这项研究得到了美国国立卫生研究院（NIH）国家牙科和颅面研究所（NIDCR）的校内研究计划以及罗斯曼大学牙科医学院的正畸和牙颌面骨科高级教育计划的支持。

人类 CBCT 扫描的 3D 头影测量标志注释演示

<ol>
	<li>Proffit, W. R., Fields, H. W., Larson, B., Sarver, D. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Contemporary+Orthodontics+-+E-Book.">Contemporary Orthodontics - E-Book.</a> Elsevier Health Sciences. , (2018).</li><li>Broadbent, B. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+x-ray+technique+and+its+application+to+orthodontia.">A new x-ray technique and its application to orthodontia.</a> The Angle Orthodontist. 1 (2), 45-66 (1931).</li><li>Hans, M. G., Palomo, J. M., Valiathan, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=History+of+imaging+in+orthodontics+from+Broadbent+to+cone-beam+computed+tomography.">History of imaging in orthodontics from Broadbent to cone-beam computed tomography.</a> American Journal of Orthodontics and Dentofacial Orthopedics. 148 (6), 914-921 (2015).</li><li>Liberton, D. K., Verma, P., Contratto, A., Lee, J. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+and+validation+of+novel+three-dimensional+craniofacial+landmarks+on+cone-beam+computed+tomography+scans.">Development and validation of novel three-dimensional craniofacial landmarks on cone-beam computed tomography scans.</a> The Journal of Craniofacial Surgery. 30 (7), e611-615 (2019).</li><li>Pittayapat, P., Limchaichana-Bolstad, N., Willems, G., Jacobs, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-dimensional+cephalometric+analysis+in+orthodontics:+a+systematic+review.">Three-dimensional cephalometric analysis in orthodontics: a systematic review.</a> Orthodontics &amp; Craniofacial Research. 17 (2), 69-91 (2014).</li><li>Lo Giudice, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+evolution+of+the+cephalometric+superimposition+techniques+from+the+beginning+to+the+digital+era:+a+brief+descriptive+review.">The evolution of the cephalometric superimposition techniques from the beginning to the digital era: a brief descriptive review.</a> International Journal of Dentistry. 2021, 6677133 (2021).</li><li>Graf, C. C., Dritsas, K., Ghamri, M., Gkantidis, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reliability+of+cephalometric+superimposition+for+the+assessment+of+craniofacial+changes:+a+systematic+review.">Reliability of cephalometric superimposition for the assessment of craniofacial changes: a systematic review.</a> European Journal of Orthodontics. 44 (5), 477-490 (2022).</li><li>Dot, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Automatic+3-dimensional+cephalometric+landmarking+via+deep+learning.">Automatic 3-dimensional cephalometric landmarking via deep learning.</a> Journal of Dental Research. 101 (11), 1380-1387 (2022).</li><li>Kang, S. H., Jeon, K., Kang, S. H., Lee, S. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=3D+cephalometric+landmark+detection+by+multiple+stage+deep+reinforcement+learning.">3D cephalometric landmark detection by multiple stage deep reinforcement learning.</a> Scientific Reports. 11 (1), 17509 (2021).</li><li>Schwendicke, F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Deep+learning+for+cephalometric+landmark+detection:+systematic+review+and+meta-analysis.">Deep learning for cephalometric landmark detection: systematic review and meta-analysis.</a> Clinical Oral Investigations. 25 (7), 4299-4309 (2021).</li><li>Yun, H. S., Jang, T. J., Lee, S. M., Lee, S. H., Seo, J. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Learning-based+local-to-global+landmark+annotation+for+automatic+3D+cephalometry.">Learning-based local-to-global landmark annotation for automatic 3D cephalometry.</a> Physics in Medicine and Biology. 65 (8), 085018 (2020).</li><li>Bookstein, F. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Morphometric Tools for Landmark Data: Geometry and Biology. , (1992).</li><li>Almpani, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Loeys-Dietz+and+Shprintzen-Goldberg+syndromes:+analysis+of+TGF-&#946;-opathies+with+craniofacial+manifestations+using+an+innovative+multimodality+method.">Loeys-Dietz and Shprintzen-Goldberg syndromes: analysis of TGF-&#946;-opathies with craniofacial manifestations using an innovative multimodality method.</a> Journal of Medical Genetics. 59 (10), 938-946 (2022).</li><li>Liberton, D. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Craniofacial+analysis+may+indicate+co-occurrence+of+skeletal+malocclusions+and+associated+risks+in+development+of+cleft+lip+and+palate.">Craniofacial analysis may indicate co-occurrence of skeletal malocclusions and associated risks in development of cleft lip and palate.</a> Journal of Developmental Biology. 8 (1), 2 (2020).</li><li>Whitman, M. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=TUBB3+Arg262His+causes+a+recognizable+syndrome+including+CFEOM3,+facial+palsy,+joint+contractures,+and+early-onset+peripheral+neuropathy.">TUBB3 Arg262His causes a recognizable syndrome including CFEOM3, facial palsy, joint contractures, and early-onset peripheral neuropathy.</a> Human Genetics. 140 (12), 1709-1731 (2021).</li><li>Kidwai, F. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+craniofacial+analysis+and+generation+of+human+induced+pluripotent+stem+cells+for+Muenke+syndrome:+A+case+report.">Quantitative craniofacial analysis and generation of human induced pluripotent stem cells for Muenke syndrome: A case report.</a> Journal of Developmental Biology. 9 (4), 39 (2021).</li></ol>

