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1.
Acta amaz ; 51(3): 199-206, set 2021.
Article in English | LILACS | ID: biblio-1353492

ABSTRACT

Enquanto o Inventário Florestal Nacional Brasileiro (IFN) está em andamento, há uma demanda crescente para entender o efeito da área do conglomerado sobre a exatidão e precisão da estimativa de atributos florestais. O objetivo deste estudo foi determinar a área mínima de um conglomerado para estimar o volume comercial (VC) com a mesma acurácia e precisão que as estimativas derivadas do conglomerado original de 8.000 m². A base de dados é proveniente de um inventário realizado em uma unidade florestal (Floresta Nacional do Bom Futuro) no sudoeste da Amazônia brasileira, onde 22 conglomerados foram distribuídos em um desenho amostral em dois estágios. Foram avaliados três produtos: (i) VC de árvores com diâmetro à altura do peito (DAP) ≥ 20 cm (P1); (ii) VC de árvores com DAP ≥ 50 cm (P2); e (iii) VC de espécies comerciais com DAP ≥ 50 cm e qualidade de fuste 'nível 1' ou 'nível 2' (P3). O estudo avaliou dez cenários em que a área do conglomerado foi reduzida de 8.000 a 800 m². A acurácia de P1, P2 e P3 foi significativamente menor para reduções < 2.400 m². A precisão foi mais sensível à variação no tamanho do conglomerado, sobretudo para P2 e P3. Os tamanhos mínimos de conglomerado foram ≥ 2.400 m² para estimar P1, ≥ 4.800 m² para estimar P2 e ≥ 7.200 m² para estimar P3. Concluímos que é possível reduzir a área do conglomerado sem perder acurácia e precisão do conglomerado original do IFN. Um conglomerado de 2.400 m² fornece estimativas com a mesma acurácia que o conglomerado original, independentemente do produto avaliado. (AU)


Subject(s)
Wood , Forests , Amazonian Ecosystem , Conservation of Natural Resources , Dimensional Measurement Accuracy
2.
Rev. Ciênc. Méd. Biol. (Impr.) ; 20(2): 240-244, set 29, 2021. fig, tab
Article in Portuguese | LILACS | ID: biblio-1354433

ABSTRACT

Introdução: a detecção da reabsorção da raiz dentária é realizada por meio de exames de imagens, pois frequentemente não apresenta sinal e sintoma clínicos. Dentre os exames de imagem disponíveis, o exame radiográfico periapical, é indicado para diagnóstico, prognóstico e acompanhamento da reabsorção radicular. Objetivo: o estudo tem como objetivo investigar a relação de diferentes resoluções espaciais com o diagnóstico de reabsorção radicular. Metodologia: foram realizados desgastes simulando reabsorção externa no terço apical e vestibular de 15 (quinze) incisivos inferiores, radiografados em crânio seco, antes e depois do desgaste. A técnica radiográfica foi realizada utilizando o sistema VistaScan (Durr Dental, Bietigheim-Bissingen, Germany), aparelho CS 2200 (Carestream Dental LLC, Atlanta-GA, USA) usando tempo de exposição de 0,15 segundos e escaneadas sob diferentes protocolos de resolução espacial, a saber, 20 pares de linhas por milímetro (pl/mm) e 40 pl/mm. Posteriormente dois avaliadores experientes fizeram análises das referidas imagens sem conhecimento prévio da resolução de escaneamento. Resultados: 75% das radiografias realizadas com 20 pl/mm foram classificadas como excelentes pelos avaliadores, contra 33% com 40 pl/mm, estatisticamente significativa. Discussão: ao avaliar a reabsorção radicular, obteve-se uma acurácia diagnóstica igual para os dois protocolos sem distinção, estatisticamente significativa, entre localização ou profundidade. Conclusão: tendo em vista que para os examinadores imagens com 20 pl/mm foram satisfatórias, com percentual de qualidade maior quando comparado a imagens obtidas com 40 pl/ mm, este estudo indica o emprego de imagens com 20 pl/mm para avaliação inicial de suspeita de reabsorções nas raízes dentárias.


Introduction: the detection of tooth root resorption is carried out by means of imaging tests, as it often does not present a clinical sign and symptom. Among the imaging tests available, the periapical radiographic examination is indicated for diagnosis, prognosis and monitoring of root resorption. Objective: the study aims to investigate the relationship of different spatial resolutions in the diagnosis of root resorption. Methods: Artificial external root resorptions were simulated using burs by drilling to the entire depth in different locations at the apical and buccal thirds of 15 (fifteen) lower incisors were worn, radiographed on a dry skull, before and after wear. The radiographic technique was performed using the VistaScan system (Durr Dental, Bietigheim-Bissingen, Germany), CS 2200 device (Carestream Dental LLC, Atlanta-GA, USA) using an exposure time of 0.15 seconds and scanned under different resolutions protocols, namely, 20 pairs of lines per millimeters (pl/mm) and 40 pl/mm. Subsequently, two experienced evaluators performed analyzes of these images without prior knowledge of the scanning resolution. Results: seventy-five percent of the radiographs taken at 20 pl/mm were rated as excellent by the evaluators, against 33% at 40 pl/mm, a statistically significant difference. Discussion: When assessing root resorption, a similar diagnostic accuracy was obtained for the two protocols without a statistically significant distinction between location or depth. Conclusions: Considering that for examiners images with 20 pl/mm were satisfactory, with a percentage of quality greater than 40 pl/mm, this study indicates the use of 20 pl/mm for initial evaluation of suspected root resorption.


