A single session of antimicrobial photodynamic therapy does not influence the alveolar repair process in rats

Abstract: The aim of this study was to use microscopic and molecular techniques to evaluate the effects of a single session of antimicrobial photodynamic therapy (aPDT) on the alveolar repair process after tooth extraction in rats. The study sample included 84 rats divided into four groups, as follows: a) Control - untreated socket; b) Laser - socket treated using photobiomodulation; c) TBO - socket treated with topic application of the photosensitizer agent, toluidine blue O (TBO); and d) aPDT - socket treated with TBO and laser irradiation. An additional rat was used for thermal mapping during socket irradiation. The animals were euthanatized at 6, 15, and 28 days after unilateral extraction of the upper incisor. Quantitative and qualitative analyses of the connective and bone tissues, blood clot, blood vessel, and inflammatory infiltrate were performed, and real-time polymerase chain reaction was used to study the expression of genes (collagen type I, osteocalcin, alkaline phosphatase [ALP], runt-related transcription factor 2 [RUNX2], and vascular endothelial growth factor [VEGF]) involved in the bone healing process. No statistically significant differences in microscopic and molecular outcomes were observed between the groups (p > 0.05). A positive correlation was seen to exist between blood clot and VEGF (p = 0.000), and a negative correlation was observed between bone tissue and ALP (p = 0.028) and blood vessel and VEGF (p = 0.018). A single session of aPDT in the dental extraction site did not influence the alveolar repair process in rats.

Analysis of the Preventative Influence of an Oral Hygiene Protocol on Ventilator-Associated Pneumonia / Análise da Influência Preventiva de um Protocolo de Higiene oral na Pneumonia Associada à Ventilação Mecânica

Ventilator-associated pneumonia (VAP) is the most commonly reported nosocomial infection among intensive care unit (ICU) patients. This study aimed to evaluate the influence of an oral hygiene protocol on VAP incidence among mechanically-ventilated (MV) ICU patients. The dentate patients admitted without VAP to the hospital's adult ICU requiring mechanical ventilation for ≥48 hours during a 4-month period in two consecutive years (2015 ­ Control group and 2016 ­ Experimental group) were included in this investigation. The oral hygiene protocol was implemented daily, once a day, in the morning hours, using a disposable brush with suction and ultrasoft bristles and 3 g of 0.12% chlorhexidine gel. Hospital-related respiratory infection data, including VAP diagnoses and microbiological analyses, were collected from the monthly health epidemiological notification bulletins issued by the hospital. T tests were applied to compare variables before versus after implementation of the oral hygiene protocol with a significance criterion of P < .05. 43.94% reduction in VAP rate after the protocol implementation was observed. Implementation of the protocol was associated with a significant reduction of Enterobacter spp infections and no cases of VAP related to the main etiological agents of the disease (i.e., S. aureus and C. albicans) were identified. It can be concluded that an oral hygiene protocol performed with a suction brush and 0.12% chlorhexidine gel can serve as an effective prophylaxis against VAP in patients under mechanical ventilation. (AU)

A pneumonia associada à ventilação (PAV) é a infecção nosocomial mais comumente relatada em pacientes de Unidade de Terapia Intensiva (UTI). Este estudo teve como objetivo avaliar a influência de um protocolo de higiene bucal na incidência de PAV entre pacientes sob ventilação mecânica (VM). Os pacientes dentados internados na UTI adulta do hospital sem PAV e que necessitaram de ventilação mecânica por ≥ 48 horas durante um período de 4 meses em dois anos consecutivos (2015 - grupo Controle e 2016 - grupo Experimental) foram incluídos nesta investigação. O protocolo de higiene bucal foi implementado diariamente, uma vez ao dia, nas primeiras horas da manhã, utilizando-se escova descartável com cerdas de sucção e ultramacia e 3 g de gel de clorexidina a 0,12%. Dados de infecção respiratória relacionada ao hospital, incluindo diagnósticos de PAV e análises microbiológicas, foram coletados dos boletins mensais de notificação epidemiológica de saúde emitidos pelo hospital. Testes t foram aplicados para comparar as variáveis antes e após a implementação do protocolo de higiene bucal com um critério de significância de P <0,05. Observamos uma redução de 43,94% na taxa de PAV após a implementação do protocolo A implementação do protocolo foi associada à uma redução significativa das infecções por Enterobacter spp e não foram identificados casos de PAV relacionados aos principais agentes etiológicos da doença (isto é, S. aureus e C. albicans). Pode-se concluir que u protocolo de higiene bucal realizado com escova de sucção e gel de clorexidina a 0,12% pode servir como uma profilaxia efetiva contra a PAV em pacientes sob ventilação mecânica. (AU)

