生理性咬合对临近微型种植体—骨界面应力分布影响的三维有限元分析
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摘要
目的：错牙合畸形可以影响牙合颌面的发育、口腔功能等，甚至造成心理和精神障碍。支抗的控制是多数正畸病例治疗成败的关键。现有的各种加强支抗的方法不能满足临床使用要求。近年来出现的微型种植体为提高疑难病例的疗效开拓了一个新的领域。但稳定性不足是其主要缺点，据报道成功率为83-89%。种植体脱落大多发生在正畸加力前和加力过程中，多由于种植体植入手术不当及种植体-骨界面不合适的应力分布造成，严重影响了种植体在临床中的普及应用。
微型种植体主要植入在牙槽骨颊舌侧牙根间的部位，由于牙根间距离有限和个人解剖结构差异，对手术的准确性要求很高，常常发生种植体植入后距离临近牙根很近或触及牙根的情况。研究表明种植体植入后距离牙根过近时脱落率明显增加。因此有必要明确微种植体植入后距牙根的安全距离。临床应用发现，种植体植入后拍摄平行投照牙片怀疑距离邻近牙根较近时，患者常有咬合痛的表现，且咬合痛与种植体脱落有较高相关性。目前种植体植入后距离牙根过近时生理性咬合对种植体稳定性的影响及牙齿的生理性咬合与种植体载荷的应力分布是否产生联合效应未见报道。本研究拟用三维有限元方法建立微型种植体-牙-颌骨的模型，分析微型种植体植入后距离牙根过近时种植体周围骨组织应力改变，牙齿生理性咬合产生的动度对种植体稳定性的影响，探讨微型种植体植入后距临近牙根的安全距离，为微植体支抗的临床应用提供理论依据。
材料与方法：
1实验设备
计算机：CPU：2.0；内存：1G
软件：Mimics10.1软件（Materialise公司）、Pro/E4.0软件、Geomagic Studio逆向工程软件、ANSYS13.0软件。
2建立微种植体-颌骨的三维实体模型
2.1上颌骨三维有限元模型的建立
采用螺旋CT对一牙齿排列整齐的健康志愿者进行扫描，CT图像以DICOM格式存储，在Mimics软件中切除，进行局部光滑处理，设定牙周膜厚度0.25mm，建立含有上颌骨-牙-牙周膜的三维有限元模型。
2.2微种植体有限元模型的建立
参照国产纯钛、微型圆柱状螺纹种植体的几何形态，设定骨内段8mm，直径为1.6mm，在Pro/E中建立种植体三维模型。
2.3装配实体种植体颌骨三维模型
2.3.1植入位置和角度：模拟临床情况，将微种植体植入在上颌骨的右侧第二前磨牙和第一磨牙之间，距离牙槽嵴顶5mm处，植入方向为垂直于牙体长轴。
2.3.2根据微种植体距临近牙根的距离，设计模型如下：
Model1：微种植体植入后接触牙根表面
Model2：微种植体植入后进入牙周膜
Model3：微种植体植入后接触牙周膜表面
Model4：微种植体植入后距临近牙周膜表面为1.0mm
3加载条件
3.1加载分两种情况
Load A：牙齿载荷，微种植体不载荷
Load B：牙齿、微种植体同时载荷
3.2微型种植体加载
加载大小：2N
加载方向：通过种植体植入点做一平行于咬合平面的直线，通过此直线做一垂直于地平面的平面，在此平面上沿与咬合平面成30度角的方向载荷(模拟内收上前牙时的正畸力)。
3.3牙齿加载
加载大小：300N
加载方向：在牙齿牙合面上，平行于牙长轴加载。
3.4计算工况
所建模型共有8种工况：Model1-A，Model1-B，Model2-A，Model2-B，Model3-A，Model3-B，Model4-A，Model4-B。
4计算并分析各模型种植体-骨界面的应力分布、应变规律。
结果：
1成功建立了微种植体-颌骨的三维有限元模型，所建模型具有良好的几何相似性和生物力学相似性，能满足生物力学运算的要求。
2牙齿加载时种植体-骨界面的应力分布
2.1种植体植入后触及牙根时（Model1），接触牙根部位（约3mm范围）的种植体-骨界面Von-Mises应力峰值较其他模型明显增高，其余部分受力很小；Model2,3,4种植体-骨界面受力很小，且变化不明显，见Fig.1。
2.2种植体植入后触及牙根时（Model1），骨界面应力峰值明显高于其他模型。各模型种植体-骨界面Von-Mises应力峰值分别为33.86MPa，1.67MPa，1.38MPa，1.09MPa。见Fig.1。
2.3种植体颈部骨界面位移值较低，体部及根部趋于上升，但种植体植入后触及牙根时（Model1），接触牙根部位的种植体-骨界面Von-Mises位移在一定范围内有一定程度的增高，见Fig.2。
2.4随着种植体距离牙根越远，位移峰值越小。各模型种植体位移峰值分别为0.88μm，0.86μm，0.76μm，0.61μm。
3牙齿和种植体均加载时种植体-骨界面的应力分布
3.1各模型的Von-Mises应力主要分布在种植体颈部皮质骨2mm范围内，Model1的应力峰值明显高于其他模型，Model2,3,4差别不太大。其中Model2,3,4松质骨内应力很小，且变化不大。而Model1除了在种植体颈部骨界面内有一个明显高的应力峰值外，在种植体触及牙根的部位出现第二个应力高峰，范围约2mm，向种植体根端方向逐渐减小，且松质骨内应力值相应高于Model2,3,4应力值。见Fig.3。
3.2种植体距离牙根越近，应力峰值越大。各模型种植体-骨界面的Von-Mises应力峰值分别为46.12MPa，8.79MPa，12.25MPa，7.63MPa。
3.3种植体植入后触及牙根时，牙齿加载与种植体加载对种植体-骨界面应力值有叠加效应，见Fig.3。
3.4种植体距离牙根越近，位移峰值受到的影响越大（位移峰值降低）。各模型种植体-骨界面的Von-Mises位移峰值分别为1.02μm，1.57μm，1.96μm，2.21μm。见Fig.4。
结论：
1种植体植入后触及邻近牙根时，牙齿的生理性咬合可以造成种植体-骨界面应力明显集中，影响种植体的稳定性。
2种植体植入后触及邻近牙根时，牙齿的生理性咬合与微型种植体载荷在种植体-骨界面可以产生应力的叠加效应，不利于种植体的稳定性。
3种植体植入后距离牙根越远，受到牙齿生理性咬合的影响越小。本实验结果建议种植体植入后距离邻近牙根在1mm以外。
Objective: Malocclusion can affect the development of themaxillofacial,oral functions and can even cause psychological and mentaldisorders.Anchorage control is the key to the orthodontic treatmentsuccessfully in the majority of orthodontic cases.Existed Efforts whichenhanced the anchorage can not satisfy the clinical requirem-ents.Mini-implants emerged Recently have opened up a new field whichimproved the efficacy of the difficult cases. However, It main disadvantage isinstability,it was reported that a success rate of83-89%. Implant often failedbefore apply the orthodontic force or in the process of it, mostly result byimproper surgery of insert mini-implant and inappropriate stress distribution inthe implant-bone interface,which had a serious impact on the application ofmini-implant widely in clinical.
