Name: force system with vertical v-bends: a 3d in vitro assessment of elastic and rigid rectangular archwires
Uploaded: 2018-07-24T12:30:00.000+00:00
Duration: 8 min 46 s
Description: Watch this Scientific Journal Video about Force System with Vertical V-Bends: A 3D In Vitro Assessment of Elastic and Rigid Rectangular Archwires at JoVE.com

作者希望感谢所有使这项工作成为可能的同事, 特别是 Drs. 阿迪亚齐柏和拉文答腊。作者感谢北京大学生物动态 & 生物工程实验室在康涅狄格健康方面所提供的设施在这个项目的发展。

1. 实验设置
<ol><li>使用定制的 "夹具", 标记在 OWT 铝钉上放置磨牙管和门牙托架的精确位置。</li>
	<li>粘结标准自结扎支架与复合材料。光治疗40秒。</li>
	<li>将 0.021 x 0.025 英寸不锈钢 (SS) ' 卵球形 ' 上颌弓插入支架插槽中。</li>
	<li>将测试仪器放在玻璃腔内。</li>
	<li>检查是否有任何意外的弓激活。任何激活的弓将自动创建一个力系统, 将显示在计算机屏幕上。</li>
	<li>如果观察到任何弓激活, 则重新定位托架。重复步骤 1.2-1.5。</li>
</ol>2. 制作模板弓 (图 4)
<ol><li>在测试仪器中放置一个弓 (0.021 x 0.025 SS)。</li>
	<li>使用永久性标记来指示以下内容: 1) 中线, 2) 一点, 紧靠门牙支架 (I) 和 3), 立即内侧到磨牙管 (M)。对弓的对侧也做同样的事。这是模板拱线。</li>
	<li>将弓与标记的点转移到图表纸上。</li>
	<li>在图形纸上制作弓的精确副本。 注: 此图纸可用于确定样品的所有矫正线的 V 形弯的位置。</li>
	<li>计算拱线段 (L) 从 I 到 m 的周长。</li>
	<li>现在, 马克11点从我到 m。每一点都是未来的 V 折弯位置。<ol>
<li>将每个点标记为0到10。</li>
		<li>请确保每个折弯位置与另一项之间的大小相等。</li>
	</ol>
</li>
	<li>通过计算每个位置的/L 为每个折弯位置获取唯一的数字/比率。</li>
</ol>3. V 型弯的放置
<ol><li>从样品中取一个新的弓。</li>
	<li>把它放在模板弓/图形纸上, 并将其中一个十一折弯位置双边地转移到弓。</li>
	<li>使用矩形弓钳或轻钢丝钳, 使对称的 V 弯在两个位置。</li>
	<li>将弓放在玻璃板/平面平台上, 并检查弓两端与量角器的角度测量。</li>
	<li>如果需要, 调整两端, 以便创建150°的角度。</li>
	<li>对示例的所有矫正线重复步骤3.1 到3.5。</li>
</ol>4. 测量力系统 (图5和 6)
<ol><li>打开用于数据记录的软件程序 (参见材料表)。</li>
	<li>为要保存的数据创建一个新文件夹。</li>
	<li>单击 "运行" 启动软件。该程序将在每个传感器上实时显示三个力和三力矩值。</li>
	<li>等待大约10-15 秒的数据记录软件的波动停止。确保该软件上的图形线为部队系统的所有组件显示 "平坦" 线。 注: 所有六测量在每个传感器将显示微不足道的价值 (力量 < 1 g 和时刻 < 10 g 毫米)。</li>
	<li>从平台上轻轻地移除 "测试设备"。使用 Weingart 钳将弓插入到摩尔管中。</li>
	<li>用牙周洁打开门牙支架的门。</li>
	<li>提起弓的前部, 并将其插入托架插槽中。确保弓中线与测试仪器的中线重合。</li>
	<li>将测试仪器返回平台并关闭玻璃室的门。</li>
	<li>将温度设置为摄氏37摄氏度。等待一分钟的温度, 玻璃室调整。</li>
	<li>单击软件上的 "开始保存" 按钮, 并允许软件保存/传输数据至少10秒。再次单击 "开始保存" 按钮以结束数据传输, 然后单击 "停止"。 注: 每个测量周期在10秒内为每个组件 (fx、fy、fz、mx、my和 mz) 生成100读数。</li>
	<li>转到包含已保存数据的文档, 并将数据集复制/导出到自定义设计的数据分析电子表格 (请参阅辅助表)。选择正确的 V 形折弯位置编号和特定导线样本以插入数据。</li>
	<li>对该特定折弯位置的10矫正线重复步骤4.3 到4.11。</li>
	<li>现在, 将矫正线的计算方法和标准偏差复制到单独的电子表格中, 以创建数据的图形表示形式。</li>
	<li>对所有折弯位置和矫正线类型重复步骤4.2 到4.13。 注: 矫正线包括不锈钢 (SS) 和β钛 (ß钛), 具有以下尺寸: 0.016 x 0.022 英寸, 0.017 x 0.025 英寸, 0.019 x 0.025 英寸。</li>
</ol>5. 错误评估
<ol><li>按照步骤 4.1-4.4 中的说明运行计算机/软件</li>
	<li>从平台上取出 "测试设备"。</li>
	<li>获得一个直长 0.021 x 0.025 英寸 SS 线。使用轻线钳, 弯曲线的一端成一个小钩。将弓的游离端插入从远端的摩尔管中。</li>
	<li>将测试仪器放回平台上。</li>
	<li>将已知重量 (50 克) 附加到挂钩上。让它在垂直平面上自由悬挂, 消除任何类型的干扰。关上玻璃室的门。</li>
	<li>执行步骤 4.10-4. 11。</li>
	<li>对切牙支架重复步骤 5.1-5.6。</li>
	<li>输入作为 "测量值" 的摩尔管的托架和 Mx 的熔体值。</li>
	<li>现在应用平衡等式 (参见补充文本) 计算 "预期值"。</li>
</ol>

