Položaj kefalometrijske točke “A” nakon širenja nepca

Objectives: Palatal expansion is used to treat severely constricted maxillary arches associated with a posterior unilateral o f bilateral crossbite. The purpose of this study was to evaluate the affects of such treatment on the position of the “A ” point. Material and Methods: Ninety six cases where palatal expansion was the first orthodontic treatment were retrospectively analyzed using lateral cephalographs taken before and after the expansion phase. Vertical movement of “A ” point was assessed relative to the perpendicular distance from the Frankfort Horizontal Plane and from the anterior cranial base (Sella-Nasion). Horizontal movement o f “A ” point was measured parallel to the Frankfort Plane using a line tangenital to the posterior limit of the pterygomandibular fissure and also parallel to the anterior cranial base from point Sella. Subgroups o f “rapid” and “slow” palatal expansion were compared. Results: Here was a mean downward and forward movement o f point “A ” during palatal expansion, with displacement being greater on average with rapid than with slow palatal expansion therapy. The mean vertical component changes relative to speed of palatal expansion was statistically significant (p 1 mm more with rapid palatal expansion compared to slow expansion; however, no statistical significance was proven. Mean increase in the mandibular plane angel was 1.4° to 2.0°. Conclusions: Palatal expansion is generally associated with a downward and forward movement o f point “A ” which is greater on average with rapid than with slow activation therapy.Širenje nepca koristi se u terapji uskih maksilarnih lukova udruženih sa jednostranim ili obostranim kriznim zagrizom. Cilj je ovog ispitivanja bio utvrditi djelovanje takvog tretmana na točku “A ”. Laterolateralni rendgenkefalogrami devedeset i šest pacijenata gdje je širenje nepce bi prvi ortodontski zahvat analizirani su prije i poslije tretmana. Vertikalni pomaci točke “A ” promatran je u odnosu na vertiklanu udaljenost od Frankfurtske horizontale do prednje kranijalne baze (sela -nasion). Horizontalni pomak točke “A ” mjeren je paralelno s Frankfurtskom horizontalom od tangente stražnjeg ruba pterigomaksilarne fisure i paralelno s prednjom kranijalnom bazom od točke sela. Podgrupe ‘forsirano” i “sporo” širenje nepca također su međusobno uspoređene. Točka “A ” značajno se pomiče prema dolje i prema naprijed, s tim da je pomak značajniji u grupi s forsiranim širenjem. Vertikalni pomak u značajnoj je vezi s brzinom širenja nepca (p<0,l). Horizontalna komponenta pomaka prosječno je za više od 1 mm veća kod fosriranog nego kod sporog širenja; statistička značaj-nost nije pronađena. Povećanje inklinacije mandibularne ravnine iznosilo je od 1,4° do 2,0°. Sirenje nepca je povezano s pomakom toćke “A ” prema dolje i prema naprijed koje je veće kod pacijenata gdje se nepce forsirano širilo

Optimum matrix acidizing: How much does it impact the productivity

Formation damage is one of the big challenges for oil and gas oilfields development. Several types of formation damage most likely exist during the entire life of producing wells. Formation damage can occur during the drilling or coring operations, well completion, work-over and production. The most important problems that affect formation during drilling operations are mud filtrate and fines invasion. There are different damage mechanisms affect reservoirs for instance pore blocking by solids, clay swelling and dispersion and liquid block which all reduce effective permeability to hydrocarbons. The reduction in production and an excessive build up pressure in injection wells indicate the formation. Many techniques are developed to remove the formation damage and to improve the productivity of wells. Matrix acidizing is one of these method which depend on injecting acids into the formation below fracturing pressure to eliminate the damage around the well. In this study, comprehensive design procedures for the acid treatment have been introduced. The procedures include the determination of the damage type and the mineralogy of the formation. Accordingly, the selection of the appropriate acid for the treatment and the optimum volume of injected acid are explained in the study. Additionally, the research presents several models for the pre-flush volume and the main acid volume based on the radius of the damaged zone and the height of the formation. New technique has been proposed for determining the final permeability improvement ratio based on current and proposed productivity index. It has been found the pre-flush volume increase as the carbonate percentage in the formation increases while the main acid volume conversely proportional with the clay content in the formation