Mini-implants is mainly implanted in buccal or lingual inter-radicular sites.Due to the limited distance between the roots and the differences of individualanatomical structure,the surgery request high accuracy.Mini-implants oftenclose to the root of teeth or contact it when implant in the placement.Reserchshowed that the failure rate of implant increased significantly as it is too closeto the root. It is necessary to determine the safe distance between mini-implantand the root. It is found in clinical that there is a high correlation betweenthe masticatory pain and implant failure, and masticatory pain occurs after themini-implant inserted in patients that is near the root in the X-ray. There is noliterature concerning that implant stability is affected by physiologic bite inthe situation of the implant close to the root and whether there is a joint effectof physiologic bite and stress distribution of implant loaded.This studyestablish implant-tooth-jaw model using three-dimensional finite element method to analyze the stress change of mini-implant bone interface when it istoo close to the root,to find out the influence of tooth mobility produced byphysiological occlusion on the implant’s stability, and to explore a safedistance between the close root and the mini-implant,and to provide atheoretical basis for the clinical application of mini-implant.
Materials and Methods：
1Equipment
Computer: CPU:2.0; Memory:1G;
Software:Mimics10.1software(Materialise companies), the Pro/E4.0software,ANSYS13.0software.
2Establish the FEA models of maxillary with mini-implant
2.1Establish FEA model of maxillary
A male with individual normal occlusion was scanned by spiral CT fromjaw to skull, and CT images were stored in DICOM,extracted in MIMICS,partial smoothed,set the periodontal membrane thickness of0.25mm,then thethree-dimensional finite element model containing the maxillary-teeth-periodontal ligament is created.
2.2Establish the finite element model of mini-plant
Regarding domestic implant size,set8mm deepth in the bone,diameter of1.6mm,pure titanium,cylindrical screw implant,3-D implant model isestablished in Pro/E.
2.3Combination solid model
2.3.1Implant location and angle:To simulate clinical situation,mini-implantwas inserted in the right side of the maxillary between the second premolarand first molar5mm from the top of alveolar crest, perpendicular to axis oftooth.
2.3.2According to the distance between mini-implant and the adjacent root ofteeth, models are established as follow:
Model1: Mini-implant contact the root surface
Model2: Mini-implant embedded in the periodontal ligament
Model3: Mini-implant contact surface of the periodontal ligament
Model4: Mini-implant1.0mm away from the adjacent periodontalligament surface
3Loading condition
3.1loading condition have two kinds of cases:
Load A:teeth loaded but mini-implant unloaded;
Load B:teeh and mini-implant both loaded;
3.2Mini-implant loaded
Loaded force:2N;
Loading direction: loads are applied on the plane (which is perpendicularto the horizon passes though the straight line that parallel to the occlusalsurface passes though the site of mini-implant inserted) with the direction of30degrees of the occlucal surface.
3.3Teeth loaded
Loaded force:300N
Loading direction:parallel to the long axis of teeth on the occlusal surface
3.4calculating cases
Eight mini-implant cases were established:Model1-A，Model1-B，Model2-A，Model2-B，Model3-A，Model3-B，Model4-A，Model4-B.
4Analysising the stress and displacement distribution of implant-boneinterface.
Result:
13-D models of jaw with mini-implant were established successfully, and allof them have well biological similarity,geometric similarity and satisfy therequirements of calculation of case,and all of them can meet the requirementsof biomechanics operation.2Stress distribution in implant-bone interface when teeth loaded2.1When implant placed contacts the root (in Model1),max Von-Mises stressof the part where is contacting the root(about3mm)on the implant-boneinterface is higher than that of other models which is tiny.In Model2,3,4,thestress on the implant-bone interface is tiny and nearly same level which isshown in Fig.1.
2.2When implant placed contacts the root (in Model1),stress on theimplant-bone interface is Obviously higher than others.Maximum peak of theVon-Mises stress on the implant-bone interface were33.86Mpa,1.67Mpa,1.38Mpa,1.09Mpa, respectively.
