腭横缝牵张环上颌缝组织学研究

目的　了解腭横缝牵张后各有关缝的组织学变化及其与上颌各部结构变动的关系。方法　采用四环素荧光标记和组织学方法对腭横缝牵张犬和相同年龄的正常犬腭横缝，颧颌缝，颧颞缝，额颌缝和前颌缝等进行观察。结果　正常幼犬各缝成骨活动较活跃，随年龄增加缝细胞成分减少。实验犬则表现成骨细胞和成纤维细胞剧增，新骨和结缔组织纤维循张力方向排列。腭横缝分离宽度最大，新生骨质最多；颧颌缝和额颌缝由于多骨性交错，骨沉积和骨吸收同时存在；颧颞缝新生骨小梁和胶原纤维由于滑动而改变排列方向；前颌缝表现牵张侧受压呈退行性变，对侧呈增殖性改变。结论　腭横缝牵张可以诱发环上颌诸缝广泛的组织反应；各缝因受力大小和方向不同而呈现多样性反应。

Tissue response in circum maxillary sutures after transverse palated suture expansion

Objective This study was carried out to investigate the histological reactions of midfacial sutures induced by transverse palatal suture expansion. Methods Nine mongrel dogs of 8 week old were used in the study. Six of them were used as experimental group as described in a previous paper. The additional three served as controls. In the experimental dogs, a NiTi shape memory alloy(NiTi SMA) arch wire was used to expand the transverse palatal suture. Tetracycline was injected intramuscularly (50mg/kg) three days before operation and at the time of sacrifice. Tissue reactions of premaxillo maxillary suture, transverse palatal suture, zygomatico maxillary suture, zygomatico temporal suture and fronto maxillary suture were observed in undecalcified tetracycline labeled sections and decalcified histological sections.Results The sutures in normal young dogs showed active bone formation. With the increase of age, the cellular components of the suture decreased. A great amount of new bone apposition was found in the bony front of expanded transverse palatal suture of the experimental dogs. Degenerative changes were found in premaxillo maxillary suture at the expanded side while the contralateral showed active osteogenesis. Other sutures manifested both bone apposition and deposition due to the irregular interdigitations. Conclusion After expansion, a great amount of new bone formed in the transverse palatal suture and thus the hard palate was lengthened. All the circum maxillary sutures reacted in different patterns.;