Estudo comparativo cefalometrico radiografico dos padrões de crescimento facial em pacientes portadores de fibromatose gengival hereditaria e pacientes portadores de oclusão normal

Orientador : Frab Norberto BoscoloDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: A presente pesquisa teve o propósito de estudar os padroes de rescimento facial em pacientes portadores de Fibromatose Gencival Hereditária,comparando-os com os de pacient.es portadores de Oclusão Normal. Para isso foram utilizadas radiografias cefalométricas. Os resultados evidenciáram que, quanto aos padrões de crescimento :facial,os pacientes portadores de Fibromatose Gengival Hereditária apresentaram um crescimento facial hiperdivergente e quando comparados com os padrões de crescimento facial de pacientes portadores de Oclusão Normal. Com relação às medidas üneares aqui estudadas, estas apresentaaram-se aumentaadas com o decorrer da idade dos pacientes. Quando analisadas as medidas ancularoes, estas se apresentaram maiores nos pacient.es portadores de F.G.H., com exceção do ânculo SNB. Os resultados mostraram ainda que os pacientes do sexo masculino apresentaram médias gerais maior-es que as do sexo f'eminino, com exceção das variáveis NS.GNc e ANBAbstract: Patterns of facial crowt.h oC pat.lent.s wit.h heredit.ary cinci val Cibrornat.osis were compared wi t.h t.hose of indi viduals wi t.h normal occlusion usinc cepha1omet.rics roent.cenocraphics t.echincs. The result.s showed . t.hat. t.he values were hfcher I in males t.han in Cernales, except. t.he variables NS-GNc and ANB , and t.hat. t.he linear measures increased wi t.h t.he ace oC t.he pat.ient.. Ancular measupes were hicher in pat.ient.s wit.h hered:1- t.ary cincival Cibrornat.osis except. t.he SNB anele. Pat.t.erns of Cadal crowt.h in pat.ient.s wit.h heredit.ary Cincival f'ibrornat.osis were hyperdi vercent. in relat.ion t.o t.he dat.a obt.ained Crom pat.ient.s wit.h normal occlusionMestradoMestre em Odontologi

Radiopacity of calcium hydroxide cement compared with human tooth structure

AIMS: All materials added to teeth should present an adequate radiopacity to allow the detection of secondary caries. Usually, in extensive cavities, base materials like calcium hydroxide cement are used for the purpose of protecting the pulp. In an attempt to improve the efficiency of radiographic detection of this material, this study aimed to determine the radiopacity of three calcium hydroxide cements and to compare the radiopacity of these materials with dentin and enamel. METHODS: Radiographs were taken of 1-mm thick specimens of three calcium hydroxide cements: Hydro-C, Dycal and Life, an aluminium stepwedge, a lead foil, and one 1-mm thick human tooth slice. Densitometric measurements were obtained after radiographic processing. The radiopacity values of the calcium hydroxide cements, dentin and enamel were expressed in terms of the equivalent thickness of aluminium. RESULTS: The analysis of variance indicated statistically significant difference only for Life, which presented the lowest radiopacity when compared to the other cements. However, all cements and enamel possessed a radiopacity equivalent to 2mm Al, while dentin presented a radiopacity equivalent to 1mm Al. CONCLUSION: All tested cements presented a similar radiopacity to that of enamel and they meet the ISO 4049 specifications.OBJETIVOS: Todos os materiais adicionados aos dentes deveriam apresentar uma adequada radiopacidade para permitir a detecção de cáries secundárias. Geralmente em cavidades extensas, materiais de base, como o cimento de hidróxido de cálcio, são usados com a função de proteger a polpa. Na tentativa de melhorar a eficiência na detecção radiográfica deste material, este estudo foi realizado com o objetivo de determinar a radiopacidade de três cimentos de hidróxido de cálcio e comparar a radiopacidade destes materiais com a da dentina e do esmalte. MATERIAIS E MÉTODO: Foram radiografados corpos de prova de 1 mm de espessura de três cimentos de hidróxido de cálcio: Hydro-C, Dycal e Life, uma escala de densidade de alumínio, uma lâmina de chumbo e um corte de dente humano de 1 mm de espessura. As densidades ópticas foram obtidas após o processamento radiográfico. Os valores de radiopacidade dos cimentos de hidróxido de cálcio, dentina e esmalte foram expressos em espessuras equivalentes de alumínio. RESULTADOS: A análise de variância indicou diferença estatisticamente significativa apenas para o cimento Life que apresentou a menor radiopacidade quando comparado aos outros cimentos. Entretanto, todos os cimentos e o esmalte possuíram uma radiopacidade equivalente a 2 mm de Al, enquanto a dentina apresentava radiopacidade equivalente a 1 mm de Al. CONCLUSÃO: Todos os cimentos testados apresentaram radiopacidades semelhantes à do esmalte, estando de acordo com as especificações da ISO 4049

