微小RNA在口腔扁平苔藓中的作用

微小RNA家族在调控基因表达中的重要作用日益受到关注,其调控的基因涉及细胞增殖、凋亡、生长、分化和代谢、血管化和免疫应答等多种生物过程,其表达谱和表达量的变化与多种疾病如肿瘤、炎症性疾病、自身免疫性疾病的发生、发展密切相关.本文对口腔扁平苔藓中微小RNA的研究现状作一综述.     

微小RNA与口腔癌前病变

微小RNA是非编码单链小分子RNA,通常在转录后水平通过降解抑制目标信使RNA参与基因调控,目前研究发现微小RNA与口腔癌关系密切,在某些口腔癌前疾病的癌变过程中发挥着重要作用,此文就微小RNA与口腔癌前病变的关系作一综述。     

微小RNA与肿瘤

微小RNA是一族非编码小RNA,具有极为重要的基因调控作用。微小RNA在肿瘤的发生、发展中具有癌基因和抑癌基因的功能,并且在不同的肿瘤当中具有特异性的表达谱。下面就微小RNA的形成、与肿瘤的关系、目前的研究现状等作一综述。     

牙髓干细胞分化中微小RNA的调控作用及其机制的研究进展

牙髓干细胞(dental pulp stem cells,DPSCs)是一种神经嵴来源的成体干细胞,具有良好的自我更新及多向分化特性,可向多种口腔组织相关细胞分化,且兼具免疫原性低等优势,因此作为种子细胞在组织工程及再生医学领域广泛应用.微小RNA(microRNA,miRNA)是一类通过作用于基因转录后RNA而调控靶...     

RNA干扰技术及其在口腔医学领域中的应用

传统认为RAN在遗传过程中只起着信息传递作用。但最近研究发现,小RNA也有基因调控作用。小RNA能关闭基因的表达或改变基因表达的水平,从而指导细胞的定向分化。本文从目前研究较多的RNA干扰的作用机制、siRNAs的制备方法及RNA干扰技术在口腔医学领域中的应用等方面作一综述。     

环状非编码RNA在间充质干细胞成骨向分化中作用的研究进展

间充质干细胞是一类具有自我更新和多向分化潜能的成体干细胞。随着对间充质干细胞研究的不断深入,对间充质干细胞的生物学特性、分化能力及临床应用有了进一步认识。环状RNA(circRNA)是在真核细胞中广泛存在且多样的内源性非编码RNA,形成共价、闭合、连续稳定的环状结构,能够发挥微小RNA分子海绵作用,调控基因转录和选择性剪接。多项研究已经证实circRNA在间充质干细胞成骨向分化过程中发挥了重要作用,是细胞分化的重要调控靶点,参与维持细胞分化特性,并且从不同的角度和不同水平研究了circRNA的调控机制。本文对目前circRNA在不同间充质干细胞成骨向分化过程中的相关研究进行综述。     

RNA干扰技术及其在口腔医学领域中的应用

传统认为PAN在遗传过程中只起着信息传递作用。但最近研究发现，小RNA也有基因调控作用。小RNA能关闭基因的表达或改变基因表达的水平，从而指导细胞的定向分化。本文从目前研究较多的RNA干扰的作用机制、siRNAs的制备方法及RNA干扰技术在口腔医学领域中的应用等方面作一综述。     

细菌非编码小RNA对细菌毒力的调控作用

在病原菌与宿主长期的交互作用过程中,病原菌可通过调节相关基因的表达响应宿主微环境的变化,以适应宿主内环境并在宿主体内生存。过去认为,细菌的基因表达调控主要发生在转录水平。近年发现,细菌非编码小RNA（sRNA）在调控细菌致病机制方面发挥着重要作用。细菌sRNA是一类长度在50~500个核苷酸之间的非编码RNA,病原菌可感受宿主微环境的变化,通过sRNA调控自身毒力相关基因的表达,促进致病菌在宿主内的生存能力,利于致病菌对宿主的侵袭及致病。相对于各种转录因子,sRNA介导的基因表达调控可使细菌更快速、灵敏地对外界环境变化作出应答。目前已发现多种与细菌毒力及致病性相关的sRNA,可在转录后水平精细调节细菌毒力及其致病机制。本文就sRNA调控细菌毒力的分子机制及其在常见病原菌致病过程中的作用进行综述。     

表观遗传在牙发育中的作用

表观遗传是指DNA序列不发生变化,基因的表达方式发生了可遗传改变的一种遗传方式,主要包括DNA甲基化、组蛋白修饰和非编码RNA调控等。在牙发育过程中,传统基因调控与表观遗传学调控共同参与协同,调节细胞增殖分化相关基因的时空表达。探索牙发育过程中的表观遗传调控机制,可为牙再生提供线索和思路,本文主要对表观遗传调控在牙发育...     

