Mohaghegh Sadra, Mohammad-Rahimi Hossein, Eslamian Ladan, Ebadifar Asghar, Badiee Mohammad Reza, Farahani Mohammadhossein, Mohebbi Rad Masoud, Motamedian Saeed Reza
Undergraduate Student, Student Research Committee, School of Dentistry, Shahid Beheshti University of Medical Sciences Tehran, Iran.
Dental Research Center, Research Institute of Dental Sciences, Shahid Beheshti University of Medical Sciences Tehran, Iran.
Am J Stem Cells. 2020 Dec 25;9(5):78-88. eCollection 2020.
One of the most common orthodontic problems is maxillary constriction, which is mostly treated by rapid palatal expansion (RPE). However, its high rate of relapse and prolonged retention period have led to some challenges for orthodontists. To encounter these issues, accelerating bone regeneration can provide long-term stability of expanded maxilla. The present study aimed to evaluate the effect of low-level laser therapy (LLLT), bone marrow-derived mesenchymal stem cells (BMSCs) and their combination on promoting bone regeneration of the inter-maxillary suture after RPE in rats.
Total of 60 rats went under RPE treatment. After 7 days, retention period started and interventions (group A, Control (saline); group B, LLLT; group C, BMSCs; group D, LLLT + BMSCs) were performed in the sutural area. After 21 days, radiographic and histological analyses were done. Histological analyses were conducted to evaluate the following criteria of the newly formed bone: the number of osteoblasts, new bone formation, vascularization, connective tissue. Moreover, sutural width was assessed in histologic images. To evaluate bone density at suture area, gray scale and Hounsfield Unit values were measured based on the occlusal radiographic and Micro-Computed topography images respectively.
Only in group C and D, osteoblasts and new bone formation were observed in all of the samples. There were no significant differences among the study groups regarding the post-treatment sutural width (P > 0.05). In the radiographic analysis, only group D showed more bone density compared to the control group (P = 0.022). Similarly, in micro-CT analysis, the most bone density was observed in group D which was significantly more than the control group (P = 0.013).
Our findings suggest that the application of LLLT and BMSCs is the most beneficial approach in accelerating bone regeneration in the inter-maxillary suture.
上颌骨狭窄是最常见的正畸问题之一，大多通过快速腭扩展（RPE）进行治疗。然而，其高复发率和延长的保持期给正畸医生带来了一些挑战。为应对这些问题，加速骨再生可提供扩展上颌骨的长期稳定性。本研究旨在评估低强度激光疗法（LLLT）、骨髓间充质干细胞（BMSCs）及其联合应用对促进大鼠RPE后上颌间缝骨再生的影响。
总共60只大鼠接受RPE治疗。7天后开始保持期，并在缝合区域进行干预（A组，对照组（生理盐水）；B组，LLLT；C组，BMSCs；D组，LLLT + BMSCs）。21天后，进行影像学和组织学分析。进行组织学分析以评估新形成骨的以下标准：成骨细胞数量、新骨形成、血管化、结缔组织。此外，在组织学图像中评估缝合宽度。为评估缝合区域的骨密度，分别基于咬合位X线片和微型计算机断层扫描图像测量灰度值和亨氏单位值。
仅在C组和D组的所有样本中观察到成骨细胞和新骨形成。各研究组治疗后的缝合宽度无显著差异（P > 0.05）。在影像学分析中，与对照组相比，仅D组显示出更高的骨密度（P = 0.022）。同样，在微型计算机断层扫描分析中，D组观察到的骨密度最高，显著高于对照组（P = 0.013）。
我们的研究结果表明，应用LLLT和BMSCs是加速上颌间缝骨再生的最有益方法。