Subject(s)
Humans , Root Resorption , Tooth Root , Diagnostic Imaging , Radiography, Dental, Digital , Research , Dimensional Measurement Accuracy , Incisor
3.
Acta odontol. Colomb. (En linea) ; 11(2): 66-85, 2021. tab, ilus, ilus, ilus, ilus, ilus, ilus, ilus, tab
Article in Spanish | LILACS, COLNAL | ID: biblio-1344621

ABSTRACT

Objetivo: establecer un protocolo estandarizado de observación de la tomografía computarizada de haz cónico (CBCT) en endodoncia, para determinar de manera sistemática las dimensiones de las lesiones apicales crónicas. Métodos: análisis y aplicación de las herramientas de los software tomográficos de haz cónico usados para la exploración de tejidos dentales y periapicales, con previa revisión bibliográfica del tema. Posteriormente, se diseñaron los pasos sistemáticos estandarizados de observación y medición de la imagen tomográfica dental en endodoncia, con lo cual se estableció el protocolo. Finalmente, se entrenaron dos endodoncistas en la aplicación del protocolo para medir sistemáticamente las dimensiones de lesiones apicales crónicas (altura, profundidad y ancho) Resultados: se generó un documento con material gráfico sobre los pasos a seguir del protocolo estandarizado y se realizó una prueba estadística de concordancia, que evidenció un alto grado de coincidencia entre las mediciones hechas por las endodoncistas entrenadas (observadoras 2 y 3) frente a las de una radióloga experta (observadora 1). El mayor grado de acuerdo se encontró entre las observadoras 1 y 2 en la vista sagital al evaluar la altura de la lesión (ICC: 0.9997545), mientras que, las observadoras 1 y 3 lograron el mayor grado de acuerdo en la vista axial (ICC 0.9996737, IC 95%) al evaluar la profundidad de la lesión. Conclusión: la aplicación de este protocolo sencillo, sistemático y estandarizado de observación de tomografía dental permite evaluar de manera confiable, reproducible y precisa la imagen de la periodontitis apical y, a su vez, alcanzar un alto grado de concordancia cuando se miden lesiones apicales.


Objective: Establish a standardized protocol for the observation of Cone Beam Computed Tomography (CBCT) in endodontics, to systematically determine the dimensions of chronic apical lesions. Methods: Analysis and application of the tools of the specific Cone Beam Computed Tomography software for the exploration of dental and periapical tissues, prior literature review of the subject. Subsequently, the design of standardized systematic steps of observation and measurement of the dental tomographic image in Endodontics, thus establishing the Protocol. Finally, training of 2 Endodontists in the application of the Protocol by an expert Radiologist, measuring the dimensions of chronic apical lesions (height, depth and width) in 45 high-resolution conical beam dental tomographs and checking its usefulness, through a concordance test using the Intraclass Correlation Index (ICC). Results: A written document was generated with explanatory graphic material on the steps to follow by the Standardized Protocol and a statistical concordance test was carried out that evidenced a high degree of agreement between the measurements of the trained endodontists (observers 2 and 3) against the expert radiologist (observer 1). The highest degree of agreement was found among observers 1 and 2 in the sagittal view when assessing the height of the lesion (ICC: 0.9997545), while observers 1 and 3 achieved the highest degree of agreement in axial vision (ICC 0.9996737, 95% CI) when assessing the depth of the lesion. Conclusion: The application of this simple, systematic and standardized protocol for the observation of dental tomography in clinical practice makes it possible to reliably, reproducibly and accurately assess the image of apical periodontitis, prior observer training, allowing a high degree of concordance to be achieved when apical lesions are measured.


Subject(s)
Humans , Periapical Periodontitis , Cone-Beam Computed Tomography , Dimensional Measurement Accuracy
4.
Braz. dent. sci ; 24(1): 1-13, 2021. tab, ilus
Article in English | LILACS, BBO | ID: biblio-1145439

ABSTRACT

Objective: The purpose of this study is to evaluate the influence of the type of scanner and scanning direction on the accuracy of the final cast. Material and Methods: A partial master cast was used as a reference. A total of 128 scans were obtained and divided into two groups: the conventional method and the digital method. The digital group was divided into three groups: TRIOS 3, Omnicam and CS 3600. Each of these groups was subdivided according to the scanning direction, and each scan was overlaid on the digital reference cast to measure the trueness and precision of the procedures. Results: The overall precision values for the type of impression were 59.89 ± 13.08 µm for conventional and 13.42 ± 4.28 µm for digital; the values for trueness were 49.37 ± 19.13 µm for conventional and 53.53 ± 4.97 µm for digital; the scanning direction trueness values were 53.05 ± 4.36 µm for continuous and 54.03 ± 5.52 µm for segmented; and the precision values were 14.18 ± 4.67 µm for continuous and 12.67 ± 3.75 µm for segmented (p> 0.05). For the scanner type, the trueness values were 50.06 ± 2.65 µm for Trios 3, 57.45 ± 4.63 µm for Omnicam, and 52.57 ± 4.65 µm for Carestream; and those for precision were 11.7 ± 2.07 µm for Trios 3, 10.09 ± 2.24 µm for Omnicam, and 18.49 ± 2.42 µm for Carestream (p <0.05). Conclusions: The digital impression method is the most favorable method regarding precision; in terms of trueness, there are no differences between the types of impressions. (AU)


Objetivo: O objetivo deste estudo é avaliar a influência do tipo de técnica de moldagem, tipo de escâner intraoral e direção do escaneamento na precisão do modelo final. Material e Métodos: Um modelo parcial mestre foi usado como referência. Um total de 128 escaneamentos foi obtido e dividido em dois grupos: o método convencional (n = 32) e o método digital (n = 96). O grupo digital foi dividido em três grupos: TRIOS 3 (n = 32), Omnicam (n = 32) e CS 3600 (n = 32). Cada um desses grupos foi subdividido de acordo com a direção do escaneamento (n = 16), e cada escaneamento foi sobreposto ao modelo de referência digital para medir a veracidade e precisão dos procedimentos. Resultados: Os valores gerais de precisão para o tipo de impressão foram 59,89 ± 13,08 µm para convencional e 13,42 ± 4,28 µm para digital; os valores de veracidade foram 49,37 ± 19,13 µm para convencional e 53,53 ± 4,97 µm para digital; os valores de veracidade para a direção de digitalização foram 53,05 ± 4,36 µm para contínua e 54,03 ± 5,52 µm para segmentada; e os valores de precisão foram 14,18 ± 4,67 µm para contínua e 12,67 ± 3,75 µm para segmentada (p> 0,05). Para o tipo de scanner, os valores de veracidade foram 50,06 ± 2,65 µm para Trios 3, 57,45 ± 4,63 µm para Omnicam e 52,57 ± 4,65 µm para Carestream; e os de precisão foram 11,7 ± 2,07 µm para Trios 3, 10,09 ± 2,24 µm para Omnicam e 18,49 ± 2,42 µm para Carestream (p <0,05). Conclusões: O método de moldagem digital é o método mais favorável em relação à precisão; em termos de veracidade, não há diferenças entre os tipos de impressão (AU)


