108 research outputs found

    The EDA/EDAR/NF-κB pathway in non-syndromic tooth agenesis: A genetic perspective

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    Non-syndromic tooth agenesis (NSTA) is one of the most common dental developmental malformations affected by genetic factors predominantly. Among all 36 candidate genes reported in NSTA individuals, EDA, EDAR, and EDARADD play essential roles in ectodermal organ development. As members of the EDA/EDAR/NF-κB signaling pathway, mutations in these genes have been implicated in the pathogenesis of NSTA, as well as hypohidrotic ectodermal dysplasia (HED), a rare genetic disorder that affects multiple ectodermal structures, including teeth. This review provides an overview of the current knowledge on the genetic basis of NSTA, with a focus on the pathogenic effects of the EDA/EDAR/NF-κB signaling pathway and the role of EDA, EDAR, and EDARADD mutations in developmental tooth defects. We also discuss the phenotypic overlap and genetic differences between NSTA and HED. Ultimately, this review highlights the importance of genetic analysis in diagnosing and managing NSTA and related ectodermal disorders, and the need for ongoing research to improve our understanding of these conditions

    The effect of capsaicin on expression patterns of CGRP in trigeminal ganglion and trigeminal nucleus caudalis following experimental tooth movement in rats

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    Objectives The aim of this study was to explore the effect of capsaicin on expression patterns of calcitonin gene-related peptide (CGRP) in the trigeminal ganglion (TG) and trigeminal subnucleus caudalis (Vc) following experimental tooth movement. Material and Methods Male Sprague-Dawley rats were used in this study and divided into small-dose capsaicin+force group, large-dose capsaicin+force group, saline+force group, and no force group. Closed coil springs were used to mimic orthodontic forces in all groups except for the no force group, in which springs were inactivated. Capsaicin and saline were injected into periodontal tissues. Rats were euthanized at 0 h, 12 h, 1 d, 3 d, 5 d, and 7 d following experimental tooth movement. Then, TG and Vc were obtained for immunohistochemical staining and western blotting against CGRP. Results Immunohistochemical results indicated that CGRP positive neurons were located in the TG, and CGRP immunoreactive fibers were distributed in the Vc. Immunohistochemical semiquantitative analysis and western blotting analysis demonstrated that CGRP expression levels both in TG and Vc were elevated at 12 h, 1 d, 3 d, 5 d, and 7 d in the saline + force group. However, both small-dose and large-dose capsaicin could decrease CGRP expression in TG and Vc at 1 d and 3 d following experimental tooth movement, as compared with the saline + force group. Conclusions These results suggest that capsaicin could regulate CGRP expression in TG and Vc following experimental tooth movement in rats

    The effect of flow resistance on water saturation profile for transient two-phase flow in fractal porous media

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    Due to the rapid development of Micro-Electro-Mechanical System, more and more attention has been paid to the fluid properties of porous media, which is significant for petroleum engineering. However, most of surfaces of pores and capillaries in porous media are rough. On the approximation that porous medium consists of a bundle of tortuous and rough capillaries, a Buckley-Leverett conceptual model with considering flow resistance is developed based on the fractal geometry theory, which is beneficial to predict water saturation profile in porous medium. The proposed Buckley-Leverett solution is a function of fractal structural parameters (such as pore fractal dimension, tortuosity fractal dimension, maximum and minimum diameters of capillaries), fluid properties (such as viscosity, contact angle and interfacial tension) and pore structure parameter (relative roughness) in fractal porous medium. Besides, the relationship between water saturation and distance is presented according to Buckley-Leverett solution. The impaction of flow resistance on water saturation profile is discussed.Cited as: Lu, T., Li, Z., Lai, F., Meng, Y., Ma, W. The effect of flow resistance on water saturation profifile for transient two-phase flow in fractal porous media. Advances in Geo-Energy Research, 2018, 2(1): 63-71, doi: 10.26804/ager.2018.01.0

    Finite element analysis of rapid canine retraction through reducing resistance and distraction

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    Objective: The aims of this study were to compare different surgical approaches to rapid canine retraction by designing and selecting the most effective method of reducing resistance by a three-dimensional finite element analysis. Material and Methods: Three-dimensional finite element models of different approaches to rapid canine retraction by reducing resistance and distraction were established, including maxillary teeth, periodontal ligament, and alveolar. The models were designed to dissect the periodontal ligament, root, and alveolar separately. A 1.5 N force vector was loaded bilaterally to the center of the crown between first molar and canine, to retract the canine distally. The value of total deformation was used to assess the initial displacement of the canine and molar at the beginning of force loading. Stress intensity and force distribution were analyzed and evaluated by Ansys 13.0 through comparison of equivalent (von Mises) stress and maximum shear stress. Results: The maximum value of total deformation with the three kinds of models occurred in the distal part of the canine crown and gradually reduced from the crown to the apex of the canine; compared with the canines in model 3 and model 1, the canine in model 2 had the maximum value of displacement, up to 1.9812 mm. The lowest equivalent (von Mises) stress and the lowest maximum shear stress were concentrated mainly on the distal side of the canine root in model 2. The distribution of equivalent (von Mises) stress and maximum shear stress on the PDL of the canine in the three models was highly concentrated on the distal edge of the canine cervix. . Conclusions: Removal of the bone in the pathway of canine retraction results in low stress intensity for canine movement. Periodontal distraction aided by surgical undermining of the interseptal bone would reduce resistance and effectively accelerate the speed of canine retraction