Use of cervical vertebral dimensions for assessment of children growth

OBJECTIVE: The purpose of this study was to investigate whether skeletal maturation using cephalometric radiographs could be used in a Brazilian population. MATERIAL AND METHODS: The study population was selected from the files of the Oral Radiological Clinic of the Dental School of Piracicaba, Brazil and consisted of 128 girls and 110 boys (7.0 to 15.9 years old) who had cephalometric and hand-wrist radiographs taken on the same day. Cervical vertebral bone age was evaluated using the method described by Mito and colleagues in 2002. Bone age was assessed by the Tanner-Whitehouse (TW3) method and was used as a gold standard to determine the reliability of cervical vertebral bone age. An analysis of variance and Tukey's post-hoc test were used to compare cervical vertebral bone age, bone age and chronological age at 5% significance level. RESULTS: The analysis of the Brazilian female children data showed that there was a statistically significant difference (p;0.05) was found between cervical vertebral bone age and bone age. Differently, the analysis of the male children data revealed a statistically significant difference (

Dental maturity as an indicator of chronological age: radiographic assessment of dental age in a brazilian population

OBJECTIVE: The purpose of this investigation was to evaluate the applicability of the methods proposed by Nolla and by Nicodemo and colleagues for assessing dental age and its correlation to chronological age. METHODS: Panoramic radiographs of 360 patients from the city of Fortaleza (CE, Brazil) aged 7-15 years were used to assess the associations between dental and chronological age. Data were submitted to statistical analysis using the BioEstat 2.0 (2000) software. Student-Neuman-Keuls test was performed and Pearson's correlation coefficients were calculated at 5% significance level. RESULTS: When the Nolla method was applied, the mean difference between true and estimated age for males and females was underestimated. The use of the method proposed by Nicodemo and colleagues also resulted in underestimation, although it was more evident in male subjects. The correlation coefficients between chronological age and estimated dental age were high, with mean values ranging between 0.87 and 0.91 for males and between 0.84 and 0.93 for females. CONCLUSION: Although both methods proved to be reliable in estimating age, the use of correction factors is recommended

In vitro induction of enamel subsurface demineralization for evaluation of diagnostic imaging methods

The aim of this study was to investigate a model of inducing enamel subsurface demineralization for evaluating diagnostic imaging methods. Fifty sound teeth had their crowns coated with acid-resistant varnish, leaving a 7 mm² circular window of exposed enamel in one of the proximal surfaces. The specimens were assigned to 5 groups (4 experimental and the control) and were kept immersed in a buffer solution at pH 4.8, 50% saturated in relation to enamel, for 60, 75, 90 and 120 days, or were not exposed to the solution. Digital radiographs were taken, prior to and after each immersion period, and interpreted by a radiologist. For validation, the enamel was submitted to microhardness profiling. In addition, the solutions were analyzed for phosphorus (Pi) and calcium (Ca) concentrations. Microhardness data were evaluated using two-way ANOVA (

Study of the aluminum-zinc alloy as an alternative means of filtration in dental X-ray devices