作者声明不存在利益冲突。

医学和牙科已经进入3D成像时代。在颅面和牙科成像学科中，CBCT扫描的使用越来越多，因为与传统CT机器相比，更新系统的辐射低，成本更低，人员使用校准简单，采集相对快速简便，患者合作最少，以及能够从一次扫描中生成多个其他诊断图像和分析。因此，临床医生和研究人员必须知道如何阅读、诊断和分析这些 3D 图像，以及如何在 3D 中研究颅面生长和发育。
为了帮助该领域的临床医生和研究人员，我们提供了一个分步协议和视频演示，用于使用人类CBCT扫描进行3D头影测量分析。这些地标之前已在之前的出版物中定义和验证，其准确性和可重复性已得到确认4.每个地标的详细细化说明也有助于用户正确注释每个地标。通过使用与每个地标应定位的区域相对应的扫描预设视图，进一步简化了地标注释过程。此功能为用户节省了大量时间和精力。然而，这涉及到一个学习曲线，用户需要练习才能获得准确的地标注释。
本协议中使用的经过验证的 3D 地标配置提供了面部、上颌骨、下颌骨和颅底骨骼组织的充分覆盖。通过这种方式，可以更准确地表示颅面结构的真实形态，以评估颅面复合体及其组成结构的尺寸、配置和方向。软组织标志不包括在此协议中，但用户可以将所选的标志添加到提供的配置中，如协议中所述。此外，出于实际原因，该协议不能包括其他3D分析软件的特定说明，但可以由每个用户相应地进行调整。
除了生成的标准头影测量的诊断价值（主要针对临床医生）之外，使用这种分析来计算任何3D地标之间的角度和线性距离所提供的自由将允许建立新的头影测量分析，以提供更详细和完整的评估。然而，我们未来的方向包括建立新的规范值，就像过去创建二维规范值一样。
此外，基于地标的GMA在颅面临床和研究领域的应用正在快速发展。进化和发育生物学以及人类学的研究人员已经使用这种分析十多年了，但最近在正畸学、牙面骨科和颅面外科领域也提出了新的临床应用。GMA还可以用作具有颅面表现的先天性疾病的定量表型的一部分，以及用于检测归因于基因突变的细微形态差异13,14,15,16。此外，通过将形态测量数据与功能分析以及遗传数据联系起来，整合不同的定量方法，可以为健康和疾病群体的颅面发育提供新知识。
由于计算和可视化的最新进展，这种类型的分析现在可以在个人计算机上进行，已经有几个软件包可用，包括Checkpoint，Geomorph（R统计软件包），Amira-Avizo和SlicerMorph。这些程序可以帮助可能不熟悉多变量统计分析的医学领域的研究人员使用内置的自动化功能进行GMA。

