Assistant professor, State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China.
Research associate, State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China.
Am J Orthod Dentofacial Orthop. 2014 Oct;146(4):442-50. doi: 10.1016/j.ajodo.2014.06.016.
Midpalatal suture expansion could induce osteogenesis to correct maxillary insufficiency; cartilage formation could also be induced, and lower-magnitude forces might generate a preferable response pattern. In this study, we aimed for an enhanced understanding of the cartilage formatting effects of expansion.
Thirty 6-week-old male C57BL/6 mice were randomly and evenly assigned to 3 groups; the animals in each group received a sustained suture expansion at 0, 10, and 20 g, respectively. Ten additional mice were fed the same as the baseline controls and received no expansion. After 7 days, the animals were killed; coronal paraffin sections were stained using toluidine blue and safranin-O. The proliferating cell nucleus antigen, the nuclear antigen Ki-67, alkaline phosphatase, and matrix metalloproteinase 13 expressions were visualized with immunohistochemistry. All data were analyzed statistically, and the differences were considered significant at P <0.05.
Compared with the control, the cartilage matrix volume was significantly increased by the 20-g expansion, showing increased cartilage matrix and hypertrophic chondrocytes with the highest matrix metalloproteinase 13 expression. The 10-g expansion formed condensed proliferating chondrocyte masses, within which the highest percentages of proliferating cell nucleus antigen and Ki-67 positive cells were present. The 10-g and the 20-g expansions equally intensified the alkaline phosphatase expression.
The lower expansion (10 g) promoted chondrocyte proliferation and induced a more preferable suture cartilage response pattern compared with the higher expansion (20 g), which just increased the cartilage matrix production.
中隔骨缝扩张可诱导成骨来矫正上颌骨不足；也可诱导软骨形成，低幅度的力可能产生更理想的反应模式。本研究旨在更深入地了解扩张对软骨形成的影响。
将 30 只 6 周龄雄性 C57BL/6 小鼠随机平均分为 3 组；每组动物分别接受 0、10 和 20 g 的持续骨缝扩张。另外 10 只老鼠作为基线对照，给予相同的喂养但不进行扩张。7 天后，处死动物；冠状石蜡切片用甲苯胺蓝和番红 O 染色。用免疫组织化学法观察增殖细胞核抗原、核抗原 Ki-67、碱性磷酸酶和基质金属蛋白酶 13 的表达。所有数据均进行统计学分析，P <0.05 时差异有统计学意义。
与对照组相比，20 g 扩张组的软骨基质体积显著增加，显示出更高的基质金属蛋白酶 13 表达的软骨基质和肥大软骨细胞。10 g 扩张形成密集的增殖性软骨细胞团，其中增殖细胞核抗原和 Ki-67 阳性细胞的比例最高。10 g 和 20 g 扩张同样增强了碱性磷酸酶的表达。
与较高的扩张（20 g）相比，较低的扩张（10 g）促进了软骨细胞的增殖，并诱导了更理想的缝间软骨反应模式，而只是增加了软骨基质的产生。