Znanstvena recenzija: ocjena vrijednosti

Objectives: Editors o f journals depend on the system of peer review to screen out poorly conceived, poorly executed and unoriginal manuscripts. This study was designed to assess the reliability and consistency of reviewers ’ responses with regard to manuscripts submitted for publication to a leading international dental journal. Methods: Three elements in the peer review process were investigated; namely: (1) reviewers\u27 reports on manuscripts to the oral and maxillofacial radiology section of Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontics were studied for consistency in the three reports for each of 78 consecutively submitted manuscripts rated as Ufull papers”; (2) ten previo sly accepted and ten previously rejected manuscripts were sent out for re-review by different panels of reviewers who were uninformed o f the prior review; and (3) questionnaires were sent to the editors o f ten leading dental journals to compare their peer review criteria and outcomes. Results: Reviewers were consistently reliable in their responses to questions regarding originality and scientific merit, and in delineating manuscript acceptability. O f manuscripts that were previously accepted eight o f ten were again accepted following a further double blind review. Of manuscripts that were rejected originally, six of ten were again rejected upon a second review by other referees. The use o f two reviewers was validated for accepted articles; but validity required at least three reviewers when manuscripts were rejected. The selected jo urnal editors reported acceptance rates of from 30 to 80% with publication waiting times form three to 24 months. Higher acceptance percentages generally were associated with greater delays in publication. Conclusions: Journal peer review is not perfectly reliable; however, it does serve the purpose of reducing the number of poorly conceived and poorly constructed research papers.Cilj istraživanja: Urednici časopisa ovise o sustavu recenzija kako bi se zaštitili od loše zamišljenih, loše izvedenih i neoriginalnih rukopisa. Cilj ove studije bio je procijeniti pouzdanost i dosljednost recenzenta prema rukopisima poslanim kako bi se objavili u vodećem međunarodnom stomatološkom časopisu. Postupak: Istraživana su tri elementa u postupku recenzije; poglavito: (1) proučeni su izvještaji recenzenata o rukopisima poslanim odsjeku za radiologiju časopisa Oral Surgery, Oral medicine, Oral Pathology, Oral Radiology and Endodontics, kako bi se ustanovila dosljednost triju recenzija za svaki od 78 redom pristiglih radova označenih kao “juli papers (2) deset već prihvaćenih i deset prethodno odbijenih radova poslano je na ponovnu recenziju različitim recenzentima koji nisu bili obaviješteni o prethodnim recenzijama; i (3) poslani su upitnici urednicima vodećih stomatoloških časopisa kako bi se usporedili kriteriji i rezultati recenzija. Rezultati: Recenzenti su bili dosljedno pouzdani u odgovorima o izvornosti, znanstvenom doprinosu i odluci o prihvatljivosti rukopisa. Od deset prethodno prihvaćenih rukopisa osam je bilo ponovno prihvaćeno nakon dvostruke slijepe recenzije. Od deset rukopisa koji su prethodno bili odbijeni šest je po odluci drugih referenata bilo ponovno odbijeno. Korištenje dva recenzenta bilo je punovrijedno za prihvaćene članke, ali da bi se postigla pravovaljanost kod odbijenih rukopisa potrebna su barem tri recenzenata. Urednici izabranih časopisa izvijestili su o prihvaćanju radova u 30 do 80% slučajeva, a vrijeme do tiska radova bilo je od 3 do 24 mjeseca. Viši postotak prihvaćenih radova općenito je bio povezan s dužim razdobljem do objave radova. Zaključak: Recenzija u časopisu nije savršeno pouzdana; međutim, ona služi da bi se i smanjio broj loše zamišljenih i loše izvedenih znanstvenih radova

Use of Cone Beam Computed Tomography in Endodontics

Cone Beam Computed Tomography (CBCT) is a diagnostic imaging modality that provides high-quality, accurate three-dimensional (3D) representations of the osseous elements of the maxillofacial skeleton. CBCT systems are available that provide small field of view images at low dose with sufficient spatial resolution for applications in endodontic diagnosis, treatment guidance, and posttreatment evaluation. This article provides a literature review and pictorial demonstration of CBCT as an imaging adjunct for endodontics

