The static magnetic field (SMF) and miRNAs are involved in the regulation of bone remodeling. Hence, this study was designed to investigate the effects of SMF on the proliferation and differentiation of osteoblasts, as well as identify related miRNAs. SMF promoted osteoblast proliferation and differentiation and inhibited osteoblast apoptosis. High-throughput sequencing identified that 41 miRNAs were upregulated and 25 miRNAs down-regulated when osteoblasts were exposed to SMF. The enrichment analysis and validation results indicated differentially expressed miR-466d and its target gene MMP13. In osteoblasts, miR-466d could directly target MMP13, and miR-466d overexpression combined with the exposure to SMF promoted differentiation, suppressing MMP13 expression. SMF increased miR-466 expression in osteoblasts, thereby inhibiting MMP13 expression and increasing osteoblast differentiation ability.

头影测量是正畸医生诊断与治疗设计的重要手段,与传统二维头影测量相比,三维头影测量提供的信息更加准确、完整,但目前尚未形成统一的三维头影测量参考坐标系建立标准.为建立完善的三维头影测量参考坐标系,本文综述了锥形束CT三维头影测量中参考坐标系建立的研究进展,按包含整个颅面部的整体参考坐标系和针对不同面部单位的局部参考坐标系,分别研究了坐标系的建立、特点及应用,以期为三维参考坐标系的标准化、统一化提供参考.

目的:观测小鼠磨牙加力不同时间点脾脏CD3+、CD8+、CD4+T淋巴细胞及Th细胞亚群的比例变化,分析正畸加力对免疫系统中T淋巴细胞变化的影响.方法:4周龄雄性C57BL/6小鼠随机分为1 d、3 d、5 d和7 d加力组以及相应时间的对照组.加力组向磨牙施加25 g力;对照组安置相同加力装置,力值为0.使用流式细胞术检测小鼠脾脏单个核细胞中CD3+比例、CD4+/CD3+比例、CD8+/CD3+比例及Th1,Th2,Th17细胞占CD4+细胞比例,以及CD3,CD4,CD8,IFN-γ,IL-4,IL-17荧光强度的变化.结果:与对照组相比,7 d实验组CD8+T细胞占CD3+T细胞的比例和Th1细胞占CD4+T淋巴细胞的比例显著增高(P<0.05);CD3,CD8,IFN-γ,IL-17平均荧光强度均显著增高(P<0.05);相反,CD4+T细胞占CD3+T淋巴细胞的比例显著降低(P<0.01).而1,3,5 d实验组与对照组间未见明显差异(P>0.05).结论:正畸加力过程可引起小鼠脾脏T细胞亚群占比和及其分泌的细胞因子发生变化.

埋伏牙是指由于萌出受阻或萌出方向与位置错误而无法正常萌出的牙齿.埋伏牙中最常见的是第三磨牙,前牙区最常见的是上颌尖牙,其次是上颌中切牙和上颌侧切牙.近年来,上颌切牙埋伏阻生的治疗常使用封闭式导萌术或开放式导萌术配合牵引,大部分预后较好;但当牙根弯曲时,常遇到牵引困难、牙根吸收和牙槽骨吸收等问题.文章对上颌切牙埋伏阻生的治疗研究进展作一综述.

Pain is a common complication in maxillary expansion treatment, which brings adverse effects to patients'lives. It is necessary to prevent or to relieve the expansion pain. This review summarizes the research progress on the mechanism, characteristics, influencing factors and intervention methods of the pain induced by maxillary expansion.