2.3Von-Mises displacement in implant neck bone interface is lower,body ofthe roots tended to rise.When implant placed contacts the root (in Model1),displacement of the position where contacts is risen in a certainrange(Fig.1).
2.4The maximum peak of the Von-Mises displacement in models is lower asfarther away from the root. Maximum peak of the Von-Mises displacementwere0.88μm,0.86μm,0.76μm,0.61μm, respectively.
3Stress distribution of implant-bone interface when both teeth and implantloaded
3.1Von-Mises stress is mainly distributed in the cervical part of implant2mmin all models, and that of model1was significantly higher than that of othermodels.The stress of model2,3,4is small and have not obviousdifference.Besides an significant high peak stress in bone interface of cervicalpart of implant, there is a second stress peak in the site of the implant touchesthe root which in the range of2mm and gradually decreases to the implantroot in model1,and the stress value in cancellous bone of model1is higherthan that of model2,3,4.(Fig.3).
3.2The implant get closer to the root,the greater the stress peak becomes.Maximum peak of the Von-Mises stress stress peak were57.14Mpa,29.78Mpa,18.79Mpa,12.37Mpa, respectively.
3.3Teeth and implant loaded produces synergistic effect on implant-boneinterface when mini-implant contact the root surface.(Fig3)
3.4The distance closer between the implant and teeth,more influence on thepeak of displacement.The peak of the Von-Mises displacement were
3.20μm,2.95μm,2.84μm,2.771μm,respectively.(Fig4)
Conclusion：
1When mini-implant contacts the root surface,the physiological occlusion can cause stress concentration of the implant-bone interface affecting the stabilityof the implant.
2When mini-implant contacts the root surface,the physiological occlusion andloaded of mini-implant can produce synergistic effect on implant-boneinterface against the stability of implant.
3The further the distance between the implant and teeth,mini-implant wasless effected by the physiological occlusion.Our results suggest that theimplant should be placed more than1mm far away from the cloest root.
微型种植体主要植入在牙槽骨颊舌侧牙根间的部位，由于牙根间距离有限和个人解剖结构差异，对手术的准确性要求很高，常常发生种植体植入后距离临近牙根很近或触及牙根的情况。研究表明种植体植入后距离牙根过近时脱落率明显增加。因此有必要明确微种植体植入后距牙根的安全距离。临床应用发现，种植体植入后拍摄平行投照牙片怀疑距离邻近牙根较近时，患者常有咬合痛的表现，且咬合痛与种植体脱落有较高相关性。目前种植体植入后距离牙根过近时生理性咬合对种植体稳定性的影响及牙齿的生理性咬合与种植体载荷的应力分布是否产生联合效应未见报道。本研究拟用三维有限元方法建立微型种植体-牙-颌骨的模型，分析微型种植体植入后距离牙根过近时种植体周围骨组织应力改变，牙齿生理性咬合产生的动度对种植体稳定性的影响，探讨微型种植体植入后距临近牙根的安全距离，为微植体支抗的临床应用提供理论依据。
材料与方法：
1实验设备
计算机：CPU：2.0；内存：1G
软件：Mimics10.1软件（Materialise公司）、Pro/E4.0软件、Geomagic Studio逆向工程软件、ANSYS13.0软件。
2建立微种植体-颌骨的三维实体模型
2.1上颌骨三维有限元模型的建立
采用螺旋CT对一牙齿排列整齐的健康志愿者进行扫描，CT图像以DICOM格式存储，在Mimics软件中切除，进行局部光滑处理，设定牙周膜厚度0.25mm，建立含有上颌骨-牙-牙周膜的三维有限元模型。
2.2微种植体有限元模型的建立
参照国产纯钛、微型圆柱状螺纹种植体的几何形态，设定骨内段8mm，直径为1.6mm，在Pro/E中建立种植体三维模型。
2.3装配实体种植体颌骨三维模型
2.3.1植入位置和角度：模拟临床情况，将微种植体植入在上颌骨的右侧第二前磨牙和第一磨牙之间，距离牙槽嵴顶5mm处，植入方向为垂直于牙体长轴。
2.3.2根据微种植体距临近牙根的距离，设计模型如下：
Model1：微种植体植入后接触牙根表面
Model2：微种植体植入后进入牙周膜
Model3：微种植体植入后接触牙周膜表面
Model4：微种植体植入后距临近牙周膜表面为1.0mm
3加载条件
3.1加载分两种情况
Load A：牙齿载荷，微种植体不载荷
Load B：牙齿、微种植体同时载荷
3.2微型种植体加载
加载大小：2N
加载方向：通过种植体植入点做一平行于咬合平面的直线，通过此直线做一垂直于地平面的平面，在此平面上沿与咬合平面成30度角的方向载荷(模拟内收上前牙时的正畸力)。
3.3牙齿加载
加载大小：300N
加载方向：在牙齿牙合面上，平行于牙长轴加载。
3.4计算工况
所建模型共有8种工况：Model1-A，Model1-B，Model2-A，Model2-B，Model3-A，Model3-B，Model4-A，Model4-B。
4计算并分析各模型种植体-骨界面的应力分布、应变规律。
结果：
1成功建立了微种植体-颌骨的三维有限元模型，所建模型具有良好的几何相似性和生物力学相似性，能满足生物力学运算的要求。
2牙齿加载时种植体-骨界面的应力分布
2.1种植体植入后触及牙根时（Model1），接触牙根部位（约3mm范围）的种植体-骨界面Von-Mises应力峰值较其他模型明显增高，其余部分受力很小；Model2,3,4种植体-骨界面受力很小，且变化不明显，见Fig.1。
2.2种植体植入后触及牙根时（Model1），骨界面应力峰值明显高于其他模型。各模型种植体-骨界面Von-Mises应力峰值分别为33.86MPa，1.67MPa，1.38MPa，1.09MPa。见Fig.1。
2.3种植体颈部骨界面位移值较低，体部及根部趋于上升，但种植体植入后触及牙根时（Model1），接触牙根部位的种植体-骨界面Von-Mises位移在一定范围内有一定程度的增高，见Fig.2。
2.4随着种植体距离牙根越远，位移峰值越小。各模型种植体位移峰值分别为0.88μm，0.86μm，0.76μm，0.61μm。
3牙齿和种植体均加载时种植体-骨界面的应力分布
3.1各模型的Von-Mises应力主要分布在种植体颈部皮质骨2mm范围内，Model1的应力峰值明显高于其他模型，Model2,3,4差别不太大。其中Model2,3,4松质骨内应力很小，且变化不大。而Model1除了在种植体颈部骨界面内有一个明显高的应力峰值外，在种植体触及牙根的部位出现第二个应力高峰，范围约2mm，向种植体根端方向逐渐减小，且松质骨内应力值相应高于Model2,3,4应力值。见Fig.3。
3.2种植体距离牙根越近，应力峰值越大。各模型种植体-骨界面的Von-Mises应力峰值分别为46.12MPa，8.79MPa，12.25MPa，7.63MPa。
3.3种植体植入后触及牙根时，牙齿加载与种植体加载对种植体-骨界面应力值有叠加效应，见Fig.3。
3.4种植体距离牙根越近，位移峰值受到的影响越大（位移峰值降低）。各模型种植体-骨界面的Von-Mises位移峰值分别为1.02μm，1.57μm，1.96μm，2.21μm。见Fig.4。
