牵张成骨腭裂整复术新骨组织骨形成蛋白的表达分布与X线影像特征

目的:观察牵张成骨术矫治腭裂新骨形成的X线影像学特征,骨形成蛋白(BMP)的表达与分布。方法:以家猫14只为实验对象,其中12只建立人工腭裂实验模型。实验组(10只):造裂手术同时安置口内腭裂牵张装置。4 周后,二期手术形成骨运送盘,术后第6日起,以每次014 mm,每日两次的频率和恒定方向进行牵张,至腭部软硬组织裂隙封闭。固定期第2、4、6、8及12周安乐处死动物各2只,切取标本行X线摄片及以Anti-BMP单抗免疫组化方法染色观察;另2只动物为实验对照组。结果:免疫组化结果显示,术后BMP广泛于牵开间隙的成骨细胞内表达, 至术后4~6周成骨活跃,骨连续性恢复。8周及12周组BMP表达渐趋减弱。X线影像亦显示新骨组织的钙化成熟是沿牵张方向由两侧向中央区域逐渐发展,二者具有时相相关性。实验对照组未见修复影像。结论:牵张成骨过程经历了一个由无到有,由弱变强至整复骨缺损,而后趋于减弱至相对静止的动态变化规律。X线影像学研究手段亦证明,牵张间隙有规律地为新骨组织完全修复,最终恢复骨连续性且结构正常。

Characteristics of BMP Expression and X-ray Films in Distraction Osteogenesis for Repair of Cleft Palate-- An Immunohistochemical and Roentgenographic Study

OBJECTIVE: The purpose of this study was to observe the roentgenographic characters of distraction osteogenesis (DO) correction of cleft palate (CP), to study the expression of BMP proportional to fixation period time intervals, and to explore the new bone formation mechanism in Cleft Palate bone shelf. METHODS: 12 cats were used to establish the CP animal model surgically, and then were assigned randomly to (1) Experimental group (12 cats): CP defects were DO repaired at the rate and rhythm of 0.4 mm x 2/day. Specimen retrieval at 2, 4, 6, 8, 12 weeks after completion of distraction, roentgenography and Anti-BMP immunohistochemistry studies were performed; (2) Experimental control group (2 cats): CP defects without any treatment procedures, and (3) Empty control group of 2 cats. RESULTS: Anti-BMP immunohistochemistry study showed positive DAB dye in early 2 weeks and most extensively positive expression of BMP in 4 to 6 weeks. The expression of BMP wore off gradually through 8 to 12 weeks. The roentgenography showed that the newly mineralized bone was developed from the cut bone edges bilaterally to the central transparent zone, and the newly formed bone bridged the defect area completely at the end of the study. The CP bone defect was reconstructed and the distraction gap was filled with de nove osteogenesis. No new bone formation was observed in experimental control group. CONCLUSION: The process of new bone formation in the distraction area is dynamic. Being stimulated primarily, the process was kept highly active till quiescence phase finally. The X-ray examination shows that there is distinctively low roentgenopeque. Nevertheless, roentgenography is so far a very effective and convenient method to evaluate and monitor the DO correction efficiency.