Augmented Vision for Dental Students' Education in Detecting Proximal Carious Lesions on Bitewing Radiographs: A Randomized Controlled Trial.

This two-arm, parallel, randomized controlled trial aimed to assess the effect of augmented vision (AV, using interactive color overlays) on the education of dental students in detecting proximal carious lesions on bitewing radiographs compared to black-and-white textbook-like illustrations. Forty-eight preclinical third-year dental students were randomized using a random number generator into two learning groups: test (AV, allowing interaction with color-highlighted carious lesions, n = 24) and control (showing the native radiograph and a black-and-white illustration displaying the carious lesion, n = 24). First, students had 2 weeks to assess 50 bitewings (lesion prevalence on the tooth level: 54.5%) in the test or control. Due to the nature of the intervention, participants could not be blinded toward the intervention. After that, they were asked to detect lesions on 10 independent bitewings and to assess lesion extent (outer/inner enamel; outer/middle/inner dentin). The reference test was constituted by two experienced dentists. No significant differences in accuracy (test 0.84 [95% CI: 0.79, 0.88]; control 0.83 [0.78, 0.87]), AUC (test 0.82 [0.81, 0.84]; control 0.81 [0.80, 0.83]) and F1 score (test 0.79 [0.75, 0.82]; control 0.77 [0.72, 0.81]) were observed between groups. Students of both groups showed difficulties in differentiating enamel from dentin carious lesions. While AV was reported to be motivating by students, it did not increase their accuracy.

Radiomic analysis of lung cancer for the assessment of patient prognosis and intratumor heterogeneity.

OBJECTIVE: To determine whether the radiomic features of lung lesions on computed tomography correlate with overall survival in lung cancer patients. MATERIALS AND METHODS: This was a retrospective study involving 101 consecutive patients with malignant neoplasms confirmed by biopsy or surgery. On computed tomography images, the lesions were submitted to semi-automated segmentation and were characterized on the basis of 2,465 radiomic variables. The prognostic assessment was based on Kaplan-Meier analysis and log-rank tests, according to the median value of the radiomic variables. RESULTS: Of the 101 patients evaluated, 28 died (16 dying from lung cancer), and 73 were censored, with a mean overall survival time of 1,819.4 days (95% confidence interval [95% CI]: 1,481.2-2,157.5). One radiomic feature (the mean of the Fourier transform) presented a difference on Kaplan-Meier curves (p < 0.05). A high-risk group of patients was identified on the basis of high values for the mean of the Fourier transform. In that group, the mean survival time was 1,465.4 days (95% CI: 985.2-1,945.6), with a hazard ratio of 2.12 (95% CI: 1.01-4.48). We also identified a low-risk group, in which the mean of the Fourier transform was low (mean survival time of 2,164.8 days; 95% CI: 1,745.4-2,584.1). CONCLUSION: A radiomic signature based on the Fourier transform correlates with overall survival, representing a prognostic biomarker for risk stratification in patients with lung cancer.

OBJETIVO: Associar características radiômicas de lesões pulmonares em imagens de tomografia computadorizada com a sobrevida global de pacientes com câncer de pulmão. MATERIAIS E MÉTODOS: Estudo retrospectivo composto por 101 pacientes consecutivos com neoplasia maligna confirmada por biópsia/cirurgia. As lesões foram semiautomaticamente segmentadas e caracterizadas por 2.465 variáveis radiômicas. A avaliação prognóstica foi baseada na análise de Kaplan-Meier e no teste log-rank, de acordo com a mediana dos valores das variáveis. RESULTADOS: Vinte e oito pacientes faleceram (16 por câncer de pulmão) e 73 foram censurados, com tempo médio de sobrevida de 1.819,4 dias (intervalo de confiança 95% [IC 95%]: 1.481,2-2.157,5). Uma característica radiômica (média de Fourier) apresentou diferença nas curvas de Kaplan-Meier (p < 0,05). Um grupo de pacientes de maior risco foi identificado a partir de valores altos da variável: sobrevida de 1.465,4 dias (IC 95%: 985,2-1.945,6) e razão de risco de 2,12 (IC 95%: 1,01-4,48). Um grupo de menor risco foi identificado a partir de valores baixos da variável (sobrevida de 2.164,8 dias; IC 95%: 1.745,4-2.584,1). CONCLUSÃO: Este estudo apresentou uma assinatura radiômica em imagens de tomografia computadorizada, baseada na transformada de Fourier, correlacionada com a sobrevida global de pacientes com câncer de pulmão, representando assim um biomarcador prognóstico.

