Three-dimensional Virtual Models Research Articles

Marginal Fit Evaluation of Zirconia Substructure Computer-Aided Design and Manufacturing (CAD/CAM) by Scanning Electron Microscope

Purpose. This in vitro study compared the vertical marginal discrepancy (MD) and absolute marginal discrepancy (AMD) between the zirconia substructure and titanium (Ti)-base abutment before and after cementation. Material and methods. An intraoral scanner (CEREC Omnicam scanner; Dentsply Sirona) was used to scan the dental model of missing tooth 36 and obtain a three-dimensional virtual model. It was designed and milled for 25 zirconia superstructures (inCoris ZI meso F2 L, Dentsply Sirona). The samples were cemented to Ti bases. The MD and AMD were measured for each sample by using a scanning electron microscope (SEM) before and after cementation. Results. The overall mean values of MD measurements before and after cementation were 14.12 μm and 20.28 μm, respectively. The overall mean values of AMD measurements prior to and after substructure cementation on the Ti base were 54.85 μm and 116.0 μm, respectively. ANOVA revealed significant differences in MD (p = 0.001) and AMD (p < 0.001) before and after cementation. Conclusions. Significant differences were observed in MD and AMD values before and after cementation. The MD and AMD values were significantly lower before cementation than after cementation. The mean MD and AMD values were clinically acceptable.

Biomechanical Fixation Analysis of Minimally Invasive Chevron Osteotomy

Category: Bunion Introduction/Purpose: The original fixation for minimally invasive Chevron-Akin ( MICA) was described with two screws: a proximal screw reaching two cortices before fixing the metatarsal head and a distal parallel screw that can reach only one cortical before fixing the head. Despite this, some authors questioned the need for two screws and were able to reproduce good results from this technique using only one screw to fix the osteotomy. Notably, no biomechanical studies evaluate this osteotomy's most stable and safe fixation. This work aims to perform a biomechanical analysis based on finite element analysis (FEM) to compare different MICA fixation configurations using screws. Our hypothesis is that the fixation of the original technique with two screws is the safest. Methods: A Three-dimensional (3D) virtual model of a foot computer tomography (CT) image was made using the Rhinoceros™ program. The element finite analysis was performed with the SimLab™ program using the Optistruct solver. From these 3D virtual models, an extracapsular chevron osteotomy with 130 degrees with 70% of lateral translation was done and fixated. Five internal fixation configurations with screws were used for fixation of MICA and assessed by FEM -: original MICA fixation with 2 screws, 2 intramedullary screws, 2 bicortical screws, 01 intramedullary screw, and 01 bicortical screw. The simulated 150 N and 300 N loads were applied to the middle foot. The FEM evaluated the total and localized displacements of the osteotomy site. For the analysis of stresses, the variables maximum principal (traction) and minimum principal (compression) were used. The equivalent von Mises stress (VMS -S) was used for the metallic implants and for the bone (VMS -O). Results: The classical fixation for MICA showed the lowest values for total and localized displacement, minimum and maximum total stress, and VMS-S and VMS-o in both conditions( 150 and 300 N). The localized displacement was statistically lower for MICA screws compared to the other fixation configurations (p < 0.05) The maximum total stress was statistically lower for MICA screws compared to the other fixation configurations (p < 0.05) Conclusion: The classical fixation for MICA yields better results in terms of total and localized displacement, minimum and maximum total stress, and VMS in both conditions. These results demonstrate that the classical fixation for MICA described in the original technique is biomechanically the most efficient and safe.

Hyper accuracy three-dimensional virtual anatomical rainbow model facilitates surgical planning and safe selective clamping during robot-assisted partial nephrectomy

