牙骨质的研究进展

本文综述了牙骨质分型，成分，发育的研究成果，讨论了上皮根鞘在成牙骨质细胞分化，牙骨形成中的可能作用，介绍了成牙骨质细胞模型的研究进展。     

成牙有质细胞培养方法的比较

尽管牙骨质在维持牙周组织健康方面发挥重要作用。但对形成牙骨质的细胞的生物学特性了解甚少，主要原因是缺乏可供体外研究的细胞模型。本文综述了近几年发展的六种成牙骨质细胞体外培养方法，它们各自取材来源和部位不同，鉴别方法各异表现出不同优缺点，可供国内学者参考。     

牙骨质附着蛋白的研究进展

目的：牙骨质是维持牙齿稳固及牙周组织健康的重要矿化组织，但由于其局部解剖结构独特等原因导致日前对其仍缺乏了解，也在很大程度上限制着我们对于成牙骨质细胞生物学特性的认识。本文综述了近年来日益受到关注的牙骨质特异性蛋白—牙骨质附着蛋白（CAP）的相关研究进展，就其发现、历史、生物活性以及作用机制等方面进行介绍，以供我国学者参考。     

下颌后牙区不同骨质内种植体即刻负载的三维有限元分析

目的 采用三维有限元分析探讨种植体在下颌后牙区不同骨质条件下即刻负载的应力分布,以期为即刻负载的应用选择提供参考.方法 建立下颌后牙区654-|种植体及上部牙冠和牙槽骨的即刻负载模型,根据骨皮质和骨松质比例构成不同分为B1(颌骨完全由均质的骨皮质构成)、B2(3 mm厚骨皮质包绕致密骨松质)、B3(1.5 mm厚骨皮质包绕致密骨松质)、B4(1.5 mm厚骨皮质包绕疏松骨松质)4种骨质条件,模拟颊舌向45°、100 N的力在修复体中心集中加载,分析各种植体在不同骨质内的von Mises应力分布.结果 颊舌向加载后von Mises应力主要集中于种植体颈部舌侧骨皮质,由B1至B4种植体4-|颈周骨内应力平均值[分别为(13.17±9.32)、(12.95±9.14)、(15.00±9.44)、(16.81±10.74)N]和种植体5-|颈周骨内应力平均值[分别为(15.51±10.32)、(14.73±8.96)、(16.79±8.40)、(18.34±8.45)N]的改变趋势一致,B3应力明显高于B1、B2,B4应力明显高于B3(P＜0.05).从B1～B4种植体6-|颈周骨内应力平均值[分别为(42.45±25.71)、(41.66±25.29)、(42.70±23.24)、(42.06±23.66)N]随骨质改变不大,但均显著高于相应骨质内4-|、5-|颈周骨内应力(P＜0.05).结论 在本项实验条件下进行即刻负载,种植体周围应力分布不仅受颌骨骨质的影响,种植体的植入位置以及建立合理的咬合同样非常重要.

Abstract：

Objective To assess and compare the peri-implant stress distribution of three posterior implants under immediate loading with 4 different bone qualities using three dimensional (3D) finite element (FE) analysis. Methods A 3D finite element model representing three implants in a portion of mandible at the 654-| region was developed, and three implants received a crown each. Four types of bone qualities (B1,B2, B3 and B4) were designed for the model. Load of 100 N was applied on the occlusal surfaces of the crowns at a 45° angle to the vertical axis of the implants. Results Von Mises stresses in the peri-implant bone of4-| in bone quality from B1 to B4 were ( 13. 17 ± 9. 32), ( 12. 95 ± 9. 14), ( 15. 00 ± 9. 44 ), and(16.81 ±10.74) MPa, and those of 5-| were (15.51 ± 10.32), (14.73 ±8.96), (16.79 ±8.40), and(18. 34 ±8.45) MPa. Stress in bone quality B4 showed the highest value, followed by B3 bone, the loweststress were found in B1 and B2 bone. It was significantly different (P ＜0. 05). However, von Mises stresses in different quality of bone around 6-| [(42.45 ±25.71), (41.66 ±25.29), (42.70 ±23.24), (42.06 ±23.66) MPa] were close to each other, and were as twice or three times as those of 4-| and 5-| , irrespective of different bone qualities. Conclusions The stress distribution around implant under immediate loading was not only affected by different bone qualities, but also by the direction of loading, and the latter may have a greater impact when a severe load delivered.     

