Relationship of poreferal tissue reconstraction and proper distraction rate with maxillary alviolar distaction

目的：观察牙槽骨牵张成骨后牙髓血流量和再生骨密度的变化。材料与方法：成年比格犬穿戴旧骨，制作实验性骨缺损。其他辅助剂均未造成骨缺损。拔除实验侧上颌切牙3颗。用微型电机修复10 mm骨缺损区。骨缺损处形成后两个月。对牙槽骨进行截骨术。潜伏期三天后，肺泡段向近侧移位。实验分为两组：1)快速牵张组。2)缓慢分心组。对照组为非分心组。在各试验组中。牺牲的时间被设定在分心开始后的100天。应用3DCT观察牵张后骨的变化及骨形成情况。再说了。结果：1.快速牵张组和缓慢牵张组新生骨的牙槽骨密度均小于非牵张组。快速牵张组和缓慢牵张组的新生骨截面积均明显小于非牵张组。实验侧尖牙的血流量先下降后逐渐增加，但发现血流量恢复到截骨前水平需要很长时间。结论：实验侧新生骨的骨面积和密度与非牵张组不同，血流量的恢复需要较长时间。

Purpose: To investigate the changes of pulpal blood f tow and the regenerated bone density after alveolar distraction ostoogenesis.Material and Method: Adult beagle dogs wore used and experimental bone defects wore made. Bone defects were not made on the other aids. After three maxillary incisors on the experimontal side were extracted. 10mm bone defect was wade using a micromotor. Two months after bone defects wore made. osteotomy on the alveolar bone were performed. After three days of latency period, the alveolar segment was mesially distracted. Experimental groups were divided into two groups:1)Rapidly distracted group. 2)Slowly distracted group. Control group was non-distracted group. In each experimental group. the timing of sacrifice was set to 100 days after the start of distraction. We Investigated the change of the distracted bone and how the now bone was formed by using 3DCT. Besides. the influence of the distraction on the canine pulpal blood flow was investigated by using laser Doppler flosmetry.Results:1. The alveolar bone density of the newly formed bone in both rapid and slowly distracted groups were smaller than that of non-distracted group.2. The sectional area of the newly formed bone In both rapid and slowly distracted groups were much smaller than that of non-distracted group.3. The canine blood flow on the experimental side first decreased and gradually increased but it was found that it took much time until the blood flow recovered to the level before osteotomy.Conoluslon: It is suggested that the newly formed bone is different In both bone area and density frouu those of non-distracted group; Also it is suggested that the recovery of the blood flow takes much time.