下颌持续前导作用下髁状突软骨改建的超微结构变化  

Ultrastructural changes of reconstructed mandibular condylar cartilage under continuous mandibular advancement

作　　者：李雪[1] 王明国[2] 杨帅[1] 高洁[1] 范园园[1] 宋岩[3] 

机构地区：[1]潍坊医学院口腔医学院,山东省潍坊市261053 [2]济南市中心医院口腔科,山东省济南市250013 [3]辽宁医学院,辽宁省锦州市121001

出　　处：《中国组织工程研究》2015年第29期4634-4639,共6页Chinese Journal of Tissue Engineering Research

基　　金：山东省科技发展项目(2014GSF11804)~~

摘　　要：背景:以往的动物实验证明,前导下颌可以导致年轻SD大鼠的颞下颌关节组织发生改建,主要表现为髁状突组织的生长速度加快,下颌骨发生继发性生长。但其髁突软骨细胞的超微结构改建研究仍是研究的关键所在。目的:观察生长期大鼠在下颌持续前导作用下髁状突软骨生长和改建的组织学和超微结构的变化。方法:将4周龄SD大鼠随机分为对照组和实验组,实验组24 h佩戴下颌前导矫治器,分别在干预3,7,14,21,30 d麻醉处死动物并取材,光学显微镜和透射电镜观察大鼠髁突软骨的组织学和超微结构的变化。结果与结论:从干预14 d开始,实验组髁突软骨厚度在观察周期中出现先增加后变薄的现象,髁状突中后部软骨厚度变化显著(P<0.01)。从干预7 d开始髁突软骨细胞的超微结构发生改建,包括细胞内细胞核固缩,粗面内质网腔隙肿胀,脂滴变小甚至消失,核周微丝变少且不规则,细胞外基质增宽变多以及出现大片空白等。结果证实,在下颌前导作用下,大鼠髁突软骨会随着承受力的时间增厚或变薄,软骨细胞基质合成能力也会显著增强。BACKGROUND：Previous animal experiments have demonstrated that mandibular advancement can cause the remodeling of temporomandibular joint tissue of young SD rats. This is mainly characterized by accelerated growth rate of the condyle tissue and secondary growth of mandible. But the ultrastructural remodeling of condylar chondrocytes remains poorly understood. OBJECTIVE：To observe the histological and ultrastructural variations of reconstructed condylar cartilage of young rats under the effect of continuous mandibular advancement. METHODS：SD rats aged 4 weeks were randomly divided into control and experimental groups. Rats in the experimental group were subjected to mandibular advancement for 24 hours and sacrificed at 3, 7, 14, 21 and 30 days of intervention. Condylar cartilage samples were harvested and their histological and ultrastructural changes were observed under optical microscope and transmission electron microscope. RESULTS AND CONCLUSION：After 14 days of intervention, the thickness of condylar cartilage in the experimental group increased first and then became thin in the period of observation. The cartilage thickness variations in the postmedian condylar were significant （P 〈 0.01）. After 7 days of intervention, the ultrastructure of condylar chondrocytes was reconstructed, including intracelular karyopyknosis, rough endoplasmic reticulum compartment sweling, smaler even absent lipid droplets, less and irregular microfilaments around the nucleus, broadened and increased extracelular matrix and the emergence of large gaps. These results demonstrate that under continuous mandibular advancement, the rat condylar cartilage wil become thick or thin with the endurance time, and chondrocyte matrix synthesis ability wil be significantly enhanced.

关 键 词：组织工程 髁 软骨 超微结构 组织构建 软骨组织工程 下颌前伸 髁状突 改建 颞下颌关节 光学显微镜 透射电镜 功能性矫治器 细胞核 

分 类 号：R318[医药卫生—生物医学工程]