牙骨质相关细胞的研究进展

到目前为止，人们对牙骨质的了解仍较少。人牙骨质再生被认为是牙周病暴露的根面上牙周组织再生的关键。本文回顾了学者们对牙骨质及其相关细胞的研究，阐述了形成牙骨质前体细胞的位置以及成牙骨质细胞的起源。     

18例良性牙骨质母细胞瘤、化牙骨质纤维瘤临床病理

良性牙骨质母细胞瘤和化牙骨质纤维瘤均是少见的实体瘤 ,前者由肿瘤性牙骨质母细胞产生的牙源性良性肿瘤 ,组织病理学上 ,该肿瘤主要由牙骨质样组织所组成 ,外周有未钙化的前期牙骨质和牙骨质母细胞 [1,2 ]。后者是以纤维组织及其衍生的钙化物取代正常骨组织的病变 ,在组织病理上是由胶原纤维、成纤维细胞或成牙骨质细胞所组成 [1,3] 。本文收集 8例良性牙骨质母细胞瘤及 1 0例化牙骨质纤维瘤并对两者的分类、临床特点、X线表现、治疗及预后进行比较 ,并复习国内外相关文献 ,旨在提高对这两种疾病的认识 ,从而减少混淆。1　临床资料1 .1　…     

成牙骨质细胞培养方法的比较

尽管牙骨质在维持牙周组织健康方面发挥重要作用,但对形成牙骨质的细胞的生物学特性了解甚少,主要原因是缺乏可供体外研究的细胞模型。本文综述了近几年发展的六种成牙骨质细胞体外培养方法,它们各自取材来源和部位不同,鉴别方法各异,表现出不同优缺点,可供国内学者参考。     

下颌后牙区不同骨质内种植体即刻负载的三维有限元分析

Objective To assess and compare the peri-implant stress distribution of three posterior implants under immediate loading with 4 different bone qualities using three dimensional (3D) finite element (FE) analysis. Methods A 3D finite element model representing three implants in a portion of mandible at the 654-| region was developed, and three implants received a crown each. Four types of bone qualities (B1,B2, B3 and B4) were designed for the model. Load of 100 N was applied on the occlusal surfaces of the crowns at a 45° angle to the vertical axis of the implants. Results Von Mises stresses in the peri-implant bone of4-| in bone quality from B1 to B4 were ( 13. 17 ± 9. 32), ( 12. 95 ± 9. 14), ( 15. 00 ± 9. 44 ), and(16.81 ±10.74) MPa, and those of 5-| were (15.51 ± 10.32), (14.73 ±8.96), (16.79 ±8.40), and(18. 34 ±8.45) MPa. Stress in bone quality B4 showed the highest value, followed by B3 bone, the loweststress were found in B1 and B2 bone. It was significantly different (P ＜0. 05). However, von Mises stresses in different quality of bone around 6-| [(42.45 ±25.71), (41.66 ±25.29), (42.70 ±23.24), (42.06 ±23.66) MPa] were close to each other, and were as twice or three times as those of 4-| and 5-| , irrespective of different bone qualities. Conclusions The stress distribution around implant under immediate loading was not only affected by different bone qualities, but also by the direction of loading, and the latter may have a greater impact when a severe load delivered.     

牙骨质在氟化物溶液和凝胶中的氟结合能力

将牙骨质块置于含０。２２％ＮａＦ，０．２２％ＫＦ，０．７６％ＮＦＰ，０．４％ＳｎＦ２的水溶液和凝胶中氟化１２０分钟后，取以上样本以磺酸氨基萘酚法测定磷含量；以离子吸收光栅光度计测定钙含量；以氟电极测定氟含量。结果显示，牙骨质在０。４％ＳｎＦ２凝胶和０。２２％ＮａＦ溶液中所结合的氟比其它各组及对照组显著地高；前者也后者高２。６６倍。本研究建立了一套测定牙骨质氟结合能力的实验方法，为预防根面龋提。。。     

牛成牙骨质细胞在体内形成牙骨质样组织的初步研究

目的：培养成牙骨质细胞（cementoblasts,CBs)，观察以CBs自身作为组织工程支架在裸鼠内形成牙骨质的可行性。方法：在矿化培养液中培养新生牛的成牙骨质细胞，使其形成多层CBs作为载体（CBs-made carrier)与CBs混合，植入裸鼠皮下。以CBs与胶原膜载体（collagen carrier) 复合体作为对照。7周后取材并做HE、von Kossa、茜素红及牙骨质附着蛋白单克隆抗体免疫组化染色。结果：CBs在体内可形成牙骨质样矿化组织，中心矿化程度较高，四周有尚未钙化的类牙骨质及CBs包绕，并有牙骨质细胞埋入矿化组织。以CBs自身作为载体所形成的牙骨质较以胶原膜作为载体所形成的牙骨质样组织多。结论：本组分离培养的CBs在体内可形成牙骨质样矿化组织；以多层细胞自身作为载体是一种较理想的生物支架材料。     

