Orientadores: Glaucia Maria Bovi Ambrosano, Paulo Sérgio Flores Campos / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-20T02:59:51Z (GMT). No. of bitstreams: 1 Aguiar_LucianaBarretoVieira_D.pdf: 775343 bytes, checksum: 32297ad518d640437e10e0db97d996fa (MD5) Previous issue date: 2012 / Resumo: O objetivo neste estudo foi avaliar a validade de medidas verticais lineares para fins de inserção de implantes dentários em mandíbula a partir de imagens paracoronais diagonais (tomógrafo k9000 3D) e imagens paracoronais ortogonais (tomógrafo i-CAT). A amostra consistiu de 11 mandíbulas humanas secas e desdentadas na região posterior. Foram realizadas, a partir dos sítios implantares, três linhas de orientação, desde o rebordo alveolar até a base da mandíbula, simulando o ângulo de implantação dos dentes na base óssea. Para que estas linhas pudessem ser visualizadas nas imagens tomográficas, foram colocadas no rebordo três esferas plásticas, para localização do sítio implantar, e cones de guta percha com 01 cm de espaçamento entre eles. A aquisição das imagens foi procedida nos tomógrafos i-CAT e k9000 3D, de acordo com os protocolos estabelecidos para este fim. Após as aquisições, três avaliadores analisaram as imagens nos softwares i-CAT Vision e do KDIS, dos respectivos tomógrafos. Para a análise das imagens do i-CAT, os avaliadores realizaram cortes paracoronais ortogonais mensurando a partir do rebordo ósseo até o teto do canal mandibular o corte com a imagem da esfera mais nítida. Nas imagens do k9000 3D, os avaliadores realizaram cortes paracoronais diagonais usando a ferramenta do próprio software e mensurando também do rebordo ósseo até o teto do canal mandibular, acompanhando a orientação da guta percha. Os avaliadores realizaram uma segunda mensuração após uma semana. As mandíbulas foram cortadas seguindo a localização e a orientação das linhas previamente tracejadas nos três sítios, sendo as alturas mensuradas com um paquímetro digital desde o rebordo ósseo até o teto do canal mandibular. As medidas assim aferidas foram utilizadas como padrão ouro. Após a tabulação, os dados foram avaliados pela análise de correlação intraclasse e a comparação entre as médias obtidas nos dois tomógrafos com o real foi realizada pelo teste t pareado (?=0,05). Observou-se que o coeficiente de correlação intraclasse intra-avaliadores foi excelente (variando de 0,98 a 0,99) para os dois tomógrafos. Para a primeira e a segunda avaliação o ICC interavaliadores para os dois tomógrafos foi de satisfatório a excelente: 0,72 a 0,99 e 0,69 a 0,98 respectivamente. Quando comparados os avaliadores com o padrão ouro, o ICC foi excelente variando de 0,76 a 0,87 e 0,82 a 0,89, para o i-CAT e o k9000 3D, respectivamente. Os resultados do ICC para os tomógrafos comparados com o padrão ouro foram excelentes (0,88 e 0,94). O resultado da estatística descritiva obteve um valor de p= 0,0002 com uma média de 13,5 para o i-Cat havendo diferença estatisticamente significativa em relação ao padrão ouro (média 12,5). O k9000 apresentou uma média de 12,7 (p=0,4454) não havendo diferença estatisticamente significativa em relação ao padrão ouro. Dessa forma, pode-se concluir que as medidas verticais reproduzem a condição anatômica e são válidas para fins de inserção de implantes dentários / Abstract: The aim of this study was to evaluate the validity of vertical linear measurements for the purpose of inserting dental implants in the mandible using diagonal parasagittal images (K9000 3D Tomograph) and orthogonal parasagittal images (i-CAT Tomograph). The sample consisted of 11 dry, human mandibles, edentulous in the posterior region. From the implant sites, three orientation lines were drawn from the alveolar ridge to the base of the mandible, simulating the angle of implantation of teeth in the bony base. So that these lines could be visualized in the tomographic images, three plastic spheres were placed on the ridge to localize the implant site, and gutta percha cones spaced at a distance of 01cm between them. Image acquisition was performed with i-CAT and K9000 3D tomographs, in accordance with the protocols established for this purpose. After acquisition, three evaluators analyzed the images by means of i-CAT Vision and KDIS software of the respective tomographs. For analysis of i-CAT images, the evaluators made parasagittal orthogonal cuts measuring the cut with the most nitid image of the sphere from the bone ridge up to the roof of the mandibular canal. In the images of the K9000, the evaluators made diagonal parasagittal cuts using the tool of the software itself and also measured from the bone ridge up to the roof of the mandibular canal, following the orientation of the gutta percha. The evaluators made a second measurement after one week. The hemi-mandibles were cut following the localization and orientation of the previously traced lines in the three sites, with the heights being measured with a digital pachymeter from the bone ridge up to the roof of the mandibular canal. The measurements thus checked were used as the gold standard. After tabulation, the data were evaluated by the interclass correlation analysis. The results demonstrated that the intraclass intra-evaluator coefficient of correlation was excellent (ranging from 0.98 to 0.99) for the two Tomographs. For the first and second evaluation the inter-evaluator ICC for the two tomographs was from satisfactory to excellent: 0.72 to 0.99 and 0.69 to 0.98 respectively. When the evaluators were compared with the gold standard, the ICC was excellent variation from 0.76 to 0.87 and 0.82 to 0.89, for i-CAT and K9000 3D, respectively. The results of the ICC for the tomographs compared with the gold standard were excellent (0.88 and 0.94). Thus, it could be concluded that the vertical measurements reproduced the anatomic condition and are valid for the purpose of inserting dental implants / Doutorado / Radiologia Odontologica / Mestre em Radiologia Odontológica

