论文部分内容阅读
目的:探讨无托槽隐形矫治器联合微种植钉内收上前牙时，先远移尖牙与整体内收两种方式内收时上颌前后牙生物力学效应。方法:采集患者上颌骨及上牙列的CBCT数据信息，使用Mimics、Geomagic Studio、HyperMesh等软件，采用逆向工程方法建立拔除上颌第一前磨牙使用无托槽隐形矫治器联合微种植钉整体内收上前牙的三维有限元模型，分析：①矫治器加力远移尖牙；②矫治器加力＋矫治器牵引钩处150 g牵引力远移尖牙；③矫治器加力＋尖牙舌钮处150 g牵引力远移尖牙；④矫治器加力整体内收上前牙；⑤矫治器加力＋矫治器牵引钩处150 g牵引力整体内收上前牙；⑥矫治器加力＋尖牙舌钮处150 g牵引力整体内收上前牙，六种工况下前后牙的牙周膜等效应力和初始位移。结果:只远移尖牙时，尖牙所受牙周膜等效应力最大，分别为5.23E-02 MPa、5.65E-02 MPa、5.87E-02 MPa；上中切牙的唇侧位移量分别为－5.08E-03 mm、－9.67E-04 mm、－1.68E-03 mm，第一磨牙牙冠近移量分别为－1.53E-02 mm、－1.40E-02 mm、－1.51E-02 mm。整体内收上前牙时，中切牙所受牙周膜等效应力最大，分别为4.69E-02 MPa、6.26E-02 MPa、4.84E-02 MPa；中切牙的冠根位移差分别为1.44E-01 mm、1.35E-01 mm、1.29E-01 mm，第一磨牙牙冠近移量分别为－2.93E-02 mm、－2.61E-02 mm、－2.33E-02 mm。结论:只远移尖牙时，切牙会为尖牙的远移提供支抗，在矫治器上牵引能够更有利于前后牙支抗的保护；整体内收上前牙时，在尖牙上牵引更有利于后牙支抗的保护和切牙的整体移动。“,”Objective:To evaluate the biomechanical effects of clear aligners combining mini-screws in anterior retraction cases either by canine-first distalization or en-masse retraction.Methods:3D finite element models of the maxillary anterior retractions with miniscrew and clear aligner were reconstructed using reverse-engineering approach with CBCT data of an adult patient who had maxillary first premolars extracted, using Mimics, Geomagic Studio and HyperMesh. The orthodontic force were divided into six groups: ① only clear aligner to distalize the canine. ② clear aligner+ 150 g force at aligner hooks to distalize the canine. ③ clear aligner+ 150 g force at canine cervical buttons to distalize the canines. ④ only clear aligner to retract en-masse. ⑤ clear aligner+ 150g force at aligner hooks to retract en-masse. ⑥ clear aligner+ 150 g force at canine cervical buttons to retract en-masse.Results:When distalizing the canine, the maximal vonmises stress focus on canine, which is 5.23E-02 MPa, 5.65E-02 MPa and 5.87E-02 MPa respectively, the labial displacement of the central incisor crown is -5.08E-03 mm, -9.67E-04 mm, and -1.68E-03 mm, respectively. The mesial displacement of the first molar crown is-1.53E-02 mm, -1.40E-02 mm, and -1.51E-02 mm, respectively. When retract en-masse, the maximal vonmises stress focus on central incisor, which is 4.69E-02 MPa, 6.26E-02 MPa, and 4.84E-02 MPa, respectively. The lingual displacement discrepancy between central incisor crown and root is 1.44E-01 mm, 1.35E-01 mm, and 1.29E-01 mm, respectively. The mesial displacement of the first molar crown is -2.93E-02 mm, -2.61E-02 mm, -2.33E-02 mm, respectively.Conclusions:The incisors will supply anchorage for canine distalization and application of retraction force at aligner will save more anchorage in anterior and posterior teeth. When retract teeth en-masse, application of retracton force at canine cervical buttons has the advantage of reducing the mesial displacement of posterior teeth and the translation of incisors.