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作者没有什么可透露的。

正畸矫正线已研究了不同的方式8,9,10,11。他们也被评估了各种机械性能, 但他们很少被分析, 以确定的力量系统, 他们将创建12,13,14,15。三点弯曲试验普遍用于评价正畸矫正线;然而, 它们通常是在没有任何弯曲的直导线上进行的。体外评估通常是优化, 以观察只有1或2个变量的时候, 不允许的结果是容易适应的临床情况。本研究的重点是试验性地确定由垂直 V 形弯曲所产生的3D 力系统, 在 interbracket 距离上放置在不同位置的矩形矫正线作为 2 x 4 装置。此协议与以前分析 V 形弯曲力学的方法有很大区别。这是第一次建立一个实际的体外设置是利用纳米传感器模仿工作的两个支架-弓几何, 而不是依赖于计算机模型或有限元方法。这个机械模型不仅测量弯矩 (第二阶导线支架相互作用), 而且扭矩 (三阶导线支架相互作用)。不施加边界条件。换句话说, 以前的研究从来没有考虑到弓的曲率, 因为它从磨牙到门牙的支架。由于这一曲线, 切牙和摩尔括号没有定位在同一平面上, 也不是平行于彼此。这种安排可以增加对力系统的分析的复杂性, 这使得他们在临床上比仅涉及两个相同的括号排列在一条直线和平行3,4更相关。
传感器的功能和数据输出可以很容易地影响的因素, 如设备的误差, 传感器灵敏度, 过热的 OWT, 人为错误的电线活化, 弯曲, 结扎, 形状, 不当的导线定位, 失活的导线在最后插入之前, 变形弓等, 因此, 用新的矫正线进行重复测量, 并运用平衡定律验证数据是很重要的。此外, 只有少数矫正线应插入测量, 以避免过热的 OWT。
每个折弯位置仅由3.7 毫米分开。因此, 准确地放置 V 型弯沿弓也是重要的。小偏差从期望的位置可能从根本上改变被记录的力量系统。一种自定义的图形纸, 包含带有 V 形弯曲位置的弓模板, 有助于达到所需的精度。铝钉上的托架定位不当也可以做同样的事。因此, 如果出现粘结故障, 则使用定制的精密夹具来获得支架的位置。
在实验过程中, 如果支架得到脱胶, 一个新的支架必须精确地放回同一位置。定制设计的夹具可以帮助找到所需的位置。无任何弯曲的被动矫正线必须用于确保支架的位置正确。如果没有, 它将不得不 rebracketed。重要的是不要重用脱胶支架, 因为有增加的可能性的支架变形。
当前方法的一个缺点是, 仅使用了两个传感器。增加更多的传感器将允许研究更复杂的力系统, 如那些包括三或更多的支架设置在拱。另一个潜在的缺点是无法模拟口腔环境。温度、唾液、闭塞等因素可能会影响产生的力系统。然而, 在这一点上是不可能同时测量的力量系统和观察到的牙齿运动在临床水平。
使用有限元分析 (FEM) 的计算机建模和模拟是一个快速出现的区域, 用于解码各种正畸器具的生物力学16、17、18、 19. 然而, 验证这些方法的一个先决条件是精确地将复杂的弓支架相互作用结合在一起, 并将假设保持在最低限度。在第二阶和第三阶中, 弓支架的相互作用很大程度上是未知的, 这可能会限制这些程序的准确性。为了更好地进行计算机模拟, 首先要找出在各种临床情况下存在的力系统, 生成一个相当可观的生物力学数据库, 然后建立一个基于该数据集的计算机模型。换言之, 更好的建模和预测将需要本协议提供的实际实验。

