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Estudo das lesões ligamentares e condrais nas fraturas articulares da extremidade distal do rádio: avaliação artroscópica / Studies of the ligament and chondral injuries in articular fractures of the distal end of the radius: arthroscopic evaluationMarcelo Araf 25 March 2008 (has links)
As fraturas da extremidade distal do rádio são muito comuns em nosso meio, sendo a mais freqüente do punho. Inúmeras pesquisas já foram realizadas sobre o tema e é conhecida a importância da redução anatômica das fraturas intra-articulares; porém, a causa de insucesso no seu tratamento pode ser a associação de outras lesões, envolvendo partes moles e cartilagem. O objetivo foi realizar uma avaliação artroscópica para analisar a incidência das lesões ligamentares e condrais associadas às fraturas intraarticulares da extremidade distal do rádio, correlacionado-a com classificação AO/ASIF. Trinta pacientes, com idade entre 20 a 50 anos, portadores de fratura fechada dos grupos B e C da classificação AO/ASIF foram selecionados. Todos eles foram submetidos à artroscopia do punho, para abordar as lesões intra-articulares e para redução e osteossíntese da fratura. Observou-se uma alta incidência de lesões intra-articulares, sendo que 76,7% deles apresentavam lesão do complexo da fibrocartilagem triangular, 36,6% do ligamento intrínseco escafo-semilunar, 6,6% do ligamento intrínseco semilunar-piramidal e 33,3% com lesão da cartilagem articular maior que três milímetros. Pacientes portadores de fraturas tipo C da classificação AO/ASIF apresentam uma incidência maior de lesões ligamentares associadas. Não houve relação entre a presença de lesão cartilaginosa e a classificação AO/ASIF das fraturas nesta casuística. / Fractures of the distal end of the radius are very frequent in our country and the most common is that of the wrist. Much research was carried out on the subject and the importance of the anatomical reduction of intra-articular fractures is well known, however the cause of unsuccessful treatment may be the association of other injuries involving soft tissues and cartilage. The purpose here was to perform an arthroscopic evaluation to analyze the incidence of ligament and chondral injuries associated to intra-articular fractures of the distal end of the radius, for correlation with the AO/ASIF classification. Thirty patients ranging from 20 to 50 years of age, bearers of closed fractures of groups B and C of the AO/ASIF classification were selected. They were submitted to wrist arthroscopy to treat the intra-articular injuries for fracture reduction and osteosynthesis. A high incidence of intraarticular injuries was noted, 76.7% of them presenting injury of the triangular fibrocartilage complex, 36.6% of the intrinsic scapholunate ligament, 6.6% of the intrinsic lunotriquetral ligament and 33.3% of an injury of the articular cartilage larger than three millimeters. Patients bearers of a type C fracture in the AO/ASIF classification present with a higher incidence of associated ligament injuries. No relation between presence of cartilage injury and AO/ASIF Classification was found in this casuistry.
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Ecoulements en milieux fracturés : vers une intégration des approches discrètes et continues.Delorme, Matthieu 02 April 2015 (has links) (PDF)
Simuler les réservoirs souterrains permet d’optimiser la production d’hydrocarbures. Les réservoirs naturellement ou hydrauliquement fracturés détiennent une part importante des réserves et exhibent un degré élevé d’hétérogénéité : les fractures, difficiles à détecter, impactent fortement la production via des réseaux préférentiels d’écoulement. Une modélisation précise de ces forts contrastes permettrait d’optimiser l’exploitation des ressources tout en maîtrisant mieux les risques environnementaux. L’enjeu est de prédire les processus d’écoulement multi échelles par un modèle simplement paramétrable. Une stratégie de simulations, qui améliore la fiabilité et les temps de calculs est mise au point dans cette thèse. Elle permet de simuler numériquement ou analytiquement la complexité d’un réservoir fracturé à grande échelle. Ces techniques dont l’intérêt est démontré sur un réservoir de roche mère trouvent des applications en géothermie ou dans la gestion des ressources en eau.
