不对称性颌间牵引对成年SD大鼠颞下颌关节软骨下骨组织形态的影响

目的 通过观察不对称牵引引起的成年SD大鼠髁突软骨下骨组织形态学变化,了解关节外不对称机械应力对髁突软骨下骨的影响.方法 选用10周龄雄性SD大鼠220只（随机分为轻力组104只、重力组104只、对照组12只）,实验组动物使用关节外固定加力装置,分别施加0.39、1.18 N,加力28 d拆除加力装置.在3、7、14、28、31、35、42、56 d取得标本,对髁突软骨的形态、骨小梁密度进行观察分析并进行统计学处理.结果 正常髁突软骨下骨骨小梁连续,与髁突表面垂直以顺应髁突的力学环境,在负荷加载后出现骨小梁形态和排列变化,密度发生相应波动.结论 髁突软骨下骨在外力刺激下,出现排列和骨小梁密度的变化以适应变化的机械应力环境.

Effect of asymmetry elastic on the subchondral bone in adult rat condyle

Objective The aim of this investigation was to study the effect of asymmetric inter-maxillary elastic on the subchondral bone in adult SD rats. Methods Two hundred and twenty SD rats were used in this study (one hundred and four rats loading 0. 39 N elastic force, another one hundred and four rats loading 1.18 N elastic force, while twelve rats for control group. ). The extra-joint device was fixed on the right side by surgery. Half of the experiment groups were killed at 3, 7,14, 28 days. The device was removed on the 28th day in the rest rats, and the rats were sacrificed at 31,35,42,56 days. The section was stained by hematoxylin and eosin. The arrangement of trabecular was observed and the percent trabecular area was measured with the use of software. Results The arrangement of trabecular in normal bony condyle was coordinated to the mechanical environment, and changed with the extra stress. Meanwhile, with the remodeling of subchondral bone, the percent trabecular area was dynamically changed among experimental groups respectively. Conclusions These results suggested that even in the adult individuals, the subchondral bone still have the remodeling ability to adapt the various mechanical environment.