临床正畸治疗的一个重要方面是了解 multibracket 装置产生的力系统。明确了解基本的生物力学原理有助于提供可预测的结果, 并尽量减少潜在的副作用1。近年来, 随着支架位置和设计的增加, 在矫正线中放置弯曲的趋势越来越远;然而, 综合正畸治疗仍需要在矫正线中放置弯曲。弯曲, 当放置在不同的类型和大小的矫正线, 可以创建各种力量系统, 适合不同类型的牙齿运动。虽然在考虑多齿时, 力系统会变得相当复杂, 但一个有用的起点可能涉及简单的双支架系统。
迄今为止, V 型弯曲力学主要是在第二阶分析, 利用数学模型1,2,3,4,5和/或基于计算机的分析/模拟6. 这已经对涉及相邻支架的拱导线的二阶相互作用所涉及到的力系统有了基本的理解 (图 1)。然而, 这些方法施加一定的边界条件, 以运行模拟, 可能不会在实际的临床情况下, 可能会发生偏差。最近, 提出了一种新的体外模型, 涉及力传感器, 以测量三维 (3D) 的力量和创造的时刻, 不仅评估第二级弓支架相互作用, 但也在第三级7。然而, 不同类型的矫正线对沿切牙磨牙弓的不同弯曲位置的力系统的影响没有得到评价。此外, 这项研究仅涉及弹性正畸矫正线的评价, 这不是牙齿运动发生的主要矫正线。因此, 本研究的目的是评估在不同位置的方形不锈钢和β钛矫正线在一个3D 设置涉及磨牙和切牙支架所产生的力系统。临床医生需要知道的力量系统应用于牙列时, 具体组合的弓支架组合被用来修复错用。
本文研究了三平面空间的正畸力系统, 模仿临床实际。据了解, 临床上测量力系统是极其困难的;因此, 这种测量必须在体外进行。假设在实验室中由 V 形弯曲产生的力系统在病人口中被复制是相似的。创建了一个工作流来评估如何配置实验设置 (图 2)。
正畸钢丝测试仪 (OWT) 是一种创新产品, 由正畸的分工与生物工程 & 北京大学生物动态实验室, 康涅狄格健康, 法明顿, CT, 美国 (图 3) 合作开发。它的目的是准确模仿上颌牙齿的安排, 在口腔内和一些内部的条件, 同时提供测量的力量系统创建的所有三平面空间。OWT 的主要机械部件是数据采集装置 (数据采集器)、纳米力/扭矩传感器、湿度传感器、温度传感器和个人电脑。测试装置放置在具有温度/湿度控制的玻璃外壳内。这允许部分模拟口腔内环境。该数据采集器作为三传感器的接口: 湿度传感器、力/力矩传感器、热敏电阻以及位于平台上的传感器的测试设备 (图 3)。这些链接与一个软件程序。软件是可视化编程的平台和开发环境, 用于控制不同类型的硬件。它被选择自动化的正畸线测试仪。
在检测仪器上设置了一系列铝钉, 以表示上颌牙弓的牙齿。两个代表右中央切牙和右第一磨牙的钉子连接到传感器/负载单元 (S1 和 S2)。负载单元是一种机械装置, 可以测量所有三个平面 (x-y) 中应用到它的力和力矩: fx、fy和 fz;mx, my, 和 mz。该钉是有系统地定位, 以创建牙科弓形式。每一个 peg 是由一个精确记录的测量分离, 用平均牙齿宽度计算, 在患者正畸治疗。为实验选择的形状是由标准模板创建的 "卵球形" 拱形式。

<table><tbody><tr><td>Force/Torque&amp;nbsp; Sensors/Transducers</td><td>Nano17 F/T Sensors,&amp;nbsp; ATI Industrial Automation, Apex, NC, USA</td><td></td><td>Part of the OWT</td></tr><tr><td>CHS Series Humidity&amp;nbsp; Sensor Units</td><td>&amp;nbsp; TDK Corporation</td><td></td><td>Part of the OWT</td></tr><tr><td>Temperature sensors</td><td>(Murata NTSDXH103FPB30 thermistor) Murata Manufacturing Co., Ltd</td><td></td><td>Part of the OWT</td></tr><tr><td>LabVIEW 7.1.&amp;nbsp;</td><td>Laboratory Virtual Instrumentation Engineering Workbench, Version 7.1</td><td></td><td>Software Program</td></tr><tr><td>Self-Ligating brackets&amp;nbsp;</td><td>Empower Series, American Orthodontics.</td><td></td><td>Orthodontic Brackets</td></tr><tr><td>Stainless steel archwires</td><td>Ultimate Wireforms, Inc. in Bristol, CT</td><td></td><td>Archwires</td></tr><tr><td>Beta-Titanium Archwires</td><td>Ultimate Wireforms, Inc. in Bristol, CT</td><td></td><td>Archwires</td></tr><tr><td>Data acquisition device (DAQ)</td><td>National Instruments (NI) USB 6210</td><td></td><td>Part of the OWT</td></tr><tr><td>Ortho Form III (Archform template)</td><td>3M Oral Care, St. Paul, MN, USA</td><td></td><td>Ovoid arch form</td></tr><tr><td>Weingart Plier</td><td>Hu-Friedy Mfg. Co., LLC Chicago, IL</td><td></td><td>Orthodontic Plier</td></tr><tr><td>Light wire Plier</td><td>Hu-Friedy Mfg. Co., LLC Chicago, IL</td><td></td><td>Orthodontic Plier</td></tr></tbody></table>

force system with vertical v-bends: a 3d in vitro assessment of elastic and rigid rectangular archwires

