中文摘要：

目的 探讨实验性咬合紊乱所致大鼠髁突软骨改建过程中的雌激素表达变化规律。方法通过正畸方法前移幼年及青春期雌性大鼠右侧上颌及左侧下颌第一磨牙，造成大鼠的实验性咬合紊乱模型，咬合紊乱组分别于2、4、6、8周后取材，去除咬合紊乱组则在实验6周时拔除第一磨牙，2周后取材。应用免疫组织化学SABC方法检测髁突软骨中雌激素的表达，并通过计算阳性细胞个数来探讨雌激素在不同时间点的表达变化规律。结果1）雌激素主要表达于大鼠髁突软骨的成熟层和肥大层；2）正常对照组大鼠髁突软骨中的雌激素表达水平自6周龄到16周龄呈逐渐降低的趋势；3）无论幼年组还是青春期组，咬合紊乱2周时雌激素表达均高于对照组（P〈0．05），4、6、8周时与对照组之间差异无统计学意义（P〉0．05）。去除咬合紊乱组雌激素表达高于正常对照及咬合紊乱8周组（P〈0．01）。结论大鼠髁突软骨中雌激素的表达随年龄增长而减少，实验性咬合紊乱可以一过性升高髁突软骨中雌激素的表达水平。

英文摘要：

Objective To investigate the effect of experimentally created ocelusal disorders （ECOD） on the expression of estrogen in rat condylar cartilage. Methods The model of ECOD was created by moving right upper and left lower first molars anteriorly. The animals in ECOD were sacrificed at 2, 4, 6, 8 weeks later. In removed occlusal disorders group, the moved first molars were extracted at 6 weeks later, and the animals were sacrificed 2 weeks later. The expression of estrogen was detected by SABC technique of immunocytochemistry, and then was analyzed by the density of estrogen-positive chondrocytes. Results 1）Estrogen was abundant in mature layer and hypertrophic layer of rat mandibular condylar cartilage. 2）In control group, the expression of estrogen decreased gradually from 6-week-old to 16-week-old. 3）In both childhood and puberty rats, the expression of estrogen in experiment group was significantly higher at 2 weeks after treatment, while no difference was found at 4, 6, 8 weeks after treatment. However, the expression in removed occlusal disorder group was higher than that in control group and 8 weeks of ECOD group. Conclusion In rat condylar cartilage, the expression of estrogen de-creases with age. Induced by ECOD, the expression of estrogen increases in early stage of remodelling activity.