【作者】 彭立国；

【导师】 樊瑜波；

【作者基本信息】 四川大学 ， 生物医学工程， 2007， 硕士

【摘要】 研究背景：自1999年开始，无托槽矫治器Invisalign应用于临床以来，由于其透明隐形无托槽、舒适美观、可摘、卫生，并可实现三维可视化矫治效果的预测等特点，受到越来越多的正畸医生以及病人的青睐。近年来，我国一些研究机构和科技公司合作，也开发出了国产无托槽隐形正畸矫治系统并开始了临床应用。无托槽技术是计算机技术在口腔正畸矫治中的高科技应用，其矫治作用原理与传统固定矫治器有明显区别。在口腔正畸矫治中，最关键的要素是把握准矫治力及其作用方式。由于正畸医生对无托槽矫治器的分布力系及其作用效果尚把握不准，这在很大程度上限制了无托槽矫治器的进一步推广和发展。到目前为止，有很多关于无托槽矫治技术的介绍及应用报道，却极少有关于无托槽矫治器作用下的口腔正畸生物力学研究报道。因此，研究无托槽矫治器作用下的口腔正畸生物力学将有重要和创新意义。目的：研究无托槽矫治器在口腔正畸矫治中的作用力系及效果，并对无托槽矫治器设计及临床应用提供指导。无托槽矫治器的作用力系为分布力系，这与传统固定矫治器的相对集中力系有着极大区别。研究分析无托槽矫治器作用下牙体及牙周组织的应力大小及分布情况，就可预见牙体移动趋势，从而初步判断治疗效果是否符合医生治疗计划的要求。研究在无托槽矫治器的多种作用方式下的上颌尖牙及牙周组织的生物力学，并与传统固定矫治器的作用方式及效果做对比，从而选取适当的作用方式，为无托槽矫治器的设计及临床应用提供指导。方法：建立包括牙槽骨、牙周膜和牙髓在内的上颌尖牙三维有限元模型及其无托槽矫治模型。根据尖牙向外倾斜的畸形情况，设计多种无托槽矫治器作用方式下的模拟算例。在此基础上分析无托槽矫治器的力、力偶和力矩等，并分析无托槽矫治器作用下的矫治力和应力分布。同时与传统的有托槽固定矫治器的相关结果作对比分析。利用基于CT的快速成型方法，建立几何相似性更高的下颌骨、全牙列及其牙周组织模型，导入有限元分析软件并完成网格划分。利用有限元分析软件的接触分析功能，完成无托槽正畸矫治器作用下的口腔生物力学研究。结果：分别在无托槽和传统的有托槽固定矫治器作用下，上颌尖牙的牙周各组织应力最大值相近；当无托槽矫治器与唇舌双侧区域接触方式作用时，牙体及牙周组织应力变化趋势相似。利用基于CT的快速成型方法，建立了几何相似性更高的下颌骨、全牙列及其牙周组织模型，并根据患者的真实情况完成了牙列的组装排列。利用接触分析，完成无托槽矫治器作用下的口腔生物力学研究分析。结论：通过无托槽矫治器作用下的口腔正畸生物力学研究，了解了无托槽矫治器的矫治力系及其作用效果，并可为无托槽矫治器的设计和临床应用提供指导。通过设计合理的无托槽矫治器，可以控制牙齿的移动，从而达到良好的临床治疗效果。更多还原

【Abstract】 Background: Since 1999 when invisalign was used in clinical application, invisalign has been popular with both orthodontists and patients for its advantages, such as being transparent, invisible, comfortable, moveable, sanitary and predictable. Recently, some institutes and a technology corporation co-operated and developed the invisible orthodontic treatment system. Their products have been applied clinically. The technology of invisible appliances is the application of computer technology in orthodontics, which is definitely different from the traditional fixed aligners. It is most important to master the force and its way of action in orthodontics. Because orthodontists can’t master accurately orthodontics forces of invisible appliances at present, invisible appliances are limited seriously to develop and spread. Up to now, there are many introductions and applications to invisible appliances, but few biomechanical researches under orthodontics forces with invisible appliances techniques. Therefore, it will be important and innovative to study biomechanics under orthodontics forces with invisible appliances techniques.Objectives: To provide directions to the design and application of invisible appliances, orthodontics forces system and biomechanics effect under orthodontics forces with invisible appliances techniques are studied. The orthodontics forces under invisible appliances are distributed, which is much different from that of traditional fixed aligners. The moving tendency of teeth can be predicted by researching and analyzing the magnitudes and distributions of teeth and tissues around teeth, which can help orthodontists estimate whether the result is right or not. Aiming at one kind of tooth’s monstrosity, several simulated cases applied with invisible appliances are designed and analyzed, which are compared with that of traditional fixed aligners to select the most proper one and direct design and clinical application of invisible appliances.Methods: A three-dimensional FE model of canine with the invisible appliance was set up, which includes alveolar bone, periodontal membrane and pulp. Aiming at one kind of tooth’s monstrosity, several simulated cases are designed and analyzed numerically. The force and stress distributions applied with the invisible appliance were obtained. And the comparative study was made between the invisible appliance and the traditional fixed aligner. With the method of rapid forming from CT, more accurate models of mandible, all teeth including tissues around them and a set of invisible appliances are set up and assembled according to the actual condition of patient. These assembled models are imported into the software of FE and meshed. To finish the biomechanical research applying with invisible appliance, contacting analysis method is used in the software of FE.Results: The maximal stresses around the maxillary canine are greatly close, and changing tendency of stresses is very similar, while applied with the invisible appliance and the traditional fixed aligner. With the method of rapid forming from CT, more accurate models of mandible, all teeth including tissues around them and a set of invisible appliances are set up. According to the actual conditions of patients, assembly of these models is completed. By contacting analysis method in the software of FE, biomechanical research of invisible appliance technique is finished.Conclusions: Orthodontic forces system and its biomechanical effect under orthodontics forces with invisible appliances techniques are studied, which can be used to direct design and clinical application of invisible appliances.更多还原