头影测量分析检查人类头骨的牙齿和骨骼关系，是头颅测量的临床应用。除了研究人类进化和颅面发育的人类学家、发育生物学家、法医专家和颅面研究人员外，口腔健康专业人员（包括牙医、正畸医生和口腔颌面外科医生）还将其用作治疗计划工具。最早在正畸学中使用头影测量分析的机构是1931年德国的Hofrath和美国的Broadbent 1,2,3。分析的主要目的是提供理论和实践资源，以评估个体的颅面比例并确定错牙合的解剖学来源1。这样可以跟踪上颌骨和下颌骨的生长模式，监测它们在空间中的关系位置，并观察软组织和牙齿位移的变化。因此，可以监测正畸治疗带来的变化，并且可以表征骨骼和牙齿的关系，以便为治疗计划做出诊断。牙颌面复合体的评估是通过将患者的头影示踪与代表年龄、种族和民族相似正常人群的参考值进行比较来完成的1。
传统的分析方法包括对三维（3D）结构的二维（2D）描述4,5。该技术的一个主要挫折是通过普通胶片或数字格式上的常规X射线成像对解剖结构进行失真和放大，这可能导致不准确的头影追踪和解释6,7。最初以轴向计算机断层扫描（CT）和螺旋CT形式引入的3D成像不包括牙科或非医疗应用，因为成本高，辐射剂量高。然而，锥形束计算机断层扫描（CBCT）扫描的出现减轻了这些担忧，因为费用和辐射剂量明显低于CT1。这种影像学叙述的转变激发了CBCT在正畸学中的广泛使用，以改善诊断和治疗计划。与传统的2D图像技术相比，3D成像的主要优点是3D允许检查者查看解剖结构，而不会叠加和空间失真（即个人的头部位置）。因此，可以更准确地定位用于进行头影测量分析的解剖标志，尤其是在面部不对称的情况下。此外，可以分析更大的解剖区域。
头颅测量领域的最新进展之一是实现深度学习（DL）用于自动地标检测8,9,10,11。尽管这些研究的结果很有希望，但地标放置的准确性水平尚不令人满意。此外，这些研究大多使用相对较小的地标集，这些标志集来自以前的二维头影测量分析，对颅底的覆盖不足，而颅底是研究颅面生长发育的重要结构。该演示视频详细介绍了一种进行手动、高精度 3D 头影测量分析的方法，该方法使用一组经过验证的 3D 骨骼组织标志，涵盖面部、颅底、下颌骨和牙齿区域，用于涉及 CBCT 成像的临床和研究4。图 1 显示了已完成的 3D 分析示例。

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Invivo6 Dental Software</td>
			<td>Anatomage</td>
			<td>N/A</td>
			<td>3D Imaging Software (including 3D analysis module)</td>
		</tr>
	</tbody>
</table>

three-dimensional cephalometric landmark annotation demonstration on human cone beam computed tomography scans

颅面头影测量分析是一种诊断工具，用于评估头部和面部各种骨骼和软组织的关系。传统上，头影测量分析使用二维X光片和标志集进行，仅限于尺寸，线性和角度测量以及2D关系。3D锥形束计算机断层扫描（CBCT）扫描在牙科领域的使用越来越多，这就决定了需要向3D头影测量分析演变，其中结合了形状和对所有三个平面纵向发展的更现实的分析。这项研究是3D头影测量分析的演示，在人类CBCT扫描中使用一组经过验证的骨骼组织标志。3D 体积上每个地标注释的详细说明作为分步协议的一部分提供。生成的测量值和地标的3D坐标可以导出并用于临床和研究目的。在基础和临床颅面研究中引入3D头影测量分析将导致颅面生长和发展领域的未来进展。