Objective: To compare condylar dimensions of young adults with Class II and Class III skeletal patterns using cone-beam computed tomography (CBCT). Materials and methods: 124 CBCTs from 18-30 year-old patients, divided into 2 groups according to skeletal patterns (Class II and Class III) were evaluated. Skeletal patterns were classified by measuring the ANB angle of each patient. The anteroposterior diameter (A and P) of the right and left mandibular condyle was assessed from a sagittal view by a line drawn from point A (anterior) to P (posterior). The coronal plane allowed the evaluation of the medio-lateral diameter by drawing a line from point M (medium) to L (lateral); all distances were measured in mm. Results: In Class II the A-P diameter was 9.06±1.33 and 8.86±1.56 for the right and left condyles respectively, in Class III these values were 8.71±1.2 and 8.84±1.42. In Class II the M-L diameter was 17.94±2.68 and 17.67±2.44 for the right and left condyles respectively, in Class III these values were 19.16±2.75 and 19.16±2.54. Conclusion: Class III M-L dimensions showed higher values than Class II, whereas these differences were minimal in A-P.

Orientador: Francisco Haiter Neto / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-26T19:01:13Z (GMT). No. of bitstreams: 1 Brasil_DanieliMoura_M.pdf: 14824425 bytes, checksum: 3057ff676ccce0f70d5ed273ef3ffed8 (MD5) Previous issue date: 2015 / Resumo: O objetivo deste estudo foi avaliar a influência da morfologia craniofacial em volumes e áreas transversais das vias aéreas superiores. Para isso, foram utilizadas 74 imagens por Tomografia Computadorizada de Feixe Cônico (TCFC) e 74 fotografias faciais em perfil lateral, que pertenciam aos mesmos pacientes, sendo 38 do sexo masculino e 36 do sexo feminino, com idades entre 18 e 56 anos (32,8 ± 1,8). As imagens foram selecionadas a partir de um arquivo de exames de pacientes atendidos em uma Clínica de Radiologia. Um radiologista experiente classificou a amostra em tipos esqueléticos ântero-posteriores (classe II e classe III) empregando a análise cefalométrica de Steiner e a medida AO-BO de Jacobson; e em padrões verticais (braquifacial, mesofacial e dolicofacial) utilizando a análise cefalométrica de Ricketts. A análise facial de perfil foi realizada para cada paciente. Medidas de volume total, de nasofaringe e de orofaringe e ainda de cinco áreas transversais ao longo das vias aéreas superiores foram realizadas, utilizando o software Insight ITK-SNAP 2.4.0®. Os resultados foram submetidos à análise estatística, em que o teste Mann-Whitney foi utilizado para analisar a influência do sexo e dos tipos esqueléticos ântero-posteriores nas variáveis do estudo, o teste Kruskal-Wallis foi aplicado para verificar a existência de relação entre os padrões verticais e as variáveis; o teste de Correlação de Spearman foi utilizado para analisar a possível correlação entre as medidas dentro dos padrões esqueléticos ântero-posteriores, dentro dos padrões verticais e dentro das variáveis da análise facial e as demais medidas propostas pelo estudo. Os resultados mostraram que o tipo esquelético ântero-posterior e o padrão vertical da face não influenciaram no volume das vias aéreas superiores; a área transversal na região de palato mole (PM) mostrou-se significativamente maior para classe III; o terço superior da face apresentou correlação negativa com as medidas da faringe e o terço médio da face mostrou correlação positiva com a área transversal PM. Concluiu-se que os padrões faciais não influenciaram no volume da faringe e que a observação fotográfica do perfil facial foi capaz de mostrar tendências de correlações entre terços da face e vias aéreas superiores / Abstract: The aim of this study was to evaluate the influence of craniofacial morphology in volumes and cross-sectional areas of the upper airway. For this 74 Cone Beam Computed Tomography (CBCT) images and 74 facial photographs in side profile were used, which belonged to the same patients, 38 males and 36 females, aged between 18 and 56 years (32.8 ± 1.8). The images were selected from a file examination of patients seen in a Radiology Clinic. An experienced radiologist classified the sample into anteroposterior skeletal types (class II e class III) using Steiner¿s analysis and the AO-BO measure Jacobson; and into vertical groups (brachyfacial, mesofacial and dolichofacial) using Ricketts¿ analysis. The facial profile analysis was performed for each patient. Measurement of volume and of five cross-sectional areas of upper airway were performed using Insight ITK-SNAP 2.4.0®. The data was subjected to statistical analysis, the Kruskal-Wallis test was used to verify the existence of a relationship between the vertical groups and other variables analyzed in the study. The Mann-Whitney test was used to analyze the influence of gender and anteroposterior skeletal types in the variables. Spearman Correlation test was used to analyze the possible correlation between measurements within vertical