ObjectiveTo highlight the role of hyper accuracy three-dimensional (3D) reconstruction in facilitating surgical planning and guiding selective clamping during robotic partial nephrectomy (RAPN). MethodsA transperitoneal RAPN was performed in a 62 years old male patient presenting with a 4 cm right anterior interpolar renal mass (R.E.N.A.L nephrometry score 7A). An abnormal vasculature was observed, with a single renal vein and two right renal arteries originating superiorly to the vein and anterior, when dividing in their segmental branches. According to the hyper accuracy 3D (HA3D®) rainbow model (MEDICS Srl, Turin, Italy), one branch belonging to one of the segmental arteries was feeding the tumor. This allowed for an accurate prediction of the area vascularized by each arterial branch. The 3D model was included in the intraoperative console view during the whole procedure, using the TilePro feature. A step-by-step explanation of the procedure is provided in the video attached to the present article. ResultsOperative time was 90 min with a warm ischemia time on selective clamping of 13 min. Estimated blood loss was 180 mL. No intraoperative complication was encountered and no drain was placed at the end of the procedure. The patient was discharged on postoperative Day 2, without any early postoperative complications. The final pathology report showed a pathological tumor stage 1 clear cell renal cell carcinoma with negative surgical margins. ConclusionThe present study and the attached video illustrate the value of 3D rainbow model during the planning and execution of a RAPN with selective clamping. It shows how the surgeon can rely on this model to be more efficient by avoiding unnecessary surgical steps, and to safely adopt a “selective” clamping strategy that can translate in minimal functional impact.

HBIM: A Tool for Enhancing the Diagnosis of Historical Buildings: The Case of St. George’s Memorial Anglican Church, Oshawa

The primary objective of this research is to address the research gap in the conservation of heritage buildings in Canada by integrating Historical Building Information Modeling (HBIM) as a tool. The proposed study aims to develop an enhanced framework for the preservation of historical buildings through the utilization of HBIM and 3D-scanning technology. As a result, the research aims to generate a comprehensive database comprising various families of models while also incorporating strategies for point-cloud clustering data. The significance of this research lies in its potential to contribute to the conservation and restoration process of historical buildings. Currently, there are a lack of standardized approaches and comprehensive databases for accurately documenting and reproducing historical buildings. By integrating HBIM and 3D-scanning technology, this research will enable the creation of highly accurate three-dimensional virtual models, consisting of millions of points, which will serve as a comprehensive dataset for the restoration of heritage buildings. The findings of this research will benefit multiple stakeholders. Preservation architects, conservationists, and heritage professionals will gain a valuable tool for documenting and analyzing historical buildings with a high level of precision. The comprehensive database and framework proposed in this study will facilitate decision-making processes during the restoration and preservation phases, ensuring that the original architectural elements and materials are faithfully reproduced. Additionally, policymakers and governmental organizations involved in heritage conservation can use the outcomes of this research to establish standardized guidelines and regulations for the preservation of historical buildings in Canada. Ultimately, the broader community will benefit from the enhanced preservation efforts, as it will contribute to the cultural and historical identity of the nation, fostering a sense of pride and connection to the past.

An Automatic Approach for Bone Tumor Detection from Non-Standard CT Images

Image processing techniques are applied in many fields of science. This study aims to detect tumors in the foot and create 3D models via computed tomography (CT), as well as to produce biometric data. 1 039 CT images were obtained from a server. The parameters used were a collimation of 64 detectors, a scanning thickness of 0,5-3 mm, and a pixel size of 512 x 512, with a radiometric resolution of the 16-bit gray levels. Noise reduction, segmentation, and morphological analysis were performed on CT scans to detect bone tumors. In addition, this study used digital image processing techniques to create a virtual three-dimensional (3D) model of bone tumors. The performance of our proposal was evaluated by analyzing the receptor operating characteristics (ROC). According to the results, the sensitivity, specificity, and precision in tumor detection were 0,96, 1, and 0,98%, respectively, with a 0,99% average F-measure. Radiologist reports were used for the sake of comparison. The proposed technique for detecting bone tumors of the foot via CT can help radiologists with its increased precision, sensitivity, specificity, and F-measure. This method could improve the diagnosis of foot and ankle tumors by allowing for the multidirectional quantification of abnormalities.

A Comparative and Collaborative Study of the Hydrodynamics of Two Swimming Modes Applicable to Dolphins.