Subject(s)
Dental Impression Technique , Dimensional Measurement Accuracy , Data Accuracy
5.
Article in English | LILACS, BBO | ID: biblio-1154999

ABSTRACT

ABSTRACT Objective: To evaluate the intra-examiner and inter-examiner reliability of linear and curvilinear measurements for the complete assessment of implant sites and jaw pathologies using Cone-Beam Computed Tomography (CBCT). Material and Methods: Fifty cone-beam computed tomographic images of patients were retrieved from the archives of Dentomaxillofacial Radiology. CBCT images taken for implant planning and evaluation of intrabony jaw pathologies (benign cyst/tumor) were included. Two expert oral and maxillofacial radiologists analyzed the images independently and made the measurements. The images for implant planning were analyzed for width, the height of the edentulous site, and the qualitative analysis of bone in the region. Jaw pathologies were assessed for linear dimensions and curvilinear measurements. Results: The inter-observer measurement error for implant site analysis ranged from 0.12 to 0.42 mm with almost perfect agreement (ICC: 0.94 to 1). The inter-observer measurement error for jaw pathology was 0.09 to 0.25 mm (ICC: 0.98-1). Curvilinear measurements showed perfect agreement between the observers. The intraobserver reliability for the various parameters used for the assessment of the implant site and jaw pathologies indicated almost perfect agreement. Conclusion: Reliability between the radiologists is high for various measurements on CBCT images taken for implant planning and jaw pathologies.


Subject(s)
Humans , Pathology, Oral , Diagnostic Imaging/instrumentation , Radiographic Image Interpretation, Computer-Assisted/instrumentation , Dental Implantation/instrumentation , Cone-Beam Computed Tomography , Mandible/diagnostic imaging , Retrospective Studies , Observational Studies as Topic/methods , Dimensional Measurement Accuracy , Radiologists , India/epidemiology , Jaw , Mandible/pathology
7.
Rev. Bras. Odontol. Leg. RBOL ; 7(3): [2-11], 20201206.
Article in Portuguese | LILACS | ID: biblio-1281457

ABSTRACT

A análise da impressão labial, conhecida como queiloscopia, pode ser útil em casos específicos de investigação forense. Este trabalho experimental teve como objetivos principais investigar a precisão na análise dos tipos de sulcos labiais, da espessura labial e da localização da comissura labial e observar diferenças estatísticas entre a classificação labial e o sexo dos indivíduos. A amostra foi composta por 100 voluntários. Foi realizada a mensuração da espessura labial com paquímetro, análise visual da comissura labial e classificação dos sulcos labiais por meio de sua impressão, sendo testada a concordância intra- e inter-observador (três avaliadores) pela reavaliação de 30% da amostra. Os resultados mostraram que é possível realizar a classificação das análises labiais, sendo que o tipo de lábio mais frequente encontrado foi o tipo I (34,25%). Em relação à espessura, o tipo misto, e a comissura do tipo abaixada, foram as predominantes, com 66% e 59% respectivamente. Além disso, observou-se que não houve diferença estatística entre os indivíduos do sexo masculino e feminino nas classificações estudadas. Em relação à precisão ao fazer as classificações as técnicas utilizadas foram consideradas aplicáveis pelos pesquisadores, uma vez que a classificação foi possível e a concordância observada foi de forte a moderada, exceto em um dos quadrantes da classificação da impressão labial


Subject(s)
Humans , Male , Female , Dimensional Measurement Accuracy , Forensic Dentistry , Lip
8.
Rev. cuba. estomatol ; 57(2): e2366, abr.-jun. 2020.
Article in Portuguese | LILACS, CUMED | ID: biblio-1126508

ABSTRACT

RESUMO Introdução: O escâner intraoral é um aparelho que surge como alternativa aos métodos convencionais de moldagem utilizando a técnica de impressão digital. O meio acadêmico vem realizando diversos estudos para avaliar a real efetividade da tecnologia e sua aplicabilidade clínica. Objetivo: Analisar resultados obtidos em estudos sobre escâneres intraorais na área de implantodontia quanto ao tipo de escâneres e acurácia, tempo de trabalho e preferência do operador e do paciente. Métodos: Foram realizadas buscas de artigos nas bases de dados "Pubmed" e "SciELO" utilizando os seguintes descritores: «intraoral AND scanner AND implant¼, «digital AND scanner AND implant¼ e «digital AND impression AND implant¼ em inglês, português e espanhol respectivamente. Os critérios de inclusão foram: artigos de avaliação clínica (in vivo) ou laboratorial (in vitro) que avaliassem o uso da técnica de escaneamento intra-oral para impressão digital de implantes com acesso integral, escritos em português, inglês ou espanhol e publicados a partir de 2013. Análise e integração da informação: Foram encontrados 158 artigos. Após a análise e seleção, 35 artigos foram incluídos, sendo 28 laboratoriais e 7 clínicos. Apesar de limitações na padronização dos estudos, percebemos o potencial e a viabilidade da técnica digital, com resultados clínicos e de acurácia favoráveis e vantagens como redução do tempo e etapas de trabalho, comunicação dinâmica com os laboratórios, preferência de pacientes e estudantes de odontologia e facilidade de incorporação por profissionais já experientes. Conclusões: Estudos laboratoriais indicam que, além de vantagens quanto ao uso de materiais de moldagem, comunicação com os laboratórios e facilidade de manipulação, a técnica digital pode alcançar resultados superiores aos da técnica convencional, assim, a técnica se mostra promissora para a área de implantodontia sendo necessário, contudo, estudos futuros, especialmente in vivo, para avaliar a consistência dos resultados clínicos(AU)