Analysis of the Gray-Value Reproducibility and Noise of a Direct Digital Radiography System / Análise da Reprodutibilidade do Valor de Cinza e Ruído de um Sistema de Radiografia Digital Direto

The digital radiograph represents a great advance in oral maxillofacial radiology because it incorporates informatics technology in the capture, interpretation, and archiving of radiographic images. Previous studies have demonstrated that it is possible to use gray values in bone lesion diagnosis and follow-up. However, these applications depend on radiograph system quality and exposure time. The aim of this study was to evaluate the gray-value reproducibility and noise produced by Dabi Atlante's IDA system, a direct digital radiography system. Radiographs were obtained in a standardized manner (70 kV, 7 mA, and 2.2-mm filtration) with a direct digital sensor and a stepwedge placed in a phantom at a 30-cm focus-film distance. Ten consecutive x-ray imaging series were completed at 0.10-s, 0.15-s, and 0.20-s exposure times. Gray values were analyzed in five regions of interest (ROIs): bone tissue (BT), soft tissue (ST), and three stepwedge steps (Step 1, Step 2, and Step 3). Mean gray values differed significantly across exposure times (p < .05) in all five ROIs. The ROI with the greatest gray-value variability (25.36%) and noise (9.46%) was ST. In conclusion, gray-value reproducibility and noise of the IDA system vary across areas with differing radiolucency. Thus, special attention is necessary for the diagnosis and follow-up of radiolucent lesions due to relatively high gray-value interference (AU).

A radiografia digital representa um grande avanço na radiologia bucomaxilofacial porque incorpora a tecnologia informática na captura, interpretação e arquivamento de imagens radiográficas. Estudos anteriores demonstraram que é possível usar os valores de cinza no diagnóstico e na proservação das lesões ósseas. No entanto, essas aplicações dependem da qualidade do sistema radiológico e do tempo de exposição. O objetivo deste estudo foi avaliar a reprodutibilidade do valor de cinza e o ruído produzido pelo sistema IDA da Dabi Atlante, um sistema de radiografia digital direto. As radiografias foram obtidas de maneira padronizada (70 kV, 7 mA e filtração de 2,2 mm) com um sensor digital direto e um penetrômetro colocados em um fantoma a uma distância de filme-foco de 30 cm. Dez imagens radiográficas consecutivas foram obtidas com tempos de exposição de 0,10-s, 0,15-s e 0,20-s. Os valores de cinza foram analisados em cinco regiões de interesse (ROIs): tecido ósseo (TO), tecido mole (TM) e três degraus do penetrômetro (Degrau 1, Degrau 2 e Degrau 3). Os valores de cinza médios diferiram significativamente entre os tempos de exposição (p <0,05) em todos as cinco ROIs. A ROI com maior variabilidade do valor de cinza (25,36%) e ruído (9,46%) foi TM. Em conclusão, a reprodutibilidade do valor de cinza e o ruído do sistema IDA variam entre áreas com radiolucência diferente. Assim, atenção especial é necessária para o diagnóstico e proservação de lesões radiolucentes devido à interferência dos valores cinza relativamente alta. (AU).