This paper presents a hydrodynamics study that examines the comparison and collaboration of two swimming modes relevant to the universality of dolphins. This study utilizes a three-dimensional virtual swimmer model resembling a dolphin, which comprises a body and/or caudal fin (BCF) module, as well as a medium and/or paired fin (MPF) module, each equipped with predetermined kinematics. The manipulation of the dolphin to simulate various swimming modes is achieved through the application of overlapping grids in conjunction with the parallel hole cutting technique. The findings demonstrate that the swimming velocity and thrust attained through the single BCF mode consistently surpass those achieved through the single MPF mode and collaborative mode. Interestingly, the involvement of the MPF mode does not necessarily contribute to performance enhancement. Nevertheless, it is encouraging to note that adjusting the phase difference between the two modes can partially mitigate the limitations associated with the MPF mode. To further investigate the potential advantages of dual-mode collaboration, we conducted experiments by increasing the MPF frequency while keeping the BCF frequency constant, thus introducing the concept of frequency ratio (β). In comparison to the single BCF mode, the collaborative mode with a high β exhibits superior swimming velocity and thrust. Although its efficiency experiences a slight decrease, it tends to stabilize. The corresponding flow structure indirectly verifies the favorable impact of collaboration.

Virtual Three-Dimensional Model Analysis in the Assessment of the Maxillary and Mandibular Donor Sites on Cone-Beam Computed Tomography Images.

Using the Mimics software to assess the maxillary and mandibular donor sites on cone-beam computed tomography (CBCT) images. This cross-sectional study was conducted on 80 CBCT scans. Data in DICOM format were transferred to the Mimics software version 21, and a maxillary and a mandibular mask according to cortical and cancellous bones were virtually created for each patient based on Hounsfield units (HUs). Three-dimensional models were reconstructed, and boundaries of donor sites, including mandibular symphysis, ramus, coronoid process, zygomatic buttress, and maxillary tuberosity, were defined. Virtual osteotomy was conducted on the 3D models to harvest bone. The volume, thickness, width, and length of harvestable bone from each site were quantified by the software. Data were analyzed by independent t-test, one-way ANOVA, and Tukey's test (alpha = 0.05). The greatest harvestable bone volume and length differences were observed between ramus and tuberosity (P < 0.001). The maximum and minimum harvestable bone volumes were found in symphysis (1753.54 mm3) and tuberosity (84.99 mm3). The greatest difference in width and thickness was noted between the coronoid process and tuberosity (P < 0.001) and symphysis and buttress (P < 0.001), respectively. Harvestable bone volume from tuberosity, length, width, volume from symphysis, and volume and thickness from the coronoid process was significantly greater in males (P < 0.05). The harvestable bone volume was the highest in symphysis, followed by ramus, coronoid, buttress, and tuberosity. The harvestable bone length and width were the highest in the symphysis and coronoid process, respectively. Maximum harvestable bone thickness was found in symphysis.

Parallel Evolution of Skull Form in Three Rodent Genera Inhabiting Steep Elevational Gradients of Ethiopian Highlands

Several rodent genera radiated in Ethiopian highlands during Pleistocene, giving rise to species specialized to different elevation zones. The zonation is accompanied by vegetation change from savannahs or forests in lower elevations, through the mid-elevation belt of ericaceous shrublands to Afroalpine moorlands on the mountain tops. Such evolution on elevation gradient is expected to promote phenotypic adaptations and several genera are known to include highly distinctive high-elevation specialists. In this study, we systematically examined shape and size differentiation of skull and mandible in three genera, Lophuromys, Arvicanthis and Stenocephalemys, each including from six to eight species inhabiting different elevation zones on both sides of the Great Rift Valley. Employing computed tomography, three-dimensional virtual models, landmark-based geometric morphometrics and a powerful toolkit of partial least squares analysis, we demonstrated the elevation-related differentiation is a prominent feature of skull and mandible shape variation in all three genera. We identified the parts of skull and mandible which change most between the successive zones. These include, notably, orbits and insertion areas of masticatory muscles, which suggests adaptive shifts in visual perception and diet. We also showed that while the same parts are modified in all three genera, they are modified in different ways and to a different degree. The evidence for size differentiation was mixed despite the universal trend of larger size in higher elevations. Our study confirms the high-elevation specialists represent the most distinctive forms, which is especially true for the species from Bale and Arsi Mountains, East of the Great Rift Valley.