RESUMEN Introducción: El escáner intrabucal es un aparato que surge como una alternativa frente a los métodos convencionales de moldeo, y el medio académico viene realizando diversos estudios para evaluar la real efectividad de esta tecnología y su aplicabilidad clínica. Objetivo: Analizar resultados obtenidos en estudios sobre escáneres intrabucales en el área de implantología en cuanto a los tipos de escáneres y la exactitud, tiempo de trabajo y preferencia del operador y del paciente. Métodos: Se realizaron búsquedas en las bases de datos "PubMed" y "SciELO" utilizando los siguientes descriptores: "intraoral AND scanner AND implant", "digital AND scanner AND implant" and "digital AND impression AND implant" en inglés, portugués y español, respectivamente. Los criterios de inclusión fueron: artículos clínicos o de laboratorio para evaluar el uso de la técnica de escaneamiento digital de los implantes, con acceso completo al artículo, escrito en portugués, inglés o español y publicados desde 2013. Análisis e integración de la información: Se encontraron 158 artículos. Después del análisis y selección, 35 artículos fueron incluidos, siendo 28 de laboratorio y 7 clínicos. A pesar de las limitaciones en la estandarización de los estudios, percibimos el potencial y la viabilidad de la técnica digital, con resultados clínicos y de precisión favorables y ventajas como reducción del tiempo y etapas de trabajo, comunicación dinámica con los laboratorios, preferencia de pacientes y estudiantes de odontología y facilidad de incorporación de profesionales experimentados. Conclusiones: Los estudios de laboratorio indican que, además de ventajas en cuanto al uso de materiales de moldeo, comunicación con los laboratorios y facilidad de manipulación, la técnica digital puede alcanzar resultados superiores a los de la técnica convencional, por lo que el uso de escáneres intrabucales se muestra prometedor para el área de implantología siendo necesario, sin embargo, estudios futuros, especialmente in vivo, para evaluar la consistencia de los resultados clínicos(AU)


ABSTRACT Introduction: Intraoral scanners are devices that emerged as an alternative to conventional impression methods. A variety of studies have been conducted to evaluate the actual effectiveness of this technology and its clinical applicability. Objective: Analyze the results obtained by studies about intraoral scanners in the area of implantology in terms of types, accuracy, working time, and operator and patient preference. Methods: A search was conducted in the databases PubMed and SciELO using the following descriptors: "intraoral AND scanner AND implant", "digital AND scanner AND implant" and "digital AND impression AND implant" in English, Portuguese and Spanish. The inclusion criteria were the following: clinical or laboratory papers evaluating the use of digital implant scanning technique, full access to the paper, written in Portuguese, English or Spanish and published as of the year 2013. Data analysis and integration: Of the 158 papers obtained and analyzed, 35 were selected: 28 laboratory and 7 clinical. Despite the limitations in the standardization of the studies, we perceive the potential and viability of the digital technique, with favorable clinical and accuracy results, as well as advantages such as a reduction in work time and stages, dynamic communication with laboratories, preference by patients and dental students and ease of technical incorporation by experienced dentists. Conclusions: Laboratory studies indicate that, in addition to the advantages concerning the use of impression materials, communication with laboratories and ease of manipulation, the digital technique may achieve better results than conventional impression techniques. The use of intraoral scanners is therefore a promising technique for the area of ​​implantology. However, further studies shouldbe conducted, especially in vivo, to evaluate the consistency of the clinical results obtained(AU)


Subject(s)
Humans , Signal Processing, Computer-Assisted , Dental Implants/trends , Review Literature as Topic , Databases, Bibliographic , Dimensional Measurement Accuracy
9.
Ciênc. Saúde Colet ; 25(3): 1073-1082, mar. 2020. tab, graf
Article in Portuguese | LILACS | ID: biblio-1089475

ABSTRACT

Resumo O objetivo deste estudo foi analisar a validade e a acurácia do Índice de Massa Corporal (IMC) e da Circunferência da Cintura (CC) na avaliação de obesidade avaliada pelo excesso de gordura corporal (GC) e propor pontos de corte mais adequados para idosos. Os pontos propostos da literatura IMC (25,27 ou 30 kg/m2) e CC (≥ 102 cm-homens e ≥ 88 cm-mulheres ou ≥ 90 cm-homens e ≥ 80 cm-mulheres) foram avaliados conforme densitometria corporal total. A elevada GC foi definida por percentil > 90. Dos 132 idosos, 60,6% eram mulheres de 60-91 anos. Os pontos de corte recomendados de IMC ≥ 25 e ≥ 27kg/m2 apresentaram desempenhos similares, sendo que o IMC ≥ 30kg/m2 apresentou alta especificidade e baixa sensibilidade no sexo masculino e melhor desempenho para GC nas mulheres. Os pontos de corte convencionais de CC não apresentaram boa sensibilidade/especificidade. Foram propostos novos pontos de corte para IMC (masculino-25 kg/m2; feminino-26,6 kg/m2) e CC (masculino-98,8 cm; feminino-77,8 cm). Estes valores demonstraram sensibilidade e especificidade > 74% e acurácia > 76%. As áreas sob a curva foram > 0,86. O presente estudo propõe a utilização de pontos de corte mais acurados para diagnóstico de obesidade/GC em idosos, sendo para homens IMC 25kg/m2 e CC de 98,8cm e para mulheres IMC de 26,6kg/m2 e CC de 77,8cm, com melhores níveis de sensibilidade e especificidade.


