支抗种植体在上颌前牵引中的组织学研究

The Histological Observation of Anchorage Implants for Maxillary Protraction

目的∶采用种植体支抗直接牵张上颌骨骨缝成骨技术探索颅颌面骨发育不足治疗新方法,观察在牵引力的作用下支抗种植体的骨结合情况。方法:实验选用猕猴4只,分为A(4岁)、B(4岁)、C(6岁)、D(8岁)。采用自行研制的前牵引支抗种植体行种植体植入术。位于前鼻嵴下方及颧牙槽嵴上各植入两枚种植体。以种植体为支抗进行牵张延长面中三分之一。牵张后4、6、8、12周分别取材。采用四环素荧光标记和组织学方法对上颌前牵引种植体支抗进行组织学观察。结果∶种植体支抗在上颌前牵引过程中稳定,组织学发现上颌前牵引支抗种植体周围有明显新骨形成,骨沉积存在于受到拉应力的一方;胶原纤维与应力方向一致。结论:种植体支抗在牵张过程中也能达到骨结合,成骨主要发生在受到拉应力的一方。

This study was conducted to investigate the osseointegration of anchorage implants in maxillary protraction by suture expansion for correction of midface deficiency and to observe the process of tissue response and regeneration surround the anchorage implants under tensile forces.Methods： four resues aged 4 to 8 years were included, animals A, B, C, D tested. Two osseointegrated titanium protraction anchorge implants were respectively placed in the prcmaxillary ridge and bilaterally on each side of zgyomaticoalveodar protuberance. Extraoral forces was use to traction the implants. Tetracycline was injected intramuscularly （50mg/kg） once a week throughout the distraction period and at the time of sacrificing, samples were taken after 4, 6,8, 12 weeks of distraction, and histological and fluorescent examinations and SEM were performed to observe the implants osseointegration during the protraction period. Results： The osseointegration were completed almost in every protraction anchorage implants There was significant new bone formatiom and a great amount of osteoblasts proliferated at the side of the tensile forces. Conclusion： The protraction anchorage implant can bear the external traction forces used in the test . The anchorage implants could be osseointegrated under the protraction force. The anchorage implants used in the study was consistently effective and the force could induce a amount of new bone formation.