uploading the cbct scan, system set-up, and annotation of 3d anatomical landmarks

人类 CBCT 扫描的 3D 头影测量标志注释演示

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.

Watch this Scientific Journal Video about Uploading the CBCT Scan, System Set-Up, and Annotation of 3D Anatomical Landmarks at JoVE.com

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

上传 CBCT 扫描、系统设置和 3D 解剖标志注释

首先，打开软件invivo six，然后单击此设备的浏览文件。选择要分析的扫描，然后单击打开。转到 3D 分析模块，然后单击保存信息软盘图标。然后选择“加载配置”并浏览配置文件。单击重新定向图标。在打开的窗口中，选择通过选取地标选项。这允许用户以相同的方式定向所有扫描。对于该协议，nasion被选为原产地。然后选择带地标的三点定义，右眶右孔左，多孔，并定义前，后轴，中矢状面与地标，鼻和基底。调整亮度和对比度，以减少屏幕左侧菜单中的CBCT诈骗图像噪音。通过按住控制键并同时左键单击并在屏幕上滑动来放大和缩小。通过按住 shift 键并同时左键单击并在屏幕上滑动，以身体方式移动图像。从设置菜单中启用剪切，以在所有空间平面中创建剖面视图。要在设置菜单中添加新地标，请单击地标，以显示可用地标选项的列表，然后选择所需的地标。要设置地标的默认视图，请选择追踪任务。单击编辑，选择地标。根据需要设置视图，然后单击使用当前视图设置。重复这些步骤以更改任何其他地标的默认视图。要注释 3D 解剖标志，请从菜单顶部选择创建追踪，然后单击开始。根据地标的定义，在应放置地标的位置直接单击鼠标左键，开始对 3D 地标进行注释。使用屏幕右侧的剖面视图调整地标的位置。如果从布局选择菜单中看不到它们，请选择剖面定位器。要确认地标的位置，请单击停止并选择所需的视图以可视化地标。然后继续放置其余的地标。要使用 3D 体积更改地标的位置，请单击追踪任务菜单底部的停止停止来停止分析。单击要移动的地标点，然后将其拖动到新的所需位置。通过双击地标旁边的勾号方块，然后对后续问题回答“是”来重新注释地标。

uploading-cbct-scan-system-set-up-annotation-3d-anatomical

Research

JoVE Journal

Medicine

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

400 次观看.  National Institute of Dental and Craniofacial Research. 首先，打开软件invivo six，然后单击此设备的浏览文件。选择要分析的扫描，然后单击打开。转到 3D 分析模块，然后单击保存信息软盘图标。然后选择“加载配置”并浏览配置文件。单击重新定向图标。在打开的窗口中，选择通过选取地标选项。这允许用户以相同的方式定向所有扫描。对于该协议，nasion被选为原产地。然后选择带地标的三点定义，右眶右孔左，多?...

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

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

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.

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

科研

医学

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.

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.