Virtual 3D Tour: A User Experience for On-Campus Orientation

With Virtual Reality being adopted by almost all the world's social media giants, it is evident that it is the next best thing. Platforms like Facebook, Steam, and YouTube have worked on this technology to make their content creative and immersive for the user to experience the best. But unfortunately, the industries of Pakistan have still not explored or worked on this domain. Hence, I missed the chance to enjoy this sweet nectar of an opportunity introduced to the world for merely a decade. This paper introduces an immersive and three-dimensional Virtual Model of Sir Syed University of Engineering and Technology. The previous work on similar projects was discussed; in the methodology, the models were created using different 3D computer graphics software and toolsets, the development phase was done by using Unity Engine to make the model dynamic in nature, and then it was finally deployed into HTC Vive and allowing of the user to interact with the environment and move in 3D space by using two handheld controllers.

Three-dimensional Virtual Models of the Kidney with Colored Perfusion Regions: A New Algorithm-based Tool for Optimizing the Clamping Strategy During Robot-assisted Partial Nephrectomy

BackgroundAn empirical selective clamping strategy based on the direction of the arterial branches can lead to failures during partial nephrectomy, even when assisted by three-dimensional virtual models (3DVMs). ObjectiveTo develop and test new 3DVMs that include kidney perfusion regions and evaluate their intraoperative accuracy in guiding selective clamping and their impact on postoperative renal function. Design, setting, and participantsFor patients with a kidney suitable for nephron-sparing surgery, 3DVMs were supplemented with a Voronoi diagram, a Euclidean distance–based mathematical tool, to calculate vascular-dominant regions the kidney. Surgical procedureRobot-assisted partial nephrectomy guided by perfusion-region (PR)-3DVMs. MeasurementsAll anatomic information given by the PR-3DVMs was collected. Selective or superselective clamping was planned and performed intraoperatively when feasible under 3DVM assistance. Changes in split renal function (SRF) and estimated renal plasmatic flow (ERPF) were evaluated for 51 patients who underwent baseline and 3-mo postoperative renal scintigraphy. Results and limitationsA total of 103 patients were prospectively enrolled. The median number of kidney and tumor perfusion regions were 8 (interquartile range [IQR] 7–10) and 3 (IQR 2–3), respectively. A clampless, selective clamping, and global clamping strategy was applied in eight (7.8%), 79 (76.6%), and 16 (15.5%) cases, respectively, with no differences between planning and surgery in terms of the number or order of arteries clamped or the perfusion regions that underwent ischemia. Among the 51 patients who underwent renal scintigraphy, the mean SRF decreased by 11.3%, 7.7%, and 1.7% after global, selective, and superselective clamping, respectively (p = 0.004). Similar results were obtained for ERPF (18.9%, 9.9%, and 6.0%; p = 0.02). The main limitation is the need for a bioengineer to manually refine the 3DVMs. ConclusionsUse of mathematical algorithms for 3DVMs allows precise estimation of kidney perfusion regions to maximize the efficacy of selective clamping and minimize renal function impairment. Patient summaryThree-dimensional models that include regions of blood flow to the kidney can be used to guide clamping of blood vessels when part of the kidney is being surgically removed. More limited clamping can reduce damage to the remaining portion of the kidney and result in better recovery of kidney function after surgery.

Three-dimensional virtual models assistance predicts higher rates of "successful" minimally invasive partial nephrectomy: an Institutional analysis across the available trifecta definitions.

