Investigating the effect of bruxism on maxillary arch length and width in children using three-dimensional digital model analysis

Background Bruxism is defined as repetitive jaw-muscle activity characterized by the grinding and clenching of teeth. The prevalence of bruxism in children is extensive, and it can cause irregularities in dental arches. The study aimed to investigate the presence of any effects of bruxism on maxillary arch length and width in children using three-dimensional (3D) digital model analysis. Method This study evaluated 30 children with bruxism. For every child with bruxism, a case control without bruxism was selected and matched for gender, age, and dentition. Digital models of the patients’ maxilla were obtained with a 3D intraoral scanner, and width and length measurements between the reference points on the maxilla were obtained on the digital models. Results The mean age of the study group was 9.13 ± 1.27. Insıgnificance differences were found between females and males within and between groups in terms of maxillary width and length. Insignificant difference was found between the control and study groups when the lengths of 3R-3L, 4R-4L, 5R-5L, 6R-6L, and IP-M were compared (p > 0.05). Conclusion Based on the study results, there were no differences in the maxillary arch length and width in patients with bruxism and patients without bruxism.

Validity and reliability of palatal rugae morphometric assessment with 3D laser scanned models

Aim: To assess the reliability and validity of morphometric features on 3D digital models produced by scanning maxillary dental casts of Malaysian Malay subjects. Methods: Dental casts of 20 subjects were scanned using a 3D laser scanner (Next Engine Inc., Santa Monica, California, USA). The palatal rugae morphometric features were assessed on the resulting 3D models using 3-Matic Research 9.0 software (Materialise NV, Heverlee, Belgium). The assessments were repeated by the first and second authors to assess the intra- and interexaminer reliability, respectively. Rugae morphometric features were also evaluated on the conventional plaster models to assess the validity of the 3D method. Results: Kappa values of the validity ranged from 0.807 to 0.922 for rugae shape, size category and direction. The intraclass correlation coefficient (ICC) for rugae number validity was 0.979. For intra-examiner reliability, kappa values ranged from 0.716-1.000 for rugae shape, size category and direction. The ICC for rugae number intra-examiner reliability was 0.949. Kappa values of interexaminer reliability for rugae shape, size category and direction were 0.723-885, while the ICC of rugae number was 0.896. Conclusion: Palatal rugae analyses on 3D digital models scanned by the 3D Next Engine laser scanner using 3-Matic Research 9.0 software are valid and reliable.

RESEARCH OF WAYS TO DEVELOP ACCURATE DIGITAL MODELS FOR OBJECTS AND NODES OF TRANSPORT INFRASTRUCTURE

The article solves the problem of finding a solution for building a digital model of the transport network or transport infrastructure object. On the basis of the analysis, the limitation of available solutions is given and the limited state of implementation of digital models in new modernizations of transport systems is fixed. The paper provides a general scheme of using documentation of the state of the transport system, nodes and elements and considers examples based on real transport systems. The paper examines the basic requirements for digital transport models and proposes a solution based on the use of unmanned aircraft systems. A model of formation of flight task variants is proposed and, as a proof of relevance of the research, the results of a real experiment are given. The task of modernizing a segment of the transport network of the city, the identification of the state of the site on the basis of data from unmanned aircraft system is considered. The article presents a solution to the problem, which has a high quality of building a digital model and the possibility of integration into other information systems for monitoring the condition and forecasting of development.

Accuracy of Master Casts Generated Using Conventional and Digital Impression Modalities: Part 1—The Half-Arch Dimension

Accurate impression-making is considered a vital step in the fabrication of fixed dental prostheses. There is a paucity of studies that compare the casts generated by various impression materials and techniques that are commonly used for the fabrication of provisional and definitive fixed prostheses. The aim of this study is to compare the accuracy of casts obtained using conventional impression and digital impression techniques. Thirty impressions were made for the typodont model (10 impressions each of polyvinyl siloxane, alginate, and alginate alternative materials). Ten digital models were printed from the same model using a TRIOS-3 3Shape intraoral scanner. Accuracy was assessed by measuring four dimensions (horizontal anteroposterior straight, horizontal anteroposterior curved, horizontal cross-arch, and vertical). A one-way ANOVA and Tukey’s test (α = 0.05) were used to analyze data. A statistically significant difference in the four dimensions of the stone casts and digital models was observed among the four groups (exception: between alginate alternative and 2-step putty–light body impression in the horizontal anteroposterior straight, horizontal anteroposterior curved, and horizontal cross-arch dimensions; between alginate and alginate alternative in the horizontal anteroposterior curved dimension; between alginate and 2-step putty–light body impression in the horizontal anteroposterior curved dimension; and between alginate alternative and digital in the vertical dimension). Polyvinyl siloxane had the highest accuracy compared to casts obtained from other impression materials and digital impressions.

