下颌全牙列数字印模口内法与口外法的准确性比较

摘要

目的:利用自制的口内参考系,定量分析并比较下颌全牙列数字印模口内法与口外法间准确性的差异.方法:利用自制的口内定位器将4枚金属球粘接于患者下颌牙列上.使用口内激光扫描仪和口外高精度坐标测量仪分别在口内和口外制取患者的下颌全牙列数字印模.以口内参考系为标准,分别测量两种数字印模中4枚钢球间的距离误差(ED)和角度误差(EA),从而全面比较两种取模法的准确性.结果:①口外法 ED显著低于口内法(P<0.05);②口内法和口外法的EA无统计学差异(P>0.05).结论:制取下颌全牙列数字印模,口外法的准确性高于口内法.%Objective:Using self-made intraoral reference system,the difference of accuracy between intraoral and extraoral digital impression methods for mandibular full arch was quantitatively analyzed and compared.Meth-ods:Four metal balls are inserted into the lower dentition of the patient by using a self-made intraoral positioner.In-traoral digital scanner and extraoral high precision coordinate measuring apparatus were used to make mandibular digital teeth impression in mouth and mouth.Based on the intraoral reference frame,the distance error(ED)and an-gle error(EA)of 4 steel balls in two kinds of digital impressions were measured respectively,so as to compare the accuracy of the two methods.Results:The EDof extraoral method was lower than that of intraoral method(P<0.05);There were no statistically significant differences in EAbetween oral and extraoral methods(P>0.05).Conclu-sion:The accuracy of extraoral method is higher than that of intraoral method in making digital impression of man-dibular full arch.