渐进性咬合紊乱对大鼠颞下颌关节的影响

The effects of gradually induced occlusion disorder on temporomandibular joint in rat.

目的:探讨渐进性咬合紊乱对大鼠颞下颌关节的影响。方法:9只成年雄性SD大鼠,随机分为实验组(3只),操作对照组(3只)和空白对照组(3只)。实验组大鼠左侧上颌第一、第二磨牙间及右侧下颌第一、第二磨牙间分别嵌入正畸用皮圈推第一磨牙向近中,造成磨牙尖窝接触不吻合的渐进性咬合紊乱。术后6周取双侧颞下颌关节作HE染色观察。结果:操作对照组与空白对照组间未见差异,实验组与对照组相比髁突软骨中部增厚,后部变薄(P<0.05);关节盘中带和后带均明显变薄(P<0.05);实验组中部和后部软骨下骨小梁变得明显垂直于髁突表面排列。结论:渐进性咬合紊乱可以引起大鼠髁突软骨及软骨下骨小梁适应性改建。

Objective: To investigate the effects of gradually induced occlusion disorder on temporomandibular joint in rat. Methods: Nine mature male Sprague-Dawley (SD) rats were randomly divided into three groups: occlusion disorder group ( n =3), sham control group ( n =3) and blank control group ( n =3). To form the disordered occlusion elastic rubbers (3M Unitek,1/8#) were inserted between the first and second molars in the left upper side and lower right side. The joints were removed 6 weeks later and stained with HE. Results: No difference was observed between sham control group and blank control group. In occlusion disorder group thickness of condylar cartilage increased in central part and decreased in posterior part and thickness of articular disc decreased obviously in intermediate zone and also in posterior band ( P < 0.05 ). The direction of condylar subchondral bone trabeculae was arranged obviously perpendicular to the articular surface in central and posterior parts in the disordered occlusion group. Conclusion: The gradually induced occlusion disorder may lead to adaptive remodeling of condyle cartilage.