scholarly journals Three-Dimensional Cephalometric Landmarking and Frankfort Horizontal Plane Construction: Reproducibility of Conventional and Novel Landmarks

2021 ◽  
Vol 10 (22) ◽  
pp. 5303
Author(s):  
Gauthier Dot ◽  
Frédéric Rafflenbeul ◽  
Adeline Kerbrat ◽  
Philippe Rouch ◽  
Laurent Gajny ◽  
...  
Keyword(s):  
Orthognathic Surgery ◽  
Three Dimensional ◽  
Ct Scans ◽  
Angular Difference ◽  
Dentofacial Deformity ◽  
Repeatability And Reproducibility ◽  
Frankfort Horizontal Plane ◽  
Cephalometric Measurements ◽  
Iso 5725 ◽  
3D Landmarks

In some dentofacial deformity patients, especially patients undergoing surgical orthodontic treatments, Computed Tomography (CT) scans are useful to assess complex asymmetry or to plan orthognathic surgery. This assessment would be made easier for orthodontists and surgeons with a three-dimensional (3D) cephalometric analysis, which would require the localization of landmarks and the construction of reference planes. The objectives of this study were to assess manual landmarking repeatability and reproducibility (R&R) of a set of 3D landmarks and to evaluate R&R of vertical cephalometric measurements using two Frankfort Horizontal (FH) planes as references for horizontal 3D imaging reorientation. Thirty-three landmarks, divided into “conventional”, “foraminal” and “dental”, were manually located twice by three experienced operators on 20 randomly-selected CT scans of orthognathic surgery patients. R&R confidence intervals (CI) of each landmark in the -x, -y and -z directions were computed according to the ISO 5725 standard. These landmarks were then used to construct 2 FH planes: a conventional FH plane (orbitale left, porion right and left) and a newly proposed FH plane (midinternal acoustic foramen, orbitale right and left). R&R of vertical cephalometric measurements were computed using these 2 FH planes as horizontal references for CT reorientation. Landmarks showing a 95% CI of repeatability and/or reproducibility > 2 mm were found exclusively in the “conventional” landmarks group. Vertical measurements showed excellent R&R (95% CI < 1 mm) with either FH plane as horizontal reference. However, the 2 FH planes were not found to be parallel (absolute angular difference of 2.41°, SD 1.27°). Overall, “dental” and “foraminal” landmarks were more reliable than the “conventional” landmarks. Despite the poor reliability of the landmarks orbitale and porion, the construction of the conventional FH plane provided a reliable horizontal reference for 3D craniofacial CT scan reorientation.

scholarly journals Reproducibility of three-dimensional landmarking and Frankfort horizontal plane construction: a comparison of conventional and novel landmarks in presurgical computed tomography scans

2021 ◽  
Author(s):  
Gauthier Dot ◽  
Frederic Rafflenbeul ◽  
Adeline Kerbrat ◽  
Philippe Rouch ◽  
Laurent Gajny ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Ct Scan ◽  
Three Dimensional ◽  
Computed Tomography Scans ◽  
Repeatability And Reproducibility ◽  
Frankfort Horizontal Plane ◽  
Cephalometric Measurements ◽  
Iso 5725 ◽  
Overall Reliability ◽  
3D Landmarks