Abstract The main objectives were to analyse the validity and accuracy of Body Mass Index (BMI) and Waist Circumference (WC) to evaluate obesity by excess of body fat in older adults and to identify more adequate cut-off points for this age group. The recommended cut-off points for BMI (25, 27 or 30 kg/m2) and WC (≥ 102 cm for men and ≥ 88 cm for women or ≥ 90cm for men and ≥ 80 cm for women) were compared to the total body densitometry. BF was defined by a value higher than the 90th percentile. Out of the 132 participants, 61% were women and aged between 60 and 91 years. The recommended cut-off points of BMI ≥ 25kg/m2 and BMI ≥ 27 kg/m2 showed similar performances. BMI ≥ 30 kg/m2 showed high specificity but low sensitivity to identify BF in men and better performance in women. Conventional WC cut-off points showed low sensitivity and specificity. Based on our analyses, new cut-off points for BMI (25 kg/m2 for men and 26.6 kg/m2 for women) and WC (98.8 cm for men and 77.8cm for women) were proposed. The new cut-off points showed sensitivity and specificity values > 74% and accuracy > 76%. The areas under the curve (ROC) were > 0.86. The new BMI and WC cut-off points proposed in the present study for the diagnosis of obesity in older adults showed the best levels of sensitivity and specificity for this age group.


Subject(s)
Humans , Male , Female , Aged , Aged, 80 and over , Body Mass Index , Waist Circumference , Dimensional Measurement Accuracy , Predictive Value of Tests , Sensitivity and Specificity , Middle Aged , Obesity/epidemiology
10.
Acta Medica Philippina ; : 454-461, 2020.
Article in English | WPRIM | ID: wpr-877187

ABSTRACT

@#Background. The use of 3D printing in medical education, prosthetics, and preoperative planning requires dimensional accuracy of the models compared to the replicated tissues or organs. Objective. To determine the dimensional accuracy of 3D-printed models replicated from metacarpal bones from cadavers. Methods. Fifty-two models were 3D-printed using fused deposition modeling (FDM), stereolithography (SLA), digital light processing (DLP), and binder jetting method from 13 right first metacarpal bones of cadavers from the College of Medicine, University of the Philippines Manila. Six dimensional parameters of the 3D-printed models and their control bones were measured using 0.01 mm calipers — length, midshaft diameter, base width, base height, head width, and head height. Mean measurements were compared using non-inferiority testing and multidimensional scaling. Results. Mean measurements of the 3D-printed models were slightly larger than their control bones (standard deviation range: 1.219-4.264; standard error range, 0.338-1.183). All models were found to be at least 90% accurate and statistically non-inferior compared to control bones. DLP-printed models were the most accurate (base width, 99.62 %) and most similar to their control bone (–0.05, 90% CI –0.34, 0.24). Through multidimensional scaling, DLP-printed models (coordinate = 0.437) were the most similar to the control bone (coordinate = 0.899). Conclusion. The 3D-printed models are dimensionally accurate when compared to bones.


Subject(s)
Stereolithography , Dimensional Measurement Accuracy , Printing, Three-Dimensional
11.
Einstein (Säo Paulo) ; 18: eAO4662, 2020. tab, graf
Article in English | LILACS | ID: biblio-1056076

ABSTRACT

ABSTRACT Objective To assess accuracy of multiparametric magnetic resonance of the prostate to estimate gland volume, comparing the results with transrectal ultrasound and surgical specimen. Methods A retrospective study of 85 patients who underwent multiparametric magnetic resonance and transrectal ultrasound (for fusion image-guided biopsy) before radical prostatectomy. Prostate measurements were obtained from magnetic resonance axial and sagittal T2-weighted images and ultrasound; the prostate volume was determined using the ellipsoid formula. The results were compared with the surgical specimen weight. Maximum interval between multiparametric magnetic resonance imaging, transrectal ultrasound, and prostatectomy was 6 months. Results The prostate volume measured by multiparametric magnetic resonance imaging was 18-157cm3 (mean of 49.9cm3) and by transrectal ultrasound, 22-165cm3 (mean of 54.9cm3); the surgical specimen weight was 20-154g (mean of 48.6g), with no statistical differences. Based on the values obtained from imaging examinations, the prostate volume obtained was very close to the real prostatic weight, and the measures by multiparametric magnetic resonance were slightly more precise. Conclusion Prostate volume measured by multiparametric magnetic resonance imaging and transrectal ultrasound showed similar values, and excellent agreement with real prostate weight of the surgical specimens. Prostate volume measured by magnetic resonance has been increasingly used in the clinical practice, and its value enables appropriate therapeutic planning and control of patients.


RESUMO Objetivo Avaliar a acurácia da ressonância magnética multiparamétrica da próstata para estimativa do volume da glândula, comparando seus resultados com a ultrassonografia transretal e correlacionando com o volume obtido da peça cirúrgica. Métodos Estudo retrospectivo incluindo 85 pacientes submetidos à ressonância magnética e, posteriormente, à ultrassonografia transretal (para orientação de biópsia com fusão de imagens) e, a seguir, à prostatectomia radical. As dimensões prostáticas foram obtidas na ressonância a partir das imagens nos planos axial e sagital em sequências ponderadas em T2 e, assim como na ultrassonografia, o volume foi calculado a partir do método da elipsoide. Os valores foram comparados com o peso prostático pós-cirúrgico. O intervalo máximo entre a ressonância e ultrassonografia e prostatectomia foi de 6 meses. Resultados O volume prostático obtido por ressonância magnética foi de 18 a 157cm3(média de 49,9cm3); pela ultrassonografia transretal, foi de 22 a 165cm3(média de 54,9cm3); e o peso da peça cirúrgica foi de 20 a 154g (média de 48,6g), sem diferenças estatísticas. A partir do valor obtido por esses métodos de imagem, provou-se que o volume prostático obtido aproximou-se bastante do peso real da próstata, com discreta maior precisão das medidas obtidas por ressonância magnética multiparamétrica. Conclusão As medidas do volume prostático adquiridas pela ressonância magnética e pela ultrassonografia transretal são semelhantes entre si, com excelente concordância com os pesos reais das próstatas obtidos das peças cirúrgicas. A avaliação desse dado, a partir da ressonância, método cada vez mais utilizado na prática clínica, permite o adequado planejamento terapêutico e o controle dos pacientes.