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Comparison of an intra-oral approach using a contra-angle hand piece with the transbuccal technique for mandibular angle fracture repairDe Waal, Andre Stephanus January 2010 (has links)
Magister Chirurgiae Dentium - MChD / Purpose: To compare the intra-oral approach using a contra-angled hand
piece with the standard transbuccal approach in the treatment of mandibular
angle fractures.
Patients and Methods: Thirty patients with isolated fractures of the
mandibular angle were treated by open reduction and internal fixation using
one three-dimensional “strut” or “geometric” Synthes® angle plate. Patients
were selected randomly for placement of two-millimeter self-threading
screws, either through the standard transbuccal technique or with an intra-oral
approach using a contra-angle hand piece. None of the patients were placed
into post-surgical maxillomandibular fixation (MMF). Swelling and pain were
measured pre-operatively and again twenty-four hours after surgery. The
actual cutting time from first incision to placement of last suture was
documented, as well as the perception of difficulty of the specific case by a
single operating surgeon.
Results: No statistically significant difference in perception of pain was
experienced between the two groups of patients during the first twenty-four
hours after surgery. There was also no statistically relevant difference in
cutting time between the two placement techniques. A small statistically
relevant difference (p-value = 0.089) was found in the amount of swelling
post-operatively between the two groups, with more swelling in the control
group.
Conclusion: The use of a contra-angle hand piece to place screws in the
compression band area in a mandible angle fracture is an acceptable
alternative to the transbuccal approach. / South Africa
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Aspects of dental cone-beam computed tomography in children and young peopleHidalgo Rivas, Jose Alejandro January 2014 (has links)
Cone-beam computed tomography (CBCT) has become increasingly popular in dentistry. It is usually associated with radiation doses that are lower than those seen with conventional computed tomography (CT) but greater than those seen with dental radiography. Because exposure to ionising radiation is associated with risks, the radiation protection principles of justification and optimisation should be applied. These are especially important in children and young people due to their greater risk of developing stochastic effects. Justification requires a balancing of the radiation risk with the potential benefits and the latter is dependent on diagnostic efficacy. There has been a proliferation of articles published on dental CBCT and there is a need to review this systematically so that diagnostic efficacy can be judged. In terms of optimisation, radiation dose reduction can be achieved in various ways, but the use of barrier materials to protect younger patients in CBCT has not been adequately tested. Reduction in exposure parameters in CBCT will lower doses but at the expense of a loss of image quality. While some efforts have been made to relate radiation exposure and image quality in CBCT, there is a need to develop low-dose CBCT protocols specifically for children and young people. The first aim of this thesis was to survey current uses of CBCT in children and young people in three United Kingdom dental hospitals. The second aim was to determine the efficacy of thyroid shielding in a child phantom testing several different designs, materials and thickness of thyroid shields. The third aim was to evaluate the evidence on diagnostic efficacy of dental CBCT for root fractures in permanent, non-endodontically treated, anterior teeth by conducting a systematic review. The fourth aim was to evaluate objective and subjective image quality in a laboratory study to determine a low-dose CBCT protocol which maintains adequate diagnostic image quality for a clinical indication in children. Finally, the aim was to evaluate this low-dose protocol in terms of image quality in real clinical situations. A high adherence to the European guidelines No 172 on radiation protection in dental CBCT was found amongst the surveyed hospitals. Thyroid shielding was found to be effective in dose reduction when performing a large field of view CBCT scan in a child phantom, but design influenced efficacy. The systematic review showed that research articles investigating CBCT diagnostic accuracy for vertical and horizontal root fractures had deficiencies in methodology, while only one study was identified addressing higher levels of diagnostic efficacy. A low-dose imaging protocol was identified in a laboratory study, which has been shown to be an effective tool in dose reduction providing an adequate diagnostic image quality and reducing radiation doses considerably for clinical indications in the anterior maxilla in children and young people.