Dimensional Stability of Alginates Molds Tridimentionally Scanned / Estabilidade Dimensional de Moldes de Alginatos Escaneados Tridimensionalmente

Alginate is among the most used materials in dentistry to create teeth negative printing and reproduction. The goal of this study was to compare dimensional changes of alginate scanned impression materials. Thirty impressions of a standard typodont were performed using three types of alginate (Hydrogum 5; Jeltrate Plus and Avagel). The impressions were scanned by the scanner 3Shape R700T and scans were performed immediately after molding. The analysis of digital models were performed at OrthoAnalyzer ™ 3D software. Measurements were carried out in relation to the transverse dimension (intercanine, interpremolares and intermolar). Method error was evaluated through the Intraclass Correlation Coefficient (ICC) and Bland-Altman. One-way ANOVA, Dunnet Post-test were used to compare the different groups in relation to Typodont (gold standard) for the different outcome variables. The data were tabulated in Statistical Package for Social Sciences version 20.0 and Minitab 17.0 softwares to compare groups. The significance level was 5%. The posterior transverse variables (D1PM, D2PM and DM) presented a statistically significant difference regarding the gold standard (Typodont) for the plaster models performed after the Avagel molding. In the digital models performed just after molding, only in DM, the Avagel material group presented values statistically higher than the control group. The alginates Hydrogum 5 and Jeltrate Plus presented dimensions closer to the gold standard.(AU).

O alginato está entre os materiais de moldagem mais utilizados na Odontologia para criar impressão e reprodução negativa dos dentes. O objetivo desse trabalho foi comparar alterações transversais de três marcas comerciais de alginato (Hydrogum, Jeltrate e Avagel) em moldes de alginatos. Trinta moldes de um Typodont padrão foram realizados, utilizando três tipos de alginato (Hydrogum 5; Jeltrate Plus e Avagel). Os moldes foram escaneados por meio do scanner 3Shape R700T e os escaneamentos realizados logo após a moldagem e logo após a obtenção dos modelos de gesso. As análises dos modelos digitais foram realizadas no software OrthoAnalyzer™ 3D. Foram realizadas mensurações em relação à discrepância transversal (inter-caninos, inter-primeiro pré-molar, inter-segundo pré-molar e inter-molares). O erro do método foi avaliado por meio do Coeficiente de Correlação Intraclasse (CCI) e Bland-Altman. Utilizou-se Análise de Variância (one-way ANOVA, Pós-teste Dunnet) para comparação dos diferentes grupos em relação ao typodont (padrão-ouro) para as diferentes variáveis de desfecho. A análise estatística foi realizada nos programas Statistical Package for Social Sciences versão 20.0 e no programa Minitab 17.0 para comparação dos grupos. O nível de significância foi de 5%. As variáveis transversais posteriores (D1PM; D2PM e DM) apresentaram diferença estatisticamente significante em relação ao padrão-ouro (manequim) para os modelos de gesso realizados após a moldagem com Avagel. Nos modelos digitais realizados logo após a moldagem, apenas na DM, o grupo do material Avagel apresentou valores estatisticamente maiores do que o grupo controle. Os alginatos Hydrogum 5 e Jeltrate Plus apresentaram dimensões mais próximas do padrão-ouro.(AU).

Avaliação do Conhecimento do Protocolo de Higiene Bucal pela Equipe de Enfermagem da Unidade de Terapia Intensiva de Dois Hospitais em Londrina/PR / Evaluation of Knowledge of the Oral Hygiene Protocol by the Nursing Team of the Intensive Care Unit of Two Hospitals In Londrina/PR

Oral hygiene in the Intensive Care Unit - ICU is considered a basic and indispensable procedure whose goal is to maintain the patients' healthy oral conditions, reducing complications and contributing to their recovery. The objective of this study was to evaluate the knowledge on the oral hygiene protocol by the ICU nursing team of two hospitals in Londrina/PR. The sample of this study was composed by the nursing and nursing technicians team of the Intensive Care Unit of the Hospital A and Hospital B, regardless of gender or age, and considering who had worked at the ICU for at least three months. A self-administered, unidentified questionnaire was used to collect data. The analyzed variables were: profession, age, sex, working time and oral hygiene. More than 80% of the professionals were Nursing Technicians, with average age above 30, female and working in the ICU of the hospital for over 3.5 years. The results of this study demonstrate the lack of knowledge of the oral hygiene protocol by more than 30% of the Nursing staff in both hospitals. Based on the methodology and the results analysis, it can be concluded that the oral hygiene protocol is unknown by more than a third of the ICU Nursing team of both surveyed hospitals.(AU).