Cephalometric analysis, which examines the dental and skeletal relationships of the human skull, is the clinical application of cephalometry. In addition to anthropologists, developmental biologists, forensic experts, and craniofacial researchers who study human evolution and craniofacial development, it is utilized by oral health professionals, including dentists, orthodontists, and oral and maxillofacial surgeons, as a treatment planning tool. The earliest institutions that used cephalometric analysis in orthodontics were Hofrath in Germany and Broadbent in the USA in 19311,2,3. The primary objective of the analysis was to provide a theoretical and practical resource to evaluate the craniofacial proportions of an individual and to define the anatomical source of malocclusion1. This allowed for the growth pattern of the maxilla and mandible to be tracked, their relational positions in space to be monitored, and changes in soft tissue and teeth displacement to be observed. As a result, changes brought about by orthodontic treatment could be monitored, and skeletal and dental relationships could be characterized for a diagnosis to be made for treatment planning. Evaluation of the dentofacial complex was done by comparing a patient&#39;s cephalometric tracing with reference values that were representative of a normal population of similar age, race, and ethnicity1.
The traditional method of analysis consisted of a two-dimensional (2D) depiction of three-dimensional (3D) structures4,5. A major setback of this technique is the distortion and magnification of anatomical structures via conventional x-ray imaging on plain film or digital formats, which can lead to inaccurate cephalometric tracings and interpretations6,7. The initial introduction of 3D imaging in the form of axial computed tomography (CT) and spiral CT did not include dental or non-medical applications due to high cost and high radiation doses. However, the emergence of cone beam computed tomography (CBCT) scans mitigated these concerns, as expenses and radiation doses were significantly lower than CT1. The shift in this imaging narrative galvanized the widespread use of CBCT in orthodontics for improvement in diagnosis and treatment planning. The main advantage of 3D imaging over the conventional 2D image technique is that 3D allows the examiner to view anatomical structures without superimpositions and spatial distortions (i.e., head position of the individual). Therefore, a much more accurate positioning of the anatomical landmarks used for the conduction of cephalometric analysis is possible, especially in cases of facial asymmetry. Moreover, a much larger anatomical area can be analyzed.
One of the most recent advances in the field of cephalometry is the implementation of deep learning (DL) for automated landmark detection8,9,10,11. Although the results of these studies are promising, the levels of accuracy in the placement of the landmarks are not yet satisfactory. Moreover, most of these studies use relatively small landmark sets that are derived from previous 2D cephalometric analyses, providing insufficient coverage of the cranial base, which is an important structure for the study of craniofacial growth and development. This demonstration video showcases in detail a methodology for the conduction of manual, high-accuracy 3D cephalometric analysis with the use of a validated set of 3D skeletal tissue landmarks covering the areas of the face, cranial base, mandible, and teeth for use in clinical and research studies involving CBCT imaging4. An example of a completed 3D analysis can be seen in Figure 1.

作者聚焦：人体锥形束计算机断层扫描的三维头影测量标志注释演示  

人体锥形束计算机断层扫描三维头影地标标注演示

The aim of this project is to provide a detailed methodology for the conduction of 3D cephalometric analysis with the use of a validated set of 3D skeletal landmarks. These landmarks cover the areas of the cranial base, face maxilla and mandible, and can be used in clinical as well as research studies. There is a learning curve for those who annotate the landmarks for the first time on the 3D volume, and a lot of practice is strongly recommended to acquire more experience and consistency before applying these landmarks on clinical and research studies.The 3D cephalometric analysis offers more accurate measures in comparison to 2D cephalometric analysis. Because of the distortion and magnification of the anatomical structures in conventional x-ray films and 2D digital formats, 2D cephalometric analysis can lead to in accurate tracings and interpretations. Moreover, the coordinates of the 3D landmarks can be exported and used for the conduction of geometric-morphometric analysis to study shape.The use of the 3D landmark data analysis can be part of an in-depth quantitative phenotypic approach in the case of craniofacial deformities. In addition, the integration of morphometric analysis with functional analysis and genetic information will provide new knowledge in the case of craniofacial development in healthy as well as disease cohorts.

使用分步协议和视频演示详细描述了经过验证的 3D 地标配置的注释。提供了用于注释 3D 体积上每个地标的具体说明，以及在对应于每个空间平面的 2D 剖面视图的帮助下细化其初始位置。通过遵循协议中提供的详细方法并结合视频说明，用户可以学习如何使用人体CBCT扫描进行头影测量分析。
图 1 显示了人类头骨全头部 CBCT 扫描的正面和四分之三视图，当前配置中包含带注释的 3D 地标。所有描述的地标都是类型 1 和类型 2。类型 1 标志代表通常在不同解剖结构的交叉点处观察到的清晰可识别的点。2 型标志表示可识别解剖结构轮廓上的最大曲率点12.该分析中不包括类型 3 或半地标。
地标标注完成后，用户可导出并进一步分析两种类型的数据：头影测量和三维坐标值。提供了诊断和评估牙龈咬合所需的关键头影测量值。这些测量提供了对所有三个空间平面（矢状面、垂直面和横向）中骨骼和牙齿关系的详细评估。可以导出每个地标的 3D 坐标值（x、y、z），并用于计算角度和线性距离。相同坐标的值可用于进行多元几何形态分析 （GMA）。GMA是一种研究形状的方法，可以利用笛卡尔地标和/或半地标坐标捕获形态上不同的形状变量。可以使用几种统计技术来检查形状，而无需考虑所检查结构的大小，位置或方向。几何形态计量学是目前最成熟的形态计量学理论体系，用于处理基于地标的数据。
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/65224/65224fig01.jpg"> 图 1：人类头骨全头部 CBCT 扫描的正面和四分之三视图，当前配置中包含带注释的 3D 地标。 <a href="https://www.jove.com/files/ftp_upload/65224/65224fig01large.jpg" target="_blank">请点击此处查看此图的大图。</a>
补充文件1：配置文件，包括本协议中使用的地标，可以直接上传到软件进行分析。<a href="https://www.jove.com/files/ftp_upload/65224/AnalysisCFGUser.zip" target="_blank">请点击此处下载此文件。</a>

