北京大学学报（医学版）2018，Vol.50Issue(1)：154-159,6.DOI:10.3969/j.issn.1671-167X.2018.01.026
磨牙非中性关系与虚拟环境下拼对终末咬合精度
Evaluation of accuracy of virtual occlusal definition in Angle class I molar relationship
摘要
Abstract
Objective: To evaluate the accuracy of virtual occlusal definition in non-Angle class I molar relationship, and to evaluate the clinical feasibility. Methods: Twenty pairs of models of orthognathic patients were included in this study. The inclusion criteria were: (1) finished with pre-surgical orthodontic treatment and (2) stable final occlusion. The exclusion criteria were: (1) existence of distorted teeth,(2) needs for segmentation,(3) defect of dentition except for orthodontic extraction ones,and (4) existence of tooth space. The tooth-extracted test group included 10 models with two premolars extracted during preoperative orthodontic treatment. Their molar relationships were not Angle class I relationship. The non-tooth-extracted test group included another 10 models without teeth extracted, therefore their molar relationships were Angle class I. To define the final occlusion in virtual environment, two steps were included: (1) The morphology data of upper and lower dentition were digitalized by surface scanner (Smart Optics/Activity 102; Model-Tray GmbH, Hamburg, Germany); (2) the virtual relationships were defined using 3Shape software. The control standard of final occlusion was manually defined using gypsum models and then digitalized by surface scanner. The final occlusion of test group and control standard were overlapped according to lower dentition morphology. Errors were evaluated by calculating the distance between the corresponding reference points of testing group and control standard locations. Results: The overall errors for upper dentition between test group and control standard location were (0.51 ±0. 18) mm in non-tooth-extracted test group and (0. 60 ±0. 36) mm in tooth-extracted test group. The errors were significantly different between these two test groups (P< 0. 05). However, in both test groups,the errors of each tooth in a single dentition does not differ from one another. There was no significant difference between errors in tooth-extracted test group and 1 mm (P>0.05); and the accuracy of non-tooth-extracted group was significantly smaller than 1 mm (P <0.05). Conclusion: The error of virtual occlusal definition of none class I molar relationship is higher than that of class I relationship, with an accuracy of 1 mm. However, its accuracy is still feasible for clinical application.关键词
计算机辅助手术模拟/正颌外科/虚拟终末咬合/中性磨牙关系Key words
Computer-assisted surgical simulation/Orthognathic surgery/Virtual occlusion definition/Angle class I molar relationship分类
医药卫生引用本文复制引用
吴灵,刘筱菁,李自力,王兴..磨牙非中性关系与虚拟环境下拼对终末咬合精度[J].北京大学学报（医学版）,2018,50(1):154-159,6.基金项目
国家自然科学基金(81400569)、首都卫生发展科研专项(2016-14103)和北京市科学技术计划项目(Z161100000116053)资助 （81400569）
Supported by the National Natural Science Foundation of China (81400569),the Capital Health Researth and Development of Special (2016-1-4103) and Beijing Municipal Science & Technology Commission (Z161100000116053) （81400569）
