Illustrated Questions in Orthodontics

Author(s):  
Claire Nightingale ◽  
Jonathan Sandy

Illustrated Questions in Orthodontics takes a problem-based approach to orthodontics, offering a unique resource for undergraduate dentists. This book contains a comprehensive set of questions mapped to undergraduate orthodontics curricula, including chapters on examination and diagnosis, treatment planning, pathology, appliances, and anchorage. Each chapter is packed with high-quality clinical photographs and x-rays to help readers to test their skills in identifying and describing various orthodontic problems and presentations. Furthermore, every question is answered with extensive feedback, setting each topic in a clinical context in order to teach as well as test. The ideal revision resource for undergraduate dentists looking to test and consolidate their knowledge ahead of placements and exams, Illustrated Questions in Orthodontics will also form a useful tool for postgraduate dentists and orthodontic therapists.

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4554
Author(s):  
Ralph-Alexandru Erdelyi ◽  
Virgil-Florin Duma ◽  
Cosmin Sinescu ◽  
George Mihai Dobre ◽  
Adrian Bradu ◽  
...  

The most common imaging technique for dental diagnoses and treatment monitoring is X-ray imaging, which evolved from the first intraoral radiographs to high-quality three-dimensional (3D) Cone Beam Computed Tomography (CBCT). Other imaging techniques have shown potential, such as Optical Coherence Tomography (OCT). We have recently reported on the boundaries of these two types of techniques, regarding. the dental fields where each one is more appropriate or where they should be both used. The aim of the present study is to explore the unique capabilities of the OCT technique to optimize X-ray units imaging (i.e., in terms of image resolution, radiation dose, or contrast). Two types of commercially available and widely used X-ray units are considered. To adjust their parameters, a protocol is developed to employ OCT images of dental conditions that are documented on high (i.e., less than 10 μm) resolution OCT images (both B-scans/cross sections and 3D reconstructions) but are hardly identified on the 200 to 75 μm resolution panoramic or CBCT radiographs. The optimized calibration of the X-ray unit includes choosing appropriate values for the anode voltage and current intensity of the X-ray tube, as well as the patient’s positioning, in order to reach the highest possible X-rays resolution at a radiation dose that is safe for the patient. The optimization protocol is developed in vitro on OCT images of extracted teeth and is further applied in vivo for each type of dental investigation. Optimized radiographic results are compared with un-optimized previously performed radiographs. Also, we show that OCT can permit a rigorous comparison between two (types of) X-ray units. In conclusion, high-quality dental images are possible using low radiation doses if an optimized protocol, developed using OCT, is applied for each type of dental investigation. Also, there are situations when the X-ray technology has drawbacks for dental diagnosis or treatment assessment. In such situations, OCT proves capable to provide qualitative images.


2004 ◽  
Vol 37 (6) ◽  
pp. 901-910 ◽  
Author(s):  
C. Seitz ◽  
M. Weisser ◽  
M. Gomm ◽  
R. Hock ◽  
A. Magerl

A triple-axis diffractometer for high-energy X-ray diffraction is described. A 450 kV/4.5 kW stationary tungsten X-ray tube serves as the X-ray source. Normally, 220 reflections of thermally annealed Czochralski Si are employed for the monochromator and analyser. Their integrated reflectivity is about ten times higher than the ideal crystal value. With the same material as the sample, and working with the WKα line at 60 keV in symmetric Laue geometry for all axes, the full width at half-maximum (FWHM) values for the longitudinal and transversal resolution are 2.5 × 10−3and 1.1 × 10−4for ΔQ/Q, respectively, and the peak intensity for a non-dispersive setting is 3000 counts s−1. In particular, for a double-axis mode, an energy well above 100 keV from theBremsstrahlungspectrum can be used readily. High-energy X-rays are distinguished by a high penetration power and materials of several centimetre thickness can be analysed. The feasibility of performing experiments with massive sample environments is demonstrated.


2017 ◽  
Vol 22 (1) ◽  
pp. 30-34
Author(s):  
Robert Stănciulescu

Abstract Specialized studies show how a fighter should physically be, not just any fighter, but the one who possesses the qualities and features of the ideal model, i.e. those elements that define the near-perfect fighter. The demands of the modern battlefield impose a high quality human potential that provides a good basis for the selection and training of fighters. Resistance to physical, climate, season and weather condition demands, to the prolonged efforts fighting requires is one of the important conditions of success. The paper presents information with particular impact in optimizing exercise capacity for future officers of the land forces, emphasizing once again the idea that a high level of motric ability is an essential objective.