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An investigation of immature rib fractures resultant from both CPR and abusive scenariosJohnson, Mark Richard January 2014 (has links)
The presence of rib fractures in deceased infants is generally considered to be highly specific of non-accidental injury, with some pathologists considering them to be evidence of abuse. Although rib fractures may occur during resuscitative efforts in adults, the general consensus is that such injuries are exceptional in infants owing to inherent plasticity within the thoracic region. The recommendation for cardiopulmonary resuscitation (CPR) of infants since the year 2000 has been for the use of the “two-thumb” technique. However, there has been limited biomechanical investigation to what injuries may occur subsequent to this specific form of CPR. The overall aim of this thesis was to determine if two-thumb CPR can cause similar rib injuries to those seen in abusive squeezing cases. In particular, whether or not this CPR technique allows for over excessive levering of the posterior rib over the transverse process of the spine. To this end, physical experimentation simulating both two-thumb CPR and abusive squeezing was performed on an immature swine model of the infant thorax. The results of these tests did not show any significant difference in the force required to compress the thorax by one third its original anterior-posterior diameter in the two scenarios. One third being the recommended depth for CPR compressions. Fractures resultant from the testing were assessed with radiography and computed tomography, techniques commonly used by post-mortem pathologists. The type and nature of the injuries observed were remarkably similar in both scenarios. Rib injuries were primarily seen in the anterior part of the thoracic cage in both CPR and abusive specimens. The specific site of rib fracture was typically close to or within the costochondral joints. There was however an apparent absence of posterior rib fractures in the abusively tested cohort. This is in part due to the slight difference in profile of the neck and head areas within the ribs of the surrogate model. This acts to reduce the mechanical advantage offered by levering over the transverse processes of the spine. This study has shown anterior fractures of the ribs result from two-thumb CPR, challenging the long held belief that CPR cannot produce rib fractures. X-ray CT offered a significant improvement on the ability to detect costochondral junction injuries. This would offer further support to the routine use of X-ray CT in post-mortem examinations of infants where the cause of death is unknown. This has the potential to offer differential interpretation to the cause of rib injuries, especially in cases of sudden unexpected deaths in infancy, where otherwise child abuse may be diagnosed.
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Acoustic velocity structure of the carboneras fault zone, SE SpainTaylor, Rochelle Louise January 2013 (has links)
The Carboneras fault zone (CFZ, Almería Province, SE Spain) is a major NE-SW trending tectonic lineament that marks part of the diffuse plate boundary between Iberia and Africa. Developed within a basement terrain dominated by mica schist, the fault system comprises two main strands within a complex zone up to 1 km wide. Between these two strands is a braided network of left-lateral strike-slip, phyllosilicate-rich fault gouge bands, ranging between 1 and 20 m in thickness, passively exhumed from up to 3 km depth. The excellent exposure in a semi-arid environment, the wide range of rock types and fault structures represented and the practicality of carrying out in-situ geophysical studies makes this fault zone particularly well suited to verifying and interpreting the results of in-situ seismic investigations. Integration of elements of field study, laboratory analysis and modelling has aided interpretation of the internal structure of the fault zone. Ultrasonic measurements were made using standard equipment over confining and pore pressure ranges appropriate to the upper 10 km of the continental crust. Seismic velocities have also been approximated from modal analysis and mineral phase elastic properties and adjusted for the effects of porosity. In-situ seismic investigations recorded P-wave velocities 40-60% lower than those measured in the laboratory under corresponding pressures and at ambient temperatures for hard rock samples. Fault gouge velocities measured in the laboratory, however, are comparable to those measured in the field because, unlike the host rocks, fault gouges are only pervasively micro-fractured and lack the populations of long cracks (larger than the sample size) that cause slowing of the velocities measured in the field. By modelling the effect of fractures on seismic velocity (by superimposing upon the laboratory seismic data the effects of crack damage) the gap between field- and laboratory-scale seismic investigations has been bridged. Densities of macroscopic cracks were assessed by measuring outcrop lengths on planar rock exposures. Assuming crack length follows a power law relation to frequency, this fixes a portion of the power spectrum, which is then extrapolated to cover the likely full range of crack sizes. The equations of Budiansky and O'Connell (1976), linking crack density to elastic moduli, were used to calculate modified acoustic velocities, and the effects of the wide range of crack sizes were incorporated by breaking the distribution down into small sub-populations of limited range of crack density. Finally, the effect of overburden pressure causing progressively smaller cracks to close was incorporated to predict velocity versus depth of burial (i.e. pressure). Determination of rock physical properties from laboratory analysis and sections constructed from geological mapping provides a representation of velocity from selected parts of the Carboneras fault zone. First break tomography images show particularly well the location of steeply-inclined fault cores, and these correlate generally well with geological mapping and laboratory velocity measurements corrected for the effect of cracks. The decoration of the fault zone with intrusive igneous material is well correlated with the results of geological observations. Comparisons made between the field (seismic) inversion model and laboratory forward velocity model in El Saltador valley show the laboratory and field velocity measurements made within the fault zone can be reconciled by accounting for the effects of crack damage in field data.
