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Peet J. van der Vyver Farzana Paleker Martin Vorster Francois A. de Wet 《Journal of endodontics》2019,45(1):62-67
Introduction
The aim of this study was to evaluate the root canal shaping effect of instruments manufactured from nickel titanium, M-Wire, and Gold wire with different glide path preparation techniques.Methods
One hundred thirty-five mesiobuccal canals of extracted human maxillary molars were randomly divided into 3 equal groups (N = 45) for glide path preparation with K-files (KF) (Dentsply Sirona, Ballaigues, Switzerland), One G (OG) files (Micro-Mega, Besançon, France), and ProGlider (PG) files (Dentsply Sirona). Specimens of each glide path group were further divided equally into 3 groups for instrumentation with ProTaper Next (PTN, Dentsply Sirona), One Shape (OS, Micro-Mega), and WaveOne Gold (WOG, Dentsply Sirona) systems (n = 15). Micro–computed tomographic imaging was used to scan teeth before instrumentation and after shaping to compare centering ratio and canal transportation values at the apical, midroot, and coronal levels and the overall changes in canal volume. Data sets were statistically analyzed (analysis of variance and Kruskal-Wallis H tests).Results
The centering ratios for all groups were statistically similar at all levels. Apical canal transportation was significantly high for K/OS and K/PTN (P = .003). Midroot canal transportation was significantly high for K/PTN, K/OS, and OG/OS (P = .0003). Coronal canal transportation was significantly high for K/PTN and K/OS (P = .011). The highest change in canal volume was observed with all PTN groups and the lowest with PG/WOG (P = .06).Conclusions
WOG manufactured from Gold wire combined with PG showed better root canal shaping ability and removed less dentin from the canal walls. The nickel-titanium (OS) and M-Wire (PTN) instruments used in combination with KF significantly transported more canals. PTN removed the most dentin from the canal walls regardless of the GPP technique. 相似文献3.
Eleftherios G. Kaklamanos Miltiadis A. Makrygiannakis Athanasios E. Athanasiou 《Orthodontics & craniofacial research》2021,24(1):39-51
Immediately after the removal of orthodontic appliances, the teeth might start to drift away from their corrected position in an attempt to reach a new equilibrium. Medications and biologic factors could potentially modulate these processes. The objective of the present systematic review is to systematically investigate and appraise the quality of the evidence regarding the effect of various medications and biologic factors on the rate of relapse following active tooth movement. Search without restrictions in eight databases and hand searching until April 2020 were conducted. Studies performed on animal models investigating the effects of medication and biologic factors on the rate of relapse following orthodontic tooth movement were considered. Following study retrieval and selection, relevant data were extracted and the risk of bias was assessed. Seventeen studies were finally identified, mostly at either high or unclear risk of bias. Ketorolac did not show any significant effects on relapse, while the administration of tetracycline, atorvastatin, psoralen and raloxifene decreased it. Overall, the same result was observed with bisphosphonates with the exception of low dosage of risedronate, which did not have an effect. Osteoprotegerin and strontium resulted in reduced relapse, but not in the immediate post-administration period. Inconsistent or conflicting effects were noted after the use of simvastatin and relaxin. The quality of the available evidence was considered at best as low. It can be concluded that specific medications and biologic factors may have an effect on the rate of relapse following tooth movement. The orthodontist should be knowledgeable about the substances potentially affecting retention. 相似文献
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Rationale:The prone position is commonly used in spinal surgery. There have been many studies on hemodynamic changes in the prone position during general anesthesia. We report a rare case of transient left bundle branch block (LBBB) in a prone position.Patient concern:Electrocardiogram (ECG) of a 64-year-old man scheduled for spinal surgery showed normal sinus rhythm change to LBBB after posture change to the prone position.Diagnosis:Twelve lead ECG revealed LBBB. His coronary angio-computed tomography results showed right coronary artery with 30% to 40% stenosis and left circumflex artery with 40% to 50% stenosis. The patient was diagnosed with stable angina and second-degree atrioventricular block of Mobitz type II.Intervention:Nitroglycerin was administered intravenously during surgery. Adequate oxygen was supplied to the patient. After surgery, the patient was prescribed clopidogrel, statins, angiotensin II receptor blocker, and a permanent pacemaker was inserted.Outcome:Surgery was completed without complications. After surgery, the transient LBBB changed to a normal sinus rhythm. The patient did not complain of chest pain or dyspnea.Lesson:The prone position causes significant hemodynamic changes. A high risk of cardiovascular disease may cause ischemic heart disease and ECG changes. Therefore, careful management is necessary. 相似文献
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Akihisa Okumura Harushi Mori Pin Fee Chong Ryutaro Kira Hiroyuki Torisu Sawa Yasumoto Hiroyuki Shimizu Tsuguto Fujimoto Keiko Tanaka-Taya 《Brain & development》2019,41(5):443-451
Objecive
To clarify the neuroimaging findings of children with acute flaccid myelitis during an outbreak of EV-D68 infection.Methods
We performed a detailed review of the spinal and cranial MRI results of 54 children with acute flaccid myelitis. We focused on the range of longitudinal lesions, the localization and appearance of lesions within a horizontal section, Gadolinium-enhancement, and changes over time.Results
All children had longitudinal spinal lesions involving central gray matter. Twenty-six children had lesions spanning the entire spine. Six of them had weakness in all limbs, whereas seven had weakness of only one limb. Thirty-eight children had lesions in both gray and white matter and limb weakness tended to be more severe in these children. During the acute period, spinal lesions showed bilateral ill-defined widespread T2 hyperintensity. During the subacute period, lesions were well defined and confined to the anterior horn. The distribution of limb weakness was correlated with the appearance of lesions during the subacute period. Gadolinium enhancement was performed in 37 children, and enhancement was seen in the cauda equina in 29 children. Enhancement was infrequent within 2?days after onset but was seen in almost all children thereafter. Twenty-two children had brainstem lesions continuous with spinal lesions.Conclusion
Extensive longitudinal spinal lesions were characteristic in children with acute flaccid myelitis. Lesions were usually bilateral and widespread during the acute period, whereas localization to the anterior horn could become obvious. Although enhancement of the cauda equina was often observed, its appearance was sometimes delayed. 相似文献6.