正确理解各种正畸器械所产生的力系统, 可以使病人的治疗效率和可预测性。将复杂的多支架装置减少到简单的双支架系统, 以进行力系统评估, 将是朝这个方向迈出的第一步。然而, 这方面的正畸生物力学大部分限于2D 实验研究, 计算机建模/分析或理论外推现有模型。本协议的目的是设计、构造和验证一种体外3D 模型, 能够测量在两个支架之间放置 V 形弯曲的弓产生的力和力矩。另外的目标是比较不同类型的矫正线在他们自己和以前的模型中产生的力系统。为此, 我们模拟了一个 2 x 4 装置, 代表一个臼齿和一个门牙。正畸导线测试仪 (OWT) 是由两个多轴力传感器或负载细胞 (纳米传感器) 构成的, 正畸支架连接。负载单元能够测量所有三平面空间中的力系统。测试了两种类型的矫正线, 不锈钢和β钛三不同大小 (0.016 x 0.022 英寸, 0.017 x 0.025 英寸和 0.019 x 0.025 英寸)。每根导线接受一个垂直的 V 弯被系统地安置在一个特定位置以预定义的角度。类似的 V 形弯曲在不同的矫正线上复制, 在11个不同的位置之间的磨牙和切牙附件。这是第一次在体外尝试使用 V 形弯曲对不同矫正线的正畸装置进行模拟。