groups; within the anteroposterior skeletal types; and within variables of facial analysis, and other measures proposed by the study. Results showed that the anteroposterior skeletal type and the vertical pattern did not influence the volume of the upper airway; soft palate (SP) cross-sectional area was significantly greater in type class III; the upper facial third was negatively correlated with measures of the pharynx, and the middle facial third had positive correlation with the SP cross-sectional area. It was concluded that facial patterns do not influence the pharynx volumes. The photographic observation of the facial profiles is able to show trends of correlations between thirds of the face and upper airway / Mestrado / Radiologia Odontologica / Mestra em Radiologia Odontológica

Orientador: Luciana Asprino / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-27T07:59:26Z (GMT). No. of bitstreams: 1 Santaella_GustavoMachado_M.pdf: 1130922 bytes, checksum: 73dd73d086d83d2c9e2fa04c5f9cd294 (MD5) Previous issue date: 2015 / Resumo: Os fótons de raios X são atenuados quando atravessam materiais, e isso afeta diretamente os valores dos tons de cinza da imagem. No presente estudo teve-se como objetivos avaliar a utilização de diferentes materiais como simuladores de tecidos moles e avaliar a influência dos tecidos moles nos tons de cinza em imagens de tomografia computadorizada de feixe cônico (TCFC). Para isso, foram utilizadas três cabeças humanas com os tecidos moles formolizados presentes e submetidas à aquisição de imagens de TCFC para determinação do grupo padrão-ouro. Posteriormente, as cabeças foram descarnadas e novamente tomografadas, com e sem a utilização de diferentes materiais simuladores de tecidos moles, seguindo o mesmo protocolo de aquisição. Quatro diferentes materiais foram testados, acrílico, água, cera utilidade e poliestireno expandido (EPS), utilizados isoladamente ou em combinação, totalizando 6 grupos de teste (sem simulador, com caixa de EPS de 2 cm de espessura, com acrílico com 0,5 cm de espessura, com caixa de EPS com cera de 1 cm de espessura, com caixa de EPS com cera de 1 cm de espessura e água no interior, e com caixa de EPS com água no interior). Um único avaliador selecionou oito regiões de interesse quadrangulares, sendo em maxila e mandíbula e incluindo dentes e ossos alveolares, e realizou as mensurações de todos os valores dos tons de cinza dos pixels das regiões. As medianas desses valores foram utilizadas para comparação pelos testes de Friedman e Dunn. Os resultados mostraram que os grupos testados não apresentaram diferenças estatisticamente significantes em comparação com o grupo padrão-ouro, com exceção dos grupos que envolveram água no interior das caixas. O EPS com 2 cm de espessura, associado ou não a uma camada de cera utilidade de 1 cm, e o acrílico com 0,5 cm de espessura foram os simuladores que forneceram imagens mais semelhantes às imagens do padrão-ouro. A água não se mostrou eficaz como simulador de tecidos moles. Os tecidos moles não influenciaram nos valores de tons de cinza mensurados na imagem de TCFC / Abstract: X-ray photons suffer attenuation as they pass through materials of different compositions, and this directly affects the values of the image grayscale. This study aimed to test the usefulness of different materials as soft tissue simulators and evaluate the influence of soft tissues on grayscale values in cone beam computed tomography (CBCT). Three human heads with formalin fixed soft tissues were obtained and CBCT images were acquired to determine the gold standard group. The heads were stripped and tomographic images reacquired with and without the use of different materials for soft tissue simulation, following the same acquisition protocol. Four different materials were tested, acrylic, water, utility wax and expanded polystyrene (EPS), and these were used singly or in combination, with a total of 6 test groups (no simulator, with EPS box 2 cm thick, with 0.5 cm thick acrylic, EPS box with 1 cm thick wax, EPS box with 1 cm thick wax and water inside, and EPS box with water inside). A single evaluator selected the eight quadrangular regions of interest, being in the maxilla and mandible and including teeth and alveolar bone, and performed the measurements of all the pixel grayscale values of the regions. The median of these values were used for comparison by Friedman's and Dunn's tests. The results showed that the tested groups showed no statistically significant differences compared to the gold standard group, with the exception of groups involving water inside the boxes. The EPS 2 cm thick, associated or not with a 1 cm layer of utility wax, and the 0.5 cm thick acrylic were the simulators that provided images more similar to the gold standard images. The water was not effective as a soft tissue simulator. The soft tissues did not influence the values of the CBCT image grayscale measured / Mestrado / Radiologia Odontologica / Mestre em Radiologia Odontológica