Radiomic analysis of lung cancer for the assessment of patient prognosis and intratumor heterogeneity / Análise radiômica do câncer de pulmão para avaliação prognóstica do paciente e da heterogeneidade intratumoral

Abstract Objective: To determine whether the radiomic features of lung lesions on computed tomography correlate with overall survival in lung cancer patients. Materials and Methods: This was a retrospective study involving 101 consecutive patients with malignant neoplasms confirmed by biopsy or surgery. On computed tomography images, the lesions were submitted to semi-automated segmentation and were characterized on the basis of 2,465 radiomic variables. The prognostic assessment was based on Kaplan-Meier analysis and log-rank tests, according to the median value of the radiomic variables. Results: Of the 101 patients evaluated, 28 died (16 dying from lung cancer), and 73 were censored, with a mean overall survival time of 1,819.4 days (95% confidence interval [95% CI]: 1,481.2-2,157.5). One radiomic feature (the mean of the Fourier transform) presented a difference on Kaplan-Meier curves (p < 0.05). A high-risk group of patients was identified on the basis of high values for the mean of the Fourier transform. In that group, the mean survival time was 1,465.4 days (95% CI: 985.2-1,945.6), with a hazard ratio of 2.12 (95% CI: 1.01-4.48). We also identified a low-risk group, in which the mean of the Fourier transform was low (mean survival time of 2,164.8 days; 95% CI: 1,745.4-2,584.1). Conclusion: A radiomic signature based on the Fourier transform correlates with overall survival, representing a prognostic biomarker for risk stratification in patients with lung cancer.

Resumo Objetivo: Associar características radiômicas de lesões pulmonares em imagens de tomografia computadorizada com a sobrevida global de pacientes com câncer de pulmão. Materiais e Métodos: Estudo retrospectivo composto por 101 pacientes consecutivos com neoplasia maligna confirmada por biópsia/cirurgia. As lesões foram semiautomaticamente segmentadas e caracterizadas por 2.465 variáveis radiômicas. A avaliação prognóstica foi baseada na análise de Kaplan-Meier e no teste log-rank, de acordo com a mediana dos valores das variáveis. Resultados: Vinte e oito pacientes faleceram (16 por câncer de pulmão) e 73 foram censurados, com tempo médio de sobrevida de 1.819,4 dias (intervalo de confiança 95% [IC 95%]: 1.481,2-2.157,5). Uma característica radiômica (média de Fourier) apresentou diferença nas curvas de Kaplan-Meier (p < 0,05). Um grupo de pacientes de maior risco foi identificado a partir de valores altos da variável: sobrevida de 1.465,4 dias (IC 95%: 985,2-1.945,6) e razão de risco de 2,12 (IC 95%: 1,01-4,48). Um grupo de menor risco foi identificado a partir de valores baixos da variável (sobrevida de 2.164,8 dias; IC 95%: 1.745,4-2.584,1). Conclusão: Este estudo apresentou uma assinatura radiômica em imagens de tomografia computadorizada, baseada na transformada de Fourier, correlacionada com a sobrevida global de pacientes com câncer de pulmão, representando assim um biomarcador prognóstico.