目的:探讨丹酚酸B通过线粒体凋亡途径抑制口腔白斑癌变的分子机制.方法:雄性叙利亚金黄地鼠随机分为正常组(15只)、丹酚酸B对照组(15只)、模型组(35只)和丹酚酸B治疗组(35只).正常组灌胃给予1 ml蒸馏水,不给予造模剂和药物干预;丹酚酸B对照组灌胃给予10 mg/kg丹酚酸B溶液,不涂布0.5％DMBA丙酮溶液;模型组金黄地鼠左侧颊囊涂布0.5％DMBA丙酮溶液,但不给予药物干预;丹酚酸B治疗组金黄地鼠左侧颊囊涂布0.5％DMBA丙酮溶液,同时灌胃给予10 mg/kg丹酚酸B溶液.各组的干预时间均为9周,其中丹酚酸B每日给药1次,0.5％DMBA丙酮溶液每周涂布3次.分别于第4、5、6、7、9周末分批处理动物,采集颊囊黏膜组织样本.HE染色后光镜下比较各组病理损伤的程度;Western blot检测线粒体凋亡途径相关蛋白Caspase 3、cleaved Caspase 3、Caspase 9、cleaved Caspase 9、Bax、Bcl-2、Cyto C以及AKT-mTOR信号通路相关蛋白AKT、p-AKT、mTOR、p-mTOR的表达.结果:①HE染色观察显示,模型组和丹酚酸B治疗组均出现颊囊黏膜异常增生和肿瘤,丹酚酸B对照组未出现异常增生、肿瘤等病变.②干预第4周起,模型组和丹酚酸B治疗组均出现不同程度的黏膜异常增生,至第9周末出现鳞癌病变,模型组肿瘤发生率为50％,丹酚酸B治疗组发生率为8％;丹酚酸B治疗组第6周和第9周的病理损伤程度较模型组明显减轻(P＜0.05).③与正常组相比,模型组金黄地鼠颊囊黏膜肿瘤和异常增生组织中cleaved Caspase 9、Bax、Cyto C蛋白表达水平均显著降低(P＜0.05,P＜0.01),而Bcl-2蛋白表达水平明显升高(P＜0.05,P＜0.01);与模型组相比,丹酚酸B治疗组cleaved Caspase 3、cleaved Caspase 9、Bax、Cyto C蛋白表达水平显著上调(P＜0.05,P＜0.01),Bcl-2蛋白表达水平明显下降(P＜0.05),且Bcl-2/Bax比值下降.④与正常组相比,模型组金黄地鼠颊囊黏膜肿瘤和异常增生组织中的AKT、p-AKT和p-mTOR蛋白表达水平均显著升高(P＜0.01);与模型组相比,丹酚酸B治疗组AKT、p-AKT和p-mTOR蛋白表达水平显著降低(P＜0.05,P＜0.01).结论:丹酚酸B可有效抑制金黄地鼠口腔白斑癌变,其作用机制可能是通过抑制AKT-mTOR通路激活线粒体凋亡途径.

This study aimed to evaluate the in vivo osseointegration of implants with hydrophobic antimicrobial GL13K-peptide coating in rabbit femoral condyles by micro-CT and histological analysis. Six male Japanese Rabbits (4 months old and weighing 2.5 kg each) were included in this study. Twelve implants (3.75 mm wide, 7 mm long) were randomly distributed in two groups, with six implants in the experimental group coated with GL13K peptide and six implants in the control group without surface coating. Each implant in the test and the control group was randomly implanted in the left or right side of femoral condyles. On one side randomly-selected of the femur, each rabbit received a drill that was left without implant as control for the natural healing of bone. After 3 weeks of healing radiographic evaluation of the implant sites was taken. After 6 weeks of healing, rabbits were sacrificed for evaluation of the short-term osseointegration of the dental implants using digital radiography, micro-CT and histology analysis. To perform evaluation of osseointegration, implant location and group was double blinded for surgeon and histology/radiology researcher. Two rabbits died of wound infection in sites with non-coated implants 2 weeks after surgery. Thus, at least four rabbits per group survived after 6 weeks of healing. The wounds healed without suppuration and inflammation. No implant was loose after 6 weeks of healing. Radiography observations showed good osseointegration after 3 and 6 weeks postoperatively, which proved that the tissues followed a natural healing process. Micro-CT reconstruction and analysis showed that there was no statistically significant difference (P > 0.05) in volume of bone around the implant between implants coated with GL13K peptide and implants without coating. Histomorphometric analysis also showed that the mineralized bone area was no statistically different (P > 0.05) between implants coated with GL13K peptide and implants without coating. This study demonstrates that titanium dental implants with an antimicrobial GL13K coating enables in vivo implant osseointegration at similar bone growth rates than gold-standard non-coated dental implants up to 6 weeks of implantation in rabbit femurs.

