Acquisition of a three-dimensional virtual model using popular cameras

Tooth wear is an unavoidable process associated with aging. Currently, virtual three-dimensional dental models are widely used and provide an advantage for studying tooth wear. However, there are no wear assessment parameters using virtual tooth models for the quantitative analysis of wear. Therefore, the aim of this study is to develop and evaluate quantitative wear measurement parameters. Ninety maxillary and mandibular dental casts were prepared and rendered as virtual three-dimensional models. For qualitative wear scoring, Hooper's new tooth wear index (NTWI) was used. For quantitative wear measurement, virtual vectors and occlusal planes were generated with reference points. Angles, height, and distance parameters were measured from reference points, vectors or planes. Intra- and interobserver reproducibility was determined for NTWI scoring and quantitative measurements. Quantitatively measurements for all parameters were subgrouped according to age groups and NTWI score groups. The mean and standard deviation were calculated for each group. One-way analysis of variance (ANOVA) test and the coefficients test were performed on the groups. Overall, intra- and interobserver reproducibility was good for both qualitative and quantitative measurement. In the ANOVA test, angle and height parameters showed significant differences between groups, whereas distance parameters did not. Similar results were observed in the coefficients test. However, plane heights and lingual side measurement parameters of the mandible are not recommended. In conclusion, this study indicates that all angle or height parameters of the maxilla and angle or vector height parameters of the buccal side of the mandible can be used as meaningful parameters in a quantitative wear study.

Objective To provide evidence of applied anatomy for the placement of pereutaneoas retrograde lag screws in the treatment of posterior column fractures of acetabulum. Methods Virtual three-dimensional models were reconstructed from computed tomography (CT) scans obtained from 60 adult patients without any bony problem. Virtual cylindrical implants were placed intraosscously into the posterior column of acetabulum. The maximum diameter, length and insertion direction were determined for screws.The distance between the insertion point (A) of virtual cylindrical implant and the distal end of the ischiadic tuberosity (B) was measured. In the same model, cross-sections of the pelvic posterior column was made at interval of 1 cm to measure their diameters. Results One hundred and twenty (58 male, 62 female) hemi-pelvic models were obtained. The mean maximum diameter of virtual cylindrical implant was 13. 16 ±1.45 mm and the mean angles to the transverse, coronal and sagittal planes were 72.02°± 6. 05°, 14. 71°±6. 98° and 8.61°±3.96° respectively. The insertion point was on the central line between the medial and lateral margins of ischiadic tuberosity. The distance between points A and B was 15.18 ± 1.97 mm. The smallest diameter of the posterior column was larger than the maximum diameter of the corresponding virtual cylindrical implant. Differences in the diameter, length, angle to sagittal plane of virtual cylindrical implant between the male and female were of statistical significance ( P ＜ 0. 001 ). Conclusions The posterior column can accommodate screws of 7.3 mm, but the insertion angle should vary from the male to female. The screw size for percutaneous fixation of posterior column fractures of aeetabulum should not be based solely on the measurement of cross-sectional diameter. Key words: Acetabulum; Fracture fixation, internal; Anatomy

Objective: The objective of this study was to relate the dimensions of the mandibular condyle with sex and age by means of three-dimensional models obtained by cone-beam computed tomography images (CBCT). Material and Methods: 120 CBCT examinations were selected belonging to the archives of the ICT-UNESP Clinic of Radiology. They were divided into five age groups, each containing 12 individuals of each sex. Virtual three-dimensional models were then created and two measurements from each mandibular condyle were taken: anteroposterior (AP) and mediolateral (ML). The t-test was used for independent samples to compare the measurements. Results: The AP measurements only of the left side showed a statistical difference between the sexes between 31 to 40 years of age; in the ML measurements, there were statistical differences between the sexes in all age groups on both sides, except in the age group above 60 years. Conclusion: The ML measurements of the mandibular condyles, regardless of side, showed significant statistical differences between sexes and age groups, with a tendency to greater values in males, and may be a determinant factor of sexual dimorphism.KeywordsX-Ray computed Tomography; Radiology; Sexual characteristics; Forensic anthropology; Forensic dentistry.

