无牙颌模型正中关系位三维重建精度的定量评价  

Quantitative evaluation of three-dimensional reconstruction accuracy of edentulous models in centric relation

作　　者：孙玉春[1] 李虹[1] 王勇[1] 王永波 吕培军[1] 

机构地区：[1]北京大学口腔医学院·口腔医院口腔医学计算机应用中心口腔修复教研室口腔数字化医疗技术和材料国家工程实验室卫生部口腔医学计算机应用工程技术研究中心,100081 [2]山东新华医疗器械股份有限公司

出　　处：《中华口腔医学杂志》2014年第6期371-374,共4页Chinese Journal of Stomatology

基　　金：国家科技支撑计划（2012BAI07B04）;国家自然科学基金（81271181）;国家高技术研究发展计划（863计划）（2013AA040801）;北京市科技新星计划（Z131107000413112）

摘　　要：目的 使用两种方法进行无牙颌模型正中关系位三维重建,定量对比垂直距离和水平关系的重建精度,以期为全口义齿的计算机辅助设计与辅助制作（computer aided design and computer aided manufacture,CAD-CAM）提供参考.方法 临床制取5例无牙颌患者的上下颌模型及蜡（牙合）托,每个单颌模型底座轴面粘接10个等尺寸定位柱,即每副模型20个,配对12对定位柱底面圆心点对,以圆心点对的垂直距离和水平距离作为测量项目.用牙颌模型三维扫描仪获取上下颌单颌模型与蜡（牙合）托的完整表面数据,再分别用转移（牙合）架固定法和皮筋固定法将上下颌模型和蜡（牙合）托固定于正中关系位,扫描模型唇颊面.基于唇颊面共同区域进行配准,重建正中关系位双颌三维模型,使用测量软件进行数字模型测量.使用机械三坐标测力臂进行实物测量.计算实物测量值与数字模型测量值的差值,即垂直距离或水平距离误差,进行配对￡检验.结果 转移（牙合）架固定法和皮筋固定法的垂直距离误差分别为（0.356±0.200）和（0.382 ±0.299） mm,差异无统计学意义（P＞0.05）;水平距离误差分别为（0.010±0.411）和（0.104±0.476） mm,差异有统计学意义（P＜0.05）.结论 与皮筋固定法相比,借助转移（牙合）架,可显著提高无牙颌模型水平关系三维重建的精度.Objective To reconstruct the centric relation of upper and lower edentulous dental models with two methods,to compare the reconstruction accuracy of the vertical and horizontal distance,and to provide some references to computer aided design and computer aided manufacture for complete denture.Methods Dental models and rims made from five edentulous patients in clinical were obtained.Each model was stocked with 10 identical size positioning cylinders （20 cylinders on each pair models） on 5 side-surfaces of basement.Twelve center point pairs were paired between upper and lower models from 20 cylinder bottoms.The vertical and horizontal distances of 12 center point pairs were regarded as the evaluation items.Firstly,upper and lower models and rims were scanned separately.Then,models and rims （fixed in centric relation respectively with positioning articulator and rubber banding） were scanned.In software,all the data were registered to reconstruct centric relation based on common region.Digital models were measured with software tools,and real models were measured with a contact measurement arm.The differences of the homologous items between two methods were analyzed with paired-t test.Results The vertical distance errors for dental articulator positioning method was （0.356 ± 0.200） mm and that of the rubber band method was （0.382 ± 0.299） mm,and paired-t test between the two methods showed no significant differences（P ＞ 0.05）.The horizontal errors were （0.010 ± 0.411） mm and （0.104±0.476） mm,and paired-t test showed significant differences （P ＜ 0.05）.Conclusions Comparing with rubber band method,dental articulator positioning can significantly increases three-dimensional reconstruction accuracy of edentulous jaw gypsum models＇ horizontal relation.

关 键 词：计算机辅助设计 颌 无牙 义齿 全口 正中关系 

分 类 号：R783.6[医药卫生—口腔医学] R319[医药卫生—临床医学]