Subject(s)
Humans , Male , Adult , Aged , Aged, 80 and over , Prostate/anatomy & histology , Prostatic Neoplasms/diagnostic imaging , Ultrasonography/methods , Multiparametric Magnetic Resonance Imaging/methods , Organ Size , Prostate/diagnostic imaging , Prostatectomy , Prostatic Neoplasms/pathology , Retrospective Studies , Image-Guided Biopsy/methods , Dimensional Measurement Accuracy , Middle Aged
12.
Rev. latinoam. enferm. (Online) ; 28: e3299, 2020. tab, graf
Article in English | LILACS, BDENF | ID: biblio-1126959

ABSTRACT

Objective: to evaluate the use of the 2D-FlexRuler as a facilitating tool for the early calculation of the predictive scar factor of chronic wounds. Method: a descriptive study with a quantitative, experimental, longitudinal and prospective approach. The sample consisted of 22 outpatients. 32 chronic wounds were analyzed. The wound edges were identified and drawn on the 2D-FlexRuler. The calculations of the areas of chronic wounds were obtained by manual, traditional methods, by software and Matlab algorithm. These areas were compared with each other to determine the efficiency of the proposed ruler in relation to traditional methods. Results: the calculation of the wound area by the traditional method and Kundin's coefficient show average errors greater than 40%. The manual estimation of the area with the 2D-FlexRuler is more accurate in relation to traditional measurement methods, which were considered quantitatively disqualified. When compared with the reference method, for example, the Klonk software, the data obtained by 2D-FlexRuler resulted in an error of less than 1.0%. Conclusion: the 2D-FlexRuler is a reliable metric platform for obtaining the anatomical limits of chronic wounds. It facilitated the calculation of the wound area under monitoring and allowed to obtain the scar predictive factor of chronic wounds with precocity in two weeks.


Objetivo: avaliar o uso da régua 2D-FlexRuler como ferramenta facilitadora para o cálculo precoce do fator preditivo cicatricial de feridas crônicas. Método: estudo descritivo com abordagem quantitativa, experimental, longitudinal e prospectiva. A amostra foi de 22 pacientes ambulatoriais. Foram analisadas 32 feridas crônicas. As bordas das feridas foram identificadas e desenhadas na 2D-FlexRuler. Os cálculos das áreas das feridas crônicas foram obtidos pelos métodos manuais, tradicionais, por softwares e algoritmo Matlab. Essas áreas foram comparadas entre si para determinar a eficiência da régua proposta em relação aos métodos tradicionais. Resultados: o cálculo da área da ferida pelo método tradicional e coeficiente de Kundin demonstram erros médios maiores do que 40%. A estimativa manual da área com a 2D-FlexRuler é mais exata em relação aos métodos tradicionais de medição, os quais foram considerados quantitativamente desqualificados. Quando comparada com o método de referência, i.e., o software Klonk, os dados obtidos pela 2D-FlexRuler resultaram em um erro menor que 1,0%. Conclusão: a régua 2D-FlexRuler é uma plataforma métrica confiável para a obtenção dos limites anatômicos de feridas crônicas. Facilitou o cálculo da área da ferida sob monitoramento e permitiu obter o fator preditivo cicatricial de feridas crônicas com precocidade em duas semanas.


Objetivo: evaluar el uso de la regla 2D-FlexRuler como herramienta facilitadora para el cálculo temprano del factor predictivo de cicatrices en heridas crónicas. Método: estudio descriptivo con enfoque cuantitativo, experimental, longitudinal y prospectivo. La muestra consistió en 22 pacientes ambulatorios. Se analizaron 32 heridas crónicas. Los bordes de la herida fueron identificados y dibujados en 2D-FlexRuler. Los cálculos de las áreas de heridas crónicas se obtuvieron por métodos manuales, tradicionales, por software y algoritmo Matlab. Estas áreas se compararon entre sí para determinar la eficiencia de la regla propuesta en relación con los métodos tradicionales. Resultados: el cálculo del área de la herida por el método tradicional y el coeficiente de Kundin muestran errores promedio superiores al 40%. La estimación manual del área con 2D-FlexRuler es más precisa en relación con los métodos de medición tradicionales, que se consideraron descalificados cuantitativamente. Al ser comparados con el método de referencia, es decir, el software Klonk, los datos obtenidos por 2D-FlexRuler arrojaron un error de menos del 1,0%. Conclusión: la regla 2D-FlexRuler es una plataforma métrica confiable para obtener los límites anatómicos de las heridas crónicas. Facilitó el cálculo del área de la herida bajo monitoreo y permitió obtener el factor predictivo de cicatriz de heridas crónicas con precocidad en dos semanas.


Subject(s)
Weights and Measures , Wound Healing , Wounds and Injuries , Software , Cicatrix , Dimensional Measurement Accuracy , Surgical Wound , Metronidazole
13.
Article in English | LILACS, BBO | ID: biblio-1135481

ABSTRACT

Abstract Objective: To verify the concordance in the evaluation of the apical limit of obturation (ALO) in filled root canals of primary teeth between digital and visual methods. Material and Methods: Twenty periapical radiographs of endodontically treated primary teeth were digitalized and evaluated by an endodontics specialist (E1), a PhD pediatric dentist (E2), and a MSc general dentist (E3). Calibrated evaluators (Kappa = 1.00) analysed the images in a light-isolated environment two times (D1 and D2) with a one-week interval between evaluations. ALO scores were categorized as overfilled, flush-filled and underfilled. Results: The intra-rater reliability between methods was 0.82 (D1) and 0.75 (D2) for E1, 0.93 (D1 and D2) for E2, and 0.94 (D1 and D2) for E3. Inter-rater reliability ranged from 0.71 (E1 × E3) and 1.00 (E1 × E2) for the visual method to 0.76 (E1 × E3) and 0.88 (E1 × E2) for the digital method. Spearman correlation coefficients showed a similar ranking among the evaluators. There was greater disagreement among the underfilled and ideal scores. For all evaluators, the digital method favoured the identification of the ideal score. Conclusion: Both methods are suitable for the determination of the ALO of filled primary teeth and can be used in clinical practice.