Introduction: Root resorption is an undesired but frequent side effect of orthodontic treatment. Several studies have already aimed to evaluate the performance of CBCT on this topic. However, none have addressed the peculiarities of the most common daily orthodontic scenario. The aim of the study was to evaluate the influence of CBCT scans on the diagnosis of artificial external root resorption in the apical third of anterior teeth. Materials and methods: One hundred extracted human anterior teeth were randomly assigned to 2 uneven groups (51 as the control and 49 as the experimental group). A limited area of the apical third of the root of the teeth of the experimental group was selected and a buffer solution was used to induce tooth subsurface demineralization. Before CBCT image acquisition, each tooth was coated with an approximately 0.3 mm thick layer of utility wax to simulate the radiographic appearance of the periodontal space and placed into an empty mandibular anterior socket of a partially edentulous dry human mandible. The mandible was placed into a polystyrene box filled with water prior to the CBCT examination to simulate soft-tissue attenuation and scattering. The CBCT images were obtained on an i-CAT unit (i-CAT Next Generation, Imaging Sciences International, Hatfield, PA) according to three protocols: (I) half scan (180°), 0.40 mm voxel size; (II) full scan (360°), 0.40 mm voxel size; and (III) full scan (360°), 0.125 mm voxel size. The 300 resultant CBCT DICOM volumes were imported into InVivo software (InVivo5, Anatomage, San Jose, CA) for evaluation by three blinded, previously calibrated observers using a five-point confidence rating scale. Cohen’s kappa was used to calculate observers’ agreement. The diagnostic values of sensitivity (Sn), specificity (Sp) and accuracy (Ac) were performed by pooling observer responses for every image modality. Receiver operating characteristic (ROC) were built and the areas under the curve (AUC) were calculated. The Sn, Sp and Ac values were compared by Cochran’s Q test. The AUC values were compared by Mann-Whitney U test. Results: The observers’ agreement ranged from 0.63 to 0.71, which was interpreted as a substantial agreement. Protocol III (0.125 mm voxel size) displayed the highest Sn (81.63 %), Ac (80.67%) and AUC (0.807). There were statistically significant differences between protocol III and the other two protocols (p < 0.001). The specificity of protocol I (84.97 %) was greater than that of protocols II (69.93 %) and III (79.74 %); however statistically significant difference was only found between protocols I and II (p = 0.005). Conclusion: Although there was no difference in accuracy between the degrees of rotation (half and full scan) within the same voxel size (0.4 mm), there was a considerable difference between those and the smallest voxel size (0.125 mm). In fact, it may be suggested that a more dedicated, high resolution scan should be acquired when one intends to investigate the early stage of external root resorption during orthodontic treatment.

No description available.

No description available.