结论：
1种植体植入后触及邻近牙根时，牙齿的生理性咬合可以造成种植体-骨界面应力明显集中，影响种植体的稳定性。
2种植体植入后触及邻近牙根时，牙齿的生理性咬合与微型种植体载荷在种植体-骨界面可以产生应力的叠加效应，不利于种植体的稳定性。
3种植体植入后距离牙根越远，受到牙齿生理性咬合的影响越小。本实验结果建议种植体植入后距离邻近牙根在1mm以外。
Objective: Malocclusion can affect the development of themaxillofacial,oral functions and can even cause psychological and mentaldisorders.Anchorage control is the key to the orthodontic treatmentsuccessfully in the majority of orthodontic cases.Existed Efforts whichenhanced the anchorage can not satisfy the clinical requirem-ents.Mini-implants emerged Recently have opened up a new field whichimproved the efficacy of the difficult cases. However, It main disadvantage isinstability,it was reported that a success rate of83-89%. Implant often failedbefore apply the orthodontic force or in the process of it, mostly result byimproper surgery of insert mini-implant and inappropriate stress distribution inthe implant-bone interface,which had a serious impact on the application ofmini-implant widely in clinical.
Mini-implants is mainly implanted in buccal or lingual inter-radicular sites.Due to the limited distance between the roots and the differences of individualanatomical structure,the surgery request high accuracy.Mini-implants oftenclose to the root of teeth or contact it when implant in the placement.Reserchshowed that the failure rate of implant increased significantly as it is too closeto the root. It is necessary to determine the safe distance between mini-implantand the root. It is found in clinical that there is a high correlation betweenthe masticatory pain and implant failure, and masticatory pain occurs after themini-implant inserted in patients that is near the root in the X-ray. There is noliterature concerning that implant stability is affected by physiologic bite inthe situation of the implant close to the root and whether there is a joint effectof physiologic bite and stress distribution of implant loaded.This studyestablish implant-tooth-jaw model using three-dimensional finite element method to analyze the stress change of mini-implant bone interface when it istoo close to the root,to find out the influence of tooth mobility produced byphysiological occlusion on the implant’s stability, and to explore a safedistance between the close root and the mini-implant,and to provide atheoretical basis for the clinical application of mini-implant.
Materials and Methods：
1Equipment
Computer: CPU:2.0; Memory:1G;
Software:Mimics10.1software(Materialise companies), the Pro/E4.0software,ANSYS13.0software.
2Establish the FEA models of maxillary with mini-implant
2.1Establish FEA model of maxillary
A male with individual normal occlusion was scanned by spiral CT fromjaw to skull, and CT images were stored in DICOM,extracted in MIMICS,partial smoothed,set the periodontal membrane thickness of0.25mm,then thethree-dimensional finite element model containing the maxillary-teeth-periodontal ligament is created.
2.2Establish the finite element model of mini-plant
Regarding domestic implant size,set8mm deepth in the bone,diameter of1.6mm,pure titanium,cylindrical screw implant,3-D implant model isestablished in Pro/E.
2.3Combination solid model
2.3.1Implant location and angle:To simulate clinical situation,mini-implantwas inserted in the right side of the maxillary between the second premolarand first molar5mm from the top of alveolar crest, perpendicular to axis oftooth.
2.3.2According to the distance between mini-implant and the adjacent root ofteeth, models are established as follow:
Model1: Mini-implant contact the root surface
Model2: Mini-implant embedded in the periodontal ligament
Model3: Mini-implant contact surface of the periodontal ligament
Model4: Mini-implant1.0mm away from the adjacent periodontalligament surface
3Loading condition
3.1loading condition have two kinds of cases:
Load A:teeth loaded but mini-implant unloaded;
Load B:teeh and mini-implant both loaded;
3.2Mini-implant loaded
Loaded force:2N;
Loading direction: loads are applied on the plane (which is perpendicularto the horizon passes though the straight line that parallel to the occlusalsurface passes though the site of mini-implant inserted) with the direction of30degrees of the occlucal surface.