CBCT与RVG对下颌恒切牙根管形态评估的对比研究

目的:对比CBCT法与数字化X线成像法(RVG)对下颌恒切牙根管形态评估的差异。方法:对101颗离体牙进行唇舌向及近远中向数字化X线片拍摄和CBCT高清牙列模式扫描,对图像进行根管数目、Vertucci根管分型、根管钙化和根尖口开口位置的评估,并通过CBCT图像建立偏角度投照的三角函数模型,计算偏向投照的角度。结果:CBCT法显示有30颗为双根管,RVG近远中向投照显示有36颗为双根管,卡方检验显示对根管数目和Vertucci根管分型两种方法均具有显著性差异(P<0.05)。两种方法对根管钙化和根尖口开口位置的评估均不具有显著性差异。30颗双根管牙中下颌恒切牙唇舌向双根管的最大距离(LaL)在0~1.5 mm之间的,85.7%的为Vertucci III型,LaL在1.5~2 mm之间的,66.7%为Vertucci IV和V型。以根尖片上双根管显示距离为1 mm计算,LaL在1~2 mm之间的,偏向投照角度为26.6°~45.0°,LaL在0.1~1 mm之间的,偏向投照角度为45.0°~84.3°。结论:CBCT高清牙列模式扫描和RVG投照对于根管数目和Vertucci根管分型的评估具有显著性差异,对于根管钙化和根尖口开口位置的评估不具有显著性差异。LaL在1~2 mm之间时,偏角度投照的临床可操作性较强。     

Integrating other therapies with radiation for head neck cancer: search for optimal solution

Purpose: To review the role of concurrent chemoradiotherapy protocols with special emphasis on selection of appropriate chemotherapy drug, its timing and schedule with respect to radiation fractionation.     

Clinical and pathological aspects on some odontogenic tumors

Odontogenic tumors constitute a very diverse group of lesions that reflects the complex processes of odontogenesis. Controversies over their classification/subtyping, terminology and diagnosis have been persisted, which has direct bearings on therapeutic and/or prognostic implications.     

Can you be too old for oral implants? An update on ageing and plasticity in the oro‐facial sensorimotor system

This review focuses on the capacity of the brain for plasticity and the utility and efficacy of oral implants in helping to restore oro‐facial sensorimotor functions, especially in elderly patients. The review first outlines the components of the oro‐facial sensorimotor system which encompasses both oro‐facial tissues and a number of brain regions. One such region is the sensorimotor cortex that controls the activity of the numerous oro‐facial skeletal muscles. These muscles are involved in a number of functions including reflexes and the more complex sensorimotor functions of mastication, swallowing and speech. The review outlines the use by the brain of sensory inputs from oro‐facial receptors in order to provide for exquisite sensorimotor control of the activity of the oro‐facial muscles. It highlights the role in this sensorimotor control played by periodontal mechanoreceptors and their sensory inputs to the brain, and how oral implants in concert with the plastic capacity of the brain may, at least in part, compensate for reduced sensorimotor functioning when teeth are lost. It outlines findings of ageing‐related decrements in oro‐facial sensorimotor functions and control. The changes in oro‐facial tissues and the brain that underlie these ageing‐related functional alterations are also considered, along with adaptive and compensatory processes that utilise the brain's capacity for plasticity. The review also notes the evidence t hat rehabilitation that incorporates adjunctive approaches such as sensorimotor training paradigms in addition to oral prostheses such as implants may enhance these processes and help maintain or facilitate recovery of sensorimotor functioning in the elderly.     

Chemotherapy using new superselective intra-arterial infusion for advanced oral cancer

Purpose: We developed a new method of superselective intra-arterial infusion via the superficial temporal artery (HFT method: Hattori, Fuwa and Tohnai reported) and preoperatively performed daily concurrent radiotherapy and chemotherapy with docetaxel (DOC) and cisplatin (CDDP) using this method for 46 patients with stage Ⅲ, Ⅳ oral cancer.     

Navigation-guided oral and maxillofacial surgery (reconstructive and plastic, orthognathic, oncology)

Purpose: Advance in the field of compeer assisted surgery enables the surgical procedures to be less invasive and more accurate for the support of diagnosis imaging, pre-operative simulation and intraoperative navigation.     