Objective This study aims to investigate the influence of different adhesive materials on the shear bond strength of metal brackets bonded to porcelain surfaces.Methods A total of 40 porcelain specimens were deglazed,etched,rinsed,dried,and treated with silane coupling agent.Then,the 40 porcelain specimens were divided into 4 groups.A total of 40 metal brackets were bonded to each group with the following 4 adhesive materials:light-cured composite resin(group A),one-component chemically cured composite resin(group B),resin-modified light-cured glass ionomer cements(group C),and two-component chemically cured resin adhesive(group D).All specimens were placed with surrounding air and then stored in an artificial saliva bath for 24 h.Shear bond strength was measured by an Instron universal testing machine.Statistical analyses were performed by ANOVA.Results The shear bond strength of group A was the highest among those of the others(P＜0.05).Meanwhile,the shear bond strength of group C was lower than that of group B(P＜0.05).No statistically significant difference was found between groups B and D and between groups C and D(P＞0.05).Conclusion Light-cured composite resin can acquire the highest shear bond strength among those of the porcelain materials tested.Resin-modified light-cured glass ionomer cements were found unsuitable for use as adhesive to bond metal brackets onto porcelain surfaces.

Dysregulation of long non-coding RNAs (lncRNAs) plays a critical role in tumor progression. LncRNA antisense non-coding RNA in the INK4 locus (ANRIL) has been reported to promote tumor progression in numerous cancers. However, its expression and function in oral squamous cell carcinoma (OSCC) remain largely unclear. Herein, we investigated the expression and clinical significance of lncRNA ANRIL in human OSCC. The results showed that the expression of ANRIL was significantly increased in OSCC tissues and cell lines. In addition, high ANRIL expression was significantly associated with the tumor grade, TNM stage and distant metastasis (P < 0.05). Patients with high expression of ANRIL had poor overall survival as compared to those with low level (P < 0.05). Cox regression analysis showed that ANRIL could act as an independent prognostic factor in OSCC (P < 0.05). Functionally, in vitro assays showed that the suppression of ANRIL expression in OSCC cells significantly inhibited cell proliferation, migration, and invasion. These results indicated that ANRIL might play an important role in OSCC progression, and could serve as a novel prognostic biomarker and therapeutic target in OSCC.

目的:观察Er-YAG激光治疗牙龈瘤的临床疗效.方法:运用Er-YAG激光切除牙龈瘤及波及的牙槽骨,术后胶质银海绵填塞创面.结果:术中出血少,术后无肿胀、出血和感染,牙龈愈合良好,形态稳定,随访无复发.结论:运用Er-YAG激光治疗牙龈瘤是一种可靠实用的方法,值得临床推广应用.

INTRODUCTION:The purpose of this study was to evaluate the effects of a newly designed magnetic palatal expansion appliance with a reactivation system. METHODS:A magnetic palatal expansion appliance was designed based on the repulsion forces of neodymium-iron-boron magnets combined with a reactivation system. Eighteen prepubertal male beagle dogs were assigned randomly to the magnetic expansion (ME) group, the mechanical screw expansion (SE) group, or the control group. Two pairs of nonmagnetic metal bone marker implants were inserted into palatal bone bilaterally 3 mm lateral to the midpalatal suture and in line with the first and fourth premolars, respectively, in each dog. The 6 animals in each group received (1) newly designed magnetic expanders, (2) jackscrew expanders, or (3) no expansion appliance. Expansion was stopped after 4 weeks when 6 mm of activation was achieved in the 2 treated groups. Three-dimensional evaluations of dental and skeletal effects were performed with cone-beam computed tomography. Histologic examinations were conducted using light microscopy to observe morphologic changes in the midpalatal suture after hematoxylin and eosin staining. RESULTS:The absolute transversal changes of both treated groups before and after expansion were significantly greater than those in the control group in all parameters (P <0.001). The differences of the distances of bilateral canines in the ME group were significantly greater than in the SE group (1.04 ± 0.16 mm; P <0.001); the differences of the distances between implants adjacent to the first premolars (0.77 ± 0.06 mm; P <0.001) and the distances between implants adjacent to the fourth premolars (0.37 ± 0.06 mm; P <0.001) in the SE group were significantly greater than in the ME group. Histologic observations of the palatal sutures in the ME and SE groups, when compared with the control group, showed widening of the sutures and many fibroblasts in an active, proliferative state. Counts of osteoblasts were increased in both expansion groups. Counts of osteoclasts were increased in the SE group. CONCLUSIONS:Both appliances expanded the maxilla effectively and induced processes of bone remodeling of the midpalatal sutures during expansion. The new magnetic palatal expansion appliances produced a smaller skeletal effect and a greater dental effect than did the mechanical screw palatal expansion appliances.