Soft Tissue Cephalometric Measurements Among Malaysian Malays and Chinese

Abstract Objective: To obtain the standardized values of individuals of Malaysian Malay and Chinese for further relevant research, such as treatment planning and aesthetical considerations. Material and Methods: In this retrospective study, 440 (305 were Malays and 135 were Chinese) standardized lateral cephalometric radiographs of orthodontic patients selected through simple random sampling are profiled using Holdaway's analysis. The independent t-test was used to assess the disparities in race and gender. The significant level was p<0.05. Results: Significant differences were found between the Malays and Chinese in their skeletal profile convexity, superior sulcus depth, inferior sulcus to the H line and nose prominence. Between Malay females and males, there are significant differences in superior sulcus depth, soft tissue subnasale to H line, basic upper lip thickness, upper lip thickness and nose prominence. Between Chinese males and females, there were differences in their skeletal profile convexity, upper lip to H line, basic upper lip thickness and upper lip thickness. Conclusion: The findings demonstrated the difference between standardized norms and the unique profiles of Malaysian Malays and Chinese. There are significant gender disparities in the soft tissue cephalometric measurements among Malaysian Malay and Chinese subjects.

CORRELATION BETWEEN AHLBÄCK CLASSIFICATION AND GONARTHROSIS RISK FACTORS.

OBJECTIVE: To demonstrate whether or not there is a correlation between the risk factors for gonarthrosis and the radiographic classification of Ahlbäck. METHODS: We studied patients with primary gonarthrosis attended at the knee outpatient clinic of the General Hospital of Vila Penteado during their routine visit. We collected data on patient age (years), weight (kg), height (meters), body mass index (BMI = patient weight/height2), personal history of hypertension or diabetes mellitus (positive or negative), sedentarism (physical activity less than three times per week, 30 minutes per session), functional demand (how many blocks walked weekly), time of onset of symptoms (in years) and laterality or bilaterality. The data were correlated with the Ahlbäck classification applied to the radiographs performed at the time of the consultation. RESULTS: A sample of 108 patients was studied. We did not find an association between the Ahlbäck classification and the patient's age, smoking, sedentary lifestyle, laterality, number of blocks walked per week, diabetes mellitus, and sex; however, a positive association was observed in hypertensive patients as well as a weak correlation with height and weight of the patient and moderate correlation with BMI. CONCLUSION: The Ahlbäck classification is unrelated to most of the risk factors for primary gonarthrosis. Level of evidence III, Case-control study.

OBJETIVO: Demonstrar se existe ou não correlação entre os fatores de risco de gonartrose e a classificação radiográfica de Ahlbäck. MÉTODOS: Estudamos pacientes com gonartrose primária, assistidos no ambulatório de joelho do Hospital Geral de Vila Penteado em sua consulta de rotina. Foram coletados dados referentes a idade do paciente (anos), peso do paciente (kg), altura (metros), índice de massa corporal (IMC= peso do paciente/altura2), antecedente pessoal de hipertensão ou diabetes mellitus (positivo ou negativo), sedentarismo (se pratica atividade física menos de três vezes por semana, 30 minutos por sessão), demanda funcional (quantas quadras caminha semanalmente), tempo do início dos sintomas (em anos) e lateralidade ou bilateralidade. Os dados foram correlacionados com a classificação de Ahlbäck aplicada às radiografias realizadas no momento da consulta. RESULTADOS: Uma amostra de 108 pacientes foi estudada. Não encontramos associação entre a classificação de Ahlbäck e a idade do paciente, tabagismo, sedentarismo, lateralidade, quantidade de quadras percorridas por semana, diabetes mellitus e sexo do paciente, porém verificou-se associação positiva em pacientes hipertensos e correlação fraca com altura e peso do paciente e correlação moderada com IMC. CONCLUSÃO: A classificação de Ahlbäck não apresenta relação com a maioria dos fatores de risco de gonartrose primária. Nível de evidência III, Estudo caso-controle .