DIGITAL MODELS OF STEADY MODES OF HEAT SUPPLY SYSTEMS BASED ON INVERSE CHARACTERISTICS

Methods and algorithms of digital models for describing and solving the calculation of steady-state hydraulic regimes of heat supply systems, a modified nodal model for calculating the flow distribution,using the method of a new approach to forming a system of equations of nodal heads, in which not direct, but inverse characteristics of passive and active elements of the pipeline network are used. The result of the analysis of the numerical efficiency of the contour and nodal models based on the developed information-graphic system is presented.

Accuracy of Dental Photography: Professional vs. Smartphone’s Camera

There is a scant literature on the accuracy of dental photographs captured by Digital Single-Lens Reflex (DSLR) and smartphone cameras. The aim was to compare linear measurements of plaster models photographed with DSLR and smartphone’s camera with digital models. Thirty maxillary casts were prepared. Vertical and horizontal reference lines were marked on each tooth, with exception to molars. Then, models were scanned with the TRIOS 3 Basic intraoral dental scanner (control). Six photographs were captured for each model: one using DSLR camera (Canon EOS 700D) and five with smartphone (iPhone X) (distance range 16-32 cm). Teeth heights and widths were measured on scans and photographs. The following conclusions could be drawn: (1) the measurements of teeth by means of DSLR and smartphone cameras (at distances of at least 24 cm) and scan did not differ. (2) The measurements of anterior teeth by means of DSLR and smartphone cameras (at all distances tested) and scan exhibited no difference. For documentational purposes, the distortion is negligeable, and both camera devices can be applied. Dentists can rely on DSLR and smartphone cameras (at distances of at least 24 cm) for smile designs providing comparable and reliable linear measurements.

THREE-DIMENSIONAL MODELING TECHNOLOGIES IN INDUSTRIAL DESIGN

Currently, specialists who use the skills of drawing, drawing, modeling and modeling in their work have largely begun to use the capabilities of computer technology and software. Working with digital models and three-dimensional modeling technologies are also within the competence of an industrial designer. This article att empts to make a selection of computer programs that are used in their work by industrial designers and classify the capabilities of this software according to its functional purpose. It is obvious that all the technologies of three-dimensional modeling listed in the article are very important for specialists engaged in technical aesthetics, artistic design, visualization, prototyping and prototyping of things.

Ecosistemas locales de aprendizaje ante la globalización tecnológica. Retos de los modelos educativos digitales pospandemia

La educación frente a la covid-19 ha puesto en práctica una infinidad de respuestas, todas urgentes, tentativas, generadas por ensayo y por error, y todavía pendientes de validación. Para comprender mejor el impacto de estas respuestas, el presente artículo defiende, partiendo de la teoría de los ecosistemas de aprendizaje, la necesidad de investigar cómo han influido las tecnologías de ámbito global en la construcción de experiencias locales de aprendizaje. Además, pone de manifiesto la necesidad de estudiar qué tipo de apoyo tanto teórico como práctico se requiere para reconducir los posibles efectos nocivos de la introducción de la tecnología de emergencia. A tal efecto, se describen las consecuencias de fenómenos globalizadores, como el tecnocentrismo, el solucionismo tecnológico, la plataformización y la economía de datos, proponiendo la reflexión, la concienciación para la transformación y la acción desde los ecosistemas locales de aprendizajes como vía imprescindible para la conceptualización de nuevos modelos educativos digitales pospandemia. El artículo también resume las aportaciones principales de los otros trabajos que forman parte de la monografía. Education has offered multiple, urgent, and tentative responses to Covid-19, generated by trial and error and still pending validation. To understand the impact of these responses, this article advocates for the study of how global technologies have influenced the pursuit of local learning experiences. In addition, the article emphasizes the need to investigate what kinds of theoretical and practical support are required to counterbalance the possible negative effects of emergency technology responses. Accordingly, it describes the consequences of globalizing phenomena, such as technocentrism, technological solutionism, platformization and data economy, and suggests that the reflection, critical consciousness engaged in transformation and action from within each local learning ecosystem are necessary to conceptualize new post-pandemic educational digital models. The article also summarizes the main contributions of the works included in this special issue.