A higiene bucal em Unidade de Terapia Intensiva - UTI é considerada um procedimento básico e indispensável cujo objetivo é manter saudáveis as condições bucais dos pacientes, reduzindo agravos e contribuindo para sua recuperação. O objetivo deste estudo foi avaliar o conhecimento do protocolo de higiene bucal pela equipe de enfermagem da UTI de dois hospitais em Londrina/PR. A amostra deste estudo foi composta pela equipe de Enfermagem (Enfermeiros e Técnicos em Enfermagem) da Unidade de Terapia Intensiva do Hospital A e do Hospital B, independente do sexo e idade, e que trabalhavam na UTI, no mínimo, há três meses. Para a coleta de dados foi utilizado um questionário autoaplicável, não identificado. As variáveis analisadas foram: profissão, idade, sexo, tempo de trabalho e higiene bucal. Mais de 80% dos profissionais eram Técnicos em Enfermagem, com idade média acima dos 30 anos de idade, do sexo feminino e atuando na UTI do hospital, em média, acima de 3,5 anos. Os resultados deste estudo demonstram a falta de conhecimento do protocolo de higiene bucal, por mais de 30% da equipe de Enfermagem, em ambos os hospitais. Com base na metodologia e análise dos resultados, pode-se concluir que o protocolo de higiene bucal é desconhecido por mais de um terço da equipe de Enfermagem da UTI de ambos os hospitais pesquisados. (AU).

Health-related quality of life of patients with squamous cell carcinoma: a comparison according to tumor location

Abstract: The aim of this study was to evaluate the health-related quality of life (QOL) of patients with squamous cell carcinoma (SCC) according to tumor location. The sample consisted of 27 patients with primary SCC in the oral cavity (n = 15), pharynx (n = 7), and larynx (n = 5) who were undergoing cancer treatment at the Cancer Hospital of Londrina, regardless of age, sex, clinical stage, and type of antineoplastic treatment. Health-related QOL was evaluated using the 30-item Cancer-Quality of Life Questionnaire (QLQ-C30), the 35-item Head and Neck Cancer-Quality of Life Questionnaire (QLQ-HN35), and the University of Washington Quality of Life Questionnaire (UW-QOL). These questionnaires were administered individually to each patient before ambulatory care. Sociodemographic data (age and sex) and clinical data (T stage, tumor location, and type of antineoplastic treatment) were collected from the patients' medical records. Scores were compared according to tumor location using the chi-squared test and one-way analysis of variance (p < 0.05). No score differed significantly according to tumor location. It can be concluded that the health-related QOL of patients with SCC was not influenced by tumor location.

Comparison between 3D volumetric rendering and multiplanar slices on the reliability of linear measurements on CBCT images: an in vitro study

OBJECTIVE: The purpose of this study was to determine the accuracy and reliability of two methods of measurements of linear distances (multiplanar 2D and tridimensional reconstruction 3D) obtained from cone-beam computed tomography (CBCT) with different voxel sizes. MATERIAL AND METHODS: Ten dry human mandibles were scanned at voxel sizes of 0.2 and 0.4 mm. Craniometric anatomical landmarks were identified twice by two independent operators on the multiplanar reconstructed and on volume rendering images that were generated by the software Dolphin®. Subsequently, physical measurements were performed using a digital caliper. Analysis of variance (ANOVA), intraclass correlation coefficient (ICC) and Bland-Altman were used for evaluating accuracy and reliability (p<0.05). RESULTS: Excellent intraobserver reliability and good to high precision interobserver reliability values were found for linear measurements from CBCT 3D and multiplanar images. Measurements performed on multiplanar reconstructed images were more accurate than measurements in volume rendering compared with the gold standard. No statistically significant difference was found between voxel protocols, independently of the measurement method. CONCLUSIONS: Linear measurements on multiplanar images of 0.2 and 0.4 voxel are reliable and accurate when compared with direct caliper measurements. Caution should be taken in the volume rendering measurements, because the measurements were reliable, but not accurate for all variables. An increased voxel resolution did not result in greater accuracy of mandible measurements and would potentially provide increased patient radiation exposure. .

