Chao Kong, Xuxia Wang, Qianqian Wang, Yuanyuan Han, Shuya Zhao, Jun Zhang
Dept. of Orthodontics, School of Stomatology, Shandong University, Jinan 250012, China.
Dept. of Oral and Maxillofacial Surgery, School of Stomatology, Shandong University, Jinan 250012, China;Key Laboratory of Oral Tissue Regeneration of Shandong Province, Jinan 250012, China.
Hua Xi Kou Qiang Yi Xue Za Zhi. 2016 Aug 1;34(4):336-340. doi: 10.7518/hxkq.2016.04.003.
This study investigated the effects of strontium ranelate (SrR) on the rats' palatal suture after rapid maxillary expansion (RME).
Thirty-six male 6-week-old Wistar rats were randomly divided into three groups: control group (A), expansion only group (B), and expansion plus SrR group (C). Each group comprised 12 rats. Neither expansion nor SrR was given to group A. Each rat in groups B and C was set an orthodontic appliance with an initial expansive force of 1 N. The rats in group C were administered with SrR (600 mg·kg⁻¹ body weight) at the same time every day after RME. All the rats were then euthanized in batches on days 4, 7, and 10. The width of the rats' upper jaw was measured. Histological observation was used to section the rats and count the osteoblasts.
After the RME, no statistical difference was observed on the rats' upper jaw width in group A (P>0.05). However, the change of upper jaw width in groups B and C presented a statistical significance (P<0.05). By contrast, no statistical difference was observed between groups B and C (P>0.05). The rats' sections were placed under a microscope, and some red fibrous tissues, mesenchymal cells, chondrocytes, and osteoblasts were observed in group A. More red fibrous tissues, mesenchymal cells, and chondrocytes were observed in groups B and C. In addition, more osteoblasts were observed on the edge of mid-palatal suture of the rats. Group C contains more osteoblasts than group B.
RME can expand the mid-palatal suture of rats, which were in the growth development period, and increase the width of dental arch. SrR may promote osteoblast differentiation and hasten new bone formation in the expanded mid-palatal suture. Both conditions accelerate new bone formation and bone deposition calcification, which may be therapeutically beneficial to prevent relapse after RME.
本研究调查了雷奈酸锶（SrR）对快速上颌扩弓（RME）后大鼠腭中缝的影响。
将36只6周龄雄性Wistar大鼠随机分为三组：对照组（A组）、单纯扩弓组（B组）和扩弓加SrR组（C组）。每组12只大鼠。A组既不进行扩弓也不给予SrR。B组和C组的每只大鼠均佩戴正畸矫治器，初始扩弓力为1 N。C组大鼠在RME后每天同一时间给予SrR（600 mg·kg⁻¹体重）。然后在第4、7和10天分批对所有大鼠实施安乐死。测量大鼠上颌宽度。采用组织学观察对大鼠进行切片并计数成骨细胞。
RME后，A组大鼠上颌宽度无统计学差异（P>0.05）。然而，B组和C组上颌宽度的变化具有统计学意义（P<0.05）。相比之下，B组和C组之间无统计学差异（P>0.05）。将大鼠切片置于显微镜下观察，A组可见一些红色纤维组织、间充质细胞、软骨细胞和成骨细胞。B组和C组观察到更多的红色纤维组织、间充质细胞和软骨细胞。此外，在大鼠腭中缝边缘观察到更多成骨细胞。C组的成骨细胞比B组更多。
RME可扩大处于生长发育期大鼠的腭中缝，并增加牙弓宽度。SrR可能促进成骨细胞分化并加速扩弓后腭中缝新骨形成。两种情况均加速新骨形成和骨沉积钙化，这可能对预防RME后复发具有治疗益处。