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Fracturing and deformation at the edges of tabular gold mining excavations and the development of a numerical model describing such phenomenaBrummer, Richard Kenneth 10 September 2014 (has links)
D.Ing. (Civil Engineering) / This thesis describes an Investigation Into the nature of the fracture and deformation mechanism which occur at the edges of tabular gold mining excavation. Published Information on these phenomena Is reviewed, and the necessary underground Investigation required to consolidate the previous work Is described. It Is concluded that the rock near the reef plane at the edges of these mining excavations Is subject to stresses sufficiently high to cause It to fracture through the formation of regular patterns of shear planes. These fractures can form In the solid rock some distance ahead of the mining excavation. Nearer the mining face, extension fractures form which result In slabbing or splitting of the exposed rock. An Idealization of the observed rock behavior Is proposed, which Is then incorporated with conventional boundary element techniques Into a numerical model (SEAMS) which Is capable of analyzing two Dimensional tabular mining excavations where the rock near the reef plane at the edge of the mining excavation fractures, deforms and sheds load. A Sensitivity analysis of the numerical model Is described which Identifies those mining parameters capable of being used to advantage In controlling the size of the fracture zone.
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Resistência de quatro técnicas de fixação utilizadas no tratamento das fraturas subcondilares = estudo in vitro em mandíbulas de poliuretano / Resistance of four fixation techniques used in the treatment of subcondyles fractures : study in vitro in mandibles of polyurethaneCavalieri-Pereira, Lucas, 1982- 18 August 2018 (has links)
Orientador: Alexandre Elias Trivellato / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-18T13:54:21Z (GMT). No. of bitstreams: 1
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Previous issue date: 2011 / Resumo: A fratura do côndilo mandibular usualmente requer tratamento cirúrgico com emprego de fixação interna estável. O objetivo neste estudo foi avaliar comparativamente a resistência de quatro técnicas de fixação utilizadas no tratamento de fraturas subcondilares. Foram empregadas 84 mandíbulas sintéticas, 147 placas retas e 546 parafusos. As mandíbulas foram submetidas a um seccionamento simulando uma fratura subcondilar esquerda e fixadas com quatro técnicas utilizando-se das placas de 2,0 e 1,5 mm, que deram origem a doze grupos experimentais, cada um com 7 mandíbulas. Chamou-se de grupos G1, G5 e G9, aqueles fixados com uma placa reta de 4 furos do sistema 2,0 mm. Os grupos G2, G6 e G10, foram fixados com uma placa de 4 furos dos sistema 2,0 mm e uma placa de 3 furos do sistema 1,5 mm. Grupos G3, G7 e G11, aqueles fixados com duas placas 2,0 mm, sendo a anterior de 3 furos; Grupos G4, G8 e G12, aqueles fixados com duas placas 2,0 mm de 4 furos. Cada sistema foi submetido ao teste de resistência com aplicação de carga no sentido súpero-inferior em máquina de ensaio EMIC, modelo DL2000. Em G1, G2, G3 e G4 a aplicação de carga foi no primeiro molar do lado da fratura simulada (MF). Em G5, G6, G7 e G8, no primeiro molar contralateral à fratura simulada (MC). Em G9, G10, G11 e G12, entre os incisivos centrais (I). Foram mensurados valores de carga para os deslocamentos de 1 mm, 2 mm e 5 mm. Os resultados obtidos no teste de resistência foram comparados utilizando análise de variância (ANOVA), seguido do teste de Tukey com nível de significância de 5%. Verificou-se valores de carga menores no grupo tratado com uma placa de 4 furos do sistema 2,0 mm, nos deslocamentos de 1 e 2 mm, com aplicação de carga em MF. Pode-se concluir que a utilização do sistema de fixação com duas placas proporciona maior resistência / Abstract: Fractures of mandibular condyles usually require surgical treatment with steady employment internal fixation. The aim in this study was to evaluate the resistance of four fixation technique used in the treatment of subcondylar fractures. Were employed 84 synthetic jaws, 147 straight plates and 546 screws. The jaws underwent a sectioning simulating a left subcondylar fracture and fixed with four techniques using 2.0 mm and 1.5 mm plates, which gave rise to twelve experimental groups, each with 7 mandibles. Drew G1, G5 and G9, those set with single straight plate 4-holes. Groups G2, G6 and G10, were fixed with one 2.0 mm system plate 4-holes and one 1.5 mm system plate 3-hole. Groups G3, G7 and G11, were fixed with two plates 2.0 mm, which more anterior had 3-hole. Groups G4, G8 and G12, those fixed with two plates 2.0 mm with 4-hole. Each system was subjected to the test of resistance with load application superior-inferior on testing machine EMIC model DL2000. In G1, G2, G3 and G4 the implementation of load was the first molar side fracture simulated (MF). In G5, G6, G7 and G8 were in the first molar contralateral to the simulated fracture (MC). In G9, G10, G11 and G12 was between the central incisors (I). Load values were measured for displacement from 1 mm, 2 mm and 5 mm. Results obtained in the test of resistance were compared using analysis of variance (ANOVA), followed by Tukey test with a significance level off 5%. There was minor loads value in the group treated with a plate of 4-hole system 2.0 mm, in displacements of 1 and 2 mm, with application in MF. Can conclude that the use of the fixation system with two plates provide greater resistance / Mestrado / Cirurgia e Traumatologia Buco-Maxilo-Faciais / Mestre em Clínica Odontológica
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Avaliação dos traumatismos dentários atendidos no Serviço de Trauma Dental da Faculdade de Odontologia de Piracicaba = estudo retrospectivo de 10 anos / Evaluation of tooth injuries treated by Dental Trauma Service at Piracicaba Dentistry School : a 10 years retrospective studyLins, Fernanda Freitas 18 August 2018 (has links)
Orientador: Adriana de Jesus Soares / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-18T14:40:53Z (GMT). No. of bitstreams: 1
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Previous issue date: 2011 / Resumo: O propósito do presente estudo restrospectivo foi avaliar os diversos aspectos relacionados às injúrias dentárias traumáticas em relação a sua etiologia, prevalência e classificação, nos pacientes atendidos no Serviço de Trauma Dental da Área de Endodontia da Faculdade de Odontologia de Piracicaba-UNICAMP, no período de Julho de 2000 a Julho de 2010. Os dados obtidos foram tabulados e a análise dos resultados incluiu distribuição de freqüência, teste Qui-quadrado e teste de Mann-Whitney, com nível de significância de 5%. O número total de pacientes foi de 450 (300 do gênero masculino e 150 do gênero feminino) com 1284 dentes traumatizados, representando aproximadamente 2,8 dentes por paciente. Os resultados mostraram que a faixa etária mais prevalente foi de 11 a 15 anos de idade (31,5%) e os fatores etiológicos mais encontrados foram as quedas (35,6%) e os acidentes ciclísticos (26,2%). Os incisivos centrais superiores foram os dentes com maior percentual de trauma (53,7%). O tipo de injúria aos tecidos dentários mais prevalente foi a fratura de esmalte e dentina, enquanto as avulsões e as subluxações foram os tipos de injúrias aos tecidos de suporte mais frequentes. O mês e o dia em que mais ocorreram os traumas foi o mês de Maio e aos Sábados. O gênero exerceu influência em relação a etiologia do trauma (p < 0,05/ Teste Qui-quadrado) e não obteve diferença significativa com as diferentes faixas etárias (p > 0,05 / Teste Mann Whitney). Concluiu-se que o gênero masculino, a faixa etária de 11 a 15 anos, as quedas, os incisivos centrais superiores, as fraturas