Subject(s)
Humans , Root Canal Obturation , Root Canal Therapy/instrumentation , Tooth, Deciduous , Pilot Projects , Dental Pulp Cavity , Dimensional Measurement Accuracy , Brazil , Radiography, Dental/instrumentation , Statistics, Nonparametric , Dentists
15.
Acta amaz ; 49(2): 91-96, abr. - jun. 2019.
Article in English | LILACS | ID: biblio-1119143

ABSTRACT

Forest inventory procedures are of utmost importance to studies of wood volume stocks, and forest structure and diversity, which provide relevant information to public policies, management plans and ecological research. The present work focused on the performance of inventory techniques in the Amazon region to evaluate wood volume stocks with higher levels of accuracy while maintaining sampling intensity fixed. Two sampling processes were assessed: simple random sampling and two-stage cluster sampling. The processes were evaluated through the allocation of sampling units with different dimensions, and the effectiveness of the generated estimators was analyzed as a function of stand density and basal area. Simple random sampling resulted in the smallest errors, reaching 9% when all species were sampled together. The method depicted forest phytosociological parameters with greater sensitivity, whereas two-stage cluster sampling produced the least accurate estimators and presented slower responses to variation in phytosociological parameters. (AU)


Subject(s)
Forests , Amazonian Ecosystem , Dimensional Measurement Accuracy
16.
Pesqui. bras. odontopediatria clín. integr ; 19(1): 4387, 01 Fevereiro 2019. tab
Article in English | LILACS, BBO | ID: biblio-997978

ABSTRACT

Objective: To compared the accuracy of digital radiography in the diagnosis of interproximal caries in permanent teeth with conventional radiography and visual examination. Material and Methods: In this descriptive-analytical study, 78 human premolars, which seem normal in primary examination, are mounted on the plaster in a pair-wise manner and their caries are visually evaluated. Conventional and digital radiographic images are taken under the same conditions and their caries are graded with Confidence Score. To determine the golden standard, after mesiodistal incision, the teeth are examined using stereomicroscopy. Finally, the results obtained by visual observation and conventional radiography as well as digital images were compared with those obtained from the stereomicroscopy to determine their accuracy in detecting the interproximal caries. Results: The consistencies between the visual, digital, and conventional methods with the standard method (microscopic histology) are 53%, 78%, and 50% respectively - all of them are significant (p<0.05). The highest and the lowest sensitivities are related to the digital (96%) and visual (88%) methods respectively, while the highest and lowest specificities are related to the digital (79%) and conventional (50%) methods respectively. The highest and lowest positive predictive value is related to the digital (79%) and conventional (80%) methods respectively. The highest and lowest negative predictive values are related to the digital (90%) and visual (71%) methods respectively. Compared with the standard methodology, the most accurate diagnostic accuracy can be seen for the digital method (91%). Conclusion: There is no significant difference in the diagnosis of interproximal caries by different methods, and the only advantage of digital radiography, compared with the conventional one, is storing radiographs without losing important information and the lower dose of radiation for the patient.


Subject(s)
Humans , Bicuspid , Dentition, Permanent , Radiography, Dental, Digital/instrumentation , Dental Caries/diagnosis , Dimensional Measurement Accuracy , Chi-Square Distribution , Epidemiology, Descriptive , Radiography, Bitewing/instrumentation , Iran
17.
Pesqui. bras. odontopediatria clín. integr ; 19(1): 4137, 01 Fevereiro 2019. tab
Article in English | LILACS, BBO | ID: biblio-998205

ABSTRACT

Objective: To evaluate the dimensional changes in three types of alginate following three different delay times after casting. Material and Methods: In this laboratory study, a maxillary arch-shaped stainless steel model was prepared and three pins with similar and determined diameters and heights were placed (one at mid-line and two on the underside of the model) as reference points to compare the dimensional stability of the three types of alginates. A special metal tray was made from the main model. The main moldel was imprisoned by the metal tray, and these were kept for a specific time in a humid environment. Gypsum Type 4 was poured over the impression to obtain 90 gypsum casts for three types of alginate. The dimensions of casts obtained from each alginate were compared in two lateral and anterior-posterior dimensions, they were compared with each other, and the alginates were also compared to the main model. Results: At a time interval of 15 minutes, the dimensional accuracy of the casts obtained from the three types of alginates, with the main model in both anterior-posterior and transverse dimensions was not significantly different (p<0.05); but there was a significant difference at 60 minutes and 24 hours in both dimensions (p<0.05). Although there was no significant difference between the alginates in both dimensions and all three studied time periods, the least difference with the main model was related to Zhermack and the highest difference was related to Golchai alginates. Pairwise comparisons showed that none of the samples had a significant difference in terms of dimensions. Conclusion: The dimensional stability of alginate was a time-dependent type of alginate and had no significant effect on the dimensional accuracy of casts.


