应用微型种植体支抗压低犬后牙过程中牙周组织改建的组织学研究

Remodelling of the periodontal tissue in the application of mini-implant anchorage for posterior tooth intrusion in dogs

目的:应用微型种植体支抗压低犬第三前磨牙,观察此方法压低牙齿时牙周组织的改建情况,为种植体支抗压低牙齿的正畸临床应用提供理论依据。方法:实验犬6只,在左右两侧上颌第三前磨牙颊侧和腭侧根分叉区各植入一枚微型种植体,使橡皮链跨越牙齿面施力,力量控制为100g,分别于加力后0、1、3、7、14、30d处死一只犬,取第三前磨牙及其牙周组织进行标本处理、组织切片、HE染色观察。结果:第三前磨牙根尖区、根分叉区与牙槽嵴顶部牙周组织改建最为活跃,主要表现为骨吸收;而唇腭侧与近中远中侧牙周组织改建不显著。结论:应用种植体支抗压低犬第三前磨牙时,牙齿仅发生垂直向的压低移动。若压低牙齿力值过大,会导致根尖吸收,因此在临床应用中应注重力值大小的选择,并尽可能使用持续性的力量压低牙齿。

AIM： To observe the remodelling of the periodontal tissue in application of mini - implant anchorage for the maxillary third premolar intrusion in dogs, in order to provide the theory foundation for clinical application. METHODS ： Six dogs were used for the experiment. On the buccal and palatal sites of the maxillary third premolar, a mini - implant was placed at the interradicular septa respectively, both on the left and right sites. An intrusive force （100g） was applied with elastic chain crossing occlusal surface of the the maxillary third premolar. An animal was sacrificed at the end of 0, 1,3,7,14 and 30 days respectively after the activation. Then HE staining was performed. RESULTS： The periodontal tissues in the apical area, interradicular furcation and the crest of the ridge remodelled most actively, which displayed alveolar bone resorption primarily. However, the periodontal tissues on the buccal and lingual sites as well as the mesial and distal sides did not remodell markedly. CONCLUSIONS： The maxillary third premolar will be only intruded vertically in the application of mini - implant anchorage. It will cause apical root resorption, if the force applied is excessive. Therefore, we should pay more attention to the level of the force and use continous force to intrude teeth in clinical practice.