Correlation between ahlbäck classification and gonarthrosis risk factors / Correlação entre a classificacão de ahlbäck e fatores de risco da gonartrose

ABSTRACT Objective: To demonstrate whether or not there is a correlation between the risk factors for gonarthrosis and the radiographic classification of Ahlbäck. Methods: We studied patients with primary gonarthrosis attended at the knee outpatient clinic of the General Hospital of Vila Penteado during their routine visit. We collected data on patient age (years), weight (kg), height (meters), body mass index (BMI = patient weight/height2), personal history of hypertension or diabetes mellitus (positive or negative), sedentarism (physical activity less than three times per week, 30 minutes per session), functional demand (how many blocks walked weekly), time of onset of symptoms (in years) and laterality or bilaterality. The data were correlated with the Ahlbäck classification applied to the radiographs performed at the time of the consultation. Results: A sample of 108 patients was studied. We did not find an association between the Ahlbäck classification and the patient's age, smoking, sedentary lifestyle, laterality, number of blocks walked per week, diabetes mellitus, and sex; however, a positive association was observed in hypertensive patients as well as a weak correlation with height and weight of the patient and moderate correlation with BMI. Conclusion: The Ahlbäck classification is unrelated to most of the risk factors for primary gonarthrosis. Level of evidence III, Case-control study.

RESUMO Objetivo: Demonstrar se existe ou não correlação entre os fatores de risco de gonartrose e a classificação radiográfica de Ahlbäck. Métodos: Estudamos pacientes com gonartrose primária, assistidos no ambulatório de joelho do Hospital Geral de Vila Penteado em sua consulta de rotina. Foram coletados dados referentes a idade do paciente (anos), peso do paciente (kg), altura (metros), índice de massa corporal (IMC= peso do paciente/altura2), antecedente pessoal de hipertensão ou diabetes mellitus (positivo ou negativo), sedentarismo (se pratica atividade física menos de três vezes por semana, 30 minutos por sessão), demanda funcional (quantas quadras caminha semanalmente), tempo do início dos sintomas (em anos) e lateralidade ou bilateralidade. Os dados foram correlacionados com a classificação de Ahlbäck aplicada às radiografias realizadas no momento da consulta. Resultados: Uma amostra de 108 pacientes foi estudada. Não encontramos associação entre a classificação de Ahlbäck e a idade do paciente, tabagismo, sedentarismo, lateralidade, quantidade de quadras percorridas por semana, diabetes mellitus e sexo do paciente, porém verificou-se associação positiva em pacientes hipertensos e correlação fraca com altura e peso do paciente e correlação moderada com IMC. Conclusão: A classificação de Ahlbäck não apresenta relação com a maioria dos fatores de risco de gonartrose primária. Nível de evidência III, Estudo caso-controle.

Accuracy of a Radiological Evaluation Method for Thoracic and Lumbar Spinal Curvatures Using Spinous Processes.

OBJECTIVE: The purpose of this study was to assess a radiographic method for spinal curvature evaluation in children, based on spinous processes, and identify its normality limits. METHODS: The sample consisted of 90 radiographic examinations of the spines of children in the sagittal plane. Thoracic and lumbar curvatures were evaluated using angular (apex angle [AA]) and linear (sagittal arrow [SA]) measurements based on the spinous processes. The same curvatures were also evaluated using the Cobb angle (CA) method, which is considered the gold standard. For concurrent validity (AA vs CA), Pearson's product-moment correlation coefficient, root-mean-square error, Pitman- Morgan test, and Bland-Altman analysis were used. For reproducibility (AA, SA, and CA), the intraclass correlation coefficient, standard error of measurement, and minimal detectable change measurements were used. RESULTS: A significant correlation was found between CA and AA measurements, as was a low root-mean-square error. The mean difference between the measurements was 0° for thoracic and lumbar curvatures, and the mean standard deviations of the differences were ±5.9° and 6.9°, respectively. The intraclass correlation coefficients of AA and SA were similar to or higher than the gold standard (CA). The standard error of measurement and minimal detectable change of the AA were always lower than the CA. CONCLUSION: This study determined the concurrent validity, as well as intra- and interrater reproducibility, of the radiographic measurements of kyphosis and lordosis in children.

