Wang Y L, Zhang J, Zhang M, Lu L, Wang X, Guo M, Zhang X, Wang M Q
Department of Oral Anatomy and Physiology and TMD, School of Stomatology, Fourth Military Medical University, Xi'an, China.
Oral Dis. 2014 Apr;20(3):301-6. doi: 10.1111/odi.12112. Epub 2013 Apr 25.
To investigate the pathological effects on temporomandibular joint cartilage of an experimentally created unilateral anterior crossbite prosthesis.
Six-week-old female Sprague-Dawley rats were divided into experimental and control groups and further divided into three subgroups for three time points (n = 9). In experimental groups, the unilateral anterior crossbite was created by bonding two metal tubes on left maxillary and mandibular incisors. 2, 4, or 8 weeks after operation, the histomorphological changes and the expression changes of PCNA, COL II, aggrecan, MMP-3, MMP-9, MMP-13, and TIMP-1 in condylar cartilage were investigated by hematoxylin-eosin and toluidine blue staining, real-time PCR, and immunohistochemistry.
In experimental groups, decreasing in chondrocytes, cell-free areas, reduction in the thickness of hypertrophic layer, and loss of extracellular matrix were noticed. The expression level of PCNA was decreased at week 2 and week 4. The mRNA expression of COL II was decreased at 4 week and that of aggrecan was increased at 2 week but decreased at 4 and 8 week. The expression of MMP-9, MMP-13, and TIMP-1 was increased at 2-week and decreased at 4- and 8-week, while that of MMP-3 was increased at 4- and 8-week.
The present unilateral anterior crossbite prosthesis led to degradation of mandibular condylar cartilage.
研究实验性制作的单侧前牙反牙合修复体对颞下颌关节软骨的病理影响。
将6周龄雌性Sprague-Dawley大鼠分为实验组和对照组，并进一步根据三个时间点分为三个亚组（n = 9）。在实验组中，通过在上颌和下颌左侧切牙上粘结两根金属管制作单侧前牙反牙合。术后2、4或8周，通过苏木精-伊红染色、甲苯胺蓝染色、实时聚合酶链反应和免疫组织化学研究髁突软骨中PCNA、Ⅱ型胶原、聚集蛋白聚糖、基质金属蛋白酶-3、基质金属蛋白酶-9、基质金属蛋白酶-13和组织金属蛋白酶抑制剂-1的组织形态学变化和表达变化。
在实验组中，观察到软骨细胞减少、无细胞区、肥大层厚度降低以及细胞外基质丢失。PCNA的表达水平在第2周和第4周降低。Ⅱ型胶原的mRNA表达在第4周降低，聚集蛋白聚糖的mRNA表达在第2周增加，但在第4周和第8周降低。基质金属蛋白酶-9、基质金属蛋白酶-13和组织金属蛋白酶抑制剂-1的表达在第2周增加，在第4周和第8周降低，而基质金属蛋白酶-3的表达在第4周和第8周增加。
目前的单侧前牙反牙合修复体导致下颌髁突软骨退变。