Objectives To assess manual landmarking repeatability and reproducibility (R&R) of a set of three-dimensional (3D) landmarks and to evaluate R&R of vertical cephalometric measurements using two Frankfort Horizontal (FH) planes as references for horizontal 3D imaging reorientation. Methods Thirty-three landmarks, divided into "conventional", "foraminal" and "dental", were manually located twice by 3 experienced operators on 20 computed tomography (CT) scans of orthognathic surgery patients. R&R of the landmark localization were computed according to the ISO 5725 standard. These landmarks were then used to construct 2 FH planes: a conventional FH plane (orbitale left, porion right and left) and a newly proposed FH plane (midinternal acoustic foramen, orbitale right and left). R&R of vertical cephalometric measurements were computed using these 2 FH planes as horizontal references for CT reorientation. Results Landmarks showing a 95% confidence interval (CI) of repeatability and/or reproducibility > 2mm were found exclusively in the "conventional" landmarks group. Vertical measurements showed excellent R&R (95% CI < 1mm) with either FH plane as horizontal reference. However, the 2 FH planes were not found to be parallel (absolute angular difference of 2.41°, SD 1.27°). The average time needed to landmark one CT scan was 14 ± 3 minutes. Conclusions The "dental" and "foraminal" landmarks tended to be more reliable than the "conventional" landmarks. Despite the poor overall reliability of the landmarks orbitale and porion, the construction of the conventional FH plane using 3 landmarks provided a reliable horizontal reference for 3D craniofacial CT scan reorientation.

scholarly journals Computer-Aided Planning in Orthognathic Surgery: A Comparative Study with the Establishment of Burstone Analysis-Derived 3D Norms

2019 ◽  
Vol 8 (12) ◽  
pp. 2106 ◽  
Author(s):  
Cheng-Ting Ho ◽  
Rafael Denadai ◽  
Hsin-Chih Lai ◽  
Lun-Jou Lo ◽  
Hsiu-Hsia Lin
Keyword(s):  
Orthognathic Surgery ◽  
Three Dimensional ◽  
Computer Assisted ◽  
Class Iii ◽  
Facial Soft Tissue ◽  
Skeletal Class ◽  
Nasolabial Angle ◽  
Normal Occlusion ◽  
Computer Aided ◽  
Cephalometric Measurements

Three-dimensional (3D) computer-aided simulation has revolutionized orthognathic surgery treatment, but scarce 3D cephalometric norms have been defined to date. The purposes of this study were to (1) establish a normative database of 3D Burstone cephalometric measurements for adult male and female Chinese in Taiwan, (2) compare this 3D norm dataset with the two-dimensional (2D) Burstone norms from Caucasian and Singaporean Chinese populations, and (3) apply these 3D norms to assess the outcome of a computer-aided simulation of orthognathic surgery. Three-dimensional Burstone cephalometric analysis was performed on 3D digital craniofacial image models generated from cone-beam computed tomography datasets of 60 adult Taiwanese Chinese individuals with normal occlusion and balanced facial profile. Three-dimensional Burstone analysis was performed on 3D image datasets from patients with skeletal Class III pattern (n = 30) with prior computer-aided simulation. Three-dimensional Burstone cephalometric measurements showed that Taiwanese Chinese males had significantly (p < 0.05) larger anterior and posterior facial heights, maxillary length, and mandibular ramus height than females, with no significant (p > 0.05) difference for facial soft-tissue parameters. The 3D norm dataset revealed Taiwanese Chinese-specific facial characteristics, with Taiwanese presenting (p < 0.05) a more convex profile, protrusive maxillary apical bases, protruding mandible, protruding upper and lower lips, and a shorter maxillary length and lower facial height than Caucasians. Taiwanese had significantly (p < 0.05) larger maxillary projection, vertical height ratio, lower face throat angle, nasolabial angle, and upper lip protrusion than Singaporean Chinese. No significant (p > 0.05) difference was observed between 3D norms and computer-aided simulation-derived 3D patient images for horizontal skeletal, vertical skeletal, and dental measurements, with the exception of two dental parameters (p < 0.05). This study contributes to literature by providing gender- and ethnic-specific 3D Burstone cephalometric norms, which can assist in the multidisciplinary-based delivery of orthodontic surgical care for Taiwanese Chinese individuals worldwide, including orthodontic management, computer-assisted simulation, and outcome assessment.

scholarly journals Pharyngeal airway changes after bimaxillary orthognathic surgery - preliminary results