传感器板中心的每个传感器所经历的总力和总力矩由其三个正交分量表示: fx、fy和 z 轴, 表示沿 x 轴、y 轴和 z 轴线的作用力,分别mx, my, mz表示在同一轴周围的时刻。传感器的初始测量将数学转换为支架所经历的力和力矩值 (图 7)。
一系列图表显示垂直力在摩尔 (熔米) 和切牙托架 (熔i), 力矩 (牙冠小费) 在摩尔支架 (mxm), 力矩/扭矩 (labio 舌小费) 在门牙支架 (mxi) 相对于从原始数据中创建的与单个齿坐标系相关的一/升比率。牙冠比表示每个 V 形弯曲的位置, 其中 ' a ' 是切牙支架的远端边缘和 V 形弯的顶端之间的距离, 和 ' L ' 的摩尔管的内侧边缘和切牙托架的远端边缘之间的距离easured 沿弓 (37 毫米)。a/升比率为 0.0 (0 毫米/37 毫米) 表示与门牙支架相邻的折弯, 每一个连续的弯曲 (a/l = 0.1, 0.2等) 的间距3.7 毫米远离上一个折弯结束与/升 = 1.0 (37 mm/37 毫米), 代表一个弯曲相邻的摩尔括号。力系统的方向由一个负/正符号表示。图表按导线类型和大小分组 (图 9和 10)。图上的每个点都表示十相似矫正线的平均值, 误差线表示上述平均值的一个标准偏差。靠近水平轴的点 (上面或下方) 表示具有低震级的力或力矩, 而从水平轴 (上方或下方) 远一点的点表示具有较高震级的力或力矩。
垂直力 (FZ) 显示六线类型的对称和线性模式 (图 8)。接近 V 弯到任一支架, 更高是垂直力量。当折弯从支架上移开, 向中心移动时, FZ的大小减小, 直到到达某一点时, 两个力都近似为零 (中性区)。当弯向更远的位置移动, FZ逐渐增加。然而, 个别力 (f 和 f子)的方向是颠倒的。定量地, SS 矫正线创造了一个明显地更大的力量系统比ß-Ti 矫正线。此外, 更高维度矫正线创建更大的力系统。令人惊讶的是, 矫正线在两个支架上创建的相对力系统在弓的大小和类型方面都相当相似。
相反, 矩 (MX) 显示了非线性和非对称模式 (图 9)。当 V 弯被放置在接近的摩尔管 (x/升比率 > 0.6), 以及在摩尔管 (红色) 的力矩方向逆转从x/升的0.0 到 0.2, 是类似于所有矫正线, 也许代表弓支架相互作用和支架方向 (二阶与第三阶) 的一个更基本的性质。在两个托架上的矩比率显示了在所有矫正线测试中观察到的特定模式 (图 10)。弯曲, 被放置在接近门牙 (0.0-0.3 为ß和 0.0-0.2 为 SS) 有两个时刻在同一方向 (mxi/mxm > 0)。从 0.3-0.6 的ß和 0.3-0.4 的 a/升为 SS, 瞬间是相反的方向 (mxi/mxm < 0) (中性区)。弯曲在0.6 或更大没有创造一个重要时刻在门牙 (≈0 g 毫米), 但一个巨大的片刻在摩尔管 (mxi/mxm≈0) 产生。
定量地, 再和垂直力一样, SS 弓所产生的力矩的大小在统计学上和临床上都大于ß-Ti 矫正线产生的, 无论是升比还是拱线的大小。
百分比错误由以下等式计算:
<img alt="Figure 1" src="/files/ftp_upload/57339/57339eq1.jpg">
小于50克的权重的% 误差被发现为 5%, 从50到500克的权重计算为0.5%。
中性区 (相等和相反弯矩) 被发现在 0.3-0.4 的ß比率为 SS 矫正线和 0.4-0.5。在这些特定的弯曲位置, 垂直力是最小的时刻作用在切牙和摩尔括号对面的方向。根据 a/d 比率, 在磨牙和切牙支架之间由 V 形弯曲产生的力系统可分为三种不同的类别 (图 11)。
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/57339/57339fig1.jpg"> 图 1: 在第二个顺序中由两个共线托架创建的强制系统.L 是两个括号之间的距离;a 是 V 形弯从支架 a 的位置;fa和 fb是分别在支架 A 和 b 上产生的垂直力;Ma是片刻在 a;Mb是括号 b 的时刻.<a href="https://www.jove.com/files/ftp_upload/57339/57339fig1large.jpg" target="_blank">请点击这里查看这个数字的大版本</a>。
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/57339/57339fig2.jpg"> 图 2: 工作流.<a href="https://www.jove.com/files/ftp_upload/57339/57339fig2large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/57339/57339fig3.jpg"> 图 3: 正畸钢丝测试仪 (OWT).A: 检测仪器, B: 测量平台, C: 温度监测器。<a href="https://www.jove.com/files/ftp_upload/57339/57339fig3large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/57339/57339fig4.jpg"> 图 4: 两个附件之间的折弯位置的示意图表示形式.每一个蓝色点是一个折弯位置, 代表距离 ' a ' 测量从切牙支架沿弓。将有11个不同的值为 ' a ' 的增量为3.7 毫米. (即蓝点与相邻的蓝点分开3.7 毫米)。L 是从切牙支架远端表面到沿弓的摩尔管远端表面测量的周长长度。<a href="https://www.jove.com/files/ftp_upload/57339/57339fig4large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 5" class="xfigimg" src="/files/ftp_upload/57339/57339fig5.jpg"> 图 5: 弓插入和持有的支架上的铝钉连接到传感器.<a href="https://www.jove.com/files/ftp_upload/57339/57339fig5large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 6" class="xfigimg" src="/files/ftp_upload/57339/57339fig6.jpg"> 图 6: 显示原始数据 (蓝色和红色盒) 的软件程序, 从连接到门牙和臼齿托架的两个传感器 (S1 和 S2) 获得.<a href="https://www.jove.com/files/ftp_upload/57339/57339fig6large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 7" class="xfigimg" src="/files/ftp_upload/57339/57339fig7.jpg"> 图 7: X Y Z 坐标及其与 OWT 的方向关系.X: 横向平面;水平平面;Z: 垂直平面。<a href="https://www.jove.com/files/ftp_upload/57339/57339fig7large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 8" class="xfigimg" src="/files/ftp_upload/57339/57339fig8.jpg"> 图 8: 垂直力 (熔) 在两个托架上的图形表示.<a href="https://www.jove.com/files/ftp_upload/57339/57339fig8large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 9" class="xfigimg" src="/files/ftp_upload/57339/57339fig9.jpg"> 图 9: 在两个托架上的横向平面 (Mx) 中的矩的图形表示.<a href="https://www.jove.com/files/ftp_upload/57339/57339fig9large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 10" class="xfigimg" src="/files/ftp_upload/57339/57339fig10.jpg"> 图 10: 相对力系统横跨不同的弓类型和大小通过时刻的比率描述 [Mx (i)/mx (m)].<a href="https://www.jove.com/files/ftp_upload/57339/57339fig10large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 11" class="xfigimg" src="/files/ftp_upload/57339/57339fig11.jpg"> 图 11: 三不同的力量系统从 V 弯.每个区域代表一个唯一的 f# 系统。"蓝色" 阴影区域描述了与类似的相对力系统的 a/d 比率。<a href="https://www.jove.com/files/ftp_upload/57339/57339fig11large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always"><tbody>
<tr>
<td>力系统</td>
			<td>摩尔 (m)</td>
			<td>切牙 (i)</td>
		</tr>
<tr>
<td>熔 (+)</td>
			<td>侵入</td>
			<td>侵入</td>
		</tr>
<tr>
<td>熔 (-)</td>
			<td>突出</td>
			<td>突出</td>
		</tr>
<tr>
<td>Mx (+) *</td>
			<td>内侧提示</td>
			<td>面部/唇尖</td>
		</tr>
<tr>
<td>Mx (-) *</td>
			<td>远端尖端</td>
			<td>腭/舌尖</td>
		</tr>
<tr>
<td colspan="3">* 所有测量均在支架上进行</td>
		</tr>
</tbody></table>表 1: 签署了部队系统的公约和方向。
<img alt="Figure 1" src="/files/ftp_upload/57339/57339supfig1.jpg"> 补充图 1: x 轴周围力矩的平衡图 (Mx).注意: 图只是比较矩的大小。mx(m) + Mx(i)和 fz(m)或 fz(i) x D 的方向将始终是相反的。因此, ΣMx= 0 (参见补充文本)。<a href="https://www.jove.com/files/ftp_upload/57339/57339supfig1large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
补充案文. <a href="https://www.jove.com/files/ftp_upload/57339/Supplementary_text.docx" target="_blank">请单击此处下载此文件.</a>