Evaluation of a digital learning object (DLO) to support the learning process in radiographic dental diagnosis.

AIMS: Studies have shown that inappropriate therapeutic strategies may be adopted if crown and root changes are misdiagnosed, potentially leading to undesirable consequences. Therefore, the aim of this study was to evaluate a digital learning object, developed to improve skills in diagnosing radiographic dental changes. MATERIALS AND METHODS: The object was developed using the Visual Basic Application (VBA) software and evaluated by 62 undergraduate students (male: 24 and female: 38) taking an imaging diagnosis course. Participants were divided in two groups: test group, which used the object and control group, which attended conventional classes. After 3 weeks, students answered a 10-question test and took a practice test to diagnose 20 changes in periapical radiographs. RESULTS: The results show that test group performed better that control group in both tests, with statistically significant difference (P = 0.004 and 0.003, respectively). In overall, female students were better than male students. Specific aspects of object usability were assessed using a structured questionnaire based on the System Usability Scale (SUS), with a score of 90.5 and 81.6 by male and female students, respectively. CONCLUSIONS: The results obtained in this study suggest that students who used the DLO performed better than those who used conventional methods. This suggests that the DLO may be a useful teaching tool for dentistry undergraduates, on distance learning courses and as a complementary tool in face-to-face teaching.

Distance learning in dental radiology: immediate impact of the implementation / Educação à distância em radiologia odontológica: Impacto imediato da implantação

Objective: This study assessed the immediate impact in terms of learning dento-maxillomandibular radiographic anatomy in intraoral periapical radiographs after entire replacement of the method of classroom learning by the distance learning using the Moodle platform. Material and Methods: Teaching of this subject by traditional educational setting in classroom was made until the first semester of 2011, “A class” (AC), using radiographic slabs from duplicated films with imprints indicating anatomical structures in images that is accompanied by textbook with its description and support teacher, who works closely with the classroom to support student learning. In the second semester of 2011, “B class” (BC), these same radiographic slabs were digitalized, including description of textbook, creating the Moodle e-course about dentomaxillomandibular anatomy in intraoral radiographs for distance learning. The impact was assessed by comparison of scores of students from two distinct classes, AC (N = 60) and BC (N = 62), after application of a similar test with all content of the topic of dento-maxillomandibular anatomy, using T-Student unpaired test (α = 0.05). A voluntary and unidentified questionnaire with 12 questions, developed in Google Docs spreadsheets, was used to evaluate the acceptance of students for this e-course. Results: No significant differences (p > 0.05) were observed in scores of the students from two classes. Among other questions, all students of BC who completed the questionnaire had interest in content of the available material in e-course, and their satisfaction level on a scale from 0 to 10 had a mean of 8.47 (SD = 1.69). Conclusion: The method of distance learning of this subject using the Moodle platform can be utilized with same educational results as of those obtained from a traditional educational setting...

