两种异常咬合刺激对小鼠髁突影像及组织形态学影响研究

目的 探究异常咬合刺激对小鼠髁突影像及组织形态学影响.方法 选取6周龄雌性C57BL/6J小鼠36只,根据饲养时间(3、7周)均分小鼠后,再随机分为对照组、单侧前牙反(unilateral anterior crossbite,UAC)组和双侧前牙咬合抬高(bilateral anterior elevation,B...

Effect of two abnormal occlusion stimulations on the imaging and histomorphology of mice mandibular condyle

Objective　To explore the imaging and histomorphology changes in mice mandibular condyle by abnormal occlusion stimulation. Methods 　Thirty-six 6-week-old female C57BL/6J mice were divided into two groups according to the feeding time（3 and 7 weeks），and then they were randomly divided into control，unilateral anterior crossbite（UAC） and bilateral anterior elevation（BAE） subgroups. There were six mice in each group. The condylar cartilage were randomly selected for HE staining，immunohistochemical staining of Col Ⅱ，immunofluorescence staining of Col Ⅹ and DMP1 and micro-computed tomography （Micro-CT） imaging. Results　（1）Micro-CT showed that subchondral bone absorption increased in both UAC and BAE groups compared with that of control group with the same feeding time.（2）HE staining showed that the UAC group had decreased chondrocytes number，disordered cell arrangement and thinner cartilage compared to control group with the same feeding time，while the BAE group had increased superficial chondrocyte number and thicker cartilage.（3）IHC staining showed that compared with control group with the same feeding time，Col Ⅱ expression increased in 3-week BAE group and decreased in UAC group and 7-week BAE group. （4）Immunofluorescence staining showed that the expression of Col Ⅹ- and DMP1-positive cells increased in UAC group compared to control group with the same feeding time，while in BAE group，DMP1 expression reduced，but there was no significant difference in Col Ⅹ expression. Conclusion　UAC promotes osteogenic differentiation of chondrocytes，while BAE does not promote endochondral osteogenesis in cartilage. Moreover，these two stimulation both lead to the loss of condylar subchondral bone.