牵张成骨联合正颌正畸治疗成人严重小下颌畸形

目的：探讨牵引成骨技术联合正颌正畸治疗重度小下颌伴偏颌畸形患者下颌骨严重发育不足及咬合关系紊乱的疗效。方法：对2例继发于儿童时期颞下颌关节损伤的小下颌伴偏颌畸形患者采用牵张成骨技术进行治疗。手术行双侧下颌角处截骨,安置牵引器,延长下颌升支及下颌体。第二期在拆除牵引器后进行正畸治疗,继而采用正颌外科方法进一步矫正颌面畸形及咬合关系,术后正畸治疗矫正咬合关系,排齐牙列。结果：2例患者均顺利完成治疗。下颌骨最小牵引距离25 mm,最大牵引距离30 mm,牵引区成骨良好,SNB角由术前平均67°增加到术后80°,小下颌及偏颌畸形得以矫治。联合正颌外科及正畸治疗后,面形及咬合功能均获得满意效果。术后经过2年6个月随访,未见复发。结论：联合应用牵张成骨和正颌外科技术并配合正畸治疗是矫治成人重度小下颌不对称性牙颌面畸形的有效治疗方案。     

Influence of different intensities of vibration on proliferation and differentiation of human periodontal ligament stem cells

Introduction

To understand the effects of low-magnitude, high-frequency (LMHF) mechanical vibration at different intensities on human periodontal ligament stem cell (hPDLSC) proliferation and osteogenic differentiation.

Material and methods

The effect of vibration on hPDLSC proliferation, osteogenic differentiation, tenogenic differentiation and cytoskeleton was assessed at the cellular, genetic and protein level.

Results

The PDLSC proliferation was decreased after different magnitudes of mechanical vibration; however, there were no obvious senescent cells in the experimental and the static control group. Expression of osteogenesis markers was increased. The expression of alkaline phosphatase (ALP) and osteocalcin (OCN) mRNA was up-regulated at 0.1 g, 0.3 g, 0.6 g and 0.9 g magnitude, with the peak at 0.3 g. The type I collagen (Col-I) level was increased after vibration exposure at 0.1 g, 0.3 g, and 0.6 g, peaking at 0.3 g. The expression levels of both mRNA and protein of Runx2 and osterix (OSX) significantly increased at a magnitude of 0.1 g to 0.9 g, reached a peak at 0.3 g and then decreased slowly. The scleraxis, tenogenic markers, and mRNA expression decreased at 0.05 g, 0.1 g, and 0.3 g, and significantly increased at 0.6 g and 0.9 g. Compared with the static group, the F-actin stress fibers of hPDLSCs became thicker and clearer following vibration.

Conclusions

The LMHF mechanical vibration promotes PDLSC osteogenic differentiation and implies the existence of a magnitude-dependent effect of vibration on determining PDLSC commitment to the osteoblast lineage. Changes in the cytoskeleton of hPDLSCs after vibration may be one of the mechanisms of the biological effects.     

Regenerative Potential of Human Schneiderian Membrane: Progenitor Cells and Epithelial‐Mesenchymal Transition

An innate osteogenic potential of the Schneiderian membrane (SM) is progressively assessed in studies ranging from non‐human species to human subjects. It has relevance for endosteal placement and osseointegration. Nestin‐expressing osteogenic progenitor cells are allegedly involved in bone formation and remodelling. Nestin phenotype was not assessed previously in human SM. We therefore aimed to fill that particular gap in the literature. Bioptic samples of human adult SM were obtained during surgery from eight adult patients, operated for non‐malignant pathologies. Immunohistochemistry on paraffin‐embedded tissue samples used primary antibodies against nestin, CD45, CD146, cytokeratin 7 (CK7), and alpha‐smooth muscle actin (α‐SMA). Nestin expression was consistently found in endothelial cells, and was scarcely encountered in pericytes, putative stromal stem/progenitor cells, as well as in glandular epithelial cells. Moreover, woven bone formation in the periosteal layer of the SM can also be regarded as evidence of the osteogenic potential of this membrane. Nestin and CD45 expression in cells of the primary bone supports the osteogenic potential of SM nestin‐expressing cells and a possible involvement of hematopoietic stem cells in maxillary sinus floor remodeling. CD146, a known inducer of epithelial‐mesenchymal transition (EMT), was expressed in epithelia, as was CK7. Isolated stromal cells were found expressing CD146, CK7 and α‐SMA, suggesting that regenerative processes happening in the SM may also involve processes of EMT which generate stem/progenitor cells. This study provides additional evidence for the regenerative potential of the Schneiderian membrane and identifies potential roles for cells of its stem niche in osteogenesis. Anat Rec, 298:2132–2140, 2015. © 2015 Wiley Periodicals, Inc.     

