Background: Hydrostatic pressure in the periodontal ligament (PDL) plays a critical role in orthodontic treatment, influencing tooth movement and remodeling of periodontal tissue. The relationship between alveolar cortical bone density and the risk of root resorption due to excessive stress in the PDL has not been clearly defined.
Objective: This study aimed to analyze hydrostatic pressure in the periodontal ligament of the tooth roots during en-masse retraction of the maxillary incisors using temporary skeletal anchorage devices (TISADs) after the first premolar extractions, as well as during full arch retraction.
Methods: A numerical model was used, varying the Young's modulus of cortical bone from 12.5 GPa to 27.5 GPa in increments of 3.0 GPa. Extreme values for bone stiffness were derived from the literature. In all the cases analyzed, the hook height was fixed at 6 mm, and the cranial surface was constrained.
Results: Doubling the stiffness of the cortical bone approximately reduced the hydrostatic pressure in the PDL by 1.5 times for both full-arch retraction and post-first premolar extraction retraction. A critical hydrostatic pressure of 4.7 kPa was exceeded in full-arch retraction for low Young's modulus of 12.5 Gpa values at forces as low as 600 g. On the contrary, for cortical bone with a high Young's modulus of 27.5 GPa, this critical pressure was reached only at forces around 960 g, approximately 1.6 times higher.
Conclusions: The density of the alveolar cortical bone significantly influences the hydrostatic pressure in the PDL of most tooth roots during orthodontic treatment. This parameter can be a critical factor in the risk of root resorption when optimal forces are exceeded. Further research is necessary to better understand these dynamics. Individual protocols for orthodontic treatment and CBCT imaging are necessary to minimize complications in the form of root resorption.
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http://dx.doi.org/10.3390/ma18040776 | DOI Listing |
Nephrol Ther
March 2025
Service de pédiatrie 1, Hôpital de Hautepierre, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
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Nat Commun
March 2025
Laboratory for Topological Quantum Matter and Advanced Spectroscopy, Department of Physics, Princeton University, Princeton, NJ, USA.
Transition metal dichalcogenides display a high technological potential due to their wide range of electronic ground states. Here, we unveil that by tuning hydrostatic pressure P, a cascade of electronic phase transitions can be induced in the few-layer transition metal dichalcogenide 1T'-WS. As P increases, we observe the suppression of superconductivity with the concomitant emergence of an anomalous Hall effect (AHE) at GPa.
View Article and Find Full Text PDFJ Chem Phys
March 2025
Laboratory of Optoelectronic Materials and Devices, School of Materials Science and Engineering, Guizhou Minzu University, Guiyang 550025, China.
In this work, the high-temperature and high-pressure ferroelectric, structural, and electrical transport properties for CuInP2Se6 upon compression and decompression under different hydrostatic environments were comprehensively studied via Raman spectroscopy, electrical conductivity, and high-resolution transmission electron microscopy observations. Upon non-hydrostatic pressurization, CuInP2Se6 experienced two successive phase transitions at 5.4 and 14.
View Article and Find Full Text PDFFront Cell Dev Biol
February 2025
Department of Radiation Oncology and Therapy, The First Hospital of Jilin University, Changchun, China.
Introduction: Glioblastoma (GBM) is the most malignant of the astrocytomas, primarily involving the cerebral hemispheres and cerebral cortex. It is one of the fatal refractory solid tumors with a 5-year survival rate of only 5% in adults. Cells in biological tissues are subjected to mechanical forces, including hydrostatic pressure, shear stress, compression and tension.
View Article and Find Full Text PDFACS Omega
March 2025
Jiangsu Haiwang Health Biotechnology Co., Ltd., Taizhou, Jiangsu 225300, China.
In this work, lactobionic acid production by SK17.001 and the variation of the cell envelope were studied after high hydrostatic pressure treatment. The production of lactobionic acid by the resting cells of SK17.
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