【作者】 许颖华；

【导师】 曲虹；

【作者基本信息】 大连医科大学 ， 口腔临床医学， 2007， 硕士

【摘要】 目的:探讨加载水平力的微型种植体对幼犬下颌骨的生长发育是否有影响,为临床生长发育期儿童应用微种植体支抗提供一定的基础实验依据。材料和方法:选用6只6～8月的本地雄性幼犬(体重9～12kg)。随机选取下颌一侧为实验组,另一侧为对照组。第一周麻醉和口腔消毒后,拔除双侧下颌第三前磨牙(P3)。第六周在下颌第四前磨牙(P4)的颊侧、第一磨牙(M1)和第二磨牙(M2)的颊舌侧,龈下6毫米(mm)处分别植入微型种植体。第八周时用结扎丝制作牵引钩并用粘结剂固定在实验侧P2牙冠上,用链状橡皮连接P4颊侧种植体与牵引钩加力远中移动P2,力值80克;M1M2处颊侧两个种植体相互加力,舌侧两个也相互加力,力值80克。链状橡皮圈每3周更换一次,共12周。对侧下颌骨不种植为对照组。6只幼犬共植入30枚种植体。第二十周6只幼犬灌流固定处死,拍摄X光片,在标本上测量同一条幼犬两侧牙槽骨的长度以及对应部位牙槽骨的宽度和高度,进行统计分析。制作组织学标本,进行显微镜下观察并进行骨形态学测量。结果:一.一般情况及X光片观察:30枚微型种植体中26枚稳定无松动,3枚微型种植体松动,1枚种植体脱落。部分种植体颈部周围有炎性反应,软组织增生。在X光片上观察P2远中移动受压侧根表面未见明显根吸收。二.用Windows SPSS 10.0软件进行两组独立样本的方差齐性检验,分析显示:实验前后实验组与对照组下颌骨长度变化量的F值为2.26,而F0.05/2(5,5)=7.15,知P > 0.05,在α=0.05水平上,可以认为实验前后下颌骨两侧长度的变化量无显著性差异;宽度变化量的F值为1.33(P>0.05);高度变化量的F值为1.86(P>0.05),可以认为实验前后下颌骨两侧宽度、高度的变化量无显著性差异。三.幼犬实验侧P2均被远中移动,效果明显。四.组织学观察:部分微型种植体颈部软组织增生的部位可以看见大量炎症细胞和纤维细胞,其余的区域均未见到炎症细胞。不同的染色切片可以看到种植体与周围骨组织之间有新骨形成;P2受压侧根表面有吸收发生,但仅限于牙骨质范围内。纵向非脱钙切片种植钉周围骨钙化面积结果通过用软件Image-Pro.Plus 4.5分析,本实验骨结合率(%)的总体均数的95%的可信区间为18.24±1.13%。五.暂时性微型钛钉种植体的拆除:微型种植体用配套的扳手很容易旋出。结论:本研究结果表明:1.加载水平力的微型种植体对幼犬下颌骨的生长发育无显著影响。2.在生长发育期应用微型种植体作为支抗可以进行有效的牙齿移动。3.加载水平力的微型种植体与生长期颌骨可形成一定的骨性结合。4.微型种植体植入方法简单,容易取出。5.微型钛钉种植体植入时应该避开唇颊系带以及移动性较大游离牙龈,有利于减少局部炎症和保持种植体的稳定。更多还原

【Abstract】 Objective: An experiment was carried out to study whether mini-implants with horizontal force have effects on normal mandibular growth in growing dogs.Methods:For this purpose 6 growing dogs were choosed .One side of mandible was randomly selected as experiment group. The other side was the control group .On the first week ,lower P3 were extracted from each of 6 dogs .On the sixth week ,mini-implants were placed on the reign of buccal side of P4 M1 M2 and lingual side of M1 M2 ,about 6 mm under the gum margin .On the eighth week , mini-implants located in the buccal of P4 was as anchorage to pull P2 distal ,applying a force 80 g with the power chain . Two mini-implants at the buccal side of M1 M2 were dred each other ,applying a force 80 g . The same to the lingual ones . The power chain was changed one time for three week .The opposite mandibular bone without implants served as a control grorp .Total 30 mini-implants were placed in 6 dogs .On the twentieth week ,6 anesthetized animals were fixed by intracardiac perfusion and taken the X-ray .The segments with mini-implants were dissected for evaluations by histological slice (calcified slice and decalcified slice )and bone morphometry (calcified slice ). The rate of osseointegration was measured by Image-Pro. Plus 4.5 on the longitudinal calcified sections.Result:1. Gross and X-ray studies: In 30mini-implants 86.67% are stable, 13.33% are failed. Few of them have some infection around the neck of the mini-implant and soft tissues hyperplasia. The surface of the compressed root of P2 was not found obviously root resorption .2. The result of measurement was dealt with Windows SPSS 10.0 by Paired-Sample homogeneity of variance test . The F of length between test group and control group is 2.26(P>0.05).The F of width between test group and control group is 1.33 (P>0.05).The F of highth between test group and control group is 1.86 (P>0.05). All of them have no significant difference .3.The teeth P2 are drew distal evidently4.For a few mini-implants there are some inflamed cells around the neck of them. The surface of the compressed root of P2 has found some resorption ,but only restricted at cement .Calcified slice and decalcified slice are shown peri-implant partially touched the mini-implant surface. The rate of osseointegration between the bone and the titanium surface is 18.24±1.13%.5. We can easily pull out the mini-implants with the screws after being used.Conclusion:1. Mini-implants with horizontal force have no significant effect on the normal madibular growth in growing dogs .2. Mini-implant as anchorage in growing period can draw theeth distal effectively .3. As for peri-implant bone, there was only a slight osseointegration between the growing bone and the titanium surface.4. Mini-implant is easy to placing and pulling out with the screws.5. The placing area should better avoid the labial and lingual frenula. After surgical placing, it is very important to keeping intraoral hygiene and stability of the mini-implant.更多还原