3D virtual models (3DVMs) are nowadays under scrutiny to improve partial nephrectomy (PN) outcomes. Five different Trifecta definitions have been proposed to optimize the framing of "success" in the PN field. Our aim is to analyze if the use of 3DVMs could impact the success rate of minimally invasive PN (mi-PN), according to the currently available definitions of Trifecta. At our Institution 250 cT1-2N0M0 renal masses patients treated with mi-PN were prospectively enrolled. Inclusion criteria were the availability of contrast-enhanced CT, baseline and postoperative serum creatinine, and eGFR. These patients were then compared with a control group of 710 patients who underwent mi-PN with the same renal function assessments, but without 3DVMs. Multivariable logistic regression (MLR) models were used to predict the trifecta achievement according to the different trifecta definitions. Among the definitions, Trifecta rates ranged between 70.8% to 97.4% in the 3DVM group vs. 56.8% to 92.8% in the control group (all p values < 0.05). 3DVMs showed better postoperative outcomes in terms of ΔeGFR, ( - 16.6% vs. - 2.7%, p = 0.03), postoperative complications (15%, vs 22.9%, p = 0.002) and major complications (Clavien Dindo > 3, 2.8% vs 5.6%, p = 0.03). At MLR 3DVMs assistance independently predicted higher rates of successful PN across all the available definitions of Trifecta (OR: 2.7 p < 0.001, OR:2.0 p = 0.0008, OR:2.8 p = 0.02, OR 2.0 p = 0.003). The 3DVMs availability was found to be the constant predictive factor of successful PN, with a twofold higher probability of achieving Trifecta regardless of the different definitions available in Literature.

Pediatric patient-specific three-dimensional virtual models for surgical decision making in resection of hepatic and retroperitoneal tumors.

Typically, preoperative imaging is viewed in two dimensions (2D) only, but three-dimensional (3D) virtual models may improve viewers' anatomical perspective by permitting them to interact with the imaging through manipulating it in space. Research into the utility of these models in most surgical specialties is growing rapidly. This study investigates the utility of 3D virtual models of complex pediatric abdominal tumors for clinical decision making, particularly the decision to proceed with surgical resection or not. 3D virtual models of tumors and adjacent anatomy were created from CT images of pediatric patients scanned for Wilms tumor, neuroblastoma or hepatoblastoma. Pediatric surgeons individually assessed the resectability of the tumors. First, they assessed resectability using the standard protocol of viewing imaging on conventional screens and then reassessed resectability after being presented with the 3D virtual models. Inter-physician agreement on resectability for each patient was analyzed using Krippendorff's alpha. Inter-physician agreement was used as a surrogate for correct interpretation. Participants were also surveyed afterward on the utility and practicality of the 3D virtual models for clinical decision making. Inter-physician agreement when using CT imaging alone was "fair" (Krippendorff's alpha α = 0.399), while inter-physician agreement when using 3D virtual models increased to "moderate" (Krippendorff's alpha α = 0.532). When surveyed about model utility, all 5 participants considered them helpful. Two participants felt the models would be practical for clinical use in most cases, while 3 felt they would be practical for select cases only. This study demonstrates the subjective utility of 3D virtual models of pediatric abdominal tumors for clinical decision making. The models are an adjunct that can be particularly useful in complicated tumors that efface or displace critical structures that may impact resectability. Statistical analysis demonstrates the improved inter-rater agreement with the 3D stereoscopic display over the 2D display. The use of 3D displays of medical images will increase over time, and evaluation of their potential usefulness in various clinical settings is necessary.

The Church of Pobeten in the XIV–XV centuries: historical and virtual reconstruction

The purpose of our work is to study the history and virtual reconstruction of the church of Pobeten, an object of historical and cultural heritage of the XIV-XV centuries. The method of analogy, creation of a digital model, photogrammetry, methods of historical informatics were used in the work. Special attention is paid to the history of the church of Pobeten and the work on creating its virtual copy. It describes working with various tools (Agisoft Metashape, Sculptris Alpha, Geomagic Studio and Sketch Up) to create photogrammetric and three-dimensional models of a historical object of the XIV century. The possibilities of using photogrammetry and three-dimensional modeling methods in the synthesis to create a virtual reconstruction of the Pobeten church are considered. The result of the work was the receipt of versatile historical data about the church of Pobeten and a virtual three-dimensional model based on them, which has the ability to edit: it can be supplemented with various elements, as well as integrated into larger works. The scope of application of the work and the results obtained can be historical local lore, preservation of objects of historical heritage, the use of the resulting product in museum installations. An interdisciplinary approach in historical research combined with computer science methods, specifically with three-dimensional computer modeling, provides exceptional opportunities, especially with the growth of information technology development, and is an actual tool of historical research in modern science.