Watch this Scientific Journal Video about Three-Dimensional Cephalometric Landmark Annotation Demonstration on Human Cone Beam Computed Tomography Scans at JoVE.com

这里介绍的是使用人锥形束计算机断层扫描进行三维头影分析的详细协议。

Craniofacial cephalometric analysis is a diagnostic tool used for the assessment of the relationship of various bones and soft tissues in the head and ...

该项目的目的是通过使用一组经过验证的3D骨骼地标，为进行3D头影测量分析提供详细的方法。这些标志物覆盖颅底、面部上颌骨和下颌骨区域，可用于临床和研究。对于那些第一次在3D体积上注释地标的人来说，有一个学习曲线，强烈建议在将这些地标应用于临床和研究之前进行大量练习，以获得更多的经验和一致性。与二维头影分析相比，3D 头影测量分析提供了更准确的测量。由于传统X射线胶片和2D数字格式中解剖结构的失真和放大，2D头影测量分析可以导致准确的跟踪和解释。此外，3D地标的坐标可以导出并用于进行几何形态分析以研究形状。在颅面畸形的情况下，使用3D地标数据分析可以成为深入定量表型方法的一部分。此外，形态计量分析与功能分析和遗传信息的整合将为健康和疾病队列的颅面发育提供新知识。

three-dimensional-cephalometric-landmark-annotation-demonstration-on

Research

JoVE Journal

Medicine

Three-Dimensional Cephalometric Landmark Annotation Demonstration on Human Cone Beam Computed Tomography Scans

1.7K 次观看.  National Institute of Dental and Craniofacial Research. 该项目的目的是通过使用一组经过验证的3D骨骼地标，为进行3D头影测量分析提供详细的方法。这些标志物覆盖颅底、面部上颌骨和下颌骨区域，可用于临床和研究。对于那些第一次在3D体积上注释地标的人来说，有一个学习曲线，强烈建议在将这些地标应用于临床和研究之前进行大量练习，以获得更多的经验和一致性。与二维头影分析相比，3D 头影测量分析提供了更准?...

视频: 作者聚焦：人体锥形束计算机断层扫描的三维头影测量标志注释演示  

Craniofacial cephalometric analysis is a diagnostic tool used for the assessment of the relationship of various bones and soft tissues in the head and face. Cephalometric analysis has been traditionally conducted with the use of 2D radiographs and landmark sets and restricted to size, linear and angular measurements, and 2D relationships. The increasing use of 3D cone beam computed tomography (CBCT) scans in the dental field dictates the need for the evolution to 3D cephalometric analysis, which incorporates shape and a more realistic analysis of longitudinal development in all three planes. This study is a demonstration of 3D cephalometric analysis with the use of a validated set of skeletal tissue landmarks on human CBCT scans. Detailed instructions for the annotation of each landmark on a 3D volume are provided as part of a step-by-step protocol. The generated measurements and 3D coordinates of the landmarks can be exported and used both for clinical and research purposes. The introduction of 3D cephalometric analysis in basic and clinical craniofacial studies will lead to future advancements in the field of craniofacial growth and development.

Presented here is a detailed protocol for the conduction of three-dimensional cephalometric analysis with the use of human cone beam computed tomography scans.