Clinical evaluation of demineralized bone allograft in a hyaluronic acid carrier for sinus lift augmentation in humans: a computed tomography and histomorphometric study

OBJECTIVES: Natural and synthetic graft materials are used routinely in sinus floor augmentations to help support implants in atrophic maxillary ridges. This clinical study was based on the hypothesis that the clinical effectiveness of demineralized freeze-dried bone allograft/demineralized bone matrix (DFDBA/DBM) in sinus lifts varies when used in combination bone graft substitute materials. To test this hypothesis, DFDBA was used together with one of three materials: in saline plus anorganic bone (DFDBA: Bio-Oss; in hyaluronic acid (DFDBA: HY, 32 : 68, w/w; DBX alone; DBX plus Bio-Oss; and DBX plus tricalcium phosphate granules (beta-TCP). MATERIAL AND METHODS: Thirty-two sinus lift procedures, eight per group, were performed on 26 patients. Before surgery and at 8 months post-surgery when implants were placed, ridge heights were visualized by computed tomography (CT) and measured by morphometric analysis. Cores of bone were removed by trephine at the sites of implant placement; these biopsies from the graft sites were used for histomorphometric analysis. RESULTS: All 32 sinus lift elevations were successful when measured by CT, increasing from an average 2.84+/-0.2 mm before treatment to 15.2+/-0.6 mm after treatment. The percent of each biopsy that was occupied by new bone and incorporated bone graft materials varied with each treatment: DFDBA+Bio-Oss, DBX+Bio-Oss, or DBX alone was higher than that for DBX+beta-TCP by approximately 10%. When comparing only newly formed bone, DBX+beta-TCP treatment resulted in 50% less bone than the other three preparations. All grafted sites received implants as per the treatment plan for each patient. CONCLUSIONS: This study confirmed the hypothesis that new bone formation is dependent on the DFDBA formulation used and demonstrated that DBX, alone or in combination with other materials, can be used successfully for sinus floor elevation.     

氟化泡沫对正畸固定矫治患者牙周指数及牙釉质脱矿的影响

目的:探讨氟化泡沫对正畸固定矫患者牙周指数及牙釉质脱矿的影响。方法:选取2013年6月~2014年6月30例舌侧正畸治疗患者(600颗牙)为研究对象,根据入院时间分为对照组15例(297颗牙)和观察组15例(293颗牙),对照组采取常规口腔卫生措施,观察组在对照组的基础上定期使用1.23%氟化泡沫。随访12 个月,观察两组牙釉质脱矿牙位分布、脱矿指数(EDI)、菌斑指数(PLI)和出血指数(BI)。结果:牙釉质脱矿主要分布于上颌侧切牙、上颌中切牙及下颌前磨牙等;观察组牙釉质釉质脱矿率11.26%明显低于对照组17.51%(χ²=4.666,P<0.05);观察组EDI、PLI、BI等均明显低于对照组(t=9.947, 4.435, 7.789,P<0.05)。结论:舌侧正畸治疗中牙釉质脱矿发生率较高,氟化泡沫有助于减少正畸治疗中的牙釉质脱矿发生,降低牙周指数。     

Tumor microenvironment in oral cancer: novel approaches for immunotherapy

Squamous cell carcinoma of the head and neck (SCCHN), which arises from the squamous mucosal epithelium of the oral cavity, pharynx and larynx, is a major health problem in the US and other parts of the world, especially in developing countries.     

Cone beam imaging: is this the ultimate imaging modality?

This review article provides an overview of cone beam (CB) imaging technology and its role in orofacial imaging, including comparison with two-dimensional (2D) radiography and multislice computed tomography (MCT). The radiation dose levels of CB systems are discussed, with reference to those delivered by MCT and common dental 2D views. The large variation in dose levels delivered by CB systems and the importance of using ultra low-dose CB units are emphasized. Low-dose MCT protocols can be used. CB and MCT image quality are compared. CB is an essential technique that all dental and orofacial clinicians must be familiar with. Where ultra low-dose systems and protocols are used, CB imaging should be considered in day-to-day clinical practice. However, CB imaging is not the technique of choice in many clinical scenarios. Rather than replacing other modalities, CB imaging complements intraoral 2D radiography, panoramic radiography, MCT and other techniques including magnetic resonance imaging, ultrasound and nuclear medicine. MCT is a much more powerful and flexible modality and presently remains the technique of choice over CB imaging in many clinical scenarios. All radiologic examinations, including CB and MCT, should be comprehensively evaluated in entirety. The responsibilities and the radiological skill levels of clinicians involved in imaging as well as the associated ethical and medico-legal implications require consideration.