SN(°)、U1-PP(mm) and the soft tissue hadstatistical significance compared with actual treatment outcome, but there were nostatistical significance in L1-MP(°) and L1-MP(mm). Ayala VTO’s prediction of U1-SN(°)、U1-PP(mm) and L1-MP(mm) had no statistical significance comparedwith actual treatment outcome, but had statistical significance in L1-MP(mm) and softtissue.3. After treatment, the difference of A,B point and NP-FH had no statisticalsignificance, but had statistical significance in OP.Conclusions:1. Ricketts VTO and Ayala VTO in the prediction of the position of dental tissueand soft tissue after treatment were not consistent.2. Ricketts VTO in the prediction of L1-MP(°) and L1-MP(mm) were consistentwith treatment outcome. Ayala VTO method in the prediction of U1-SN(°)、U1-PP(mm) and L1-MP(mm) were consistent with treatment outcome. The two methods inthe prediction of soft tissue were not consistent.3. After treatment, there was no obvious change in A, B point and NP-FH, but itchanged obviously in OP.