Objetivo: Este estudo avaliou o impacto imediato em termos de aprendizagem da anatomia radiográfica dento-maxilo-mandibular em radiografias periapicais intrabucais, após toda a substituição do método de ensino em sala de aula pela educação a distância com a plataforma Moodle. Material e Métodos: O ensino desta disciplina no ambiente educacional tradicional em sala de aula foi feito até o primeiro semestre de 2011, classe A (AC), utilizando pranchas de filmes radiográficos duplicados com marcações que indicavam estruturas anatômicas nas imagens eum livro texto com a descrição da referida estrutura, além de professor de apoio, que trabalhava na sala de aula junto com os alunos como apoio de aprendizagem. No segundo semestre de 2011, para a “classe B” (BC), essas mesmas pranchas radiográficas foram digitalizadas, incluindo a descrição do livro texto, para criar o curso digital Moodle sobre anatomia dentomaxilo- mandibular em radiografias intra-orais para educação a distância. O impacto dessa substituição foi avaliado pela comparação das notas dos alunos dessas duas classes distintas, AC (N= 60) e BC (N = 62), após a aplicação de uma prova semelhante com todo o conteúdo do tema da anatomia dentomaxilo- mandibular, utilizando teste T-Student não pareado (α = 0,05). Um questionário voluntário e não identificado com 12 questões, desenvolvido em planilhas do Google Docs, foi utilizado para avaliar a aceitação dos alunos em relação ao curso digital. Resultados: Não houve diferença significativa (p > 0,05) entre as notas dos alunos das duas classes. Em relação às respostas do questionário, todos os alunos da BC que responderam ao questionário tinham interesse no conteúdo do material disponível no curso digital e o nível de satisfação medido em uma escala de 0 a 10 obteve média de 8,47 (DP = 1,69)...

Radiopacity of restorative composites by conventional radiograph and digital images with different resolutions.

PURPOSE: This study was performed to evaluate and compare the radiopacity of dentin, enamel, and 8 restorative composites on conventional radiograph and digital images with different resolutions. MATERIALS AND METHODS: Specimens were fabricated from 8 materials and human molars were longitudinally sectioned 1.0 mm thick to include both enamel and dentin. The specimens and tooth sections were imaged by conventional radiograph using #4 sized intraoral film and digital images were taken in high speed and high resolution modes using a phosphor storage plate. Densitometric evaluation of the enamel, dentin, restorative materials, a lead sheet, and an aluminum step wedge was performed on the radiographic images. For the evaluation, the Al equivalent (mm) for each material was calculated. The data were analyzed using one-way ANOVA and Tukey's test (p<0.05), considering the material factor and then the radiographic method factor, individually. RESULTS: The high speed mode allowed the highest radiopacity, while the high resolution mode generated the lowest values. Furthermore, the high resolution mode was the most efficient method for radiographic differentiation between restorative composites and dentin. The conventional radiograph was the most effective in enabling differentiation between enamel and composites. The high speed mode was the least effective in enabling radiographic differentiation between the dental tissues and restorative composites. CONCLUSION: The high speed mode of digital imaging was not effective for differentiation between enamel and composites. This made it less effective than the high resolution mode and conventional radiographs. All of the composites evaluated showed radiopacity values that fit the ISO 4049 recommendations.

Anterior and medial angulations of the styloid process in subjects with TMD: clinical and radiographic findings

This study investigated the existence of association between the angulation of the styloid process on the anterior and medial directions with the intensity of temporomandibular dysfunction (TMD) symptoms. Fifty patients (8 men and 42 women) aged 25 to 70 years, with relevant TMD symptoms were evaluated. Clinical examinations were performed to determine the severity of TMD symptoms (orofacial pain, headache, tinnitus and dizziness) based on the RDC/TMD criteria and the visual analogue scale (VAS), and digital radiographic images of the styloid process were obtained: lateral cephalometric skull radiograph (analysis of anterior angulation) and posteroanterior skull radiograph (reverse Towne's projection) (analysis of medial angulation). The anterior angulation average of the styloid process was 20.89° while the medial angulation average was 19.1° in the right side and 19.04° in the left side. There was no statistically significant difference among the patient groups (severe, moderate and mild symptoms) associating the TMD symptoms and the anterior or medial angulation of the styloid process (p>0.05). There was no correlation between the intensity of the TMD symptoms and the measurements of anterior and medial angulation of the styloid process using either lateral cephalometric or posteroanterior radiographs (reverse Towne's projection).

