A Comparison Of The Arch Expansion Between The Planed Amount And The Final Outcome And An Analysis Of Psychological Change At The Beginning Of The Orthodontic Treatment With Clear Aligner Treatment

Objective:1.To compare the planed arch expansion to the actual outcome with Clear Aligner Treatment,knowing the predictability of arch expansion.2.To analyze the psychological change on adult patients' at the beginning of the Clear Aligner Treatment.Materials and methods:1.64 adult patients were selected according to the inclusion criteria,each patient was treated with Angelalign in the orthodontic department of the First Affiliated Hospital from September 2014 to December 2016.Take the pre-and post-treatment silicone rubber models,scaned by the high precision industrial computed tomography,thus gaining the digital models,then treated with the iortho 6.2 software.linear values of upper and lower arch widths were measured for canines,the first and second premolars and the first molars at two different points:cusp tips and lingual gingival margins.Use a paired t-test to compare the expansion planed with the post-treatment measurements.Calculate the amount of change achieved in percentage.2.80 adult patients were selected according to the inclusion criteria,each patient was treated with Angelalign in the orthodontic department of the First AffiliatedHospital from September 2014 to December 2016.Symptom Checklist-90 was employed to evaluate their mental health status when they came to the hospital,7days after orthodontic treatment,1month after orthodontic treatment and 3 months after orthodontic treatment.An Independent-Sample Test was used to compare the scales before treatment with the ones of national norms.Use a paired t-test to compare the scales of the Symptom Checklist-90 at different points.Results:1.For maxillary measurements,there was a statistically significant difference between the planed expansion and the final outcome(P<0.05)For the lower every arch measurement,at the lingual gingival margin,there was a statistically significant difference between the planed expansion and the final outcome(P<0.05).At the cusp tips,the measurements showed nonstatistically significant difference between the planed expansion and the final outcome(P>0.05).The prediction accuracy at the cusp tips of the maxillary are as follows:89.1±15.7%,84.2±13.5%,80.7±19.9%,75.8±16.3%,at the lingual gingival margins are:68.2±11.2%,67.6±21.4%,62.5±24.8%,53.3±10.4%.The prediction accuracy at the cusp tips of the mandibular are:100±8.7%,96.2±10.1%,96.8±20.4%,100±9.5%,at the lingual gingival margins are:59.3±13.4%,87.8±17.6%,84.6±17.6%,72.2±14.6%.The accuracy at the gingival margins was lower than that at the cusp tips(P<0.05).2.The mean scores of obsessive-compulsive,interpersonal sensitivity,depression,anxiety,psychoticism of the adult patients before treatment were higher than those of the national norms(P<0.05).results comparing the scores of Symptom Checklist-90 before treatment with those at one week after the placement of Angelalign,there was a significant increase in obsessive-compulsive symptom,interpersonal sensitivity,depression,anxiety,psychoticism,hostility,paranoia(P<0.05).there was a certain extent of negative psychological influence on adults.Compare the scores between 1month after the placement and before treatment,then there was a significant increase in obsessive-compulsive,depression,anxiety,psychoticism(P<0.05).Then there was no significant difference when patients had wear the appliance 3 months(P>0.05).Themental health status had gradually restored to that of pretreatment with patients adapting to the Clear Aligner Treatment.Conclusion:1.(1)The mean accuracy of expansion planed with Clear Aligner Treatment for maxillary was 72.8±20.7%.The lower arch presented an overall accuracy of86.9±15.6%.(2)The accuracy became worsening toward the posterior region of the maxillary arch.(3)The prediction of expansion involves more bodily movement of the teeth than that can be seen clinically,more dental tipping is observed.2.(1)The adult patients accepting Clear Aligner Treatment have low mental health status.(2)During the initial treatment of adult patients,the mental health status is not stable.In the early stage,patients' mental health status proved worse than that of pretreatment.With adapting to the appliance,patients' mental health status become better and better.