2015 ◽  
Vol 143 (5-6) ◽  
pp. 267-273 ◽  
Author(s):  
Neda Stefanovic ◽  
Branislav Glisic ◽  
Predrag Nikolic ◽  
Jovana Juloski ◽  
Juan Palomo
Keyword(s):  
Orthognathic Surgery ◽  
Statistical Significance ◽  
Three Dimensional ◽  
Time Points ◽  
Pharyngeal Airway ◽  
Paired Samples ◽  
Maxillary Advancement ◽  
Dentofacial Deformity ◽  
Bimaxillary Orthognathic Surgery ◽  
Facial Proportions

Introduction. Dentofacial deformity, a deviation from normal facial proportions and dental relationships, is corrected by jaw repositioning in all three spatial planes, which changes the position and tension of the surrounding tissues, bones and muscles. These changes may also affect the dimensions of the pharyngeal airways (PA). Objective. The aim of this study was to evaluate and compare three-dimensional PA changes in patients treated by a combination mandibular set-back/maxillary advancement versus patients that had bimaxillary advancement with genioplasty. Methods. The sample consisted of 7 patients treated by combined mandibular set-back/maxillary advancement and 7 patients treated with bimaxillary advancement surgery. Nasopharyngeal (NP) volume, oropharyngeal (OP) volume and the area of maximum constriction (AMC) in the OP were measured on CBCT scans (2 mA/120 kV/12?? FOV) taken before (T1) and 3 months after surgery (T2). Paired samples t-test was used for analyzing statistical significance of changes (p?0.05). Results. OP volume and AMC increase after bimaxillary advancement was statistically significant, while for the mandibular set-back group the increase was non-significant. NP volume was not reduced in any of the two groups. No significant differences in PA dimensions were found between groups at neither T1 nor T2 time points. Conclusion. Results suggest that the combination of mandibular set-back/maxillary advancement did not reduce airway dimensions, while bimaxillary advancement surgery led to a statistically significant increase in the OP dimensions.

scholarly journals Repeatability and reproducibility of landmarks--a three-dimensional computed tomography study

2011 ◽  
Vol 34 (3) ◽  
pp. 276-286 ◽  
Author(s):  
I. Titiz ◽  
M. Laubinger ◽  
T. Keller ◽  
K. Hertrich ◽  
U. Hirschfelder
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
Repeatability And Reproducibility

Diagnosis of COVID-19 using 3D CT scans and vaccination for COVID-19

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Gangadhar Ch ◽  
S. Jana ◽  
Sankararao Majji ◽  
Prathyusha Kuncha ◽  
Fantin Irudaya Raj E. ◽  
...  
Keyword(s):  
Virus Isolate ◽  
Research Work ◽  
Three Dimensional ◽  
Ct Scans ◽  
Data Sets ◽  
Content Type ◽  
Infected People ◽  
3D Data ◽  
Ct Classification ◽  
First Time

Purpose For the first time in a decade, a new form of pneumonia virus, coronavirus, COVID-19, appeared in Wuhan, China. To date, it has affected millions of people, killed thousands and resulted in thousands of deaths around the world. To stop the spread of this virus, isolate the infected people. Computed tomography (CT) imaging is very accurate in revealing the details of the lungs and allows oncologists to detect COVID. However, the analysis of CT scans, which can include hundreds of images, may cause delays in hospitals. The use of artificial intelligence (AI) in radiology could help to COVID-19-positive cancer in this manner is the main purpose of the work. Design/methodology/approach CT scans are a medical imaging procedure that gives a three-dimensional (3D) representation of the lungs for clinical purposes. The volumetric 3D data sets can be regarded as axial, coronal and transverse data sets. By using AI, we can diagnose the virus presence. Findings The paper discusses the use of an AI for COVID-19, and CT classification issue and vaccination details of COVID-19 have been detailed in this paper. Originality/value Originality of the work is, all the data can be collected genuinely and did research work doneown methodology.

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