下颌牵张成骨过程中血管生成和血供重建的立体形态构筑

Spatial and temporal features of proliferating vessels during mandibular distraction osteogenesis

目的: 观察下颌牵张成骨过程中血管生成和血供重建的立体形态构筑。方法: 用自行研制的牵张器将12只成年雄性山羊双侧下颌骨以1mm/d的速率延长10mm,在牵张开始当天、牵张第5天、牵张结束当天、固定第10天、第20天和第30天分别处死2只动物,另选取2只山羊不实施手术作为正常对照组。采用树脂灌注微血管铸型技术,酸蚀后用扫描电镜观察牵张区血管的立体形态构筑。结果: 在牵张期,骨断端骨膜血管和骨髓内血管密度明显增加,以向牵张间隙中央增生为主,并开始相互连接形成血管网;在固定早期,在间隙中央仍可见少量血管增生,膨大的静脉窦排列方向与牵张方向趋于一致;随着固定时间的延长,牵张区的血管连接更加广泛,血管新生现象逐渐消失,血管系统变得更加成熟。结论:牵张区的血管新生与新骨的生成和矿化之间存在紧密的时空联系;牵张间隙的新骨组织同时接受来源于骨膜和骨髓的血供。

Objective:To study the spatial and temporal features of p roliferating vessels during mandibular distraction osteogenesis. Methods :Bilateral mandibles of twelve adult goats were lengthened by 10 mm wit h a custom-made distractor at 1 mm/d, two animals were killed at each intervals . Two additional goats were used as normal control. SEM microvascular corrosion casting was used to examine the spatial and temporal features of proliferative v essels within distraction gap. Results:During distraction perio d, numerous vessels from bone marrow and periosteum were regenerated into distra ction gap and began to form vascular network. In the early phase of fixation per iod, the orientation of vein sinus was in accord with distraction orientation. A long with the time, more vessles were connected, regeneration of vessels vanishe d, and the vascular system within distraction gap became more mature.Con clusion:Angiogenesis during DO is closely related to the osteogenesis; the blood supply of new bone in distraction gap is from both bone marrow and per iosteum.