Introduction: We argue, for studies of growth or treatment changes, superimposed CBCT images ought to be employed routinely. The location of 3D landmarks on curved structures, however, has been complex. In this study, a reliable method of CBCT superimposition was developed with the aid of AMIRA XImage® software. The specific focus was to develop a practical method for cranial base superimpositions at sella turcica in serial CBCT images. Subsequently, evaluations of the anterior curvature of hypophyseal fossa during growth were completed to confirm the stability. Comparisons of surface changes in the superimposed images in different regions were also made. Methods: Samples of pre- and post-orthodontic CBCT data were procured from Case Western Reserve University. Cranial base changes in 10 adolescent patients of Class I and II hypodivergent, normodivergent, and hyperdivergent malocclusions, were observed over an average interval of 2 years and 5 months. Cranial base models were superimposed using a rigid registration technique, and 3D models constructed from manual segmentation in the AMIRA software. Surface distance changes of the entire cranial base were compared to that of the anterior portion of sella turcica. Results: Mean surface distance changes for the entire cranial base and anterior sella were 0.73-1.57 ± 0.71-1.30 mm and 0.37-0.63 ± 0.29-0.43 mm, respectively. The area above a threshold of 0.5 mm was 61.02-74.11% (cranial base) and 40.70-50.94% (anterior sella) as well. Paired t-tests were applied to compare differences between the mean distance and area above the threshold for data of cranial base versus anterior sella. Both illustrated p-values less than 0.0001 and were statistically significant. Intra-rater reliability was evaluated by completing segmentation and registration three consecutive times on each CBCT volume. Mean surface differences were within 0.01 mm with the exception of one patient. In addition, all subjects exhibited less than 1.00% deviation except three patients, which deviated by 1.03%, 1.46%, and 1.64%, respectively. Conclusions: A practical method of superimposition of serial CBCT images was developed. Through production of color maps, the surface distance of the anterior portion of sella turcica was shown to change much less than the clivus and remaining cranial base structures in pre- and post-treatment scans of growing children. Lastly, the method of superimposition developed here may assist future studies of skeletal changes with accuracy. / Oral Biology

Yes / The suspected scaphoid fracture remains a diagnostic conundrum with over-treatment a common risk-averse strategy. Cross-sectional imaging remains the gold standard with MRI recommended but CT used by some because of easier access or limited MRI availability. The aim of this feasibility study was to evaluate whether cone beam computed tomography (CBCT) could support early diagnosis, or exclusion, of scaphoid fractures. Patients with a suspected scaphoid were recruited fracture between March and July 2020. All underwent a 4-view X-ray. If this examination was normal, they were immediately referred for a CBCT scan of the wrist. Those with a normal scan were discharged to research follow-up at 2 and 6-weeks. 68 participants were recruited, 55 had a normal or equivocal X-ray and underwent CBCT. Nine additional radiocarpal fractures (16.2%) were demonstrated on CBCT, the remainder were discharged to research follow-up. Based on the 2-week and 6-week follow up three patients (4.4%) were referred for MRI to investigate persistent symptoms with no bony injuries identified. CBCT scans enabled a rapid pathway for the diagnosis or exclusion of scaphoid fractures, identifying other fractures and facilitating early treatment. The rapid pathway also enabled those with no bony injury to start rehabilitation, suggesting that patients can be safely discharged with safety-net advice following a CBCT scan.

Yes / Purpose: Cone-Beam CT (CBCT) is well established in orofacial diagnostic imaging and is currently expanding into musculoskeletal applications. This systematic review sought to update the knowledge base on radiation dose comparisons between imaging modalities in MSK imaging and consider how research studies have reported dose measures. Methods: This review utilised a database search and an online literature tool. Studies with potential relevance were screened then before full text review, each performed by two independent reviewers, with a third independent reviewer available for conflicts. Data was extracted using a bespoke tool created within the literature tool. Results: 21 studies were included in the review which compared CBCT with MSCT (13), conventional radiography (1), or both (7). 19 studies concluded that CBCT provided a reduced radiation dose when compared with MSCT: the factor of reduction ranging from 1.71 to 50 with an average of 12. Studies comparing CBCT to DR found DR to have an average dose reduction of 4.55. Conclusions: The claims that CBCT produces a lower radiation dose than MSCT is borne out with most studies confirming doses less than half that of MSCT. Fewer studies include DR as a comparator but confirm that CBCT results in a higher effective dose on average, with scope for CBCT to provide an equivalent radiation dose. This review highlighted a need for consistency in methodology when conducting studies which compare radiation dose across different technologies. Potential solutions lie outside the scope of this review, likely requiring multi-discipline approach to ensure a cohesive outcome.