3.3Teeth loaded
Loaded force:300N
Loading direction:parallel to the long axis of teeth on the occlusal surface
3.4calculating cases
Eight mini-implant cases were established:Model1-A，Model1-B，Model2-A，Model2-B，Model3-A，Model3-B，Model4-A，Model4-B.
4Analysising the stress and displacement distribution of implant-boneinterface.
Result:
13-D models of jaw with mini-implant were established successfully, and allof them have well biological similarity,geometric similarity and satisfy therequirements of calculation of case,and all of them can meet the requirementsof biomechanics operation.2Stress distribution in implant-bone interface when teeth loaded2.1When implant placed contacts the root (in Model1),max Von-Mises stressof the part where is contacting the root(about3mm)on the implant-boneinterface is higher than that of other models which is tiny.In Model2,3,4,thestress on the implant-bone interface is tiny and nearly same level which isshown in Fig.1.
2.2When implant placed contacts the root (in Model1),stress on theimplant-bone interface is Obviously higher than others.Maximum peak of theVon-Mises stress on the implant-bone interface were33.86Mpa,1.67Mpa,1.38Mpa,1.09Mpa, respectively.
2.3Von-Mises displacement in implant neck bone interface is lower,body ofthe roots tended to rise.When implant placed contacts the root (in Model1),displacement of the position where contacts is risen in a certainrange(Fig.1).
2.4The maximum peak of the Von-Mises displacement in models is lower asfarther away from the root. Maximum peak of the Von-Mises displacementwere0.88μm,0.86μm,0.76μm,0.61μm, respectively.
3Stress distribution of implant-bone interface when both teeth and implantloaded
3.1Von-Mises stress is mainly distributed in the cervical part of implant2mmin all models, and that of model1was significantly higher than that of othermodels.The stress of model2,3,4is small and have not obviousdifference.Besides an significant high peak stress in bone interface of cervicalpart of implant, there is a second stress peak in the site of the implant touchesthe root which in the range of2mm and gradually decreases to the implantroot in model1,and the stress value in cancellous bone of model1is higherthan that of model2,3,4.(Fig.3).
3.2The implant get closer to the root,the greater the stress peak becomes.Maximum peak of the Von-Mises stress stress peak were57.14Mpa,29.78Mpa,18.79Mpa,12.37Mpa, respectively.
3.3Teeth and implant loaded produces synergistic effect on implant-boneinterface when mini-implant contact the root surface.(Fig3)
3.4The distance closer between the implant and teeth,more influence on thepeak of displacement.The peak of the Von-Mises displacement were
3.20μm,2.95μm,2.84μm,2.771μm,respectively.(Fig4)
Conclusion：
1When mini-implant contacts the root surface,the physiological occlusion can cause stress concentration of the implant-bone interface affecting the stabilityof the implant.
2When mini-implant contacts the root surface,the physiological occlusion andloaded of mini-implant can produce synergistic effect on implant-boneinterface against the stability of implant.
3The further the distance between the implant and teeth,mini-implant wasless effected by the physiological occlusion.Our results suggest that theimplant should be placed more than1mm far away from the cloest root.
引文
1Kuroda S, Yamada K, Deguchi T, et al Root proximity is a major factor forscrew failure in orthodontic anchorage. Am J Orthod Dentofacial Orthop.2007,131(Suppl):S68-S73
2Poggio PM, Incorvati C, Velo S, et al ‘‘Safe zones’’: a guide for miniscrewpositioning in the maxillary and mandibular arch. Angle Orthod.2006,76:191-197
3Fabbroni G,Aabed S,Mizen K,et al Transalveolar screws and the incidenceof dental damage: a prospective study. Int J Oral Maxillofac Surg.2004,33:442-446
4Maino BG,Weiland F,Attanasi A,et al Root damage and repair after contactwith miniscrews. J Clin Orthod.2007,41:762-766
5Asscherickx,K.,Vannet,B.V.,Wehrbein.Root repair after injury frommini-screw.Clinical Oral Implants Research.2005,16:575-578
6Motoyoshi M,Ueno S,Okazaki N,et al Bone stress for a mini-implant closeto the roots of adjacent teeth-3D finite element analysis [J].Int OralMaxillofac Surg,2009,38:363-368
7Wehrbein H, Merz BR, Hammerle CHF, et al Bone-to-implant contact oforthodontic implants in humans subjected to horizontal loading. Clin OralImplants Res.1998,9:348-353
8邓锋，张磊，张翼等.微植体支抗一骨界面的生物力学研究及微植体颈部优化设计探讨.四川大学学报，2007；38（4）:701-704
9Janga H,Kwonb S,Kimc S,et al. Effects of washer on the stress distributionof mini-implant A finite element analysis.AngleOrthod.2012,82(1):137-44
10Motoyoshi M,Inaba M,Ono S,et al The effect of cortical bone thickness onthe stability of orthodontic mini-implants and on the stress distribution insurrounding bone [J].Int J Oral Maxillofac Surg,2009,38:13-18