Analysis of the reproducibility of the gray values and noise of a direct digital radiography system

The aim of this study was to evaluate the reproducibility of the gray values and noise of a direct digital radiography system (Visualix eHD) for various exposure times and analyzed regions. To obtain radiographic images in a standardized manner, the digital sensor of the system and a stepwedge were positioned in a phantom at a focus-film distance of 30 cm in a dental device at 70 kV, 7 mA and 2.2 mm filtration. Ten consecutive repetitions of X-ray imaging were performed at each exposure time (0.05, 0.07, 0.09 and 0.13 s). Gray values were analyzed using ImageJ software in five regions of interest (ROIs): alveolar bone (AB), soft tissue (ST) and three steps of the stepwedge (S1, S2 and S3). The results showed that both the variability of the gray values and the noise were statistically greater (p < 0.05) in the most radiolucent region (ST). Only the noise was affected by the exposure time. In conclusion, the reproducibility of the gray values and the noise of the Visualix eHD system can vary in specific areas with different radiolucency.

Forâmen lingual lateral – relato de dois casos clínicos através da tomografia computadorizada de feixe cônico / Lateral lingual foramina (LLF) – two case reports with the use of cone beam computed tomography (CBCT)

O reconhecimento do forâmen lingual lateral (FLL) e muito importante, especialmente na implantodontia. Assim, a tomografia computadorizada feixe cônico (TCFC) permite a visualização de estruturas anatômicas nao detectadas na radiografia convencional, com o FLL. Este artigo relata dois casos de FLL ambos no lado direito em dois pacientes distintos. Ambos os exames foram obtidos pelo I-Cat e avaliados no programa I-Cat Vision. A injúria aos vasos que atravessam a FLL pode causar hematoma no assoalho bucal e, em situações mais graves, a obstrução das vias aéreas superiores

Lateral lingual foramen (LLF) recognition is very important, especially to dental implant practitioners. In this way, cone-beam computed tomography (CBCT) allows visualization of anatomic structures not detected in conventional radiography, such as LLF. This paper reports two LLF cases both at the right side in two different patients. Both exams were obtained through I-CAT Classic device and evaluated with the I-CAT Vision software. Injuries to LLF contained vascular bundles might cause hematoma at the floor of the mouth and, in worst cases, subsequent upper airway obstruction.

Fabrication of plaster models with radiographic features of human bone: a pilot study by fractal analysis / Confecção de modelos de gesso com características radiográficas compatíveis com osso humano: estudo piloto por meio da análise fractal

Objective: This study attempted to fabricate plaster models that reproduce the radiographic characteristics of human bone. Methods: A section of an edentulous dry mandible was radiographed and molded. The inside of the templates was lined with dental wax and filled with gypsum plaster mixed with sawdust or rice flour in proportions of 25%, 33.3% and 50% to simulate the trabecular pattern. Once this mixture settled, the wax lining was removed and the space filled with stone plaster to simulate the cortical bone. Three plaster models were fabricated for each proportion of each material. The models were radiographed and the radiographs that best resembled that of human bone were selected, one for each proportion of each material. The chosen radiographs were digitalized, and the digital images were Gaussian-blurred, binarized, skeletonized and submitted to fractal analysis. Results: All binary (p=0.000) and most skeletonized (p=0.000) images of the two groups were significantly different from that of the human mandible section, except for the skeletonized image of the model containing 50% rice. Conclusion: Although the results of this study did not allow consistent conclusions, they showed that the methodology is appropriate and practical for other similar studies. More studies are needed using different proportions of the same materials and bigger sample sizes for more reliable assessments of different mixtures.

Objetivo: Desenvolver modelos de gesso que possam reproduzir radiograficamente osso humano. Métodos: Uma secção de mandíbula edêntula foi radiografada e moldada. O molde obtido recebeu um alívio no interior com cera 7. Para vazá-lo utilizou-se gesso pedra misturado à serragem ou a arroz triturado nas proporções de 25; 33,3 e 50% para simular osso medular. Após o tempo de presa, a cera foi retirada e vazou-se nesse espaço gesso pedra para simular osso cortical. Foram obtidos três modelos em cada proporção estabelecida para os dois materiais. Estes modelos foram radiografados e a imagem mais semelhante à arquitetura óssea da mandíbula foi selecionada. As radiografias foram digitalizadas e as análises radiográficas realizadas por meio das imagens binária e esqueletonizada aplicando-se o protocolo de processamento Gaussian-Binary-Skeletonize. Resultados: Quando comparados com a mandíbula, todos os grupos apresentaram diferença estatisticamente significativa tanto para as imagens binárias (p= 0,000) quanto esqueletonizadas (p= 0,000), com exceção do Grupo Arroz 50% (A50) para imagem esqueletonizada. Conclusão: Embora os resultados deste estudo, não tenham permitido conclusões mais consistentes, eles serviram para determinar uma metodologia que se mostra prática e adequada para aplicação em estudos da mesma natureza. Porém, existe a necessidade de testar diferentes proporções dos materiais adicionados ao gesso pedra e aumentar o número das amostras para se obter uma avaliação mais fidedigna destes materiais.