微小RNA在骨分化过程中的作用机制

在口腔种植治疗过程中常常会遇到骨量不足的问题,植入骨替代材料是目前临床上最主要的重建骨缺损方法之一,因此骨替代材料的成骨性能及其分子机制成为了研究热点。微小RNA（miRNA）是一种短链非编码RNA,通过转录后调控细胞分化、增殖、程序性死亡等病理生理过程。miRNA可影响成骨相关因子的表达和激活成骨相关信号转导通路中的信号转导,从而对骨组织动态改建过程进行调控。本文就miRNA与成骨细胞特异性转录因子、核心结合因子-α1基因、Smad基因、转化生长因子-β诱导因子,与骨形态发生蛋白信号转导通路、无翅型小鼠乳房肿瘤病毒整合位点家族信号转导通路、促丝裂原激活蛋白激酶信号转导通路、成脂信号转导通路以及miRNA与口腔相关材料和miRNA在骨缺损修复中的应用研究进展作一综述。     

聚类分析在义耳修复分型中的临床应用

作者对300只耳朵的记存模型进行聚类分析，根据聚类的结果制定义耳型号，制成模具和预成蜡义耳，在临床修复中可“对号入座”。     

New concepts of destructive periodontal disease

The most common forms of destructive periodontal disease have been thought to slowly and continuously progress until treatment or tooth loss. Recently, data have become available which are inconsistent with this "continuous disease" hypothesis. Data from longitudinal monitoring of periodontal attachment levels and alveolar bone in humans and in animals suggest that periodontal disease progresses by recurrent acute episodes. In addition, rates of attachment loss have been measured in individual sites which are faster than those consistent with the continuous disease hypothesis or slower than those expected from estimates of prior loss rates. To account for these observations, a model of destructive periodontal disease is described in which bursts of activity occur for short periods of time in individual sites. These bursts appear to occur randomly at periodontal sites throughout the mouth. Some sites demonstrate a brief active burst of destructive periodontal disease (which could take a few days to a few months) before going into a period of remission. Other sites appear to be free of destructive periodontal disease throughout the individual's life. The sites which demonstrate destructive periodontal activity may show no further activity or could be subject to one or more bursts of activity at later time periods. Comparison of monitored loss rates for a year with mean loss rates prior to monitoring suggested that there may be relatively short periods in an individual's life in which many sites undergo periodontal destruction followed by periods of extended remission. An extension of the random disease model is also suggested in which bursts of destructive periodontal disease activity occur with higher frequency during certain periods of an individual's life.     

Extended modified postauricular incision of the temporomandibular joint

The traditional postauricular approach to the temporomandibular joint has excellent cosmetic results since the entire incision is concealed in the postauricular flexure. Excellent posterior joint exposure, good lateral joint exposure, and fair anterior joint exposure are obtained. The risk of injury to the facial nerve is decreased. An extended modification of the postauricular incision was developed to overcome some of the disadvantages of the postauricular incision while maintaining its advantages. The incision begins inferiorly in a curvilinear manner, over the mastoid tip and progresses superiorly 3 mm posterior to the postauricular flexure. As it ascends superiorly above the level of the external auditory canal, it progresses posteriorly from the flexure. It then progresses superiorly in a curvilinear fashion in the temporal area slightly superior to the customary superior aspect of the preauricular incision. The dissection is carried to and through the temporalis fascia and periosteum, over the root of the zygomatic arch, and anteriorly after crosscut of the external auditory canal to the parotideomasseteric fascia. Dissection anteriorly deep to these fused structures allows a single flap to the skin. With this anterior dissection, the temporal and zygomatic branches of the facial nerve are protected and contained within the skin-fascia flap. The capsule is thus exposed and further dissection into the joint is described. A representative case presentation demonstrates the extended modified postauricular incision.     