Video Subtraction: Dynamic Temporal Change Versus Intrinsic Colour Instability

Svrha: Vrjednovati metodu digitalnog oduzimanja mirujućih videoslika za prikaz promjena u pokusima djelotvornosti stimulirane oralne higijene. Metode: Za točno premještanje videokamere tipa Stoma Vision (STV, -Trophy Radiologie, Vincennes, France) kod promatranja prednjih zuba i zubnoga mesa modela tipa DXTRR (Dentsply/Rinn, Elgin, Illinois) bio je upotrebljen akrilički fiksator. Slike su bile spremljene u binarnom obliku (16 bita: 5 za crveno, 5 za plavo, 6 za zeleno) unutar VG/STV-PC softwarea što ga je isporučio proizvođač kamere. Za simuliranje promjena u prekrivanju sredstvima za razotkrivanje naslaga i uaple zubnoga mesa na model je nanesen crveni vosak. Izrađivane su video snimke tijekom stanovitoga vremena, ali bez manipuliranja modelom, da bi se procijenila prirođena nestabilnost boje sustava. Suptrakcija vrijednosti slika provodila se je po sljedećoj jednadžbi: g(x1,y)=f(x1,y)-h(x1,y), kojom se računaju rezlike odgovarajućih čestica slike (pixel) od f i h, što je dalo novu sliku y. Histogramske raščlambe za svaku od boja (crvena, plava i zelena) slijedile su diskretnu funkciju P(rk)=N/n, gdje je rk razina boje kth, Nk broj čestica u slici uz tu razinu boje i područje &=0,i,2,...L\u277. Rezultati: Suptrakcija videoslika pružila je solidan uvid u dinamičke privremene promjene kad je kontrast boje bi znatan (npr. na krunu zuba stavljena točkica crvenoga voska). Između ostalih čimbenika, opazena je unutarnja nestabilnost boje tijekom vremena, zbog promjene temperature izvora svjetla, osobito kada je STV bila sktivirana više od jednoga sata. Zaključci: Video suptrakcija pokazuje potencijal kao metoda za kvantificiranje promjena razotkrivanja statusa dentalne higijene ili promjena boje zuba tijekom vremena; no zbog nestalnosti temperature boje tijekom vremena, treba faktorirati promjene.Objectives: To evaluate digital subtraction of still video images to show temporal change in a simulated oral hygiene effectiveness trial. Methods: An acrylic stent was used for the accurate repositioning of a Stoma Vision (STV) video camera (Trophy Radiologie, Vincennes, France) to view the anterior teeth and gingivae of a DXTRR manikin (Dentsply/Rinn, Elgin, Illinois). Images were stored in binary form (16 bit: 5 red; 5 blue: 6 green) within the RVG/STV-PC software provided by the manufacturer of the camera. Red wax was applied to the manikin to simulate changes in the coverage o f plaque disclosing solutions and gingival inflammation. Videos were also taken over time without manipulation o f the model to evaluate intrinsic colour instability o f the system. Image subtraction followed the formula: g(x1,y)=f(x1,y)-h(x1,y), computing the differences of corresponding pixel from f and h, given the new image y. Histogram analysis for each (red, blue and green) followed the discrete function P(rk)=N/n, where rk is the kth colour level, Nk is the number of pixels in the image with that color level and k=0,l,2,...L~1 is range. Results: Subtraction o f video images provided solid evidence o f dynamic temporal change where colour contrast was substantial (e.g. placing a wax red dot over the crown of a tooth). Intrinsic colour instability due to the temperature of light source among other factors was seen over time, especially when the STV was activated for more than one hour. Conclusions: Video subtraction shows potential as a method to quantify changes in disclosed dental hygiene status or tooth coloration over time; however, changes due to colour temperature modification over time need to be factored

1-(4-Ethoxy­benzo­yl)-4-(4-methoxy­phen­yl)thiosemicarbazide

The title compound, C17H19N3O3S, crystallizes with two closely similar independent mol­ecules related by a pseudotranslation of c/2. Each mol­ecule consists of three approximately planar moieties centred on the N2CS group and the two ring systems. The packing involves classical H bonds of the form Namide—H⋯S and Nhydrazine—H⋯OC, together with various weak hydrogen bonds and Nhydrazine—H⋯π inter­actions. The overall packing is three-dimensional, but layer substructures parallel to the xz plane can be readily identified. Each mol­ecule forms a topologically equivalent set of hydrogen-bond inter­actions

2-(2-Fluoro­biphenyl-4-yl)-N′-(propan-2-yl­idene)propanohydrazide

In the title compound, C18H19FN2O, the hydrazide side chain is approximately perpendicular to the central ring [dihedral angle = 76.80 (5)°]. The F atom is disordered over two positions with occupancies of 0.818 (2) and 0.182 (2). The packing consists of chains of mol­ecules parallel to the a axis, connected by a bifurcated N—H⋯(O,N) hydrogen bond and a weak Cphen­yl—H⋯O hydrogen bond. The packing is extended to a layer structure parallel to the ab plane by a weak Cphen­yl—H⋯F hydrogen bond

Accessing Stereochemically Rich Sultams via Microwave-Assisted, Continuous Flow Organic Synthesis (MACOS) Scale-out

The generation of stereochemically-rich benzothiaoxazepine-1,1′-dioxides for enrichment of high-throughput screening collections is reported. Utilizing a microwave-assisted, continuous flow organic synthesis platform (MACOS), scale-out of core benzothiaoxazepine-1,1′-dioxide scaffolds has been achieved on multi-gram scale using an epoxide opening/SNAr cyclization protocol. Diversification of these sultam scaffolds was attained via a microwave-assisted intermolecular SNAr reaction with a variety of amines. Overall, a facile, 2-step protocol generated a collection of benzothiaoxazepine-1,1′-dioxides possessing stereochemical complexity in rapid fashion, where all 8 stereoisomers were accessed from commercially available starting materials