A Complete Digital Workflow for Planning, Simulation, and Evaluation in Orthognathic Surgery

The purpose of this study was to develop a complete digital workflow for planning, simulation, and evaluation for orthognathic surgery based on 3D digital natural head position reproduction, a cloud-based collaboration platform, and 3D landmark-based evaluation. We included 24 patients who underwent bimaxillary orthognathic surgery. Surgeons and engineers could share the massive image data immediately and conveniently and collaborate closely in surgical planning and simulation using a cloud-based platform. The digital surgical splint could be optimized for a specific patient before or after the physical fabrication of 3D printing splints through close collaboration. The surgical accuracy was evaluated comprehensively via the translational (linear) and rotational (angular) discrepancies between identical 3D landmarks on the simulation and postoperative computed tomography (CT) models. The means of the absolute linear discrepancy at eight tooth landmarks were 0.61 ± 0.55, 0.86 ± 0.68, and 1.00 ± 0.79 mm in left–right, advance–setback, and impaction–elongation directions, respectively, and 1.67 mm in the root mean square direction. The linear discrepancy in the left–right direction was significantly different from the other two directions as shown by analysis of variance (ANOVA, p < 0.05). The means of the absolute angular discrepancies were 1.43 ± 1.06°, 0.50 ± 0.31°, and 0.58 ± 0.41° in the pitch, roll, and yaw orientations, respectively. The angular discrepancy in the pitch orientation was significantly different from the other two orientations (ANOVA, p < 0.05). The complete digital workflow that we developed for orthognathic patients provides efficient and streamlined procedures for orthognathic surgery and shows high surgical accuracy with efficient image data sharing and close collaboration.

Evaluation of the Local Geodetic Network in Jurmala City

In order to evaluate the accuracy of the local geodetic network of Jurmala City, in research, comparison of forty-seven selected polygonometry network point coordinates with the obtained data was made by performing measurements by real time cinematic (RTK) method in LatPos base station system. Points were chosen so in order to cover evenly the entire territory of the city. At present, gradual renewal and improvement of the local geodetic network takes place in Jurmala. The linear discrepancy of coordinates obtained in measurements varies from 0.016 m to 0.259 m, mean linear discrepancy in the measured points is fixed 0.110 m. Discrepancy of plane coordinates in different regions of Jurmala is not even. It is rather even within approximate boundaries of the determined regions, this is indicated by different directions of offset vectors, which in eastern part of the city are pointed mainly in NW direction, in central part directions are pointed in W direction, but in the western part of the city pointed in NE direction. Concerning heights, only for 3 of measured points discrepancy exceeds 0.05 m error and there are no connection concerning some specific region. 15% of the measured points of the local geodetic network are with appropriate accuracy of plane coordinates. The linear discrepancy of plane coordinates for points of the local geodetic network, which are measured by RTK method and compared with data from the improved network is 0.024 (m), which indicates the high accuracy of RTK method in measurement data. In Jurmala City, obtaining of data by GNNS data receivers is encumbered by large density of trees. Therefore the local geodetic network in city has very important role in order to ensure performance of geodetic measurements of high quality in the territory of the city. Aim of the research is to evaluate the accuracy of the local geodetic network of Jurmala City. The following tasks have been set for achieving the aim: research of the given problem, visit of the local geodetic network points, performing control measurements, data processing and analysis.

Discussion of Shared Information Can Increase the Influence of Divergent Members

Based on the theoretical frameworks of information-sharing in groups and the linear discrepancy model, this study highlights the importance of communicating shared information for a divergent member to influence a group. Participants received information concerning whether “under God” should be in the Pledge of Allegiance. After stating individual opinions, they discussed the issue in small groups and came to a group decision on a continuous, ordered scale. Low divergent members, who had opinions closer to the average of other group members, had more influence than high divergent members. Group members with high divergence were more confident and talked more than others. However, there was no relationship between the amount divergent members talked or their confidence level and their amount of influence. Highly divergent group members who mentioned more shared information were more influential and came across as more knowledgeable.