1996 ◽  
Vol 14 (4-6) ◽  
pp. 341-352 ◽  
Author(s):  
W. F. Kuhs ◽  
F. C. Bauer ◽  
R. Hausmann ◽  
H. Ahsbahs ◽  
R. Dorwarth ◽  
...  

2020 ◽  
pp. 105566562095106
Author(s):  
Steven Daws

The ideal age to undergo orthognathic surgery approximates the age of majority, and as a result a considerable portion of the patient population undergoing orthognathic surgery are legal minors. When a patient cannot legally provide consent, assent is often sought. Assent for surgical orthodontics is complicated by particular changes in cognitive variables during adolescence, the multiphased and multi-provider treatment course, and the intervention’s elective nature. Ultimately, inclusion of a high-quality assent process can help identify patients most likely to benefit from orthognathic surgery and increase patient satisfaction.


Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3490
Author(s):  
Krishna P. Khakurel ◽  
Borislav Angelov ◽  
Jakob Andreasson

Crystallography has long been the unrivaled method that can provide the atomistic structural models of macromolecules, using either X-rays or electrons as probes. The methodology has gone through several revolutionary periods, driven by the development of new sources, detectors, and other instrumentation. Novel sources of both X-ray and electrons are constantly emerging. The increase in brightness of these sources, complemented by the advanced detection techniques, has relaxed the traditionally strict need for large, high quality, crystals. Recent reports suggest high-quality diffraction datasets from crystals as small as a few hundreds of nanometers can be routinely obtained. This has resulted in the genesis of a new field of macromolecular nanocrystal crystallography. Here we will make a brief comparative review of this growing field focusing on the use of X-rays and electrons sources.


2016 ◽  
Vol 1735 ◽  
Author(s):  
Youzhen Li ◽  
Xuemei Xu ◽  
Chenggong Wang ◽  
Congong Wang ◽  
Fangyan Xie ◽  
...  

ABSTRACTLead halide perovskites have proven their great power conversion efficiency (PCE) in the last few years and attracted more and more attentions. Evaporation is an important method to get high quality perovskite films, especially for surface and interface investigation, which is important for the solar cell performance. In this paper, we present our investigations on growing PbI2 and CH3NH3I films by evaporation, and then CH3NH3PbI3 films by co-evaporation. X-ray photoemisson spectroscopy (XPS) was used to characterize the films. The results showed that CH3NH3I film was not stable in vacuum. Both N and I decreased in vacuum with time elapsing. PbI2 and CH3NH3PbI3 films are quite stable. The atomic ratio of CH3NH3PbI3 films (C: N: Pb: I =1.29:1.07:1.00:2.94) is very close to the ideal CH3NH3PbI3, which indicates that evaporation is a good method to get high quality perovskite films with accurate atomic ratio.


2014 ◽  
Vol 21 (3) ◽  
pp. 497-501 ◽  
Author(s):  
Istvan Mohacsi ◽  
Petri Karvinen ◽  
Ismo Vartiainen ◽  
Vitaliy A. Guzenko ◽  
Andrea Somogyi ◽  
...  

High-efficiency nanofocusing of hard X-rays using stacked multilevel Fresnel zone plates with a smallest zone width of 200 nm is demonstrated. The approach is to approximate the ideal parabolic lens profile with two-, three-, four- and six-level zone plates. By stacking binary and three-level zone plates with an additional binary zone plate, the number of levels in the optical transmission function was doubled, resulting in four- and six-level profiles, respectively. Efficiencies up to 53.7% focusing were experimentally obtained with 6.5 keV photons using a compact alignment apparatus based on piezoelectric actuators. The measurements have also been compared with numerical simulations to study the misalignment of the two zone plates.


2015 ◽  
Vol 10 (5) ◽  
pp. 86-94
Author(s):  
Розанова ◽  
Nina Rozanova

The article presents the results of sociological research to identify the ideal and real reputational image of regional power by «eyes of the power» – on the example of public civil servants of executive authorities of the Smolensk region. Degree of compliance of the valid and desirable reputation characteristics is shown that allows to allocate priority directions in the activity of authorities in work on themselves and high-quality improvement of a reputational image.


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