11Roberts WE,Helm FR,Marshall K,et al.Rigid endosseous implants fororthodontic and orthopedic anchorage.Angle Orthod,1989,9(4):247
12Gracco A,Cirignaco A,Cozzani M,et al Numerical/experimental analysis ofthe stress field around miniscrews for orthodontic anchorage. Eur J Orthod.2009,31:12-20
13华楠，孙皎，愈合时间和微动效应对种植义齿形成骨性结合的影响.综述，口腔材料器械杂志，2007，16（2）:75-77
14Szmukler-Moncler S,Piattelli A,Favero GA,et al.Considerations prelim-inary to the application of early and immediate loading protocols in dentalimplantology[J].Clin Oral Implants Res,2000,11(1):12-25
15Melsen B,Costa A.Immediate loading of implants used for orthodonticanchorage.Clin Orthod Res,2000,3(1)l:23-28
16Lee Y,Kim J,Baek S,et al.Root and Bone Response to the Proximity Of aMini-Implant under Orthodontic Loading.Angle Orthod.2010,80:452-458
17邓卓峰，毛靖，李平，谢晖，正畸微型种植体支抗稳定性的临床研究，临床口腔医学杂志，2006，22（3）:175-177
18Chen YH,Chang HH,Chen YJ,et al Root contact during insertion ofminscrews for orthodontic anchorage increases the failure rate: an animalstudy. Clin Oral Implants Res.January2008,19:99-106
19Hohmanna A,Wolframb U,Geigera M,et al Periodontal LigamentHydrostatic Pressure with Areas of Root Resorption after Application of aContinuous Torque Moment,Original Article,2007,77(4):653-659
20Chen J,Chen K,Gart to L P.Mechanical response to functional andtherapeutic loading of a retro-molar endosseous implant used fororthodontic anchorage to mesially translate mandibular molars.ImplantDent,1995,4(4):246-258
21Himmlova L,Dostalova T,Kacovsky A,et al Influence of implant lenngthand diameter on stress distribution:a finite element analysis.J Prost hetDent,2004,91(1):20-25
22Motoyoshi M,Yano S,Tsuruoka T,et al.Biomechanical effect of abutmetonstability of orthodontic mini-implant[J].Clin Oral Implants Res,2005,1648:480-485
23Mellal A,Wiskott HW,Botsis J,et al.Stimulating effect of implant loadingon sur rounding bone.Comparison of three numer ical models andvalidation by in vivo data[J].Clin Oral Implants Res,2004,15(2):239-248
24Liou EJ, PaiBC, Lin JC.Do miniscrews remain stationary under orthodontic forces?Am J Orthod Dentofacial Orthop2004,126:42-7
25Schnelle MA,Beck FM,Jaynes RM, Huja SS.A radiographic evaluation ofthe availability of bone for placement of miniscrews. Angle Orthod2004,74:832-7
26Jung BA,Yildizhan F,Wehrbein H.Bone-to-implant contact of orthodonticimplants in humans-a histomorphometric investigation.Eur J Orthod.2008,30(6):552-7
27邢晓健，刘宝林，不同种植体-骨结合部位对骨界面应力分布的影响西安医科大学学报2002,23（4）152-154
1Kanomi R.Mini-implant for orthodontic anchorage.J Clin Orthod.1997,31:763-7
2Tseng Y C,Hsieh C H,Chen C H,et al The application of mini-implants fororthodontic anchorage. International Journal of Oral and MaxillofacialSurgery.2006,35:704-707
3Miyawaki S,Koyama I,Inoue M,et al Factors associated with the stabilityof titanium screws placed in the posterior region for orthodontic anchorageAm J Orthod Dentofacial Orthop.2003,24:373-378
4Motoyoshi M, Hirabayashi M, Uemura M, et al Recommended placementtorque when tightening an orthodontic mini-implant. Clinical Oral ImplantResearch.2006,17:109-114
5Okazaki J et al A torque removal study on the primary stability oforthodontic titanium screw mini-implants in the cortical bone of dogfemurs.International Journal of Oral and Maxillofacial Surgery2008,37:647-650
6Wilmes B,Ottenstreuer S,Drescher D Impact of implant design on primarystability of orthodontic mini-implants. Journal of Orofacial Orthopedics2008;69:42-50
7Wilmes B, Su Y Y, Drescher D Insertion angle impact on primary stabilityof orthodontic mini-implants. Angle Orthodontist2008;78:1065-1070
8Vande Vannet B,Sabzevar MM,Wehrbein H et al Osseointegration ofminiscrews:a histomorphometric evaluation.Eur J Orthod2007,29:437-442
9朱胜吉,荣起国,周彦恒微螺钉型种植体支抗长度及直径对应力分布影响的三维有限元研究.口腔正畸学.2006,13(2):49-52
10Crismani A G,Bertl M H,Celar A G,et al Miniscrews in orthodontictreatment: Review and analysis of published clinical trials.Am J OrthodDentofacial Orthop2010,137:108-13
11Mah J,Bergstrand F.Temporary anchorage devices:a status report. J ClinOrthod.2005,39(3):132-6
12Berens A,Wiechmann D,Dempf R.Mini-and micro-screws for temporaryskeletal anchorage in orthodontic therapy.Journal of Orofacial Orthopedics2006,67:450-458
13Carano A,Velo S,Leone P,et al Clinical applications of the miniscrewanchorage system.Journal of Clinical Orthodontics2005,39:9-24
14Gracco A,Cirignaco A,Cozzani M,et al Numerical/experimental analysisof the stress field around miniscrews for orthodontic anchorage.Eur JOrthod2009,31:12-20
15Lim JE,Lim WH,Chun YS,Quantitative Evaluation of Cortical BoneThickness and Root Proximity at Maxillary Interradicular Sites forOrthodontic Mini-Implant Placement.Clin Anat.2008,21(6):486-91