Microradiographic investigations of carious changes in the enamel in the ground sections made perpendicularly to tooth axis

Carious changes in the enamel in the undermineralized ground sections made perpendicularly to tooth axis were investigated using microradiography. By this way, relationship between carious invasion and the enamel lamellae and tuft, which has been not able to be examined in the longitudinal ground sections, could be clarified. 1) Direction of progress of demineralization and contour of demineralization front in the enamel are closely related to arrangement of enamel prisms. This findings strongly suggest that carious demineralization progresses along the enamel prisms. 2) Mode of carious demineralization in the enamel lamellae can be divided into two types; in the first type, demineralization progresses through the enamel lamellae more quickly than in the surrounding enamel and, in the second type, the enamel lamellae and its surrounding enamel show higher mineralization degree than the demineralized part in the rest of enamel, probably due to remineralization. The second type is observed more frequently than the first. 3) Mode of carious demineralization in the enamel tuft are also divided into two types; the first type which shows that demineralization progresses more quickly through the enamel tuft than the surrounding enamel and the second type that the enamel tuft and its surrounding narrow enamel are highly mineralized probably due to remineralization, whereas the rest of enamel is prominently demineralized. The second type is more frequently observed than the first. 4) In the ground sections made perpendicularly to tooth axis, it is more clearly observed that the interprismatic area is very highly remineralized whereas the main body of prism is easily demineralized, than in the longitudinal ground sections. 5) Striae of Retzius is composed of the band which appear to resist to demineralization and that which is easily demineralized. However, in the later case, demineralization which progresses laterally along the band can not be observed. 6) The degree and width of hypermineralized layer appeared in sound enamel along the demineralization front seem to be related to the rate of demineralization and arrangement of enamel prisms.     

牙髓再生的研究现状

目前,根管治疗术在临床上已得到了广泛的应用并成功的保存了患牙,但其仍有许多术后并发症。随着组织工程技术在口腔领域的应用,构建一种组织工程化牙髓进行牙髓-牙本质复合体的再生治疗成为可能。近年来国内外已有很多关于牙髓再生的研究,并且已经取得了一定成果。本文将对目前国内外牙髓再生的研究进展现状作一综述。     

Why does supragingival calculus form preferentially on the lingual surface of the 6 lower anterior teeth?

Many authors have assumed that the reason supragingival calculus tends to form preferentially on the lingual surface of the 6 lower anterior teeth is because saliva from the adjacent submandibular ducts is a source of calcium and phosphate ions and because loss of CO2 as the saliva enters the mouth increases the local pH. However, the fluid phase of plaque in all locations is supersaturated with respect to the calcium phosphates in calculus and there is always a tendency for calculus to deposit, except after sugar consumption, when plaque pH may fall below the critical level and the plaque fluid becomes unsaturated. pH is least likely to fall below the critical level in plaque lingual to the lower anterior teeth, as this plaque is very thin, sugar concentration after sugar intake is lowest in that area and its clearance rate is fastest, and the high salivary film velocity there promotes loss of any acid formed in plaque. A high salivary film velocity also brings more salivary urea to the site, which facilitates plaque alkalinization. These factors all contribute to the development of shallow Stephan curves of short duration and together provide a more reasonable explanation for the fact that supragingival calculus deposition progresses most easily on the lingual surface of the lower anterior teeth.     

Autoimmune oral mucosal diseases: clinical, etiologic, diagnostic, and treatment considerations

This article discusses the classic autoimmune diseases: pemphigus vulgaris, mucosal pemphigoid, and oral lichen planus. These are generally considered of autoimmune origin or, at a minimum, immune system mediated. Cause, diagnosis, and treatment are discussed. As management of these diseases progresses, continued advances in molecular pathogenesis will allow insight into which strategies can be employed in interfering with the complex cascade of events leading to mucosal impairment and clinical morbidity.     

Shear strength of composite bonded to laser-pretreated dentin

As research progresses, laser energy moves closer to acceptable usefulness. Laser application to prepare dentin creates a more retentive surface for composite bonding.     

同种异体舌移植的研究进展

先天或后天原因所致舌严重畸形、缺损或缺失是口腔颌面外科临床中常见问题。目前常规方法修复存在很多问题,效果尚不能令人满意。学者们逐渐将目光转向同种异体舌移植。本文就舌同种异体移植外科技术方面及抑制免疫排斥反应等方面的研究进展作一综述。