认知功能障碍是严重危害老年人的常见病,为了降低老年人认知功能障碍的发病率,有必要研究认知障碍的危险因素有哪些.咀嚼运动是咀嚼肌在各神经系统的综合支配下产生的随意和非随意的节律性运动,大脑在咀嚼过程中发挥了重要作用,反过来咀嚼对脑功能乃至全身健康也产生重要影响.大量研究表明咀嚼功能减退与认知功能下降有关.目前咀嚼功能减退影响认知功能的机制研究主要关注以下 3 个方面:(1)感觉反馈机制与咀嚼功能减退导致的认知功能障碍的相关性;(2)咀嚼功能减退与运动控制的补偿能力的相关性;(3)小脑功能减退在认知功能下降和咀嚼功能减退的作用.本文对认知功能与咀嚼功能减退的关系做一综述,旨在了解二者的相关性研究进展.

Objective:To investigate the regulation of proliferation and differentiation of bone marrow mesenchymal stem cells(BM-SCs)by CKIP-1 in vitro.Methods:BMSCs from CKIP-1 nock out(KO)and wild type(WT)C57 mice were isolated and cultured u-sing adherence method in vitro.BMSCs of the 3rd passage were induced to osteogenic and adipgenic differentiation.Cell proliferation was examined by MTT assay.Cell surface markers were tested by FCM.The osteogenic and adipogenic differentiation was studied by alkaline phosphatase (ALP)staining,alizarin red staining and oil red O staining.Results:The proliferation and cell marke expression of the 2 groups were similar.ALP staining of KO group was strong than that of WT group after osteogenic induction.Alizarin red stai-ning showed that there were more mineralized nodules in BMSCs of KO group than in those of WT group.Oil red O staining of KO mice BMSCs was stronger than that of WT.Conclusion:CKIP-1 deficiency can enhance the osteogenic and adipogenic differentiation without influence on the proliferation of BMSCs.

This study aimed to investigate the prevalence and associated factors of malocclusion among children with primary dentition in Xi’an, China.

PURPOSE:Mini-implants have been used as anchorage for years, but failure is common in clinical practice. Mini-implant design is a critical factor affecting its stability. The aim of this study was to evaluate the effect of continuous and simultaneous variations of thread height and pitch on the biomechanical properties of an orthodontic mini-implant.METHOD:A 3D finite element model, composed of a posterior maxilla section and an orthodontic mini-implant, was created. Mini-implant thread height ranged from 0.10 to 0.40 mm, and thread pitch ranged from 0.50 to 2.00 mm. Effects of the implant thread height and pitch on the maximum Von Mises stresses in maxilla and mini-implant, as well as maximum displacements in the mini-implant, were evaluated by a finite element method. Bivariate analysis was used to determine the optimal range of thread height and pitch.RESULTS:Variation of thread height and pitch decreased the maximum Von Mises stresses in cortical bone, cancellous bone and mini-implant by 54.9, 78.4 and 23.6 %, respectively. The maximum displacement in the mini-implant decreased by 21.8 %.CONCLUSION:Maxillary stress and mini-implant stability were influenced by mini-implant thread height and pitch. Increased thread height with a thread pitch of 1.20 mm was better for orthodontic mini-implant in the maxillary posterior region. Thread height played a more significant role than the thread pitch in reducing maxillary stress and enhancing orthodontic mini-implant stability.

We investigated the response of rat bone mesenchymal stem cells (BMSC) placed on the titanium-6aluminium-7niobiuim (Ti-6Al-7Nb) alloy modified by hydrofluoric acid etch combined with subsequent anodic oxidation. Pure titanium (Ti) discs and Ti-6Al-7Nb discs were treated by hydrofluoric acid etch and anodic oxidation, and polished pure Ti discs and Ti-6Al-7Nb discs without surface modification served as controls (n=35 in each group). Scanning electron microscopy, atomic force microscopy, and radiographic photoelectron spectroscopy assays were used to detect the properties of the samples' surface. The morphology, adhesion, proliferation, and alkaline phosphatase activity of BMSC were examined using various techniques of microscopic and biological characterisation. The results showed that both Ti-6Al-7Nb samples and the pure Ti samples showed hierarchical micro/nanotopographies, and fluorine emerged on the surfaces of the samples after modification. The hierarchical micro/nanotopographies significantly increased the spreading, adhesion, and proliferation of BMSC and activity of alkaline phosphatase. In addition, modified samples of Ti-6Al-7Nb showed significantly higher alkaline phosphatase activity than modified pure Ti samples (p<0.05). The experiment successfully confirmed that Ti-6Al-7Nb alloy with hierarchical micro/nanotopographies treated by hydrofluoric acid etch and anodic oxidation possessed good biocompatibility, and may be a promising candidate for dental implants.

