TMJ FUNCTION AND MECHANICS--EXPERIMENTAL MODELS

描述：这项工作的长期目标是了解 颞下颌关节(TMJ)的生物力学环境 阐明环境变化如何导致重塑或 退化。本项目是进一步开展工作的先决条件，其目的是 为了满足研究界对经过验证的动物和 TMJ功能的生物力学模型。双管齐下的有组织的攻击 是提议的。首先，小型猪将被确立为动物 功能研究的模型。第二，这个带有BE的实验系统 与计算机模拟的优势相联系。如果模拟是 成功地在猪身上复制了关节加载和运动模式， 并预测由扰动引起的变化，然后使用这些 在人体上进行模拟将获得相当大的可信度。 将解决四个具体目标。具体目标1是描述 猪TMJ骨和软组织成分的载荷和运动 在正常功能期间。这些研究将涉及生理学 测量骨骼的内部压力和表面应变， 韧带组织的紧张度和肌肉活动。年龄和性别 我们将研究这些措施的效果。TMJ骨性组件的压缩载荷 在咀嚼过程中，动作将被量化。具体的假设是 测试表明，胶囊及其与骨骼的连接处于张力状态。 在不对称的下巴运动中。 具体目标2是确定骨骼的力学性能和 猪TMJ的软组织成分。体外试验将用于 确定每个组织的硬度和强度。骨软组织 准备工作将用于评估软体的粘弹性特性 纸巾及其附件。预计最薄弱的环节是 该系统是将韧带组织附着到骨中，特别是 将盘状物和囊状物连接到关节盘的外侧极 髁状突。还预计，该结构的强度和刚度 青春期后男性椎间盘的韧带和附着物大于 女性，并将随着年龄的增长而增加，无论男女。 具体目标3是构建猪的动态和静态计算机仿真 使用从上述研究中获得的信息来确定TMJ的运动和负荷。 验证测试将确定模型性能的可接受性 整个实验条件范围。预计这些模型将 对椎间盘运动、韧带伸展和髁突做出有效的预测 菌株。他们将提供额外的、不可记录的物理数据，解释说 机械事件，并预示着未来计算机的潜在价值 模拟人类的TMJ。具体目标4是研究细胞 对机械环境的反应。在中断后 侧向附着，将进行较长期的研究，以允许关节 组织要么适应(重塑)，要么失败。细胞周转，高度硫酸盐化 糖胺多聚糖(GAG)含量和胶原蛋白组成将与 控制。张力增加的韧带组织预计会显示 细胞复制和I型胶原合成增加，但减少 硫酸盐化的GAG含量；张力降低预计会产生相反的结果 结果。此外，改建的附着体预计会有更多的类型III 胶原蛋白，特别是在青春期后的雌性动物中。改建是 预计在较年轻的人群中最有效。

DESCRIPTION: The long-range goal of this work is to understand the biomechanical environment of the temporomandibular joint (TMJ) and to elucidate how alterations in that environment lead to remodeling or degeneration. The present project is prerequisite to further work, and aims to address the need of the research community for validated animal and biomechanical models of TMJ function. A double-pronged, coordinated attack is proposed. First, the miniature pig will be established as an animal model for functional studies. Second, this experimental system with be linked with the strengths of computer simulation. If the simulations are successful in reproducing joint loading and movement patterns in the pig, and predicting changes resulting from perturbations, then use of such simulations in humans would gain substantial credibility. Four specific aims will be addressed. Specific aim 1 is to characterize the loads and movements of the bony and soft tissue components of the pig TMJ during normal function. These studies will involve physiological measurement of internal pressures and surface strains from the bones, tensions in ligamentous tissues, and muscle activity. Age and gender effects will be examined. Compressive loads on the TMJ bony components during chewing movements will be quantified. The specific hypothesis to be tested is that the capsule and its attachments to bone are under tension during asymmetric jaw movements. Specific aim 2 is to determine the mechanical properties of the bony and soft tissue components of the pig TMJ. In vitro testing will be used to determine stiffness and strength of each tissue. Bone-soft tissue preparations will serve to assess viscoelastic properties of the soft tissues and their attachments. It is expected that the weakest points of the system are the attachments of ligamentous tissue into bone, specifically the attachments of the disc and capsule into the lateral pole of the condyle. It also is expected that the strength and stiffness of the ligaments and attachments of the disc is greater in postpubertal males than females, and will increase with age in both genders. Specific aim 3 is to construct dynamic and static computer simulation of pig TMJ movements and loads using information gained from the above studies. Validation tests will determine the acceptability of model performances for the entire range of experimental conditions. The models are expected to make valid predictions of disc motions, ligament stretch, and condylar strains. They will provide additional, unrecordable physical data, explain mechanical events, and indicate the potential value of the future computer simulations of the human TMJ. Specific aim 4 is to investigate cellular responses to the mechanical environment. Following interruption of the lateral attachments, longer-term studies will be conducted to allow joint tissues to adapt (remodel) or fail. Cell turnover, highly sulfated glycosaminoglycan (GAG) content and collagen composition will be compared to controls. Ligamentous tissues under increased tension are expected to show increased cell replication and type I collagen synthesis but decreased sulfated GAG content; decreased tension is expected to have the opposite results. Further, remodeling attachments are expected to have more type III collagen, particularly in postpubertal female animals. Remodeling is expected to be most effective in the younger age group.