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Numerous surgical techniques have been developed as effective means to facilitate orthodontic treatment, but they may cause significant postoperative discomfort. Piezocision was established as a flapless and minimally invasive technique to accelerate orthodontic tooth movement by combining small vertical incisions and piezoelectric corticotomies. Computed tomography is combined with the Piezocision technique to fabricate CAD/CAM surgical guides to prevent iatrogenic damage. A method to combine computer-assisted dynamic navigation with Piezocision is introduced here. CBCT was combined with motion-tracking technology to allow real-time tracing of the piezoelectric instruments during the surgical procedure. This technique delivers the location of the piezoelectric knife in regard to roots and important anatomical structures to increase the safety and accuracy during corticotimies. [ABSTRACT FROM AUTHOR]

Field-Road Trajectory Segmentation (FRTS) is one of the important tasks of agricultural machinery. A sequence of field-road segments of a trajectory can be automatically divided for the big data in precision agriculture. The parameter of the FRTS model can also determine the segmentation accuracy and precision. However, the traditional parameter selection cannot obtain the superior solution, limiting the segmentation performance of the model. Therefore, this study aims to investigate the performance improvement of the FRTS model from the perspective of parameter optimization. Two aspects were mainly contained as follows. Firstly, the metaheuristic algorithms were used to determine the parameter configuration of the model. The classification accuracy was considered as an objective to transform the parameter into a single-objective optimization. Specifically, the parameter structure of the model was abstracted as the searched individual of the optimization. The reasonable fitness function was set, according to the metrics of FRTS evaluation. Then, the fitness was used to evaluate the search of the individual in the solution space. The location of the searched individual was also continuously adjusted, according to the calculation rules of the optimization. As such, the global optimal parameter structure was achieved to converge. Secondly, a Multiplex Oscillation Slime Mould Algorithm (MOSMA) was proposed to realize the parameter optimization with the nonlinear characteristics and multiple locally optimal solutions. A dynamic guidance strategy was also established to adaptively change the individual movement for the better exploitation capability of the model, according to the search process of the population. Then, a strategy (called multivariate oscillation) was proposed to improve the segmentation performance and exploration capability of the model. Different search paths were utilized to produce multiple oscillations before the individual moves, and the priori rule was then to evaluate the qualities of paths. As such, the path with the highest quality was selected to move. The synergy of the two strategies enhanced the optimization capability of the model. Dynamic guidance and a multiplex oscillation strategy enhanced the oscillation contraction patterns of the slime mould and the process of the cytoplasm flows, thereby improving the optimization performance of the model. The experiments were also performed on real agricultural trajectory datasets with different sampling frequencies. A comparison was then made with the Grid Search (GS) and Particle Swarm Optimization (PSO) to validate the effectiveness of the model. The experiment results show that the new optimization effectively improved the accuracy and performance of the FRTS model using direction distribution (BDFRTS). The average accuracy of the MOSMA-BDFRTS on high-density trajectory data was increased by 25 percentage points and 28 percentage points compared with GS-BDFRTS and PSO-BDFRTS. MOSMA-BDFRTS achieved more competitive results on low-density trajectory data, whose average accuracy of segmentation was improved by 17 percentage points and 14 percentage points compared with GS-BDFRTS and PSO-BDFRTS. The proposed method provides a generalized parameter optimization solution for field-road trajectory segmentation models, and it can be applied directly to other types of model instances. The study also provides a reference for the research of the agricultural machinery movement trajectory segmentation technology. [ABSTRACT FROM AUTHOR]

Abstract Background The insertion of dental implants in the atrophic posterior maxilla can be a challenge. One option is to modify the residual native bone in preparation for proper, prosthetically-driven implant placement. The procedure presented in this study is called Navigated Antral Bone Expansion (N.A.B.E). This procedure employs the use of a navigation system to plan and guide the initial pilot drilling, bone expansion, final site preparation, and implant insertion. The aim of this study was to compare the distance between the alveolar ridge and the sinus floor measured before and after the surgery performed using the N.A.B.E. technique. Methods Thirty-seven partially edentulous patients who were candidates for implant supported restoration in the posterior maxilla, with a bone height ranging from 4 to 7 mm were enrolled. The N.A.B.E procedure was used to increase the bone height. Paired-samples t-test evaluated the distance between the alveolar ridge and the sinus floor measured before and after surgery. The occurrence of post-surgical complications, and the angular deviation between the planned osteotomy and the actual placed implant trajectories were evaluated. Results Out of the 37 consecutive patients enrolled in the study, 35 were considered in the data analyses. Patients’ bone height after surgery compared to the bone height before surgery showed a statistically significant increase (p