16Kyung HM,Park HP,Bae SM,et al Development of Orthodontic Micro-Implants for Intraoral Anchorage.J Clin Orthod.2003,37(6):321-328
17Kravitz ND,Kusnoto B.Risks and complications of orthodontic miniscrews.Am J Orthod Dentofacial Orthop.2007,131:S43-51
18Melsen B,Costa A.Immediate loading of implants used for orthodonticanchorage.Clin Orthod Res.2000,31:23-28
19Schnitman PA,Wohrle PS,Rubenstein JE,et al Ten-year results forBranemark implants immediately loaded with fixed prostheses at implantplacement.The International Journal of Oral and Maxillofacial Implants1997,12:495-503
20Balshi TJ,Wolfinger GJ.Immediate loading of Branemark implants inedentulous mandibles: a preliminary report.Implant Dentistry1997,6:83–8
21Wallace SS,Froum SJ.Effect of maxillary sinus augmentation on thesurvival of endosseous dental implants.A systematic review. Annals ofPeriodontology/The American Academy of Periodontology2003,8:328–43
22Ko CC,Swift JQ,DeLong R,et al An intra-oral hydraulic system forcontrolled loading of dental implants.Journal of Biomechanics2002,35:863-9
23Zhao LX,PhD,Xu ZhR,et al Orthodontic mini-implant stability in differenthealing times before loading:A microscopic computerized tomographicand biomechanical analysis.Oral Surg Oral Med Oral Pathol Oral RadiolEndod.2009,108:196-202
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33Friberg, B., Sennerby, L., Roos, J.&Lekholm, U. Identification of bonequality in conjunction with insertion of titanium implants. A pilot study injaw autopsy specimens. Clinical Oral Implants Research1995,6:213-219
34Friberg B,Sennerby L,Meredith N,Lekholm U.A comparison betweencutting torque and resonance frequency measurements of maxillaryimplants.A20-month clinical study. Int J Oral Maxillofac Surg1999,28:297-303
35Meredith, N.Assessment of implant stability as a prognostic determinant.International Journal of Prosthodontics1998,11:491-501
36Park HS,Lee SK,Kwon OW Group distal movement of teeth usingmicroscrew implant anchorage.Angle Orthod.2005,75:602-609
37Motoyoshi M,Hirabayashi M,Uemura M, Shimizu N.Recommendedplacement torque when tightening an orthodontic mini-implant.Clin. OralImpl. Res.17,2006,109-114
38O¨zcelik TB,DDS,PhD et al Biomechanical Evaluation of Tooth-andImplant-Supported Fixed Dental Prostheses with Various NonrigidConnector Positions:A Finite Element Analysis.Journal of Prosthodontics2011,20:16-28
39Liou EJ,PaiBC,Lin JC.Do miniscrews remain stationary under orthodonticforces? Am J Orthod Dentofacial Orthop2004,126:42-7
2Poggio PM, Incorvati C, Velo S, et al ‘‘Safe zones’’: a guide for miniscrewpositioning in the maxillary and mandibular arch. Angle Orthod.2006,76:191-197
3Fabbroni G,Aabed S,Mizen K,et al Transalveolar screws and the incidenceof dental damage: a prospective study. Int J Oral Maxillofac Surg.2004,33:442-446
4Maino BG,Weiland F,Attanasi A,et al Root damage and repair after contactwith miniscrews. J Clin Orthod.2007,41:762-766
5Asscherickx,K.,Vannet,B.V.,Wehrbein.Root repair after injury frommini-screw.Clinical Oral Implants Research.2005,16:575-578
6Motoyoshi M,Ueno S,Okazaki N,et al Bone stress for a mini-implant closeto the roots of adjacent teeth-3D finite element analysis [J].Int OralMaxillofac Surg,2009,38:363-368
7Wehrbein H, Merz BR, Hammerle CHF, et al Bone-to-implant contact oforthodontic implants in humans subjected to horizontal loading. Clin OralImplants Res.1998,9:348-353
8邓锋，张磊，张翼等.微植体支抗一骨界面的生物力学研究及微植体颈部优化设计探讨.四川大学学报，2007；38（4）:701-704
9Janga H,Kwonb S,Kimc S,et al. Effects of washer on the stress distributionof mini-implant A finite element analysis.AngleOrthod.2012,82(1):137-44
10Motoyoshi M,Inaba M,Ono S,et al The effect of cortical bone thickness onthe stability of orthodontic mini-implants and on the stress distribution insurrounding bone [J].Int J Oral Maxillofac Surg,2009,38:13-18
11Roberts WE,Helm FR,Marshall K,et al.Rigid endosseous implants fororthodontic and orthopedic anchorage.Angle Orthod,1989,9(4):247
12Gracco A,Cirignaco A,Cozzani M,et al Numerical/experimental analysis ofthe stress field around miniscrews for orthodontic anchorage. Eur J Orthod.2009,31:12-20
13华楠，孙皎，愈合时间和微动效应对种植义齿形成骨性结合的影响.综述，口腔材料器械杂志，2007，16（2）:75-77
14Szmukler-Moncler S,Piattelli A,Favero GA,et al.Considerations prelim-inary to the application of early and immediate loading protocols in dentalimplantology[J].Clin Oral Implants Res,2000,11(1):12-25
15Melsen B,Costa A.Immediate loading of implants used for orthodonticanchorage.Clin Orthod Res,2000,3(1)l:23-28
16Lee Y,Kim J,Baek S,et al.Root and Bone Response to the Proximity Of aMini-Implant under Orthodontic Loading.Angle Orthod.2010,80:452-458
17邓卓峰，毛靖，李平，谢晖，正畸微型种植体支抗稳定性的临床研究，临床口腔医学杂志，2006，22（3）:175-177