《Journal of Medical Imaging and Radiation Sciences》2019,50(2):252-260
BackgroundThe main purpose of this study was to assess the structural changes in the bladder wall of prostate cancer patients treated with intensity-modulated radiation therapy using magnetic resonance imaging texture features analysis and to correlate image texture changes with radiation dose and urinary toxicity.MethodsEthical clearance was granted to enroll 33 patients into this study who were treated with intensity-modulated radiation therapy for prostate cancer. All patients underwent two magnetic resonance imagings before and after radiation therapy (RT). A total of 274 radiomic features were extracted from MR-T2W–weighted images. Wilcoxon singed rank-test was performed to assess significance of the change in mean radiomic features post-RT relative to pre-RT values. The relationship between radiation dose and feature changes was assessed and depicted. Cystitis was recorded as urinary toxicity. Area under receiver operating characteristic curve of a logistic regression–based classifier was used to find correlation between radiomic features with significant changes and radiation toxicity.ResultsThirty-three bladder walls were analyzed, with 11 patients developing grade ≥2 urinary toxicity. We showed that radiomic features may predict radiation toxicity and features including S5.0SumVarnc, S2.2SumVarnc, S1.0AngScMom, S0.4SumAverg, and S5. _5InvDfMom with area under receiver operating characteristic curve 0.75, 0.69, 0.65, 0.63, and 0.62 had highest correlation with toxicity, respectively. The results showed that most of the radiomic features were changed with radiation dose.ConclusionFeature changes have a good correlation with radiation dose and radiation-induced urinary toxicity. These radiomic features can be identified as being potentially important imaging biomarkers and also assessing mechanisms of radiation-induced bladder injuries. 相似文献
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目的 基于四维计算机X线断层扫描(Computed tomography,CT)血管成像(Dynamic four-dimensional CTA,4D-CTA)测量,计算颅内动脉瘤心动周期内膨胀率,探讨颅内动脉瘤破裂与膨胀率的相关性。方法 回顾性分析2018年5月-2020年5月就诊于哈尔滨医科大学附属第四医院微创神经外科一病区64例(其中未破裂动脉瘤24个,破裂动脉瘤40个)患者的完整资料; 所有患者均行4D-CTA扫描并重建图像; 依据动脉瘤破裂与否,患者分为未破裂组、破裂组; 将1个心动周期的图像数据分成20个阶段,判断动脉瘤是否存在异常搏动点; 同时记录和量化每个阶段动脉瘤的形态特征,计算其体积变化率(膨胀率); 分析动脉瘤破裂相关的危险因素。结果 未破裂组中男女患者比例差异不大; 破裂组女性患者则占70%,女性患者比例显著高于男性; 破裂组吸烟史的比例明显高于未破裂组; 破裂组瘤高(4.63±1.56)mm,瘤宽(4.72±3.68)mm,瘤颈宽(3.86±1.69)mm均大于未破裂组; 破裂组异常搏动点有29个(占72.5%)、膨胀率(14.56±6.25)%; 未破裂组异常搏动点13个(占54.2%)、膨胀率(10.21±3.26)%; 2组有明显差异(P<0.05)。此外,多因素Logistic回归分析显示动脉瘤破裂与吸烟史、纵横比、异常搏动点、膨胀率有关(P<0.05)。ROC分析中纵横比临界值为1.145(P=0.002),灵敏度为77.5%,特异性为58.3%; 存在异常搏动点与否的阈值为0.5(P=0.032),灵敏度为72.5%、特异性为45.8%; 膨胀率的临界值为9.775%(P=0.001),灵敏度为85.0%、特异性为54.2%。结论 借助4D-CTA能观察心动周期内颅内动脉瘤动态变化; 本研究成功量化了动脉瘤膨胀率,颅内动脉瘤破裂与膨胀率有关; 当膨胀率>9.775%,或纵横比>1.145,或存在异常搏动点时动脉瘤破裂风险将进一步增加。 相似文献
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The Polish dietary supplement market is growing steadily. However, even though these products may have an impact on health they are not as strongly regulated as pharmaceuticals. In 2016/17 the introduction of new regulations covering the marketing of dietary supplements in Poland was proposed. This article briefly describes the Polish market for dietary supplements and assesses the benefits and risks associated with its development. A range of potential legislative changes, such as a total ban on dietary supplements, a ban on using the images and recommendations of authoritative entities, increased fines for breaking the law, and other measures are under consideration. We describe the advantages (e.g., better customer protection, and the limitation of inappropriate, misleading advertising) and disadvantages (e.g., a decrease in product innovation, deterioration in product offerings, and rises in product prices) of the proposed changes. As a European Union member, Poland adopts EU law, but EU directives have only harmonized some issues relating to dietary supplement marketing, other key aspects remaining within the competence of member states, but it is noted that some proposed changes in Polish law (e.g., an advertising ban) are so strict that they are unlikely to be acceptable to the EU. 相似文献