Cone beam computed tomography (CBCT) is a modern imaging technique that uses X-rays to investigate the structures of the dento-maxillary apparatus and obtain detailed images of those structures. The aim of this study was to determine a functional mathematical model able to evaluate the elastic force intensity on each bracket and tube type element and the ways in which those components act on the orthodontic system being used. To analyze a real orthodontic system, we studied the case of a 13-year-old female patient. To transfer geometric information from tomographic images, we used the InVesalius software. This software can generate three-dimensional reconstructions based on sequences and files in the DICOM format and was purchased from CBCT equipment. We analyzed and processed the geometries of the converted tissues in InVesalius using the Geomagic software. After using the Geomagic software, we exported the resulting model to the SolidWorks software used in computer-aided design. In this software, the model is transformed into a virtual solid. After making the geometric model, we analyzed the model using the Ansys Workbench software, which incorporates finite element analysis techniques. Following the simulations, we obtained result maps, which showed the complete mechanical behavior of the analyzed structures.

In the first stage of research, real bone components were analyzed to determine the main visual geometric shapes. After that, it was used a CT or MRI device to get parallel sections of studied bone components. In the third stage, the images were transferred to a 2D CAD software like AutoCAD, where the outer and inner contours of the bone were approximated by polygonal lines composed of multiple segments. To obtain virtual bones was used a parametric CAD software that allows defining models with a high degree of difficulty. The contours were transferred to a 3D CAD software, which, step by step, each section was used to define each virtual component of bone. For some components, such as vertebrae, bones of the jaw, the skull bones, was used in a preliminary model consists of curves in parallel planes. Based on this model can be defined the main curves for the final virtual 3D solid model. Also, were defined innovative orthopedic metal components as tibia nail, plates and screws or prosthetic elements. Were defined simulations to determine the behavior of the new orthopedic models through FEA method.

To generate a virtual human hip is a main goal for our research team. Also, starting from the normal virtual hip joint and using the important orthopedics information was defined the affected hip joint. All these models were generated in a 3D virtual environment starting with CT scanning images. Using an original method all the scanned CT images were re-defined and re-drawn and transferred to the 3D software. The resulted curves were used to generate the bones and the virtual complex system of both hip joints. With motion and geometric constrains the bio-mechanical assemblies were defined, starting from anatomical information. The normal hip joint and the model of the affected hip were defined and exported to ANSYS, software based on Finite element analysis.

The human skull and the maxillary bones have a very complicated architecture, determined by the outer walls, by the internal bone structures and their joining. In this paper CAD parametric software has been used to define complex virtual models. First, the mandible and jaw were defined using CT images. These images were imported into a CAD software using specific techniques and methods. These models have been finalized in SolidWorks where the virtual model of the studied system has been generated. Then, the virtual models were exported to a software for FEA simulation and prepared for every dentistry simulations. The structure of the maxillary bones contains spongy bone tissue, cortical bone tissue along with dental tissues. Each of these tissues have certain properties (elasticity, plasticity, density) assessed by flexibility. The analysis of the mechanical tension of the dental structures has been a subject of interest in recent years in order to determine the state of tension in the dental structures and to improve the mechanical strength of these structures. Such numerical techniques can give a better understanding of reactions and interactions of individual tissues. This involves a series of computational procedures to calculate stress in each element. Field variables can be interpolated by using form functions for scientific verification and validation of clinical assumptions. Various loadings have been applied to a personalized skull obtained from CT images using CAD techniques and procedures. On this system, FEM simulations were made and maps of stress, displacements and deformations were obtained that show the mechanical behavior of the maxillary dental system. Finally, important conclusions were highlighted.

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Performance-based research policies and programmes have fundamentally altered both organisational and individual behaviours and expectations, putting immense pressure on researchers. The soundness of research, originality, valorisation potential, and societal and economic impacts are highly valued and expected characteristics of research. Yet, our understanding of the effects of various systemic and organisational factors on research performance is limited. In an exploratory, single-country case, this paper aimed to develop and examine different models of research performance as perceived by researchers themselves using a large cross-disciplinary sample of 553 researchers from 72 public research organisations in Romania. A pre-tested questionnaire was self-administered online, comprising seven scales: (1) recruitment and selection, (2) research recognition and value, (3) participation in research projects and teams, (4) work incentives, (5) job payment and salary, (6) career development opportunities, and (7) leadership effectiveness. Maximum likelihood and Bayesian estimators were used to test three structural models: (M1) mono-factor; (M2) intercorrelated dimensions, and (M3) the dimensions are indicators of a general construct. Additionally, a path analysis was carried out to study the relationships among the dimensions. We found that M2 and M3 fit the empirical data better. The results showed that career development programmes and opportunities gain centrality in achieving research performance by directly influencing participation and research projects and teams and mediating the effect of job payment. Revealingly, powerful work incentives within research organisations are international mobilities or appreciation awards. When informing evidence-based policies, the models we propose could serve the goal of improving research performance through talent development as the main proxy.

Treatment of hip pathology has evolved over the last two centuries, ranging from rudimentary surgical procedures to modern hip arthroplasty, with an explosion marked in the last 30 years, considered to be one of the most successful surgeries to date. Hip arthroplasty is a permanent challenge due to the desire to discover the "supreme prosthesis", for which competition is still open. Hip disorders requiring prosthesis show a change in articular morphology. Among the most common medical conditions that have as final therapeutic solution hip arthroplasty are: coxarthrosis, both primary and secondary, followed by traumatic conditions: femoral neck collapse and femoral neck pseudarthrosis, aseptic head necrosis femoral stage III, as well as rheumatic coxitis from rheumatoid arthritis, ankylosing spondylitis or juvenile art. Endoprosthetic arthroplasty can be defined as an intervention of reconstructive surgery with bone sacrifice and prosthetic replacement of the articular components. It is, in the end, an operation aimed at restoring joint mobility and normal functioning of the muscles, ligaments and other periarticular structures that control joint movement. The materials initially used (glass, metal, plastic) did not have the desired bone strength and integration capacity. It followed the development of cemented implants, obtaining different types of cement with better and better quality. Problems arising from cemented arthroplasty (decimation, involving prosthetic revision) have led to a parallel development of the design and materials used for uncured prostheses with the possibility of very good integration of prosthetic material into the bone, raising them to the top of preferences in recent years. Treatment of hip pathology has evolved over the last two centuries, ranging from rudimentary surgical procedures to modern hip arthroplasty, with an explosion marked in the last 30 years, considered to be one of the most successful surgeries to date. The purpose of this study was to obtain the three-dimensional models of the hip joint and the prosthesis for the use of these models for various analyzes and virtual experiments. At the end of the paper important conclusions were drawn based on the results obtained in the simulations using the finite element method.

The subject of this paper permits the cooperation between many researchers which activate in different fields, which have the capacity to develop informational methods and technologies to solve difficult problems given by the complexity of the scientifically target. Using computer-aided design (CAD) and dynamic simulation programs was developed a virtual model of the cervical human spine that includes the main muscle groups simulated by springs with dynamic parameters, nonlinear and variable. Were studied the main types of movements (displacements) lateral bending (left-right) and flexion-extension movements.