微支抗种植体及不同矫治力作用下髁突软骨中核心结合因子a1的表达

背景:近年来微支抗种植体以其操作简单、创伤小、支抗强等优点被正畸医生广泛应用于口腔正畸临床,但鲜见用于Ⅱ类颌间的牵引。目的:以微种植体为支抗,探讨不同矫治力促兔下颌前导后髁突软骨中核心结合因子a1蛋白的表达及与髁突改建的影响。方法:8周龄健康新西兰大耳白兔随机分为实验组和对照组,实验组根据矫治力的不同分为100g、200g、300g和400g组。实验组动物以微型螺钉种植体为支抗,对兔下颌进行Ⅱ类颌间牵引。实验后4周取材,检测髁突软骨中Cbfa1的表达。结果与结论:下颌持续牵引后,髁突后区各层的厚度明显高于髁突中前部。与对照组相比随矫治力的增加髁突各层厚度增加,髁突软骨中Cbfa1表达也明显增加,至200g时达到峰值,而后随矫治力的增加,髁突各层厚度逐渐变薄,髁突软骨中Cbfa1表达也逐渐降低(P<0.05),提示矫治力能影响髁突软骨中Cbfa1的表达,说明适宜的矫治力作用有利于髁突软骨的改建。

Core binding factor alpha 1 expression in condylar cartilage under different microscrew anchorage orthodontic forces

BACKGROUND:Recently,microscrew anchorage implant has been widely used in the orthodontics due to its simple operation,little trauma and strong anchorage,but it is rarely used in type Ⅱ intermaxillary extraction.OBJECTIVE:To establish the animal experiment model of orthodontic microimplant,to investigate the effects of orthodontic forces on the expression of core binding factor a1(Cbfa1) in condylar cartilage and on condylar process modification.METHODS:Thirty 8-week-old healthy New Zealand rabbits were randomly divided into experimental group(n=24) and control group(n=6).According to different forces,the experimental group was randomly subdivided into four groups:100 g,200 g,300 g,and 400 g.Rabbits from the experimental group were performed type Ⅱ intermaxillary extraction taking microscrew implants as anchorages.At 4 weeks after surgery,Cbfa1 expression in the condylar cartilage was detected.RESULTS AND CONCLUSION:Different orthodontic forces resulted in different Cbfa1 expression in the condylar cartilage.When orthodontic force was 100 g and 200 g,Cbfa1 expression was significantly higher compared with the control group and orthodontic force of 200 g lead to highest Cbfa1 expression.When the orthodontic force was 300 g,there was no significant difference between the experimental and control groups(P > 0.05).When orthodontic force was 400 g,Cbfa1 expression was significantly greater in the experimental group than in the control group(P < 0.05).Orthodontic force can influence the expression of Cbfa1 in the condylar cartilage,suggesting that appropriate orthodontic forces have good effects on remodeling condylar cartilage.