The role of three-dimensional virtual models to plan a minimal surgical impact robot assisted partial nephrectomy for the treatment of small renal masses

The role of three-dimensional virtual models to plan a minimal surgical impact robot assisted partial nephrectomy for the treatment of small renal masses

Design and Research of Automatic Garment-Pattern-Generation System Based on Parameterized Design

Personalization in the apparel industry shows importance and the potential for demand, but the existing personalization has unreasonable time cost, labor cost, and resource waste. To solve the problems of the waste of resources as well as both time and labor cost caused by manual pattern making in clothing personalization, a method of automatic garment pattern generation based on a parametric formula and the Python language was proposed. Based on the classification of common curves in patterns, three curve fitting algorithms based on different parameters were derived and combined with the Python language to achieve personalized generation of different patterns by classifying the parameters in the system into key parameters, secondary parameters, and variable parameters. Three different methods for verifying the accuracy of the garment patterns were proposed based on curve fitting similarity and three-dimensional virtual modeling, and the accuracy of the proposed system was verified. The results show that the accuracy and comfort of the patterns generated via the system were high. Meanwhile, the Python-language-based system fits well with the production system of enterprises, which can improve the rapid response capability of garment personalization, greatly save the time cost and labor cost of enterprises, reduce resource loss, and contribute to the sustainable development of the garment industry.

Bone Grafting Can Promote the Prognosis of Displaced Femoral Neck Fractures: A Follow-up of the Clinical Significance of Bone Defects.

Femoral neck fractures (FNFs) comprise a large proportion of osteoporotic fractures in Asia. However, the full range of prognostic variables that affect prognosis remains unclear. Here, we aimed to determine whether the severity of bone defects at the fracture site and other variables impact the prognosis of displaced FNFs. We evaluated the incidence of FNF internal fixation failures at regular intervals after surgery in data collected retrospectively. Digital Imaging and Communications in Medicine (DICOM) magnetic resonance imaging data of the displaced FNFs of 204 patients (> 20 years old; mean age, 52.3 years; men, 55.4%) who underwent internal fixation were used to construct three-dimensional (3D) virtual models of the femoral neck region. We calculated the position and volume of bone defect (VBD) using our independently developed algorithm and Mimics software. Each participant was followed up for at least 24 months; complications were noted and correlated with VBD and demographic and clinical variables. On the basis of VBD values calculated from virtual reduction models, 57 patients were categorized as having a mild defect, 100 as having a moderate defect, and 47 as having a severe defect. Age (p = 0.046) and VBD (p < 0.001) were significantly correlated with internal fixation failure. Multivariate analysis revealed that severe bone defects were associated with internal fixation failure (adjusted odds ratio [aOR], 23.073; 95% confidence interval [CI], 2.791-190.732) and complications (aOR, 8.945; 95% CI, 1.829-43.749). In patients with a severe defect, bone grafting was inversely associated with internal fixation failure (aOR, 0.022; 95% CI, 0.002-0.268) and complications (aOR, 0.023; 95% CI, 0.002-0.299). Bone defect severity was associated with internal fixation failure and other complications. For young adults with large VBDs, bone grafting of the defect can reduce the risk of internal fixation failure. These results provide useful new quantitative information for precisely classifying displaced FNFs and guiding subsequent optimal treatments.

Three-dimensional of lingual arch form and creation of templates in Iraqi normal occlusion.

To evaluate the lingual dental arch form types in class I canine and molar relationship based on scanning dental cast models using three-dimensional laser scan and to give a new lingual arch form pattern created on this classification to be used for clinical submission by studying three-dimensional virtual models of the normal occlusion samples. Maxillary and mandibular casts of 120 young adults (18-24 ± 1.84 years) have normal occlusion that was scanned using a 3Shape E1 laser scanner, and then, the data were analyzed using SPSS software; then, we used K-means cluster to classify the arch form into clusters depending on the measurement of 10 landmarks designated on the lingual surface of the teeth. Many dental arch patterns have been established for both the mandible and the maxilla. The minimum sizes were found in the females, and the biggest sizes were found in the male subjects, and three sets were well defined for each sex; three categories for each mandible and maxilla are as follows: narrow, mid, and broad. The lingual arch form can be classified into three groups based on posterior and anterior dimensions, so a template of the three arch forms has been exemplified.

