| ObjectiveContrast and analysis of the clinical treatment effect and open mechanism of occlusion of invisalign appliance and straight wire appliance with reverse-curve arch for patients with deep overbite,in order to provide reference for orthodontists to choose appropriate appliances and judge prognosis.MethodsFrom June 2015 to June 2018,30 patients who were treated in the Department of Orthodontics of the First Affiliated Hospital of Zhengzhou University and met the following inclusion criteria were selected,including 11 male patients and 19 female patients.The cases were invisible appliance group(15 cases)and straight wire arch appliance(15 cases).Before and after treatment,the two groups of patients were taken cast gypsum models and taken cephalometric,use PAR index to analyze the clinical efficacy of two methods for the treatment of deep overbite,and use cephalometric software to measure the cephalometric before and after treatment to analysis the changes of patients’ soft and hard tissues.Results1.PAR index analysis:In the invisible group,there were statistically significant changes in tooth misalignment,buccal area occlusal relationship,overbite,overjet,and midline before and after treatment,except for the midline,the changes in each measurement index in the fixed group were also statistically significant(P<0.05);In the invisible group,the PAR index score after treatment was less than that before treatment(P<0.05),the overall treatment effect rating was greatly improved in 4 cases,improved in 11 cases,and increased or not improved in 0 cases.In the fixed group,the PAR index score after treatment was less than that before treatment(P<0.05),the overall treatment effect rating was greatly improved in 2 cases,improved in 13 cases,and increased or not improved in 0 cases.There was no significant difference in the comparison of the above indexes before and after treatment in the invisible group and the fixed group(P>0.05).2.cephalometric analysis:①Hard tissue measurement project:The U1-SN angle,U1-NA distance,L1-MP angle,L1-NB distance,ANS-Me distance,N-Me distance increased,U1-PP distance,L1-MP distance decreased after treatment in the invisible group,the difference is statistically significant(P<0.05);The U1-SN angle,U1-NA distance,Ll-MP angle,L1-NB distance,MP-FH angle,ANS-Me distance,N-Me distance increased,U1-PP distance,L1-MP distance decreased after treatment in the fixed group,the difference is statistically significant(P<0.05);In the comparison between the invisible group and the fixed group before and after the treatment,the invisible group U1-SN,U1-NA,L1-MP,U6-PP,L6-PP,MP-FH,ANS-Me distance and N-Me distance changed less than the fixed group,U1-PP distance and Ll-PP distance changed more than the fixed group,the difference was statistically significant(P<0.05).② Soft tissue measurement project:The changes of soft tissue measurement items after treatment in the invisible group were not statistically significant(P>0.05);The Z angle decreased after treatment in the fixed group,and the decrease was greater than that in the invisible group,the difference was statistically significant P<0.05),other measurement items are not statistically significant(P>0.05).Conclusion1.Both the invisible appliance and the straight wire fixed appliance with reverse-curve arch can effectively open the bite and correct the deep overbite,and there is no significant difference in the overall treatment effect of the deep overbite patients.2.The mechanism of the open bite of the invisible appliance is mainly the depression of the upper and lower anterior teeth and the lip inclination of the upper and lower anterior teeth,the extension of the molar is not obvious.Clinically with IPR may reduce the inclination of anterior teeth to a certain extent.3.The mechanism of the straight wire fixed appliance with reverse-curve arch to open the bite is mainly the depression of the upper and lower anterior teeth,the extension of the molars,and the lip inclination of the upper and lower anterior teeth.At the same time,the lower jaw will rotate clockwise.4.For non-extraction cases,in the process of lower anterior teeth,invisible appliances have better control of anterior lip inclination than straight wire fixed appliances with reverse-curve arch. |
PDF Full Text Request