Este estudo investigou a existência de associação entre a angulação do processo estiloide nas direções anterior e medial e a intensidade dos sintomas de disfunção temporomandibular. Cinquenta pacientes (8 homens e 42 mulheres) com idade entre 25 a 70 anos, com sintomas relevantes de DTM foram avaliados. Os exames clínicos foram realizados para determinar a severidade dos sintomas da DTM (dor orofacial, cefaleia, zumbido e tontura) com base nos critérios do RDC / DTM e na escala visual analógica (EVA), e imagens de radiografias digitais do processo estiloide foram obtidas: cefalométrica lateral com incidência reversa (análise de angulação anterior), e póstero-anterior do crânio (projeção reversa de Towne) (análise de angulação medial). A média de angulação anterior do processo estilóide foi 20,89°, enquanto a média da angulação medial foi 19,1° no lado direito e 19,04° no lado esquerdo. Não houve diferença estatisticamente significativa entre os grupos de pacientes (sintomas severos, moderados ou leves) em associação com os sintomas de DTM e as angulações anterior ou medial do processo estiloide (p>0,05). Não houve correlação entre a intensidade dos sintomas de DTM e as medidas das angulações anterior e medial do processo estiloide utilizando a radiografia cefalométrica lateral ou a póstero-anterior (projeção reversa de Towne).

Chitosan-based biomaterials used in critical-size bone defects: radiographic study in rat's calvaria / Biomateriais a base de quitosana na correção de defeitos ósseos críticos criados em calvaria de ratos: avaliação radiográfica

Objetivo: Este estudo avaliou através de imagens radiográficas digitais, a ação de biomateriais de quitosana e de cloridrato de quitosana, com baixo e alto peso molecular, utilizados na correção de defeitos ósseos de tamanho crítico (DOTC)em calvária de ratos. Material e MétodoO: DOTCs com 8 mm de diâmetro foram criados cirurgicamente na calvária de 50 ratos Holtzman. Em 10 animais o defeito foi preenchido foram preenchidos com coágulo sanguíneo (controle negativo). Os 40 animais restantes foram divididos de acordo com o biomaterial utilizado no preenchimento do defeito (quitosana de baixo peso e de alto peso molecular, e cloridrato de quitosana de baixo e de alto peso molecular), e foram avaliados em dois períodos experimentais (15 e 60 dias), totalizando 5 animais/biomaterial/período de avaliação. Resultado: A avaliação radiográfica foi feita utilizando duas radiografias digitais do crânio do animal: uma tomada logo após o defeito ósseo ser criado e a outra no momento do sacrifício. Nessas imagens, foi avaliada a densidade óssea radiográfica inicial e a final na área do defeito, que foram comparadas. As análises na densidade óssea radiográfica indicaram aumento da densidade óssea radiográfica dos DOTCs tratados para todos os biomateriais testados, em ambos os períodos. Resultados semelhantes foram encontrados no grupo controle. Conclusão: Conclui-se que os biomateriais de quitosana testados não foram capazes de aumentar a densidade radiográfica em DOTC realizados em calvária de ratos.

Objective: This study evaluated, using digital radiographic images, the action of chitosan and chitosan hydrochloride biomaterials, with both low and high molecular weight, used in the correction of critical-size bone defects (CSBD's) in rat's calvaria. Material and Method: CSBD's with 8 mm in diameter were surgically created in the calvaria of 50 Holtzman rats and these were filled with a blood clot (Control), low molecular weight chitosan, high molecular weight chitosan, low molecular weight chitosan hydrochloride and high molecular weight chitosan hydrochloride, for a total of 10 animals, which were divided into two experimental periods (15 and 60 days), for each biomaterial. The radiographic evaluation was made using two digital radiographs of the animal's skull: one taken right after the bone defect was created and the other at the moment of the sacrifice, providing the initial and the final radiographic bone density in the area of the defect, which were compared. Result: Analysis of radiographic bone density indicated that the increase in the radiographic bone density of the CSBD's treated with the proposed biomaterials, in either molecular weight, in both observed periods, where similar to those found in control group. Conclusion: Tested chitosan-based biomaterials were not able to enhance the radiographic density in the CSBD's made in rat's calvaria.

