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Intrusion with a three-piece arch is routinely achieved during orthodontic treatment. This study aimed to experimentally determine how the cantilever design influences the generated force system. Both straight and arch-formed cantilever designs: tip-back (TB), flat curve (FC) deep curve (DC), and 3 mm and 6 mm high utility arch (UA3; UA6) were activated for 5 mm and 10 mm. Force systems were determined by a hexapod. Typodonts simulating a three piece-intrusion arch were scanned using an intraoral scanner (3Shape, TRIOS, Denmark) before (T0) and after (T1) the experiment and superimposed with Mimics software (Materialise, Leuven, Belgium). Data were analyzed. All straight designs displayed an extrusive force in the vertical plane, and all arch-formed an intrusive force. DC and TB showed a retrusive force in the sagittal plane and UA6 a protrusive. For the medial/lateral forces, DC and TB displayed a medial, and UA6 a lateral force. Configurations can be distinctively ranked from DC, FC, TB to UA3, and UA6 according to the increasing protrusive nature of the generated sagittal forces. A DC or TB configuration should be used for intrusion and retraction, while for an intrusion and a protrusion, a UA6 configuration. All straight configurations showed a higher force level than the arch-formed configurations.
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http://dx.doi.org/10.3390/ma15144815 | DOI Listing |
Proc Natl Acad Sci U S A
September 2025
Department of Artificial Intelligence, Donders Center for Cognition, Radboud University, Nijmegen, GD 6525, Netherlands.
We present a geometric design rule for size-controlled clustering of self-propelled particles. We show that active particles that tend to rotate under an external force have an intrinsic, signed parameter with units of curvature which we call curvity, that can be derived from first principles. Experiments with robots and numerical simulations show that properties of individual robots (radius and curvity) control pair cohesion in a binary system, and the stability of flocking and self-limiting clustering in a swarm, with applications in metamaterials and in embodied decentralized control.
View Article and Find Full Text PDFPLoS Negl Trop Dis
September 2025
The Kirby Institute, University of New South Wales, Sydney, Australia.
Trachoma, caused by repeated ocular infection with Chlamydia trachomatis, remains a leading infectious cause of blindness globally, with significant implications for public health. The World Health Organization and partners aim to eliminate trachoma as a public health problem by 2030, targeting specific prevalence thresholds for trachomatous trichiasis (TT) and trachomatous inflammation-follicular (TF). Diagnosis is primarily clinical.
View Article and Find Full Text PDFPLoS Negl Trop Dis
September 2025
Swiss Tropical and Public Health Institute, Allschwil, Switzerland.
Background: Soil-transmitted helminth (STH) infections remain a public health problem in Uganda despite biannual national deworming campaigns implemented since the early 2000s. Recent surveys have indicated a heterogeneous STH infection prevalence, suggesting that the current blanket deworming strategy may no longer be cost-effective. This study identified infection predictors, estimated the geographic distribution of STH infection prevalence by species, and calculated deworming needs for school-age children (SAC).
View Article and Find Full Text PDFPLoS One
September 2025
China Institute of Sport Science, General Administration of Sport of China, Beijing, China.
Background: Golf is a sophisticated sport that integrates precision, skillfulness, and strategic thinking, with swing techniques of different clubs exhibiting distinct biomechanical characteristics. This study aims to investigate the biomechanical characteristics of golfers' full swings with different clubs from kinematic and dynamics perspectives, thereby providing insights for optimizing full swing techniques.
Methods: Ten low-handicap right-handed college male golfers were recruited, and their full swing parameters with the driver, 5-iron, and 7-iron (each club was successfully collected 10 times) were synchronously collected using a 250 Hz infrared motion capture system and a 1000 Hz three-dimensional force platform.
Med Sci Sports Exerc
September 2025
Department of Engineering Mechanics, Tsinghua University, Beijing, CHINA.
Purpose: Develop a musculoskeletal-environment interaction model to reconstruct the dynamic-interaction process in skiing.
Methods: This study established a skier-ski-snow interaction (SSSI) model that integrated a 3D full-body musculoskeletal model, a flexible ski model, a ski boot model, a ski-snow contact model, and an air resistance model. An experimental method was developed to collect kinematic and kinetic data using IMUs, GPS, and plantar pressure measurement insoles, which were cost-effective and capable of capturing motion in large-scale field conditions.