实验性前导斜度改变的大鼠模型的建立及其颞下颌关节滑膜组织病理学观察

Establishment of rat models with altered anterior guidance and observation of histological changes in temporomandibular joint synovium

目的建立稳定的前导斜度改变的大鼠模型,探索其对大鼠颞下颌关节(TMJ)滑膜的组织病理学影响。方法将32只大鼠随机分为4组,分别是对照组(C)、前导缺失组(T1)、前导斜度增大15°组(T2)、前导斜度增大30°组(T3)。在大鼠上前牙粘接舌侧增大15°、30°金属冠改变相应前导斜度。采用低速金刚砂轮打磨大鼠上下前牙,使下颌在各个方向运动时上下牙切缘不接触,造成前导缺失。3、7、14、28 d各处死2只。实验结束后取大鼠一侧TMJ作石蜡切片苏木精-伊红(HE)染色,通过组织病理学诊断鉴定大鼠TMJ滑膜的改变。结果 T1组体重短暂下降后缓慢增加(P<0.05),T3组体重明显下降后略回升,但始终低于初始体重(P<0.05),T3组滑膜衬里细胞增生,血管扩张明显(P<0.05)。结论本研究所建立的前导斜度增大30°大鼠模型能较好地模拟临床上前导斜度过大造成的TMJ滑膜出现的组织病理变化过程。提示前导斜度增大越多,发生TMJ滑膜损伤的风险越大。而前导缺失对TMJ滑膜的影响有待进一步确定。

Objective This study aims to establish a stable animal model with altered anterior guidance and investigate histological changes on temporomandibular joint （TMJ） synovium in rats. Methods Thirty-two rats were divided into four groups, namely, control group, anterior-guidance-deficient group （T1）, and anterior guidance inclined up to 15 degree （T2） and 30 degree （T3） groups. Metal crowns that add 15 and 30 degrees to the palatal side were cemented to the incisors of maxilla to increase the inclination of anterior guidance. The low-speed diamond wheel shorts for both upper and lower incisors of rats were applied to avoid contact between anterior teeth in all direction, thus establishing an anterior guidance deletion model. TMJ joints on one side of two animals in each group were harvested after 3, 7, 14, and 28 days. Pathological changes were investigated in the TMJ synovium using hematoxylin-eosin （HE） staining. Results The weight of T1 decreased briefly at first, and then increased slightly （P〈0.05）. The weight of T3 obviously reduced and then slowly increased, but remained below the initial weight （P〈0.05）. T3 manifested obvious synovial lining proliferation and vascular dilation （P〈0.05）. Conclusion The rat model of anterior guidance inclined up to 30 degree could imitate the pathological features of TMJ synovium with excessive increase in anterior guidance. A higher inclination of anterior guidance might cause more damage of TMJ synovium. The effect of anterior guidance deletion on TMJ synovium is yet to be determined.