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Experimental Study On Orthodontic Tooth Movement Through Alveolar Bone Regenerates Following Mandibular Distraction Osteogenesis in Dogs

犬下颌牵引成骨后牙槽骨再生正畸牙齿移动的实验研究

基本信息

批准号：
11672035
负责人：
NAGASAKA Hiroshi
金额：
$ 2.24万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11672035/
关键词：
tooth movement distraction osteogenesis bone regenerate mandible cosolidation root resorption 組織学的評価

项目摘要

The purpose of this study was to evaluate the effects of orthodontic tooth movement into immature or mature new alveolar bones created by distraction osteogenesis in the canine mandible.Six adult male beagles underwent 10 mm of bilateral mandibular lengthening by using custom-made intraoral bone-borne distractors between the 3rd and 4th premolars. After 2 weeks (Group 1) or 12 weeks (Group 2) of consolidation period, the 3rd premolars were distalized into the distracted bones at 100g of orthodontic force for 12 weeks. At the same time, the 2nd premolars were distalized (Control) . After the tooth movement was completed, the dogs were sacrificed for the histological evaluation.When compared the 3rd premolars in Group 1 to those in Group2 or Control's teeth, Group 1 showed that the rate of tooth movement was significantly faster(P<.05). The amount of tooth movement in Group 1 was significantly larger than that of Control (P<.01). Clinically and radiographically, the retracted 3rd premolars in Group 1 at completion of tooth movement showed distal tipping and extrusion into the regenerate, higher tooth mobility, loss of lamina dura and horizontal alveolar bone on the pressure side of the distal root, and lateral root resorption. In the histological sections obtained from Group 1, a large amount of lateral root resorption extended from enamel-cement junction to the root apex was observed and the thickness of the dentin reduced into nearly half of that of Control.These results demonstrated that severe root resorption would occur by orthodontic tooth movement into immature fibrous distracted bones, because of the higher magnitude of orthodontic force or the higher remodeling activity of bone regenerate. Further studies are needed to optimize the timing and the force magnitude for tooth movement through regenerate alveolar bone after distraction osteogenesis.

本研究的目的是评价正畸牙齿移动到未成熟或成熟的新牙槽骨中的影响。6只成年雄性比格犬在第3和第4前磨牙之间使用定制的口内骨载牵引器进行了10 mm的双侧下颌骨延长。在固位期2周(组1)或12周(组2)后，以100g正畸力将第三前磨牙向牵张的骨内后移12周。同时将第二前磨牙前移(对照组)。当牙齿移动完成后，处死动物进行组织学评价，将第一组的第三前磨牙与第二组或对照组的牙齿进行比较，第一组的牙齿移动速度明显快于对照组(P&lt；0.05)。第1组牙齿移动量明显大于对照组(P&lt；.01)。临床和X线片显示，第1组牙齿移动完成后，第三前磨牙向远中倾斜和向再生区内挤入，牙齿活动度较高，远中牙根压力侧硬膜层和水平牙槽骨丢失，牙根侧方吸收。在实验1组的组织切片中，观察到从釉质-水泥结合部到根尖的大量侧向牙根吸收，牙本质厚度减少到对照组的近一半。这些结果表明，正畸牙移动到未成熟的纤维性牵张骨中会导致严重的牙根吸收，这是因为正畸力较大或骨再生的改建活性较高。牵张成骨后通过再生牙槽骨来优化牙齿移动的时机和力大小还需要进一步的研究。