Yang Liu1, Yi Tang2, Ling Xiao2, Sean Shih-Yao Liu3, Haiyang Yu4. 1. Assistant professor, State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China. 2. Research associate, State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China. 3. Assistant professor, Department of Orthodontics and Oral Facial Genetics, School of Dentistry, Indiana University, Indianapolis, Ind. 4. Professor and vice dean, State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China. Electronic address: yhyang6812@scu.edu.cn.
Abstract
INTRODUCTION: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
INTRODUCTION: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
Authors: Akram S Alyessary; Adrian U Yap; Siti A Othman; Mohammad T Rahman; N M Al-Namnam; Zamri Radzi Journal: J Orofac Orthop Date: 2018-04-11 Impact factor: 1.938