Avaliação de métodos indiretos de digitalização de radiografias cefalométricas em comparação ao método digital direto / Evaluation of indirect methods of digitization of cephalometric radiographs in comparison with the direct digital method

OBJETIVO: avaliar métodos de digitalização indireta de radiografias cefalométricas em comparação ao método digital direto. MÉTODOS: a amostra foi composta de dez radiografias cefalométricas adquiridas pelo Orthopantomograph OP100/Orthocef OC100 (GE - Instrumentarium), digital direto. As imagens foram inseridas no programa Adobe Photoshop® e cinco pontos cefalométricos foram marcados. Procedeu-se a impressão em transparência e foi feita a digitalização indireta das imagens impressas, por meio das câmeras fotográficas digitais Sony® DSC-W5 e Canon® Rebel XT/EOS 350D, fixas em estativa, nas distâncias de 25cm e 60cm e com o scanner Scan Jet 4C Hewlett Packard®. As imagens diretas e indiretas foram inseridas e calibradas no software Radiocef Studio (Radiomemory®, Brasil), marcando-se o centro dos pontos previamente assinalados. A análise cefalométrica computadorizada gerou três grandezas angulares e quatro lineares, as quais foram submetidas a tratamento estatístico. RESULTADOS: as imagens do scanner Scan Jet 4C HP® demonstraram pequenas alterações significativas, porém, sem relevância clínica. Quando da digitalização a 60cm da radiografia, as duas câmeras causaram distorções que foram significativas mas clinicamente aceitáveis; e, a 25cm, causaram as maiores distorções, com importância clínica, na Canon® Rebel XT. CONCLUSÃO: o scanner Scan Jet 4C HP® com leitor de transparências foi o melhor método e as câmeras operando a 60cm mostraram-se adequadas para digitalização de radiografias. As câmeras na distância de 25cm causaram distorções na imagem que alteraram as medidas lineares, podendo a Canon® Rebel XT comprometer o diagnóstico ortodôntico.

OBJECTIVE: To evaluate the indirect digitization method of cephalometric radiographs in comparison with the direct digital method. METHODS: The sample was composed of ten cephalometric radiographs acquired by Orthopantomograph OP100/Orthocef OC100 (GE - Instrumentarium), digital direct. In the AdobeÕ Photoshop program, five cephalometric landmarks were set in the images and the impression in transparencies was made. The indirect digitization of the images was performed through the SonyÕ DSC-W5 and CanonÕ Rebel XT/EOS 350D digital photographic cameras-fixed in a copy stand, at the distances of 25 cm and 60 cm-and through the Hewlett PackardÕ Scan Jet 4C scanner. The direct digital images and the indirect ones were inserted and gauged in the Radiocef Studio (RadiomemoryÕ, Brazil) software and the center of the previously marked landmarks was set. The cephalometric computerized analysis generated three angular measurements and four linear ones which were submitted to statistical analysis. RESULTS: The images from the scanner demonstrated small statistically significant alterations, without clinical significance. When digitizing the radiographs at 60 cm, both cameras caused distortions which were statistically significant, but clinically acceptable. At 25 cm, the cameras caused the largest distortions, being more expressive and with clinical significance in the images of CanonÕ Rebel XT. CONCLUSIONS: The Hewlett PackardÕ Scan Jet 4C scanner with transparency reader and the SonyÕ DSC-W5 and CanonÕ Rebel XT/EOS cameras operating at 60 cm were shown appropriate for the digitization of cephalometric radiographs. In 25 cm, the digital cameras caused distortions in the image which altered the linear measurements with possibilities of jeopardizing the orthodontic diagnosis.