Association of biomechanical responses of the alveolar and craniofacial bones to orthodntic forces with the biologic remodelings

为探讨正畸力对牙槽骨改建的影响，结合大鼠上磨牙实验性移动和牙周组织有限元应力分析，对正畸力对牙槽骨改建的影响进行了一系列生物力学研究。结果表明，实验性牙齿移动，牙周组织的老化变化大大降低了牙齿移动的效率。此外，从这项研究中发现，牙齿移动减少的基本因素是PDL中与牙槽骨重塑相关的细胞活性降低。这些结果与有限元应力分析相结合，表明压缩区局部应力的增加是牙槽骨吸收和随后的牙齿移动的启动器，可能会延迟骨重建， ...更多信息 为了探讨颅颌面骨改建与矫形和功能载荷的力学刺激之间的关系，对鼻-上颌复合体和下颌骨进行了有限元应力分析。在鼻上颌骨复合体中，检查了对矫形上颌骨内收力的缝合反应。这项研究证明了缝线的生物力学响应在复合体的生长和重塑中的重要作用，这也由力的不同方向决定。对于颞下颌关节（TMJ）的组成部分，在垂直方向上的应力分布进行了分析与不同的颅面形态。从分析中，垂直差异的颅面复合体被证明是高度相关的异常髁状突吸收，偶尔在日常正畸实践中经历。总结这些研究，得出结论，各种骨重建的颅面区域，无论对特发性的治疗，都与来自人工和功能负荷的机械应力高度相关，这些机械应力也受到各种生物因素的影响。少

A series of biomechanical stucies were conducted by use of finite element analysis in order to elucidate the association between bone remodeling in the craniofacial region and mechanical stresses.For the association of alveolar bone remodeling with mechanical stimuli from orthodonitic forces, experimental movement of rat upper molars and finite element stress analysis for the periodontium were integrated. As a result the experimental tooth movement, aging changes in the periodontium were demonstrated to substantially decrease the efficiency of tooth movement. Further, it was revealed from this study that essential factor for the reduced tooth movement was a decreases in cellular activity in the PDL pertinent to alveolar bone remodeling. These findings were then integrated with finite element stress analysis, indicating that local ncrease in stress in the compression area, which is an initiator for alveolar bone resorption and the subsequent tooth movement, may delay bone remodeling in … More adults in association with the less cellular activity.For the association of craniofacial bone remodeling with mechanical stimuli from therapeutic orthopedic and functional loadings, finite element stress analysis was applied to the naso-maxillary complex and mandible. In the naso-maxillary complex, sutural responses to orthopedic maxillary retraction forces were examined. This study demonstrated an important role of biomechanical responses of the sutures, which are also determined by the varying directions of forces, in growth and remodeling of the complex. For the temporomandibular joint (TMJ) components, stress distributions were analyzed with various craniofaical morphologies in the vertical direction.From the analysis, vertical discrepancies in the craniofacial complex were shown to highly relate to abnormal condylar resorption, occasionally experienced in daily orthodontic practice.In summary of these studies, it is concluded that various bone remodelings in the craniofacial region, irrespective of therapeutic on idiopathic ones, are highly pertinent to mechanical stresses from artificial and functional loading, which are also affected by various biologic factors. Less