Virtual Fossils for Widening Geoeducation Approaches: A Case Study Based on the Cretaceous Sites of Figueira da Foz (Portugal) and Tamajón (Spain)

Accessible palaeontological sites conform highly adequate out-of-school environments for meaningful learning experiences regarding formal and non-formal teaching of geosciences. With a perspective of international cooperation, two correlative Cenomanian–Turonian (Upper Cretaceous) outcrops from the Iberian Peninsula have been chosen as the focus of this project—the sections of Figueira da Foz (Portugal) and Tamajón (Spain)—along with the Palaeontological and Archaeological Interpretation Centre of Tamajón (CIPAT). Virtualization of fossil samples and sites has been undertaken by means of phase-shift scanning, photogrammetry, and small object scanning by structured light and laser triangulation, resulting in three-dimensional virtual models of the main fossil tracks and invertebrate fossil samples. These virtual fossils have allowed the development of transdisciplinary didactic activities for different educational levels and the general public, which have been presented as file cards where the age of participants, objectives, multiple intelligences, European Union key competences, needed resources, development, and further observations are specified. This work aims to contribute to improving the design and development of didactic sequences for out-of-school education at these sites, organizing effective transdisciplinary teaching tools, and developing awareness, values, and responsibility towards geoheritage.

From Lecture Halls to Zoom Links: How Can Educational Theory Help Us to Deliver Effective and Engaging Teaching in an Online Environment?

Anatomical education has a long and colourful history, ranging from the anatomical theatre and artistic flourish of the renaissance period to modern-day virtual reality. Over the centuries, the body has been taken apart and mapped in exquisite detail. We are now able to access virtual models of the body anywhere, anytime, which allow for unlimited dissection and manipulation. Despite this progress, the majority of anatomical educators continue to deliver anatomy in a laboratory setting, using hands-on learning approaches such as dissection of cadaveric material. These methods are robustly supported by educational theories, such as information processing theory and experiential learning but require students to be present in a dissection room with access to human cadaveric material.The 2020 COVID-19 pandemic forced anatomy educators out of familiar dissection laboratories and into unfamiliar and uncomfortable virtual environments. When moving online during the pandemic, active learning theories, which form the basis of face-to-face classes, were used to construct interactive anatomy webinars to replace the on-campus practical laboratory-based teaching. The focus of these webinars was on student interactivity, and visual content with drawing activities, breakout groups, virtual three-dimensional models, and identifying activities being integrated into each session. Student feedback showed an appreciation of the interactive nature of these sessions, and staff were surprised at how well the webinars delivered engaging and interactive teaching at a time of limited social contact. This approach was not only useful during the restrictions of a pandemic but could offer a complementary approach to delivering practical anatomy teaching as we return to blended and on-campus learning again.

Validity and reliability of three-dimensional modeling of orthodontic dental casts using smartphone-based photogrammetric technology

The development of intraoral scanning technology has effectively enhanced the digital documentation of orthodontic dental casts. Albeit, the expense of this technology is the main limitation. The purpose of the present study was to assess the validity and reliability of virtual three-dimensional (3D) models of orthodontic dental casts, which were constructed using smartphone-based 3D photogrammetry. A smartphone was used to capture a set of two-dimensional images for 30 orthodontic dental casts. The captured images were processed to construct 3D virtual images using Agisoft and 3DF Zephyr software programs. To evaluate the accuracy of the virtual 3D models obtained by the two software programs, the virtual 3D models were compared with cone-beam computed tomography scans of the 30 dental casts. Colored maps were used to express the absolute distances between the points of each compared two surfaces; then, the means of the 100%, 95th, and 90th of the absolute distances were calculated. A Wilcoxon signed-rank test was applied to detect any significant differences. The differences between the constructed 3D images and the cone-beam computed tomography scans were not statistically significant and were accepted clinically. The deviations were mostly in the interproximal areas and in the occlusal details (sharp cusps and deep pits and fissures). This study found that smartphone-based stereophotogrammetry is an accurate and reliable method for 3D modeling of orthodontic dental casts, with errors less than the accepted clinically detectable error of 0.5 mm. Smartphone photogrammetry succeeded in presenting occlusal details, but it was difficult to accurately reproduce interproximal areas.