Objective To investigate the influence of different silane coupling agents and different adhesive materials on the shear bond strength of metal brackets bonded to porcelain surface. Methods 90 porcelain specimens were deglazed by 1 000 grit water sandpaper and etched with 9. 6% HF acid for 120 s, rinsed with distilled water and dried before being applied with the silane primer. All specimens were divided randomly into 3 groups according to different silane coupling agents. Each group was subdivided into 3 sub-groups depending on different adhesive materials, and every subgroup had 10 porcelain facets. 90 metal brackets were bonded to ce-ramic specimens with 3 kinds of adhesive materials. All specimens were stored in artificial saliva bath at 37 ℃ for 24 h after brackets being bonded for 60 min. Then the specimens underwent shear testing with Instron universal testing machine. Results The shear bond strength of the groups treated with silane primer was higher than that of the groups without silane primer (P<0. 05). There was no sta-tistical significance in the shear bond strength between the group of one-mix silane coupling agent and the group of two-mix silane cou-pling agent (P>0. 05). The shear bond strength of the group with light-cured composite resin was higher than that of the other groups (P<0. 05). The groups treated without silane coupling agent showed lower porcelain fracture than those treated with silane coupling a-gent. Conclusions Silane coupling agent can improve the shear bond strength between metal brackets and porcelain surface. The group of light-cured composite resin treated with two-mix silane coupling agent can get the highest shear bond strength.

OBJECTIVE:To explore the effect of maxillary expansion on orthodontics.METHODS:Eight beagle dogs were randomly divided into two groups, with 4 dogs in each group. Dogs in group 1 were executed immediately and received the direct physical measurement. The magnetic expansion appliance was used in group 2 for the maxillary expansion. After the expansion, the model was taken again and they were executed after cone beam CT (CBCT) scanning. The model measurement method was adopted in group 1 to measure the dental measurement indicators and width of base bone arch. The CBCT measurement method was employed to measure the above dental indicators and bone indicators. The difference in the indicators measured by different methods was compared and analyzed.RESULTS:Before the expansion, there was no significant difference in the bone measurement indicators between the CBCT measurement method and direct physical measurement method. After the expansion, there was no significant difference in indicators between the CBCT measurement method and direct physical measurement. But there was significant difference among the model measurement method, CBCT measurement method and direct physical measurement method. There was the significant difference in the dental indicators between the CBCT measurement method and model measurement, as well as the bone indicators of posterior marginal spacing of greater palatine foramen, posterior marginal spacing of incisive foramen, width of base bone arch and spacing of implant anchorage.CONCLUSIONS:There is no significant difference between the effect of CBCT measurement method and direct physical measurement method, but CBCT is significantly better than the model measurement.

OBJECTIVE:To investigate the expression and clinical significance of miRNA-155 and miRNA-146a in peripheral blood mononuclear cells (PBMC) and plasma of oral lichen planus (OLP) patients.METHODS:Twenty-five female and seven male OLP patients (OLP group) aged 25 to 54 years were selected from January 2012 to May 2013. The diagnosis was confirmed by pathology and the lesions were divided into two non-erosive OLP group (18 cases) and erosive OLP group (14 cases). Twenty healthy sex and age matched volunteers served as control. miRNA-155 and miRNA-146a expressions in PBMC and plasma were examined by real-time PCR. The difference between OLP group and control group was statistically analyzed.RESULTS:The expressions of PBMC and plasma miRNA-155 were higher in OLP patients than those in the healthy control (median, 0.07 vs 0.03, P < 0.05; 5.84 vs 1.32, P < 0.01). The median expression level of miRNA-146a in PBMC and plasma of OLP patients and healthy controls were (1.26 vs 0.58, P < 0.05) and (412.60 vs 238.42, P < 0.01). The plasma miRNA-155 and miRNA-146a expressions were significantly higher in erosive OLP group than those in non-erosive OLP group. There were no significant differences in the expression of PBMC miRNA-155 and miRNA-146a between the two groups.CONCLUSIONS:The expressions of PBMC and plasma miRNA-155 and miRNA-146a are higher in OLP patients. The expressions of plasma miRNA-155 and miRNA-146a are associated with OLP severity. The over expression of miRNA-155 and miRNA-146a in OLP may play a role in the pathogenesis of OLP.

