透明压膜保持器戴用前后咬合变化的T-scan分析

T-scanⅢanalysis of occlusal contact changes before and after the use of clear thermoplastic retainers

目的运用T-scanⅢ数字化咬合分析系统采集分析正畸固定矫治结束患者戴用透明压膜保持器前后的咬合接触,探究透明压膜保持器在正畸保持期间对咬合产生的影响。方法选取结束固定矫治且在拆除矫治器后佩戴透明压膜保持器进行保持的患者34例。在患者固定矫治结束即刻(T0期)和戴用透明压膜保持器3个月(T1期)时采集患者最大牙尖交错位的咬合数据。对T0和T1期牙合接触点数目、牙合接触面积、牙合力中心点矢状向位移等咬合参数进行统计分析。结果T0和T1期的咬合参数变化具有统计学差异。牙合接触点总数和牙合接触总面积显著减小,其中牙弓前部的牙合接触点数目和牙合接触面积增大,牙弓后部的牙合接触点数目和牙合接触面积减小;牙合力中心点向近中发生移位。结论正畸固定治疗结束后,使用透明压膜保持器会改变患者的最大牙尖交错位的咬合;戴用透明压膜保持器3个月后最大牙尖交错位的总咬合接触点和咬合接触面积减小,其中后牙区减小而前牙区增加。

Objective To analyze the change of occlusal contacts of patients before and after they wearing clear thermoplastic retainers and explore the effect of clear thermoplastic retainers on occlusion during orthodontic retention.Methods The T-scanⅢdigital occlusion analysis system was used to collect and analyze the occlusion contacts in maximum intercuspal position of 34 patients.The occlusion data were collected upon the end of fixed orthodontic treatment(T0)and after wearing clear thermoplastic retainers for 3 months(T1).The number of occlusal contacts(NOC),the area of occlusal contacts(AOC)and sagittal displacement of the center point of force(COF)before and after wearing clear thermoplastic retainers were compared.Paired t-test and wilcoxon rank sum test were utilized in data analysis.Results The patients’occlusal contacts in maximum intercuspal position changed after wearing clear thermoplastic retainers for 3 months.From the end of fixed orthodontic treatment(T0)to wearing clear thermoplastic retainers for 3 months(T1),the total number and area of occlusal contacts decreased significantly,while the number and area of anterior dental arch increased(P<0.05)and posterior dental arch decreased.The center point of occlusal force was obviously shifted mesially(P<0.05).Conclusion The use of clear thermoplastic retainers changes the occlusion contacts of the patients after fixed orthodontic treatment.After wearing the clear thermoplastic retainers for 3 months,the total occlusal contact area in maximum intercuspal position reduces,and occlusal contact gets shallower in posterior occlusal area and gets deeper in anterior area.