LATERAL PTERYGOID MUSCLE FUNCTION/CONDYLAR GROWTH

临床与科研相结合培训的研究计划 该计划分为两个阶段。 第一阶段，描述为 在本提案中详细说明，将在 并将于2003年完成。 使用 第一阶段的研究作为基础，第二阶段的培训计划 将解决一个或多个关于髁突的具体问题， 生长和肌肉的适应，从最初的两年， 的研究项目。 第一阶段将解决的具体研究问题 关注（i）翼外肌和浅表的作用 咬肌在下颌骨生长和适应中的作用 髁和（ii）发生在外侧内的适应 翼肌和咬肌浅肌对 下颌骨功能性突出。 实验室老鼠将 用作实验动物。 具体的假设， （i）功能性下颌前伸导致 翼外肌的紧张性活动增加 以及，在较小程度上，浅咬肌和（ii） 这种肌肉活动与髁突的增加有关， 增长 实验的具体目的是：（一） 检查外侧翼骨和浅表的适应性 咬肌改变下颌位置 定量形态学和生理学技术（即， 纤维长度组织学分析，纤维组织化学分析 类型和区域、刺激咬合力和收缩特性 （二）在分析的背景下研究这些结果， 发生在下颌骨髁状突内的形态变化 与软骨细胞增殖和软骨内分泌有关 骨化（即，髁突生长的放射自显影分析， 下颌生长和形状的头影测量分析）。

The research plan for the combined clinical-research training program is organized into two phases. Phase I, which is described in detail in this proposal, will be initiated at the start of the award and will be completed by year 03 of the award. Using phase I research as a foundation, phase II of the training program will address one or more of the specific questions about condylar growth and muscle adaptation that arise from the first two years of the research project. The specific research problems that will be addressed in phase I concern (i) the role of the lateral pterygoid and superficial masseter muscles in the growth and adaptation of the mandibular condyle and (ii) the adaptations that occur within the lateral pterygoid and superficial masseter muscles in response to functional protrusion of the mandible. Laboratory rats will be used as experimental animals. The specific hypotheses that will be addressed are: (i) functional mandibular protrusion results in an increase in the tonic activity of the lateral pterygoid muscle and, to a lesser extent, the superficial masseter muscle and (ii) this muscle activity is associated with an increase in condylar growth. The specific purposes of the experiment are: (i) to examine adaptations within the lateral pterygoid and superficial masseter muscles to altered mandibular position using quantitative morphologic and physiologic techniques (i.e., histologic analysis of fiber length, histochemical analysis of fiber types and area, stimulated bite force, and contractile properties analysis) and (ii) to examine these findings within the context of morphologic variations that occur within the mandibular condyle related to cartilage cell proliferation and endochondral ossification (i.e., autoradiographic analysis of condylar growth and cephalometric analysis of mandibular growth and form).