Soluble form of FGFR2 with S252W partially prevents craniosynostosis of the apert mouse model

Background: Apert syndrome (AS) is characterized by craniosynostosis, midfacial hypoplasia, and bony syndactyly. It is an autosomal dominantly inherited disease caused by point mutations (S252W or P253R) in fibroblast growth factor receptor (FGFR) 2. These mutations cause activation of FGFR2 depending on ligand binding. Recently, an AS mouse model, Fgfr2^+/S252W, showed phenotypes similar to those of AS patients. We previously reported that the soluble form of FGFR2^S252W (sFGFR2IIIc^S252W) efficiently inhibits enhanced osteoblastic differentiation caused by FGFR2 activation in AS in vitro, presumably because FGFs binding to FGFRs is interrupted. In this study, we developed Fgfr2^+/S252W (Ap) mice expressing the sFGFR2IIIc^S252W protein, and we investigated the effects of sFGFR2IIIc^S252W on AS‐like phenotypes. Results: In Ap mice, the coronal suture (CS) was fused prematurely at P1. In addition, the mice exhibited a widened interfrontal suture (IFS) with ectopic bone and thickened cartilage formation. In Fgfr2^+/S252W sFGFR2IIIc^S252W (Ap/Sol) mice, the CS was similar to that of wild‐type mice. Ap/Sol mice did not show any ectopic bone or cartilage formation in the IFS, but showed a wider IFS than that of the wild‐type mice. Conclusions: sFGFR2IIIc^S252W may partially prevent craniosynostosis in the Apert mouse model by affecting the CS and IFS in vivo. Developmental Dynamics 243:560–567, 2014. © 2013 The Authors Developmental Dynamics published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists.     

牵张成骨和引导骨再生术在垂直骨增量上的比较研究

随着种植外科的进展,大量垂直向和水平向骨增量技术得到了发展。许多种植患者存在垂直向骨量不足的问题,需要增加垂直向骨量;但垂直向骨增量相对于水平向骨增量难度比较大,预见性较差,往往易致较多的并发症;因此,垂直向骨增量技术受到了越来越多的关注。引导骨再生技术和牵张成骨术是2类较常用的垂直向骨增量技术,在临床上已得到一定的应用,本文对其在垂直向骨增量上的研究进展作一综述。     

弧形牵张成骨重建人体下颌骨颏部节段性缺损的三维有限元研究

目的:建立下颌骨颏部节段性缺损弧形牵张成骨的三维有限元模型,研究弧形牵张成骨重建下颌骨颏部节断性缺损过程中,不断变化方向的牵张力对新骨组织形成的影响。方法:建立颏部节段性缺损的三维有限元模型,并把简化后的弧形牵张器有限元模型置入截断后的下颌骨,模拟弧形牵张成骨,并测量在弧形牵张成骨过程中下颌骨整体位移及其von Mises应力分布。结果:在未考虑唇颊侧软组织作用的前提下,弧形牵张成骨形成的新骨向舌侧生长,重建的下颌骨弧度较原下颌骨弧度变小。von Mises应力主要集中于牵张器在下颌骨的固位处。结论:在弧形牵张成骨重建下颌骨缺损过程中,牵张力本身就促使新骨组织向舌侧生长,从而使重建的下颌骨弧度较正常时小。此项研究为临床上如何克服弧形牵张成骨所形成的下颌骨弧度较小的不足,提供了一定的理论依据。     

兔骨髓基质干细胞骨向诱导实验研究

目的:研究兔骨髓基质干细胞(bone marrow stromal cells,BMSC)的体外培养以及骨向诱导分化情况,进一步探讨其作为骨组织工程种子细胞的可行性。方法:无菌条件下抽取兔的股骨骨髓,然后进行骨髓基质干细胞的分离和体外培养,并向成骨细胞定向诱导分化。结果:体外分离的骨髓基质细胞呈贴壁生长,改良MTT法测定显示骨髓基质细胞于第7.8天左右可达到增殖高峰;诱导后BMSC可向成骨细胞分化,细胞呈成骨细胞形态为梭形和多角形并可形成钙化结节。改良钙钴染色法检测诱导细胞碱性磷酸活性呈强阳性。扫描电镜观察细胞呈较典型的成骨细胞状态,并可见钙盐沉积。结论:骨髓基质细胞具有来源充足,取材方便,创伤小无明显并发症。骨髓基质干细胞分化增殖能力较强,成骨能力确定。所以采用骨髓基质细胞作为种子细胞构建组织工程骨有比较可靠的依据。