Watch this Scientific Journal Video about Force System with Vertical V-Bends: A 3D In Vitro Assessment of Elastic and Rigid Rectangular Archwires at JoVE.com

Force System with Vertical V-Bends: A 3D In Vitro Assessment of Elastic and Rigid Rectangular Archwires

本文提出的方法是建立和验证体外3D 模型, 能够测量由两个支架之间放置的 V 形弯曲的不同矫正线所产生的力系统。另外的目标是比较这个力系统与不同类型的矫正线和以前的模型。

垂直 V 形弯曲力系统: 3D 弹性和刚性矩形矫正线的体外评价

A proper understanding of the force system created by various orthodontic appliances can make treatment of patients efficient and predictable. Reducing ...

force-system-with-vertical-v-bends-3d-vitro-assessment-elastic-rigid

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Force System with Vertical V-Bends: A 3D In Vitro Assessment of Elastic and Rigid Rectangular Archwires

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10.6K 次观看.  University of Connecticut Health. 本文提出的方法是建立和验证体外3D 模型, 能够测量由两个支架之间放置的 V 形弯曲的不同矫正线所产生的力系统。另外的目标是比较这个力系统与不同类型的矫正线和以前的模型。

视频: Force System with Vertical V-Bends: A 3D In Vitro Assessment of Elastic and Rigid Rectangular Archwires

Tri-layered Electrospinning to Mimic Native Arterial Architecture using Polycaprolactone, Elastin, and Collagen: A Preliminary Study

Throughout native artery, collagen and elastin play an important role, providing a mechanical backbone, preventing vessel rupture, and promoting recovery under pulsatile deformations. The goal of this study was to mimic the structure of native artery by fabricating a multi-layered electrospun conduit composed of poly(caprolactone) (PCL) with the addition of elastin and collagen with blends of 45-45-10, 55-35-10, and 65-25-10 PCL-ELAS-COL to demonstrate mechanical properties indicative of native arterial tissue, while remaining conducive to tissue regeneration. Whole grafts and individual layers were analyzed using uniaxial tensile testing, dynamic compliance, suture retention, and burst strength. Compliance results revealed that changes to the middle/medial layer changed overall graft behavior with whole graft compliance values ranging from 0.8 - 2.8 % / 100 mmHg, while uniaxial results demonstrated an average modulus range of 2.0 - 11.8 MPa. Both modulus and compliance data displayed values within the range of native artery. Mathematical modeling was implemented to show how changes in layer stiffness affect the overall circumferential wall stress, and as a design aid to achieve the best mechanical combination of materials. Overall, the results indicated that a graft can be designed to mimic a tri-layered structure by altering layer properties.

The aim of this study was to mimic the native three layered architecture of the arterial wall. To accomplish this, electrospinning was employed with the use of a 3-1 (input-output) nozzle and blends of polycaprolactone, elastin, and collagen.

三层次的静电，以模仿母语动脉结构采用聚己内酯，弹性和胶原的初步研究

Throughout native artery, collagen and elastin play an important role, providing a mechanical backbone, preventing vessel rupture, and promoting recovery ...

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Directed Cellular Self-Assembly to Fabricate Cell-Derived Tissue Rings for Biomechanical Analysis and Tissue Engineering

Each year, hundreds of thousands of patients undergo coronary artery bypass surgery in the United States.1 Approximately one third of these patients do not have suitable autologous donor vessels due to disease progression or previous harvest. The aim of vascular tissue engineering is to develop a suitable alternative source for these bypass grafts. In addition, engineered vascular tissue may prove valuable as living vascular models to study cardiovascular diseases. Several promising approaches to engineering blood vessels have been explored, with many recent studies focusing on development and analysis of cell-based methods.2-5 Herein, we present a method to rapidly self-assemble cells into 3D tissue rings that can be used in vitro to model vascular tissues.
To do this, suspensions of smooth muscle cells are seeded into round-bottomed annular agarose wells. The non-adhesive properties of the agarose allow the cells to settle, aggregate and contract around a post at the center of the well to form a cohesive tissue ring.6,7 These rings can be cultured for several days prior to harvesting for mechanical, physiological, biochemical, or histological analysis. We have shown that these cell-derived tissue rings yield at 100-500 kPa ultimate tensile strength8 which exceeds the value reported for other tissue engineered vascular constructs cultured for similar durations (&lt;30 kPa).9,10 Our results demonstrate that robust cell-derived vascular tissue ring generation can be achieved within a short time period, and offers the opportunity for direct and quantitative assessment of the contributions of cells and cell-derived matrix (CDM) to vascular tissue structure and function.