Subject(s)
Dental Impression Technique , Models, Dental , Alginates , Dimensional Measurement Accuracy , Analysis of Variance , Dental Impression Materials , Iran
18.
Article in English | WPRIM | ID: wpr-763989

ABSTRACT

PURPOSE: Cone-beam computed tomography (CBCT) is widely used for 3-dimensional assessments of cranio-maxillofacial relationships, especially in patients undergoing orthognathic surgery. We have introduced, for reference in CBCT cephalometry, an anatomical mid-sagittal plane (MSP) identified by the nasion, the midpoint between the posterior clinoid processes of the sella turcica, and the basion. The MSP is an updated version of the median plane previously used at our institution for 2D posterior-anterior cephalometry. This study was conducted to test the accuracy of the CBCT measures compared to those obtained using standard posterior-anterior cephalometry. MATERIALS AND METHODS: Two operators measured the inter-zygomatic distance on 15 CBCT scans using the MSP as a reference plane, and the CBCT measurements were compared with measurements made on patients' posterior-anterior cephalograms. The statistical analysis evaluated the absolute and percentage differences between the 3D and 2D measurements. RESULTS: As demonstrated by the absolute mean difference (roughly 1 mm) and the percentage difference (less than 3%), the MSP showed good accuracy on CBCT compared to the 2D plane, especially for measurements of the left side. However, the CBCT measurements showed a high standard deviation, indicating major variability and low precision. CONCLUSION: The anatomical MSP can be used as a reliable reference plane for transverse measurements in 3D cephalometry in cases of symmetrical or asymmetrical malocclusion. In patients who suffer from distortions of the skull base, the identification of landmarks might be difficult and the MSP could be unreliable. Becoming familiar with the relevant software could reduce errors and improve reliability.


Subject(s)
Cephalometry , Cone-Beam Computed Tomography , Dimensional Measurement Accuracy , Humans , Malocclusion , Orthognathic Surgery , Sella Turcica , Skull Base
19.
Rev. odontol. UNESP (Online) ; 48: e20190098, 2019. tab, ilus
Article in Portuguese | LILACS, BBO | ID: biblio-1099193

ABSTRACT

Resumo Introdução Recentemente, vêm surgindo no mercado alguns alginatos de armazenamento prolongado. Não há, no entanto, um consenso na literatura a respeito da estabilidade dimensional destes materiais durante este armazenamento Objetivo Avaliar, por meio de método prático experimental, a estabilidade dimensional de um alginato de armazenamento tardio. Material e método O material de moldagem utilizado foi o alginato Hydrogum 5 (Zhermack). Uma matriz metálica cilíndrica foi utilizada para a realização das moldagens, com 38 mm de diâmetro externo, 30 mm de diâmetro interno e cuja superfície superior apresenta três linhas paralelas entre si com 25 mm de comprimento e 20, 50 e 75 µm de largura. Após o tempo de geleificação do material de moldagem, 16 moldes foram colocados em um umidificador e essas amostras foram fotografadas utilizando-se uma câmera digital (Canon EOS Rebel 3Ti, Canon) associada a um software para análise das imagens obtidas (ImageJ 1.52a, U.S. National Institutes of Health; DI). A calibragem da régua foi 10 cm e, posteriormente, três linhas foram medidas três vezes, para se obter uma média dos comprimentos das linhas. As amostras foram fotografadas nos seguintes intervalos: imediatamente, 24, 48, 72, 96 e 120 horas. Resultado Os dados mostraram diferenças estatisticamente significantes para o fator tempo quando comparada a leitura imediata com os demais períodos de tempo de leitura (p<0,001) e quando comparada a leitura após 24 h de armazenagem com os demais períodos de tempo (p<0,001). Não houve diferença estatística (p>0,05) quando os tempos de armazenamento de 48 h, 72 h, 96 h e 120 h foram comparados entre si. Todos os valores encontravam-se dentro dos valores preconizados pela ISO 21563:2013. Conclusão Os moldes dos alginatos testados podem ser armazenados por até cinco dias em 100% de umidade relativa.


Abstract Introduction Recently, some extended-pour alginate impression materials have been placed in the market. However, there is no consensus in the literature regarding the dimensional stability of these materials during these storage. Objective To evaluate, through the experimental model, the durability and velocity with respect to dimensional alteration, analyzing the material and detecting distortions. Material and method The material for molding in this test was alginate (Hydrogum 5, Zhermack). A cylindrical metallic matrix was used to make the moldings with: 38 mm of external diameter, 30 mm of internal diameter and superior of the upper series of the card 3d transport lines with each 25 mm in length and 20, 50 and 75μm in width. After the time of jellification / polymerization of the molding material, 16 molds were inserted in a doser and were photographed with a digital camera (Canon EOS Rebel 3Ti, Canon) associated with a software for analysis of sacred images (ImageJ 1.52a, US National Institutes of Health, DI). The calibration of the ruler was performed in 10 cm and then in 3 lines were means 3 (three) times to obtain a mean of the lengths of the lines. The photographs were taken at the following intervals: immediately, 24, 48, 72, 96 and 120 hours after being cast. Result The data were found when compared with the other parts of the reading time (p <0.001) and when compared to the execution after 24 hours of locomotion with the other parts of the time (p <0.001). The rest time of 48 hours, 72 hours, 96 hours and 120 hours were compared to each other. Conclusion The molds of the tested alginates can be stored for 5 days in 100% relative sauce.


Subject(s)
Dental Impression Materials/standards , Alginates , Dimensional Measurement Accuracy
20.
Braz. j. oral sci ; 18: e191692, jan.-dez. 2019. ilus
Article in English | LILACS, BBO | ID: biblio-1095302

ABSTRACT

Aim: This study compared impression techniques and double pouring by means of cast's accuracy. Methods: For each patient (n=10), impressions from right maxillary canine to first molar were made with acrylic resin trays and vinyl-polysiloxane using one single-step, and four two-steps techniques: relief with poly(vinyl chloride) film; tungsten-carbide bur/scalpel blade; small movements of the tray; non-relief. Total visible buccal surface area of crowns was measured three times using photographs from patients (Baseline) and casts. Mean area values (mm2) between Baseline and casts differences were analyzed by two-way repeated-measures ANOVA (α=.05; 1-ß=85%). Results: No significant differences were observed for Impression Techniques (P=.525), Double Pouring (P=.281), and their interaction (P=.809). Conclusion: All impression techniques and double pouring produced casts with similar accuracy


Subject(s)
Humans , Male , Female , Dental Impression Technique , Photography, Dental , Dental Impression Materials , Dimensional Measurement Accuracy
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