不同食性动物颞下颌关节组织结构的比较研究

A COMPARATIVE STUDY OF THE HISTOLOGICAL STRUCTURE IN TMJ OF MAMMALIANS WITH DIFFERENT FOODSTUFF

目的 观察比较大白鼠、山羊、家猫和猴颞下颌关节 (tem porom andibular joint,TMJ)的组织结构 ,探讨咬合与 TMJ的解剖和功能的关系。方法 用大白鼠、山羊、家猫和猴各 5只 ,取双侧 TMJ,HE及弹力纤维染色。结果 因动物不同 ,弹力纤维、胶原纤维以及组织各层次的分布有所不同。结论 不同的咬合类型和咀嚼运动方式对 TMJ组织结构的影响不同。

Objective TMJ is considered to be unique because it is usually described as ginglioarthrodial on the mammaliansand human body. The movement and function of the mammalian TMJ is obviously more delicate and complex as compared with the joints elsewere. Historically, the effect of the occlusion and mastication type on the structure and function of TMJ has concerned many investigators. So even today, considerable differences of view still exists in the research community when focused on the relationship between the type of occlusion and mastication and the structure of TMJ. To find the effect of the occlusion and mastication type on the structure and function of TMJ, this study observed and compared histological structure in TMJs of rodent (rats), herbivore (goats), carnivore (cats) and omnivora (monkeys). Methods HE and stain of fibers were employed to elastic fiber, and TMJ structure of rats, goats, cats and monkeys was observed separately. Results Because of different animals, there are different distribution of collaginous fibers, elastic fiber and tissue each gradation. Rodent (rats): The bilateral side of TMJ are reinforced and restricted by osteo, muscular and ligmentous tissue structures. The functional zone is located at the top of condyle, where as, the other part of articular surface born relatively lower compression. Herbivore (goat): The condyle glided along the convex surface of fossa. There is relatively little restriction factors surrounding the joint, this strcuture characteristics enable the joint to move in a widerange. Carnivore (cats): The TMJ fossa is strictly constituded by osteo structures, which could only allows the condyle to act in rotation. The surface soft tissue is relatively under developed compared with other three kinds of mammalians. Omnivora (monkeys): TMJ can be seen that there is some osteologicand ligmentous restriction factors ensures the TMJ function, which resulted in a enhencement of compression on the articular surface. The surface collegen is packed in a dense network, and fibrous cartilage is thickened with a dense structure of subchondra bone, to enduring friction and compression. There is hardly any elastic fibers, vasculature and nerve fibers in the articular surface. Conclusion Occlusal alteration might induce an occlusal biomechanic change which inturn bring fourth mechanical alteration of TMJ, followed by the joint remodeling. The similar change could also be found on the case of abnormal occlusion which might usually be one of the important etiologic factors of tempormandibular joint disfunction syndrome.