This article outlines a versatile method to create cell-derived tissue rings by cellular self-assembly. Smooth muscle cells seeded into ring-shaped agarose wells aggregate and contract to form robust three-dimensional (3D) tissues within 7 days. Millimeter-scale tissue rings are conducive to mechanical testing and serve as building blocks for tissue assembly.

定向细胞自我组装制造，为生物力学分析与组织工程细胞衍生的组织环

Each year, hundreds of thousands of patients undergo coronary artery bypass surgery in the United States.1 Approximately one third of these patients do ...

An Improved Mechanical Testing Method to Assess Bone-implant Anchorage

Recent advances in material science have led to a substantial increase in the topographical complexity of implant surfaces, both on a micro- and a nano-scale. As such, traditional methods of describing implant surfaces -&#160;namely numerical determinants of surface roughness -&#160;are inadequate for predicting in vivo performance. Biomechanical testing provides an accurate and comparative platform to analyze the performance of biomaterial surfaces. An improved mechanical testing method to test the anchorage of bone to candidate implant surfaces is presented. The method is applicable to both early and later stages of healing and can be employed for any range of chemically or mechanically modified surfaces -&#160;but not smooth surfaces. Custom rectangular implants are placed bilaterally in the distal femora of male Wistar rats and collected with the surrounding bone. Test specimens are prepared and potted using a novel breakaway mold and the disruption test is conducted using a mechanical testing machine. This method allows for alignment of the disruption force exactly perpendicular, or parallel, to the plane of the implant surface, and provides an accurate and reproducible means for isolating an exact peri-implant region for testing.

An improved method to mechanically test bone anchorage to candidate implant surfaces is presented. This method allows for alignment of the disruption force exactly perpendicular, or parallel, to the plane of the implant surface, and provides an accurate means to direct the disruption forces to an exact peri-implant region.

一种改进的机械性能测试方法来评估骨种植体支抗

Recent advances in material science have led to a substantial increase in the topographical complexity of implant surfaces, both on a micro- and a ...

Stereolithographic 3D Printing with Renewable Acrylates

The accessibility of cost-competitive renewable materials and their application in additive manufacturing is essential for an efficient biobased economy. We demonstrate the rapid prototyping of sustainable resins using a stereolithographic 3D printer. Resin formulation takes place by straightforward mixing of biobased acrylate monomers and oligomers with a photoinitiatior and optical absorber. Resin viscosity is controlled by the monomer to oligomer ratio and is determined as a function of shear rate by a rheometer with parallel plate geometry. A stereolithographic apparatus charged with the biobased resins is employed to produce complex shaped prototypes with high accuracy. The products require a post-treatment, including alcohol rinsing and UV irradiation, to ensure complete curing. The high feature resolution and excellent surface finishing of the prototypes is revealed by scanning electron microscopy.

A protocol for additive manufacturing with renewable photopolymer resins on a stereolithography apparatus is presented.

Stereolithographic 3D 印刷用可再生丙烯酸酯

The accessibility of cost-competitive renewable materials and their application in additive manufacturing is essential for an efficient biobased economy. ...

化学

Measuring the Complete-arch Distortion of an Optical Dental Impression

Digital workflows have actively been used to produce dental restorations or oral appliances since dentists started to make digital impressions by acquiring 3D images with an intraoral scanner. Because of the nature of scanning the oral cavity in the patient&#39;s mouth, the intraoral scanner is a handheld device with a small optical window, stitching together small data to complete the entire image. During the complete-arch impression procedure, a deformation of the impression body can occur and affect the fit of the restoration or appliance. In order to measure these distortions, a master specimen was designed and produced with a metal 3D printer. Designed reference geometries allow setting independent coordinate systems for each impression and measure x, y, and z displacements of the cylinder top circle center where the distortion of the impression can be evaluated. In order to evaluate the reliability of this method, the coordinate values of the cylinder are calculated and compared between the original computer-aided design (CAD) data and the reference data acquired with the industrial scanner. The coordinate differences between the two groups were mostly less than 50 &#181;m, but the deviations were high due to the tolerance of 3D printing in the z coordinates of the obliquely designed cylinder on the molar. However, since the printed model sets a new standard, it does not affect the results of the test evaluation. The reproducibility of the reference scanner is 11.0 &#177; 1.8 &#181;m. This test method can be used to identify and improve upon the intrinsic problems of an intraoral scanner or to establish a scanning strategy by measuring the degree of distortion at each part of the complete-arch digital impression.

Here, we present a protocol to measure the degree of distortion at each part of the compete-arch digital impression acquired from an intraoral scanner with 3D-printed metal phantom with standard geometries.

测量光学牙科印象的完整拱形失真

Digital workflows have actively been used to produce dental restorations or oral appliances since dentists started to make digital impressions by ...