    Synthesis, Elasticity, and Spin State of an Intermediate MgSiO3‐FeAlO3 Bridgmanite: Implications for Iron in Earth’s Lower Mantle

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    Fe‐Al‐bearing bridgmanite may be the dominant host for ferric iron in Earth’s lower mantle. Here we report the synthesis of (Mg0.5Fe3+0.5)(Al0.5Si0.5)O3 bridgmanite (FA50) with the highest Fe3+‐Al3+ coupled substitution known to date. X‐ray diffraction measurements showed that at ambient conditions, the FA50 adopted the LiNbO3 structure. Upon compression at room temperature to 18 GPa, it transformed back into the bridgmanite structure, which remained stable up to 102 GPa and 2,600 K. Fitting Birch‐Murnaghan equation of state of FA50 bridgmanite yields V0 = 172.1(4) Å3, K0 = 229(4) GPa with K0′ = 4(fixed). The calculated bulk sound velocity of the FA50 bridgmanite is ~7.7% lower than MgSiO3 bridgmanite, mainly because the presence of ferric iron increases the unit‐cell mass by 15.5%. This difference likely represents the upper limit of sound velocity anomaly introduced by Fe3+‐Al3+ substitution. X‐ray emission and synchrotron Mössbauer spectroscopy measurements showed that after laser annealing, ~6% of Fe3+ cations exchanged with Al3+ and underwent the high‐ to low‐spin transition at 59 GPa. The low‐spin proportion of Fe3+ increased gradually with pressure and reached 17–31% at 80 GPa. Since the cation exchange and spin transition in this Fe3+‐Al3+‐enriched bridgmanite do not cause resolvable unit‐cell volume reduction, and the increase of low‐spin Fe3+ fraction with pressure occurs gradually, the spin transition would not produce a distinct seismic signature in the lower mantle. However, it may influence iron partitioning and isotopic fractionation, thus introducing chemical heterogeneity in the lower mantle.Plain Language SummaryFe‐Al‐bearing bridgmanite may be the dominant mineral in the lower mantle, which occupies more than half of Earth’s volume. A subject of much debate is whether spin transition of Fe in bridgmanite produces an observable influence on the physics and chemistry of the lower mantle. In this study, we synthesized a new (Mg0.5Fe3+0.5)(Al0.5Si0.5)O3 bridgmanite with the highest Fe3+‐Al3+ coupled substitution known to date. We studied its structure, elasticity, and spin state by multiple experimental and theoretical methods. The high Fe content allowed us to better resolve a pressure‐induced spin transition of Fe3+ caused by Fe‐Al cation exchange at high temperature. Our results suggest that the spin transition is enabled by cation exchange but has a minor effect on the seismic velocity, although it may introduce chemical heterogeneity in the lower mantle. Our study helps resolve existing discrepancies on the nature of spin transition of Fe‐Al bridgmanite and its influence on the physics and chemistry of the lower mantle.Key PointsBridgmanite may contain 50% trivalent cations through Fe3+‐Al3+ coupled substitutionThe bulk sound velocity of (Mg0.5Fe3+0.5)(Al0.5Si0.5)O3 bridgmanite is 7.7% lower than MgSiO3Through Fe‐Al cation exchange, Fe3+ in (Mg0.5Fe3+0.5)(Al0.5Si0.5)O3 bridgmanite undergoes gradual spin transition at lower mantle conditionsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156245/3/jgrb54280-sup-0001-2020JB019964-SI.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156245/2/jgrb54280.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156245/1/jgrb54280_am.pd

    The effect of antibiotics on the periodontal treatment of diabetic patients with periodontitis: A systematic review and meta-analysis

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    Background: The aim of this meta-analysis was to compare the effects of periodontal treatment with or without adjunctive antibiotic on periodontal status and blood glucose level in diabetic patients with periodontitis.Methods: A search using electronic database (MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials) and a manual search were performed up to July 2022. Eligible 13 RCTs were included according to inclusion and exclusion criteria. Reviewers independently performed data screening, data selection, data extraction, and risk of bias. Quality assessment was performed according to the Cochrane Handbook for Systematic Reviews of Interventions. Weighted mean differences and 95% confidence intervals (CIs) for continuous outcomes were calculated using random or fixed-effects models. This review is registered in the PROSPERO database (CRD42022347803).Results: Of the 13 included articles, eight were on the use of systemic antibiotics and five on topical antibiotics. The results showed statistically significant improvement in periodontal status (probing depth, clinical attachment loss and bleeding on probing) at 6 months with systematic antibiotics use (PD-6M p = 0.04, BOP-6M p < 0.0001, CAL-6M p = 0.002). The improvement in PD with topical antibiotics was statistically significant at 1 month (p = 0.0006). However, there was no statistically significant improvement in periodontal status at 3 months with adjuvant systemic antibiotics.Conclusion: Antibiotics can improve the periodontal condition of diabetic patients with periodontitis to a certain extent. In clinical practice, it is necessary to comprehensively consider the balance of benefits and risks before deciding whether to use antibiotics.Systematic Review Registration: Identifier CRD42022347803, https://www.crd.york.ac.uk/PROSPERO/
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