The detection and correction of malocclusions and other dental abnormalities is a significant area of work in orthodontic diagnosis. To assess the quality of occlusion between the teeth the orthodontist has to estimate distances between specific points located on the teeth of both arches. Distance measuring is based on the observation, by the orthodontist, of a plaster model of the mouth. Gathering of information required to make the diagnosis is a time consuming and costly operation. On the other hand, obtaining and manipulation of plaster casts constitute a huge problem in clinics, due to both the large space needed and high costs associated with plaster casts manufacturing. For this problem we present a new system for three-dimensional orthodontic treatment planning and movement of teeth. We describe a computer vision technique for the acquisition and processing of three-dimensional images of the profile of hydrocolloids dental imprints taken by mean of a own developed 3D laser scanner. Profile measurement is based on the triangulation method which detects deformation of the projection of a laser line on the dental imprints. The system is computer-controlled and designed to achieve depth and lateral resolutions of 0.1 mm and 0.2 mm, respectively, within a depth range of 40 mm. The developed diagnosis software system (named MAGALLANES) and the 3D laser scanner (named 3DENT) are both commercially available and have been designed to replace manual measurement methods, which use costly plaster models, with computer measurements methods and teeth movement simulation using cheap hydrocolloid dental wafers. This procedure will reduce the cost and acquisition time of orthodontic data and facilitate the conduct of epidemiological studies.
Download full-text PDF |
Source |
---|
Sci Rep
January 2025
College of Geosciences and Engineering, North China University of Water Resources and Electric Power, Zhengzhou, 450046, China.
The failure of locked-segment landslides is associated with the destruction of locked segments that exhibit an energy accumulation effect. Thus, understanding their failure mode and instability mechanism for landslide hazard prevention and control is critical. In this paper, multiple instruments, such as tilt sensors, pore water pressure gauges, moisture sensors, matrix suction sensors, resistance strain gauges, miniature earth pressure sensors, a three-dimensional (3D) laser scanner, and a camera, were used to conduct the physical model tests on the rainfall-induced arch locked-segment landslide to analyze the resulting tilting deformation and evolution mechanism.
View Article and Find Full Text PDFSensors (Basel)
January 2025
Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20878, USA.
Terrestrial laser scanners (TLS) are portable dimensional measurement instruments used to obtain 3D point clouds of objects in a scene. While TLSs do not require the use of cooperative targets, they are sometimes placed in a scene to fuse or compare data from different instruments or data from the same instrument but from different positions. A contrast target is an example of such a target; it consists of alternating black/white squares that can be printed using a laser printer.
View Article and Find Full Text PDFSensors (Basel)
January 2025
School of Environment and Spatial Informatics, China University of Mining and Technology, Xuzhou 221000, China.
In recent years, mobile laser measurement systems have markedly enhanced the capabilities of deformation detection and defect identification within metro tunnels, attributed to their superior efficiency, precision, and versatility. Nevertheless, challenges persist, including substantial equipment costs, inadequate after-sales support, technological barriers, and limitations in customization. This paper develops a mobile laser measurement system that has been specifically developed for the purpose of detecting deformation in metro tunnels.
View Article and Find Full Text PDFSensors (Basel)
January 2025
InViLab, Department of Electromechanical Engineering, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
Laser-based systems, essential in diverse applications, demand accurate geometric calibration to ensure precise performance. The calibration process of the system requires establishing a reliable relationship between input parameters and the corresponding 3D description of the outgoing laser beams. The quality of the calibration depends on the quality of the dataset of measured laser lines.
View Article and Find Full Text PDFMicromachines (Basel)
January 2025
Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
This paper presents, for the first time, a rotary actuator functionalized by an inclined disc rotor that serves as a distal optical scanner for endoscopic probes, enabling side-viewing endoscopy in luminal organs using different imaging/analytic modalities such as optical coherence tomography and Raman spectroscopy. This scanner uses a magnetic rotor designed to have a mirror surface on its backside, being electromagnetically driven to roll around the cone-shaped hollow base to create a motion just like a precessing coin. An optical probing beam directed from the probe's optic fiber is passed through the hollow cone to be incident and bent on the back mirror of the rotating inclined rotor, circulating the probing beam around the scanner for full 360° sideway imaging.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!