PURPOSE:To establish the 3-D finite element models of maxillary first molar, and calculate the stress magnitude and distribution within the PDL of maxillary first molar when loaded with intrusion force.METHODS:Date from CT scanning image of the maxillary first molar was used to establish the 3-D finite element model of maxillary first molar. By simulating the horizontal unbalanced bone resorption model sequentially, the magnitude and distribution of PDL stress at these models were calculated under intrusion force.RESULTS:The 3-D finite element models of maxillary first molar were constructed. With constant decrease of alveolar bone height, stress of the PDL increased non-linearly. The stress in PDL changed slowly when alveolar bone height reduced from normal level to 3.5 mm, but it increased dramatically when the height of alveolar bone resorption exceeded 6.0 mm and root furcation was exposed. The high-stress concentrated in root furcation of maxillary first molar when root furcation had not been exposed, and it would be transfered to apex or one third of root length when root furcation had been exposed.CONCLUSIONS:With the sustained decrease of alveolar bone height (less than 6 mm), orthodontic force value should be reduced according to the degree of periodontal bone loss. When the alveolar bone loss reduces to more than 6 mm and the root furcation exposes completely, orthodontic force value should be reduced significantly. Supported by Natural Science Foundation of Jiangxi Province (0540091).

目的 对自酸蚀粘接系统和磷酸酸蚀粘接系统24 h内抗剪切强度的变化进行对比研究,为临床操作提供参考.方法 选正畸治疗需要拔除的人类上颌前磨牙100颗为实验样本,随机分为A、B组,每组50颗.A组使用自酸蚀偶联剂(TPSEP)和光固化树脂(Transbond XT)粘接托槽.B组使用37%磷酸和光固化树脂粘接托槽.分别在5 min、15 min、30 min、60 min和24 h使用Instron力学材料试验机测试其剪切强度并记录.观察去除托槽后的牙釉质面,用ARI积分法记录牙面残留粘接剂的量,用SPSS 15.0进行数据统计并分析.结果 A、B组之间抗剪切强度比较差异无统计学意义.同组中24 h抗剪切强度最高[A组:(9.97±1.14) Mpa,B组:(9.21±1.25) Mpa],其他时间(5 min、15 min、30 min、1 h)抗剪切强度比较差异无统计学意义.ARI指数两组比较差异无统计学意义.结论 自酸蚀粘接系统1 h内抗剪切强度和磷酸酸蚀粘接系统抗剪切强度相似.自酸蚀粘结系统粘接托槽5 min能够获得足够的抗剪切强度,1 h内抗剪切强度无明显变化,24 h抗剪切强度明显高于1 h内抗剪切强度.

<正>自从1971年G.F.Andreasen[1-2]将镍钛弓丝用于正畸临床开始,在正畸治疗过程中,镍钛矫治弓丝扮演了很重要的角色,它产生的持续柔和的机械弹力使得牙列能快速排齐整平。镍钛弓丝发展至今共经历了3个阶段:1)第1代镍钛弓丝即普通型弓

磁力,在20世纪70年代后期被引入正畸学领域以来[1],就备受关注.其介导的矫治器,如1987年Vardimon A.D.等 [2]发明的磁力介导的扩弓矫治器,具有面与面之间的作用力有利于控制牙齿、复诊简便、患者戴用舒适及易保持清洁等优点[3-5].而随着时代的进步,材料越来越先进,象后来发现的永磁体,它的磁力持续时间更长,衰变更慢,使得矫治器的装置越来越先进,类型也越来越多.

<正>矫正弓丝的机械弹力是正畸的主要力源之一,如何使弓丝在临床使用过程中产生持续柔和的矫治力量,国内外学者做了大量的研究。1971年美国Andreasen GF等[1-2]首次将镍钛丝引入正畸临床应用。而镍钛合金因其优良的生物相容性、机械性能、抗腐蚀性能和形状记忆功能,并且能在较大