de esmalte e dentina e as avulsões foram os achados mais freqüentes / Abstract: The purpose of this retrospective study was to evaluate several aspects related to traumatic dental injuries regarding its etiology, prevalence and classification in the patients of Service of Dental Trauma of the Endodontics Area, Faculty of Dentistry of Piracicaba-UNICAMP, from July 2000 to July 2010. The statistical treatment analysed data from frequency distribution, Chi-square test and Mann-Whitney test. The level of significance was set at 5% for all analyses. A total of 450 patients (150 females and 300 males) with 1284 injured teeth, approximately 2,8 per patient. The results showed that the prevalent age group was 11 to 15 years (31.5%) and the most frequent etiological factors of tooth injuries were falls (35.6%) and bicycle accidents (26.2%). The upper central incisors were the teeth with higher percentage of trauma (53.7%). The most prevalent type of injury to dental tissue was fracture of enamel and dentin, while avulsions and subluxations were the most frequently types of injuries to the supporting tissues. The month and day that most occurred dental injuries was May and Saturday respectively. Gender exerted influence over the etiology of trauma (p <0.05 / Chi?square) and had no significant difference with the different age groups (p> 0.05 / Mann Whitney). It was concluded that male gender, age range 11 to 15 years, falls, upper central incisors, the enamel and dentin fractures and avulsions were the most frequently findings / Mestrado / Endodontia / Mestre em Clínica Odontológica
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Influência do uso da ferramenta de redução do artefato no diagnóstico de fraturas radiculares verticais em exames de tomografia computadorizada de feixe cônico : estudo in vitro / Influence of an artifact reduction tool on the diagnosis of vertical root fractures in teeth with metal postsBezerra, Ilana Sanamaika Queiroga, 1984- 26 August 2018 (has links)
Orientadores: Deborah Queiroz de Freitas França, Gláucia Maria Bovi Ambrosano / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-26T13:33:44Z (GMT). No. of bitstreams: 1
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Previous issue date: 2014 / Resumo: O objetivo neste trabalho foi verificar a influência da ferramenta para redução de artefato (FRA) na qualidade da imagem e no diagnóstico de FRVs, em dentes com pino metálico intracanal. A amostra foi composta por trinta dentes unirradiculares, que tiveram suas coroas removidas e seus canais instrumentados. Do total, foram induzidas fraturas completas e incompletas em vinte raízes e ao final, todas as raízes foram divididas em três grupos: controle (n=10), fratura radicular completa (n=10) e fratura radicular incompleta (n=10). Cada raiz recebeu um pino metálico intracanal e foi escaneada duas vezes no tomógrafo Picasso Trio 3D® (Vatech, Hwaseong, Coreia do Sul): uma sem e uma com o emprego da FRA. As imagens foram avaliadas objetiva e subjetivamente. A avaliação objetiva foi feita no ImageJ (NIH, Bethesda, MD, EUA), em uma região de interesse circular padronizada, na qual foram mensuradas os valores médios e a variação dos tons de cinza e a taxa contraste-ruído (TCR) nas imagens com e sema FRA. A avaliação subjetiva foi realizada de duas formas: inicialmente, cinco avaliadores (cirurgiões-dentistas, especialistas em Radiologia Odontológica) treinados analisaram as imagens no software EZ3D quanto à presença de FRV, utilizando uma escala de cinco pontos: Posteriormente, um avaliador quantificou os artefatos formados. Foram avaliados o cupping, as bandas hipodensas e as estrias hiperdensas. A imagem obtida com FRA foi comparada à sua respectiva sem FRA para atribuição de um dos três escores: (0) não houve mudança na quantidade de artefato formado; (1) houve diminuição e (2) houve aumento. As concordâncias intra e interexaminador foram avaliadas pelo teste Kappa