Using dynamical systems techniques, a new algorithm to direct the trajectory of gliders to a preassigned target point is proposed. The algorithm is applicable to any unpowered lift-enabled vehicle (glider) traveling in planetary atmospheres, locally determining the shortest path to the target point. The guidance commands are chosen taking into account the drag and lift coefficients of the glider, with a parameterization based on wind tunnel data. As a proof of concept, the new algorithm has been applied to the guidance of the Space Shuttle during its return flight to Earth. Numerical simulations over a wide range of parameter values have shown that the algorithm is resilient to changes in both the initial conditions and the atmospheric conditions. For a typical gliding flight in the Earth's atmosphere, from an altitude of 30 km down to 3 km, the margin of error for reaching the target ranges from 20 to 80 m. [ABSTRACT FROM AUTHOR]

This paper researched the relation of road conditions and time on the basis of people-machine-environmental coupling, and proposed a prediction method of time recursive to confirm the shortest time of route. This method was as an accumulated experience basing on the idea of supervised learning in artificial neural network, colligating with the difference of road conditions during different time section, the human factors function, and the randomness of the accident in course of driving, thus realized the guidance of the traffic route. Comparing with the real-time road conditions and accumulated experience, the method of time guidance prediction could offer real-time and effective road information for drivers. This guidance technology assists drivers to judge correctly in time and reduces the time losses because of the lack of the experience and the accidents. The guidance technology can be applied to the vehicles, which is with GPS. The example indicates that the model is effective combined with the real data. [ABSTRACT FROM AUTHOR]

Background: The insertion of dental implants in the atrophic posterior maxilla can be a challenge. One option is to modify the residual native bone in preparation for proper, prosthetically-driven implant placement. The procedure presented in this study is called Navigated Antral Bone Expansion (N.A.B.E). This procedure employs the use of a navigation system to plan and guide the initial pilot drilling, bone expansion, final site preparation, and implant insertion. The aim of this study was to compare the distance between the alveolar ridge and the sinus floor measured before and after the surgery performed using the N.A.B.E. technique. Methods: Thirty-seven partially edentulous patients who were candidates for implant supported restoration in the posterior maxilla, with a bone height ranging from 4 to 7 mm were enrolled. The N.A.B.E procedure was used to increase the bone height. Paired-samples t-test evaluated the distance between the alveolar ridge and the sinus floor measured before and after surgery. The occurrence of post-surgical complications, and the angular deviation between the planned osteotomy and the actual placed implant trajectories were evaluated. Results: Out of the 37 consecutive patients enrolled in the study, 35 were considered in the data analyses. Patients' bone height after surgery compared to the bone height before surgery showed a statistically significant increase (p <.0005) of 3.96 mm (95% CI, 3.62 mm to 4.30 mm). No post-operative complications were observed in the 35 patients. The mean angular deviation between the planned osteotomy trajectory and the placed implant trajectory ranged between 12.700 to 34.900 (mean 25.170 ± 5.100). Conclusions: This study provides evidence that N.A.B.E. technique is able to provide a significant bone increase, and could be considered an alternative method to the management of the atrophic posterior maxilla with a minimally invasive approach. [ABSTRACT FROM AUTHOR]

Background and Objective: The motor-imagery based brain-computer interface supplies a potential approach for motor-impaired patients, not only to control rehabilitation facilities but also to promote recovery from motor dysfunctions. To improve event-related desynchronization during motor imagery and obtain improved brain-computer interface classification accuracy, we introduce dynamic video guidance and complex motor tasks to the motor imagery paradigm., Methods: Eleven participants were included in the experiment; 64-channel electroencephalographic data were collected and analyzed during four motor imagery tasks with different guidance. Time-frequency analysis, spectral-time variation analysis, topographical distribution maps, and statistical analysis were utilized to analyze the event-related desynchronization patterns. Common spatial patterns were used to extract spatial pattern features and support vector machines were used to discriminate the offline classification accuracies in three bands (the alpha band, beta band, alpha and beta band) for comparison., Results: The experimental outcomes showed that complex motor imagery tasks coupled with dynamic video guidance induced significantly stronger event-related desynchronization than other paradigms, which use simple motor imagery tasks or static guidance. Similar results were obtained during analysis of the motor imagery brain-computer interface classification performance; namely, the highest average classification accuracy in complex and dynamic guidance was improved by approximately 14%, compared with static guidance. For individually specified paradigms, all participants obtained a classification accuracy that exceeded or was equal to 87.5%., Conclusions: This study provides an optional route to enhance the event-related desynchronization activities and classification accuracy of a motor imagery brain-computer interface through optimization of motor imagery tasks and instructive guidance., (Copyright © 2018 Elsevier Ltd. All rights reserved.)