Análise de medidas lineares da mandíbula em modelos tridimensionais reformatados a partir da tomografia computadorizada de feixe cônico / Mandibular linear measurements on 3D CBCT models

Avaliar a precisão e a acurácia de medidas lineares da mandíbula em modelos tridimensionais gerados a partir da tomografia computadorizada de feixe cônico (TCFC) em dois programas (Dolphin®. Material e Métodos: Dez mandíbulas com marcadores de sílica foram submetidas à TCFC seguindo o protocolo de voxel 0,3 mm do aparelho i-CAT Classic®. Vinte medidas lineares foram realizadas duas vezes, de maneira aleatória, nos modelos tridimensionais nos programas Dolphin®, nos filtros Translúcido e Sólido-1, e InVesalius®. As medidas físicas foram realizadas com um paquímetro digital diretamente nas mandíbulas por um segundo examinador. Análise de variância para medidas repetidas (ANOVA), coeficiente de correlação intraclasse, teste de Bland-Altman e erro absoluto e percentual foram utilizados para avaliar a precisão e a acurácia (p<0,05). Resultados: Alta precisão foi encontrada no programa Dolphin®, filtro Translúcido e Sólido-1 e InVesalius®, com diferença máxima entre as mensurações de 0,27; 0,26 e 0,17 mm, respectivamente. Com relação à acurácia, 10 variáveis no filtro Translúcido; oito no filtro Sólido-1 e 13 no programa inVesalius® foram diferentes estatisticamente em relação as medidas físicas. Porém, 95%, 100% e 90% das medidas apresentaram valores abaixo do valor considerado clinicamente relevante (1 mm) nos filtros Translúcido e Sólido-1 e no programa InVesalius®, respectivamente. Conclusão: Os modelos tridimensionais com marcadores hiperdensos, gerados pelos programas Dolphin®, filtro Translúcido e Sólido-1, e InVesalius® podem ser utilizados com precisão e acurácia para a obtenção de medidas lineares.

The purpose of this study was to determine the accuracy and reliability of mandibular linear measurements obtained from 3-dimensional cone-beam computed tomography (CBCT) scans of dry human mandibles using different software (Dolphin® and InVesalius®). Methods: Ten dry human mandibles were scanned at voxel size of 0.3 mm (i-CAT Classic®). Twenty measurements were made twice, randomized, on 3D model generated by the software Dolphin (filter Translucent and Solid-1) and InVesalius. Subsequently, physical measurements were made using a digital caliper. Analysis of variance for repeated measures (ANOVA), Intraclass correlation (ICC) BlandAltman, absolute and percentage mean error were used for evaluating accuracy and reliability (p<0.05). Results: Excellent reliability values were found for linear measurements from CBCT volume rendering images in all methods (Dolphin Translucent, Solid-1 and InVesalius), with the mean measurement of 0.27; 0.26 and 0.17 mm, respectively. Ten measurement errors for Dolphin Translucent, eight for Solid-1 and 13 for InVesalius were statistically significant different from physical measurements; however, 95%, 100% and 90% of the measurements were, respectively, below the value clinically relevant (1 mm). Conclusion: Linear measurements on 3D model generated by the software Dolphin (Translucent and Solid-1) and InVesalius are reliable and accurate and can be used for linear measurements.