目的:评价纯钛经氢氟酸酸蚀+阳极氧化及氢氟酸酸蚀+磁控溅射处理后纯钛表面涂层的理化性能.方法:30个纯钛钛片平均分成两组,A组进行氢氟酸酸蚀+阳极氧化处理,B组进行氢氟酸酸蚀+磁控溅射处理.处理后的样品通过扫描电镜(SEM)、原子力学显微镜(AFM)观察其表面形貌,通过X射线能谱分析(EDS)、X射线衍射物相(XRD)观察表面化学成分,通过环氧树脂对接拉伸实验检测涂层的结合强度.结果:SEM显示两种表面处理后都可形成微/纳米级表面形貌,其中A组表面形貌为纳米管;B组表面形貌为纳米柱.AFM显示两种表面处理后形成的微/纳米级表面,粗糙度相近.EDS显示两种处理的表面都载入氟元素,其中B组以钛酸锶为靶材进行溅射后,表面载入锶元素.XRD显示两种表面主要晶相均为α钛.环氧树脂对接拉伸实验显示B组结合强度高于A组(P＜0.01).结论:两种处理方法在纯钛表面构建了不同结构的微/纳米涂层,其中氢氟酸酸蚀+磁控溅射表面载入锶元素,但都未形成新的晶相.磁控溅射组涂层的结合强度优于阳极氧化组.

AIM: To examine the coating of strontium-substituted titanium implant and to observe the effects of the coating surface on early osseointegration in vivo. METHODS: Strontium-substituted biomimetic surface titanium implants were manufactured by radio-frequency magnetron sputtering. The morphology and the component of the coating were examined by SEM and energy dispersive X-ray spectroscopy( EDS). The surface-coated implants( experimental group) and machanically-surfaced implants( control group) were randomly inserted into the distal femura of 20 SD rats,dual fluorochrome sequential labeling was used for osseointergration observation. 4 weeks after the surgery, the morphology was observed by histological examination. The maximal pull-out force of the specimens was measured by universal material testing machine. RESULTS: The strontium-substituted coating presented a micro / nanorough structure,in the coating the content of Sr was 1. 2%. Stronger osteogenic activity at early stage of bone healing was observed in experimental group. The bone implant contact,mineral apposition ration and maximal pull-out forces of experimental group were significantly higher than those of control group( P 0. 05). CONCLUSION: Modification with strontium-substituted biomimetic surface can promote osseointegration of dental implants in early stage of implantation.

后牙锁(牙合)畸形一般需要通过拔牙手段才能得到有效矫治.结合临床,本文提出了以下矫治理念:(1)制定矫治计划时上下牙列尽可能选择正畸拔牙矫治;(2)欲矫治第二磨牙的错(牙合),应先拔除第三磨牙才能获得满意的疗效;(3)有时可直接拔除锁(牙合)的第二磨牙,让第三磨牙自行调整至正常位置;(4)为消除咬合干扰,在矫治之前在前牙区放置一平面导板,有利于锁(牙合)牙的快速纠正.

AIM:To investigate the surface morphology and chemical composition of HF acid etch and anodic oxidation modified Ti-6Al-7Nb alloy and to observe the effects of surface modification on the biological characteristics of rat bone marrow mesenchymal stem cells(BMSCs).METHODS:30 Ti samples and 30 Ti-6Al-7Nb samples were used.15 pure Ti and 15 Ti-6Al-7Nb samples were treated by HF acid etch and anodic oxidation,another 15 of each brand were untreated as the controls.The morphology of the samples was observed by SEM and atomic force microscope(AFM).The chemical composition was examined by X-ray photoelectron spectroscopy(XPS).Rat BMSCs were cultured on the samples and the cell morphology was observed by SEM.Cell adhesion and proliferation rate were tested by MTT assay.Alkaline phosphatase(ALP) activity of BMSCs was determined by ALP kit.RESULTS:The treated surface exhibited uniform nanotube array and the main chemical composition was titania with trace fluorine and aluminum.HF acid etch and anodic oxidation treatment significantly enhanced BMSCs adhesion,proliferation and ALP activity of both pure Ti group and Ti-6Al-7Nb alloy groups(P < 0.05).Modified Ti-6Al-7Nb alloy group showed significantly higher ALP activity than modified pure Ti groups(P < 0.05).CONCLUSION:HF acid etch and anodic oxidation modified Ti-6Al-7Nb alloy surface may promote adhesion,proliferation and ALP activity of BMSCs on the surface.

The invention discloses a preparation method of an anti-osteoporotic and high-bonding-strength micro/nano biomimetic coating of a bone implant. The method comprises: (1) putting the implant into a hydrofluoric acid solution for acid etching; and (2) putting the implant after the acid etching as a matrix into a magnetron sputtering sample introduction chamber, putting anti-osteoporotic strontium salt used as a target material into a main sputtering chamber, vacuumizing the main sputtering chamber and the sample introduction chamber, pre-sputtering the matrix for 20 minutes in the sample introduction chamber, sending the implant matrix into the main sputtering chamber, sputtering for 2-4 hours, taking out the samples from the main sputtering chamber, and performing post-treatment in a heat treatment furnace, with a post-treatment temperature being 300-500 DEG C and an insulation time being 2-4 hours. The coating provided by the invention has characteristics of high adhesion strength with the matrix, osteoporosis resistance, micro/nano biomimetic structure.