18Chen YH,Chang HH,Chen YJ,et al Root contact during insertion ofminscrews for orthodontic anchorage increases the failure rate: an animalstudy. Clin Oral Implants Res.January2008,19:99-106
19Hohmanna A,Wolframb U,Geigera M,et al Periodontal LigamentHydrostatic Pressure with Areas of Root Resorption after Application of aContinuous Torque Moment,Original Article,2007,77(4):653-659
20Chen J,Chen K,Gart to L P.Mechanical response to functional andtherapeutic loading of a retro-molar endosseous implant used fororthodontic anchorage to mesially translate mandibular molars.ImplantDent,1995,4(4):246-258
21Himmlova L,Dostalova T,Kacovsky A,et al Influence of implant lenngthand diameter on stress distribution:a finite element analysis.J Prost hetDent,2004,91(1):20-25
22Motoyoshi M,Yano S,Tsuruoka T,et al.Biomechanical effect of abutmetonstability of orthodontic mini-implant[J].Clin Oral Implants Res,2005,1648:480-485
23Mellal A,Wiskott HW,Botsis J,et al.Stimulating effect of implant loadingon sur rounding bone.Comparison of three numer ical models andvalidation by in vivo data[J].Clin Oral Implants Res,2004,15(2):239-248
24Liou EJ, PaiBC, Lin JC.Do miniscrews remain stationary under orthodontic forces?Am J Orthod Dentofacial Orthop2004,126:42-7
25Schnelle MA,Beck FM,Jaynes RM, Huja SS.A radiographic evaluation ofthe availability of bone for placement of miniscrews. Angle Orthod2004,74:832-7
26Jung BA,Yildizhan F,Wehrbein H.Bone-to-implant contact of orthodonticimplants in humans-a histomorphometric investigation.Eur J Orthod.2008,30(6):552-7
27邢晓健，刘宝林，不同种植体-骨结合部位对骨界面应力分布的影响西安医科大学学报2002,23（4）152-154
1Kanomi R.Mini-implant for orthodontic anchorage.J Clin Orthod.1997,31:763-7
2Tseng Y C,Hsieh C H,Chen C H,et al The application of mini-implants fororthodontic anchorage. International Journal of Oral and MaxillofacialSurgery.2006,35:704-707
3Miyawaki S,Koyama I,Inoue M,et al Factors associated with the stabilityof titanium screws placed in the posterior region for orthodontic anchorageAm J Orthod Dentofacial Orthop.2003,24:373-378
4Motoyoshi M, Hirabayashi M, Uemura M, et al Recommended placementtorque when tightening an orthodontic mini-implant. Clinical Oral ImplantResearch.2006,17:109-114
5Okazaki J et al A torque removal study on the primary stability oforthodontic titanium screw mini-implants in the cortical bone of dogfemurs.International Journal of Oral and Maxillofacial Surgery2008,37:647-650
6Wilmes B,Ottenstreuer S,Drescher D Impact of implant design on primarystability of orthodontic mini-implants. Journal of Orofacial Orthopedics2008;69:42-50
7Wilmes B, Su Y Y, Drescher D Insertion angle impact on primary stabilityof orthodontic mini-implants. Angle Orthodontist2008;78:1065-1070
8Vande Vannet B,Sabzevar MM,Wehrbein H et al Osseointegration ofminiscrews:a histomorphometric evaluation.Eur J Orthod2007,29:437-442
9朱胜吉,荣起国,周彦恒微螺钉型种植体支抗长度及直径对应力分布影响的三维有限元研究.口腔正畸学.2006,13(2):49-52
10Crismani A G,Bertl M H,Celar A G,et al Miniscrews in orthodontictreatment: Review and analysis of published clinical trials.Am J OrthodDentofacial Orthop2010,137:108-13
11Mah J,Bergstrand F.Temporary anchorage devices:a status report. J ClinOrthod.2005,39(3):132-6
12Berens A,Wiechmann D,Dempf R.Mini-and micro-screws for temporaryskeletal anchorage in orthodontic therapy.Journal of Orofacial Orthopedics2006,67:450-458
13Carano A,Velo S,Leone P,et al Clinical applications of the miniscrewanchorage system.Journal of Clinical Orthodontics2005,39:9-24
14Gracco A,Cirignaco A,Cozzani M,et al Numerical/experimental analysisof the stress field around miniscrews for orthodontic anchorage.Eur JOrthod2009,31:12-20
15Lim JE,Lim WH,Chun YS,Quantitative Evaluation of Cortical BoneThickness and Root Proximity at Maxillary Interradicular Sites forOrthodontic Mini-Implant Placement.Clin Anat.2008,21(6):486-91
16Kyung HM,Park HP,Bae SM,et al Development of Orthodontic Micro-Implants for Intraoral Anchorage.J Clin Orthod.2003,37(6):321-328
17Kravitz ND,Kusnoto B.Risks and complications of orthodontic miniscrews.Am J Orthod Dentofacial Orthop.2007,131:S43-51
18Melsen B,Costa A.Immediate loading of implants used for orthodonticanchorage.Clin Orthod Res.2000,31:23-28
19Schnitman PA,Wohrle PS,Rubenstein JE,et al Ten-year results forBranemark implants immediately loaded with fixed prostheses at implantplacement.The International Journal of Oral and Maxillofacial Implants1997,12:495-503
20Balshi TJ,Wolfinger GJ.Immediate loading of Branemark implants inedentulous mandibles: a preliminary report.Implant Dentistry1997,6:83–8
21Wallace SS,Froum SJ.Effect of maxillary sinus augmentation on thesurvival of endosseous dental implants.A systematic review. Annals ofPeriodontology/The American Academy of Periodontology2003,8:328–43
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