Análise de medidas lineares da mandíbula em modelos tridimensionais reformatados a partir da tomografia computadorizada de feixe cônico / Mandibular linear measurements on 3D CBCT models

Avaliar a precisão e a acurácia de medidas lineares da mandíbula em modelos tridimensionais gerados a partir da tomografia computadorizada de feixe cônico (TCFC) em dois programas (Dolphin®. Material e Métodos: Dez mandíbulas com marcadores de sílica foram submetidas à TCFC seguindo o protocolo de voxel 0,3 mm do aparelho i-CAT Classic®. Vinte medidas lineares foram realizadas duas vezes, de maneira aleatória, nos modelos tridimensionais nos programas Dolphin®, nos filtros Translúcido e Sólido-1, e InVesalius®. As medidas físicas foram realizadas com um paquímetro digital diretamente nas mandíbulas por um segundo examinador. Análise de variância para medidas repetidas (ANOVA), coeficiente de correlação intraclasse, teste de Bland-Altman e erro absoluto e percentual foram utilizados para avaliar a precisão e a acurácia (p<0,05). Resultados: Alta precisão foi encontrada no programa Dolphin®, filtro Translúcido e Sólido-1 e InVesalius®, com diferença máxima entre as mensurações de 0,27; 0,26 e 0,17 mm, respectivamente. Com relação à acurácia, 10 variáveis no filtro Translúcido; oito no filtro Sólido-1 e 13 no programa inVesalius® foram diferentes estatisticamente em relação as medidas físicas. Porém, 95%, 100% e 90% das medidas apresentaram valores abaixo do valor considerado clinicamente relevante (1 mm) nos filtros Translúcido e Sólido-1 e no programa InVesalius®, respectivamente. Conclusão: Os modelos tridimensionais com marcadores hiperdensos, gerados pelos programas Dolphin®, filtro Translúcido e Sólido-1, e InVesalius® podem ser utilizados com precisão e acurácia para a obtenção de medidas lineares.

The purpose of this study was to determine the accuracy and reliability of mandibular linear measurements obtained from 3-dimensional cone-beam computed tomography (CBCT) scans of dry human mandibles using different software (Dolphin® and InVesalius®). Methods: Ten dry human mandibles were scanned at voxel size of 0.3 mm (i-CAT Classic®). Twenty measurements were made twice, randomized, on 3D model generated by the software Dolphin (filter Translucent and Solid-1) and InVesalius. Subsequently, physical measurements were made using a digital caliper. Analysis of variance for repeated measures (ANOVA), Intraclass correlation (ICC) BlandAltman, absolute and percentage mean error were used for evaluating accuracy and reliability (p<0.05). Results: Excellent reliability values were found for linear measurements from CBCT volume rendering images in all methods (Dolphin Translucent, Solid-1 and InVesalius), with the mean measurement of 0.27; 0.26 and 0.17 mm, respectively. Ten measurement errors for Dolphin Translucent, eight for Solid-1 and 13 for InVesalius were statistically significant different from physical measurements; however, 95%, 100% and 90% of the measurements were, respectively, below the value clinically relevant (1 mm). Conclusion: Linear measurements on 3D model generated by the software Dolphin (Translucent and Solid-1) and InVesalius are reliable and accurate and can be used for linear measurements.

Visibility of the mandibular canal on CBCT crosssectional images

The identification of the mandibular canal (MC) is an important prerequisite for surgical procedures involving the posterior mandible. Cone beam computed tomography (CBCT) represents an advance in imaging technology, but distinguishing the MC from surrounding structures may remain a delicate task. OBJECTIVES: The aim of this study was to assess the visibility of the MC in different regions on CBCT cross-sectional images. MATERIAL AND METHODS: CBCT cross-sectional images of 58 patients (116 hemi-mandibles) were analyzed, and the visibility of the MC in different regions was assessed. RESULTS: The MC was clearly visible in 53 percent of the hemi-mandibles. Difficult and very difficult visualizations were registered in 25 percent and 22 percent of the hemi-mandibles, respectively. The visibility of the MC on distal regions was superior when compared to regions closer to the mental foramen. No differences were found between edentulous and tooth-bearing areas. CONCLUSIONS: The MC presents an overall satisfactory visibility on CBCT cross-sectional images in most cases. However, the discrimination of the canal from its surrounds becomes less obvious towards the mental foramen region when cross-sectional images are individually analyzed.