ponderado. A comparação dos resultados do diagnóstico de FRV com o padrão-ouro foi realizada pela curva ROC (Receive Operating Characteristic). Além disso, também foram calculados os valores de sensibilidade, especificidade e acurácia. A comparação dos resultados da análise objetiva, dos valores das áreas sob a curva ROC e dos testes de diagnóstico nas aquisições com e sem a FRA foi realizada por meio do Teste t. A presença de artefatos foi avaliada por análise descritiva. Os resultados mostraram diminuição significativa dos valores médios dos tons de cinza (p=0,002) e da TCR (p=0,000) com utilização da FRA. Quanto à avaliação subjetiva, os valores das áreas sob a curva ROC, sensibilidade, especificidade e acurácia também foram inferiores com a utilização da FRA, sendo os dois últimos estatisticamente significativos, para os casos de fratura incompleta (p=0,028 e p=0,037, respectivamente) e fratura completa (p=0,021 e p=0,031, respectivamente). Em relação aos artefatos avaliados, de uma maneira geral houve diminuição dos mesmos nas imagens com FRA. Dessa forma, concluiu-se que a utilização da FRA causou uma diminuição nos artefatos formados, porém não houve não houve melhora na qualidade da imagem avaliada de maneira objetiva nem repercussão no diagnóstico de FRVs em raízes com pino metálico intracanal, uma vez que o mesmo foi prejudicado / Abstract: This study aimed to verify the influence of the artifact reduction algorithm in the image quality and the diagnosis of VFR. The sample was composed of thirty single-rooted teeth, which the crown was removed and the root canal was prepared. In twenty roots, fractures were induced. The roots were divided into three groups: control (n=10), complete (n=10) and incomplete (n=10) VRF. In each root canal it was inserted a well-fitted metal post and it was scanned in the Picasso Trio 3D® CBCT device (Vatech, Hwaseong, South Korea) with and without the artifact reduction algorithm. The images were evaluated objective- and subjectively. The objective evaluation was performed in the ImageJ software (NIH, Bethesda, MD, USA), by a standard round region of interest, on which it was measured the mean value of the grey level and contrast-to-noise ratio (CNR). Five observers (oral radiologists) performed blindly the subjective evaluation in EZ3D software to diagnosis VRF, which was classified according to a 5-point scale. Posteriorly, one observer quantified the presence of the beam hardening artifacts. It was evaluated the cupping artifacts, hypodense halos and streak artifacts. The images with and without the artifact reduction algorithm was compared according three scores: no change, increase or decrease of the beam hardening artifact. The intra- and interobserver agreement were calculated by the weighted-Kappa test. The ROC (Receiver Operating Characteristic) curve was used to compare the diagnosis of VRF and the gold standard. Also, the sensitivity, specificity and accuracy were obtained. The comparison of the grey levels and the CNR were performed by the t-Test. The production of beam hardening artifacts was descriptive analyzed. The results showed a significant decrease of the grey level (p=0,002) and CNR (p=0,000) with the artifact reduction algorithm. The ROC curve values, sensitivity, specificity and accuracy were lower with the artifact reduction algorithm for the diagnosis of VRF. It was observed a statistically significant difference in the specificity and accuracy. Regarding to the quantity of the beam hardening artifacts, it was observed an overall reduction in images with the artifact reduction algorithm. In conclusion, the use of the artifact reduction algorithm produced a decrease of the beam hardening artifacts; however, it was observed negative influence in image quality and in the diagnosis of VRF in the presence of metal post / Doutorado / Radiologia Odontologica / Doutora em Radiologia Odontológica
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