The invention belongs to maxillofacial surgery, relates to the field of basic research of the oral implantology of alveolar surgery and the matched machinery, and discloses a modeling method of a jawbone osteoporosis in-vitro model and a vacuum decalcification auxiliary device thereof. In the modeling method of a jawbone osteoporosis in-vitro model, a vacuum reaction environment is provided by use of a vacuum decalcification auxiliary device, so that the decalcification liquid is in contact with the jawbone outer cortical bone and inner cortical bone at the same time in the largest range to ensure synchronous decalcification of the inner and outer sclerotin of a jawbone specimen; and meanwhile, by controlling the reaction time, jawbone osteoporosis in-vitro models with different bone mineral densities can be quickly and controllably established.

Objective:To evaluate the effect of micro/nanorough-surface on osseointegration in early stage of dental implants.Methods:Forty implants were equally divided into two groups:machined-surface implants as the control group;micro/nanorough-surface implants as the experimental group.All implants were inserted into the distal femurs of 20 rats randomly.At week 0 and 2 following implantation,microcomputed tomography(micro-CT) scanning in vivo was used to assess micro-architectural changes in the bone around.Two weeks after implantation,all the rats were killed and the femurs with implants were harvested for histomorphometry analysis and biomechanical test.Results:Micro-CT analysis showed that the bone volume ratio,the trabecular thickness and number all increased significantly in the micro/nanorough-group compared with the machined-group,while the trabecular separation decreased significantly in the micro/nanorough-group.The bone-implant-contact were 38.94±9.48% and 51.49±12.49% in the machined-group and the micro/nanorough-group.The maximum pull-out forces were 64.95±6.11N and 81.90±13.10N,respectively.There was significant difference between the two groups in the BIC value and the maximal pull-out forces.Conclusion:Modification with micro/nanorough-surface could promote dental implants osseointegration in early stage of implantation.

Objective:To culture mouse incisor cervical-loop epithelial cells.Method:The primary cells were isolated from labial cervical loops of PN 7～8 d mouse mandibular incisor by explants with enzymatic digestion method.Immunostaining with antikeratin antibody is used to characterize the cell lineage.Result:Primary cells consisted of epithelial and mesenchymal cells.Purified epithelial cells were cobblestone-shaped and positive stained for cytokeratin.Conclusion:Mouse incisor cervical-loop epithelial cells can be sucessfully cultured by explants with enzymatic digestion method.

目的:了解西安市学龄前儿童乳牙龋病患病情况,便于更好地指导并开展龋病防治工作.方法:对西安市6所幼儿园2 829名学龄前儿童进行口腔检查.结果:2 829名受检儿童中,乳牙患龋儿童2329名,患龋率82.33％,龋均4.4,乳磨牙窝沟封闭率为1.28％,性别间患龋率无差异,患龋率和龋均随年龄增高而上升,6岁患儿最高.结论:西安市学龄前儿童乳牙患龋率高于全国平均水平,应当引起足够重视,提高家长和社会的口腔健康意识,加大防治力度,保护儿童健康成长.

AIM: To observe the effects of nicotine and/or α-BTX on the production of MMP-1 and 3 in human periodontal ligament cells cultured in vitro.METHODS: Human periodontal ligament cells were cultured using explant culture technique.The cells were put in the presence of nicotine and/or α-BTX,a specific angatonist of α7-nicotinic aeetylcholine receptor(α7nAChR),at the concentration of 10-4mol/L and 1.25×10-9mol/L,respectively.Then the expression of MMP-1 and 3 was measured by reverse transcription-polymerase chain reaction(RT-PCR) and enzyme linked immunosorbent assay(ELISA).RESULTS: At the exposure of nicotine alone,MMP-1 and 3 were both increased significantly at the mRNA and protein level,which ould be inhibited by α-BTX.CONCLUSION: Nicotine can stimulate MMP-1 and 3 production by hPDLCs and this process can be mediated by α7nAChR pathway.

AIM: To understand the latest prevalence rate of primary teeth caries in Xi'an preschool children and give better guide to caries prevention and treatment.METHODS: Oral examination was conducted in 2 829 preschool children from 6 kindergartens in Xi'an.RESULTS: Among the 2 829 preschool children investigated,2 329 showed primary caries.The caries prevalence rate was 82.33%,mean DMFT was 4.4.No gender difference was observed.The rate of pit-and-fissure sealing in primary molars was 1.28%.Caries prevalence rate and mean DMFT showed positive correlation with age,and 6 year old children were most susceptible to caries.CONCLUSION: Caries prevalence rate of preschool children in Xi'an is higher than that of the national average.More active measures,including parental oral health education and pit-and-fissue sealing,should be implemented so as to prevent primary dental caries.