Clinical relevance Patients forget up to 80% of verbal communication. Visual aids improve understanding and information retention. A virtual, three-dimensional, interactive eye model (the One Right Eye model) is a new tool for eye care providers. The utility of three-dimensional models has been studied in other specialities, but never in ophthalmology. Background This study investigates whether the One Right Eye model improves patient satisfaction and understanding during ophthalmic outpatient appointments. Methods In a single-centre, open-label, randomised controlled trial, 92 patients were divided into two groups: a control group receiving a standard face-to-face consultation (n = 45) or an interventional group receiving the same consultation supplemented with a virtual eye model demonstration (n = 47). Key outcomes included patient satisfaction, understanding of their ocular condition, and rating of their explanation from their doctor. Results The interventional group rated their explanation from their doctor statistically significantly higher than the control group (89% versus 69% ‘very good’, p = 0.03). Trends also indicated improved understanding (81% versus 62%, ‘completely understood’, p = 0.05) and greater satisfaction (83% versus 69% ‘very satisfied’, p = 0.12) in the interventional group compared to controls. While the latter two results did not reach statistical significance, the data suggest clinical improvements. Conclusion The virtual three-dimensional eye model improved patients’ perception of their explanation from their doctor and likely improved patient satisfaction and understanding of their ophthalmic condition. The One Right Eye, a virtual eyeball model, shows promise to enhance ophthalmic communication.

Three-dimensional Augmented Reality–guided Robotic-assisted Kidney Transplantation: Breaking the Limit of Atheromatic Plaques

A detailed visualization of the interocclusal relationship is essential in a three-dimensional virtual planning setup for orthognathic and facial orthomorphic surgery. The purpose of this study was to introduce and evaluate the use of a wax bite wafer in combination with a double computed tomography (CT) scan procedure to augment the three-dimensional virtual model of the skull with a detailed dental surface. A total of 10 orthognathic patients were scanned after a standardized multislice CT scanning protocol with dose reduction with their wax bite wafer in place. Afterward, the impressions of the upper and lower arches and the wax bite wafer were scanned for each patient separately using a high-resolution standardized multislice CT scanning protocol. Accurate fitting of the virtual impressions on the wax bite wafer was done with surface matching using iterative closest points. Consecutively, automatic rigid point-based registration of the wax bite wafer on the patient scan was performed to implement the digital virtual dental arches into the patient's skull model (Maxilim, version 2.0; Medicim NV, St-Niklaas, Belgium). Probability error histograms showed errors of < or =0.16 mm (25% percentile), < or =0.31 mm (50% percentile), and < or =0.92 (90% percentile) for iterative closest point surface matching. The mean registration error for automatic point-based registration was 0.17 +/- 0.07 mm (range, 0.12-0.22 mm). The combination of the wax bite wafer with the double CT scan procedure allowed for the setup of an accurate three-dimensional virtual augmented model of the skull with detailed dental surface. However, from a clinical workload, data handling, and computational point of view, this method is too time-consuming to be introduced in the clinical routine.

Differences of percutaneous retrograde screw fixation of anterior column acetabular fractures between male and female: A study of 164 virtual three-dimensional models

Restoration of artifacts can cause secondary damage as restoration materials come directly in contact with the missing parts, and inappropriate restoration parts are unavoidably removed. However, restoration using three-dimensional (3D) digital technology can minimize the contact of restoration materials with artifacts and can facilitate the modification of restoration parts. In this study, virtual restoration modeling is performed based on 3D scanning of the severely damaged head of the Korean Stone Seated Bodhisattva sculpture. In addition, the restoration is completed using multiple 3D printing technologies. In particular, to examine the applicability of the assembly, 3D printing via material extrusion using the polylactide filament is applied to obtain production design mock-up results. 3D printing via photo polymerization using a liquid-type resin is utilized for the final restoration because it exhibits similar texture and color to the artifact. This study will greatly contribute to the improvement of the applicability of 3D printing for restoring damaged artifacts.