科研

医学

Uploading the CBCT Scan, System Set-Up, and Annotation of 3D Anatomical Landmarks

To begin, open the software invivo six, and click on browse file from this device. Select the scan to be analyzed and click open. Go to the 3D analysis module and click on the save information floppy disk icon.Then select load a configuration and browse for the configuration file. Click on the reorientation icon. In the window that opens, select the by picking landmarks option.This allows the user to orientate all the scans, in the same way. For this protocol nasion is selected as the origin landmark. Then three point definition with landmarks, right orbitally right porion left, porion, and define anterior, posterior axis, midsagittal plane with landmarks, nasion and basion are selected.Adjust the brightness and contrast, to reduce the CBCT scam image noise from the menu on the left side of the screen. Zoom in and out by holding down the control key and left clicking simultaneously and sliding across the screen. Move the image in a bodily manner by holding down the shift key and left clicking simultaneously and sliding across the screen.Enable clipping from the settings menu to create sectional views in all planes of space. To add new landmarks in the settings menu, click on landmarks, to reveal a list of available landmark options and then select the landmark of choice. To set a default view for landmarks, select tracing task.Click on edit, choose landmark. Set the view as desired, and click on use current view settings. Repeat these steps to change the default view for any additional landmark.To annotate 3D anatomical landmarks, select create tracing from the top of the menu, and click start. Start annotating the 3D landmarks by left clicking directly on the 3D volume at the location where the landmark should be placed, based on its definition. Adjust the location of the landmark using the section views on the right of the screen.In case they cannot be seen from the layout selection menu, select slice locator. To confirm the placement of a landmark, click stop and select the desired view to visualize the landmark. Then proceed to place the remaining landmarks.To change the position of the landmark using the 3D volume, stop the analysis by clicking on stop at the bottom of the tracing tasks menu. Click on the landmark point to be moved, and drag it to the new desired position. Re-annotate a landmark by double clicking on the ticked square next to the landmark and then answering yes to the follow-up question.

上传 CBCT 扫描、系统设置和 3D 解剖标志注释

Definition and Specific Annotation Instructions for the 3D Cephalometric Landmarks

Start with the annotation of the preselected origin landmarks. The midpoint on the anterior border of the anterior curvature of the foramen magnum is called basion. To annotate basion for the axial section, locate the deepest end of the curvature of the section of the foramen magnum.For the sagittal section, look for the most posterior point of the midsection of the foramen magnum. For the coronal section, look for the inferior midpoint of the curvature of the foramen magnum. The most superior, posterior and external point located at the upper margin of each ear canal is called porion.To annotate porion for the axial section, look for the edge of the margin of the external auditory meatus. For the sagittal section, look for the point of intersection of the eustachian tube with the bony canal. For the coronal section, look for the midpoint on the inferior border of the superior curvature.The vertical line through the point roughly bisects the ear canal. The landmark nasion is located at the intersection of the suture between the frontal bone and the nasal bones. For the axial section, look for the midpoint at the height of curvature of the suture.For the sagittal section, look for the anterior point of the suture where the frontal and nasal bones meet. For the coronal section, look for the center of the frontal nasal suture. The vertical line through it roughly bisects the nose.Orbitale is the most an inferior point on the inferior orbital rim. To annotate this, set the frontal view or bony window as default and clip axially from inferior to superior until the curvature of the lower margin of the orbit is reached to locate the inferior most point of the lower curvature of the orbit. Use 2D views to confirm that the landmark is on the bone.Adjust the sagittal and coronal sections to reflect the anterior positioning of orbitale. Ensure that the landmark is anterior in position just to the point where the orbital rim starts to curve out. The most superior and anterior point of the superior orbital rim is called supraorbitale.To annotate it, set the frontal view as default in the 3D volume, and gradually clip axially from superior to inferior until the curvature of the upper margin of the orbit is reached to locate the most superior point of the upper border of the orbit. Adjust the sagittal and coronal sections to reflect the anterior positioning of the landmark. Ensure that the landmark is anterior in position just to the point where the orbital room starts to curve out.For the sella midpoint, look for the center of the sella turcica or hypophyseal fossa, which is a saddle shaped depression in the body of the sphenoid bone where the pituitary gland or hypothesis is positioned. Adjust the landmark to the center of the sella turcica in all planes. For the sagittal section, place the landmark in the center of the sella turcica.For the axial and coronal sections, adjust the views accordingly. Next, trace the right mandibular profile with a series of points. Then do the same for the left mandibular profile.After tracing the mandibular profile, the landmarks, condilion, gonion, and antigonion are annotated automatically. Identify the condilion as the most posterior and superior point on the condyle and the gonion as the most outward point on the angle formed by the junction of the ramus and the body of the mandible. Then identify the antigonion as the highest point of the concavity of the lower border of the ramus where it joins the body of the mandible.The frontal and three-quarter views of a full head CBCT scan of a human skull with all the annotated three D landmarks included in the current configuration are presented in this figure.