Aging related changes on tne reactivity of the microvasculature in the periodontal ligament for occlusal force or orthodontic force

1.大鼠牙槽骨细胞间网络的发育性年龄依赖性变化观察了出生后1~12个月大鼠牙槽骨细胞间网络的发育性年龄依赖性变化。用荧光显微镜观察类骨质、低钙化骨和钙化骨的分布。铸型扫描电镜观察骨细胞陷窝的形态、数量，骨小管的变化、数量和厚度.咬合力对牙周膜微血管的影响及内皮素的作用用免疫组织化学和组织学方法观察咬合功能减退对牙周膜微血管及内皮素表达的影响。提示内皮素可能影响咬合功能减退时牙周膜微血管的调节. BALB/C-bm/bm小鼠错牙合畸形动物模型的建立利用X线微计算机断层扫描技术对先天性前牙反牙合的BALB/C-bm/bm小鼠进行了颅面形态学观察。结果表明，颅面形态的影响，即使在纯合子小鼠的前牙反牙合的存在。BALB/C-bm/bm小鼠是一种较理想的先天性前牙反咬实验模型.近红外光谱技术评价咀嚼肌疲劳趋势咀嚼咬合力的增龄性变化是机械刺激对牙周微血管影响的增龄性变化的重要因素。建立了咬肌疲劳倾向的客观评价方法。建立了近红外光谱法监测咬肌组织氧合的方法，确定了咬肌疲劳倾向评价的合适参数和正常值范围。

1. Developmental age dependent changes of the intercellular network: in rat alveolar boneDevelopmental age dependent changes of the intercellular network in rat alveolar bone were examined chronologically from 1 through 12 months after birth. Distribution of osteoids, low calcified bone, and calcified bone were examined by fluorescence microscopy. The morpholigy and number of osteocyte lacunae as well as changes, number and thickness of bone canaliculi were examined by plastic casting/scanning electron microscopy.2. Effects of occlusal force on maintaining the size of microvasculature in periodontal ligament and the role of endothelinEffects of occlusal hypofunction on the vasculature and endothelin expression in periodontal ligament were examined using immunohistochemical and histological methods. The results suggest that endothelin may affect regulation of the periodontal ligament microvasculature under occlusal hypofunction.3. Establishment of experimental model of malocclusion using BALB/C-bm/bm mouseCraniofacial morphology of BALB/C-bm/bm mouse which possesses inherent anterior crossbite was assessed using X-ray micro-computed-tomography. The results suggested that craniofacial morphology was affected by the presence of anterior crossbite even in homozygotic mouses. BALB/C-bm/bm mouse was considered to be an adequate experimental model of inherent anterior crossbite.4. Assessment of fatigue tendency of masseter muscle using near-infrared spectroscopyAge related change on the masticatory occlusal force was important factor of the changes by aging on mechanical stimulations against the periodontal microvasculatures. The objective assesment methods for the fatigue tendency of masseter muscle were established. After the method to monitor the tissue oxygenation was developed using near-infrared spectroscopy, the proper parameters and the normal ranges were established for the assessment of masseter muscle fatigue tendency.