3D virtual models plus near-infrared fluorescence guidance for the best selective clamping strategy during robotic partial nephrectomy

Nowadays, there has been an increasing interest in the preservation of natural dentition and the proper occlusion related to tooth wear for quality of life. To overcome the problems of the existing qualitative tooth wear analysis method, virtual three-dimensional models have been used. This study was designed to develop and validate a new quantitative method using tooth wear measurement parameters with angles obtained from virtual vectors and planes of the three-dimensional models. Sixteen parameters were evaluated in the virtual models of 20 students (7.57±1.55 years old) and 20 adults (56.85±6.34 years old). There were 12 angle and 4 height parameters, and the number of parameters measured from the virtual planes and vectors were 10 and 6, respectively. For each parameter, means and standard deviations were calculated, and an unpaired sample t test was performed to compare the young and the adult groups. Also, differences between the means were determined and expressed as percentages. The results were statistically significant between the two groups (P<0.001). In general, parameters using virtual vectors showed greater change than virtual plane. Although there were statistically significant differences among all parameters using virtual planes (P<0.001), the changes of the three angles were similar, except distolingual cusp angle. It was found that the parameters using virtual vectors were effective and tooth wear took place in both buccal and lingual cusps. Likewise, the validation of the new measurement parameters suggests that they can also be applied in the assessment of tooth wear related to dental biomaterials.

This chapter presents a three-dimensional virtual reality model aimed at assisting the user to visually explore social network structures and relationships. The three-dimensional model uses a combination of nodes and paths to represent actors and the strength and direction of their relationships. Virtual reality provides the mechanism for manipulation of the developed model in real-time. The effectiveness of this visual tool is demonstrated empirically by having postgraduate students, organised into focus groups, engage in a social network analysis exercise with data collected in an academic work environment.

TEVAR (thoracic endovascular aortic repair) is the preferred approach for treating descending thoracic aortic aneurysm (DTAA). After the procedure, patients require lifelong CTA (computed tomography angiography) follow-up to monitor the aorta’s remodeling process and the possible development of associated complications. With CTA, the aorta is usually measured with maximum diameters taken at specific locations, and even in experienced centers, this type of evaluation is prone to inter-observer variability. We introduce a new volumetric analysis of aortic changes after TEVAR using three-dimensional (3D) anatomical models. We applied the volumetric analysis to 24 patients who underwent TEVAR for DTAA. For each patient, the descending thoracic aorta was evaluated using both the maximum diameter from CTA and the volume from 3D reconstructions, at discharge and 12 months after TEVAR. Both volume and diameter evaluations were then related to the development of TEVAR complications. The group with TEVAR-related complications showed a 10% volume increase in the descending aorta, while the group with no TEVAR-related complications only had a 1% increase. An increase of 40 mL in the descending aorta volume at 12 months seemed to be predictive of complications, with 94% specificity and 75% sensitivity. Volumetric analysis is a promising method for monitoring DTAA remodeling after TEVAR, and it may help in the early identification of high-risk patients who may benefit from a stricter follow-up, even if further evaluations on a larger sample size are required to confirm these preliminary results.

Diagnosis and treatment planning in surgical orthodontic therapy

Combined with virtual visualization technology, a modeling method is proposed for shipyard production resources. Aiming at the research on the representation method of target objects, texture processing is carried out, and a three-dimensional virtual model corresponding to the actual physical prototype is established. The completed model resources and material texture are managed through the model database to build a virtual visual shipyard environment and improve the management level of the shipyard.

Pediatric cardiovascular imaging plays an important role in the diagnosis, monitoring, and management of congenital and acquired heart diseases. Although echocardiography remains the most widely used modality in pediatric cardiology, cross-sectional imaging techniques such as cardiac magnetic resonance imaging (MRI) and computed tomography (CT) provide complementary anatomic and functional information. However, time-consuming diagnostic processes and patient-specific characteristics remain major limitations to early and precise diagnosis, as well as optimal clinical outcomes. With technological advancements, artificial intelligence (AI) has been increasingly integrated into cardiovascular magnetic resonance imaging (MRI) and computed tomography (CT) to enhance image acquisition, segmentation, interpretation, and diagnosis, and to facilitate predictive modeling of clinical outcomes. This review summarizes current and emerging AI applications in pediatric cardiovascular MRI and CT, emphasizing workflow optimization, diagnostic automation, and quantitative analysis. Emerging frontiers include multimodal data integration for risk stratification, clinical decision-making support, digital twin models, three-dimensional virtual modeling, and the application of computational fluid dynamics, as well as the potential of AI to improve access to care in low-resource settings.