工程学

Cantilever Bending of Murine Femoral Necks

Fractures in the femoral neck are a common occurrence in individuals with osteoporosis. Many mouse models have been developed to assess disease states and therapies, with biomechanical testing as a primary outcome measure. However, traditional biomechanical testing focuses on torsion or bending tests applied to the midshaft of the long bones. This is not typically the site of high-risk fractures in osteoporotic individuals. Therefore, a biomechanical testing protocol was developed that tests the femoral necks of murine femurs in cantilever bending loading to replicate better the types of fractures experienced by osteoporosis patients. Since the biomechanical outcomes are highly dependent on the flexural loading direction relative to the femoral neck, 3D printed guides were created to maintain a femoral shaft at an angle of 20&#176; relative to the loading direction. The new protocol streamlined the testing by reducing variability in alignment (21.6&#176; &plusmn; 1.5&#176;, COV = 7.1%, n = 20) and improved reproducibility in the measured biomechanical outcomes (average COV = 26.7%). The new approach using the 3D printed guides for reliable specimen alignment improves rigor and reproducibility by reducing the measurement errors due to specimen misalignment, which should minimize sample sizes in mouse studies of osteoporosis.

The present protocol describes the development of a reproducible testing platform for murine femoral necks in a cantilever bending set-up. Custom 3D printed guides were used to consistently and rigidly fix the femurs in optimal alignment.

鼠股颈悬臂弯曲

Fractures in the femoral neck are a common occurrence in individuals with osteoporosis. Many mouse models have been developed to assess disease states and ...

骨折易感性机械测试的原则和方案

Practical Considerations for the Design, Execution, and Interpretation of Studies Involving Whole-Bone Bending Tests of Rodent Bones

Skeletal fragility leading to fracture is an American public health crisis resulting in 1.5 million fractures each year and $18 billion in direct care costs. The ability to understand the mechanisms underlying bone disease and the response to treatment is not only desired, but critical. Mechanical testing of bone serves as a valuable technique for understanding and quantifying a bone&#39;s susceptibility to fracture. While this method appears simple to perform, inappropriate and inaccurate conclusions may be reached if governing assumptions and key steps are disregarded by the user. This has been observed across disciplines as studies continue to be published with misuse of methods and incorrect interpretation of results. This protocol will serve as a primer for the principles associated with mechanical testing along with the application of these techniques-from considerations of sample size through tissue harvesting and storage, to data analysis and interpretation. With this in hand, valuable information regarding a bone&#39;s susceptibility to fracture may be obtained, furthering understanding for both academic research and clinical solutions.

作者聚焦：提高全骨弯曲测试的准确性和可重复性 

Mechanical testing of rodent bones is a valuable method for extracting information regarding a bone's susceptibility to fracture. Lacking proper practical understanding, the results may be overinterpreted or lack validity. This protocol will serve as a guide to ensure mechanical tests are performed accurately to provide valid and functional data.

设计、执行和解释涉及啮齿动物骨骼全骨弯曲试验的研究的实际考虑因素

Skeletal fragility leading to fracture is an American public health crisis resulting in 1.5 million fractures each year and $18 billion in direct care ...

3D Imaging of PDL Collagen Fibers during Orthodontic Tooth Movement in Mandibular Murine Model

Orthodontic tooth movement is a complex biological process of altered soft and hard tissue remodeling as a result of external forces. In order to understand these complex remodeling processes, it is critical to study the tooth and periodontal tissues within their 3D context and therefore minimize any sectioning and tissue artefacts. Mouse models are often utilized in developmental and structural biology, as well as in biomechanics due to their small size, high metabolic rate, genetics and ease of handling. In principle this also makes them excellent models for dental related studies. However, a major impediment is their small tooth size, the molars in particular. This paper is aimed at providing a step by step protocol for generating orthodontic tooth movement and two methods for 3D imaging of the periodontal ligament fibrous component of a mouse mandibular molar. The first method presented is based on a micro-CT setup enabling phase enhancement&#160;imaging of fresh collagen tissues. The second method is a bone clearing method using ethyl cinnamate that enables imaging through the bone without sectioning and preserves endogenous fluorescence. Combining this clearing method with reporter mice like Flk1-Cre;TdTomato provided a first of its kind opportunity to image the 3D vasculature in the PDL and alveolar bone.

We present a protocol for generating orthodontic tooth movement in mice and methods for 3D visualization of the collagen fibers and blood vessels of periodontal ligament without sectioning.

垂直 V 形弯曲力系统: 3D 弹性和刚性矩形矫正线的体外评价

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此视频中的章节

三层次的静电，以模仿母语动脉结构采用聚己内酯，弹性和胶原的初步研究

定向细胞自我组装制造，为生物力学分析与组织工程细胞衍生的组织环

一种改进的机械性能测试方法来评估骨种植体支抗

Stereolithographic 3D 印刷用可再生丙烯酸酯

测量光学牙科印象的完整拱形失真

鼠股颈悬臂弯曲

设计、执行和解释涉及啮齿动物骨骼全骨弯曲试验的研究的实际考虑因素

设计、执行和解释涉及啮齿动物骨骼全骨弯曲试验的研究的实际考虑因素

设计、执行和解释涉及啮齿动物骨骼全骨弯曲试验的研究的实际考虑因素

曼迪布勒穆林模型中矫形牙齿运动期间 PDL 胶原蛋白纤维的 3D 成像