O objetivo neste trabalho foi avaliar os efeitos da filtração alternativa da liga alumínio-zinco em aparelhos de raios X odontológicos, em relação ao espectro de energia dos feixes de raios X, a taxa de kerma no ar, o índice de contraste nas radiografias obtidas e a qualidade das imagens radiográficas. Este estudo foi realizado comparando-se o filtro convencional de alumínio com várias espessuras do filtro de liga alumínio-zinco, em diferentes porcentagens do elemento zinco na liga (2%, 3%, 4% e 5%). Foi utilizado um aparelho de raios X odontológico convencional, operando com 60 kVp e 70 kVp, e filmes radiográficos dos grupos D e E de sensibilidade. Foram realizadas radiografias de um "phantom" e de uma escala de densidade de alumínio. Os resultados mostraram que o uso dos filtros de liga Al-Zn resultou em um não-endurecimento dos feixes. A taxa de kerma no ar diminuiu em até 18,53%, sem alteração no contraste das radiografias e a qualidade das imagens teve uma boa aceitação pelos examinadores. A análise dos resultados nos levou a concluir que o filtro de liga Al-Zn 2%, com 1,99 mm de espessura, tensão de 60 kVp, quando usado com filme D, foi o que obteve melhor desempenho, reduzindo a taxa de kerma no ar sem variar o índice de contraste das radiografias, mantendo a qualidade da imagem aceitável para diagnóstico, sem contudo aumentar o tempo de exposição.The aim of this study was to evaluate the effects of alternative filtration with the aluminum-zinc alloy in dental X-ray devices, regarding the energy spectrum, dose, contrast and image quality. This study was carried out comparing the conventional aluminum filter with aluminum-zinc alloy filters of various thicknesses and with different percentages of zinc in the alloy (2, 3, 4 and 5%). A conventional X-ray device operating with 60 and 70 kVp as well as D- and E-speed films were utilized in order to obtain images of a phantom and an aluminum step wedge. The utilization of Al-Zn filters resulted in a spectrum without hardening of beams. The rate of kerma in the air decreased 18.53%, without any alteration in contrast and image quality. The results revealed that the 2% Al-Zn alloy filter with 1.99 mm of thickness, utilized with the tension of 60 kVp and D-speed film, had the best performance. It reduced the rate of kerma without varying the indices of contrast and maintained image quality at acceptable levels, without increasing the time of exposure

The influence of different scan resolutions on the detection of proximal caries lesions

This study was conducted to evaluate the effect of different spatial resolutions of a photostimulable phosphor plate (PSP) radiography system on the detection of proximal caries lesions. Materials and Methods: Forty-five extracted human permanent teeth were radiographed using a PSP system (VistaScan Perio Plus) and scanned at the 4 resolutions (10 lp/mm, 20 lp/mm, 25 lp/mm, and 40 lp/mm) available in the system. Three independent examiners scored the images for the presence and absence of proximal caries lesions using a 5-point scale. The presence or absence of caries was confirmed by histological sections of the examined teeth (defined as the gold standard). Intra-and inter-observer reproducibility was calculated by the weighted kappa test. One-way analysis of variance with the post hoc Tukey test was used to compare the area under the receiver operating characteristic curve for the classifications made with each resolution. Results: For the detection of enamel lesions, the spatial resolution of 10 lp/mm was significantly superior to the other resolutions. However, the spatial resolution did not affect the detection of caries lesions in dentin (P>0.05). Conclusion: Spatial resolution may influence the accuracy of the detection of incipient caries lesions in radiographs with PSP plates. Images with low spatial resolution seem to be more appropriate for this purpose49297102sem informaçãosem informaçã

Comparison of automatic and visual methods used for image segmentation in Endodontics: a microCT study

To calculate root canal volume and surface area in microCT images, an image segmentation by selecting threshold values is required, which can be determined by visual or automatic methods. Visual determination is influenced by the operator's visual acuity, while the automatic method is done entirely by computer algorithms. Objective: To compare between visual and automatic segmentation, and to determine the influence of the operator's visual acuity on the reproducibility of root canal volume and area measurements. Material and methods: Images from 31 extracted human anterior teeth were scanned with a μCT scanner. Three experienced examiners performed visual image segmentation, and threshold values were recorded. Automatic segmentation was done using the “Automatic Threshold Tool” available in the dedicated software provided by the scanner's manufacturer. Volume and area measurements were performed using the threshold values determined both visually and automatically. Results: The paired Student's t-test showed no significant difference between visual and automatic segmentation methods regarding root canal volume measurements (p=0.93) and root canal surface (p=0.79). Conclusion: Although visual and automatic segmentation methods can be used to determine the threshold and calculate root canal volume and surface, the automatic method may be the most suitable for ensuring the reproducibility of threshold determination

Uso de la tomografía computarizada en el diagnóstico de la anquilosis de la articulación temporomandibular: presentación de dos casos clínicos

La anquilosis de la articulación temporomandibular es definida como la abolición o limitación de los movimientos de dicha articulación. Radiográficamente la anquilosis demuestra aspectos bien característicos que facilitan el diagnóstico, sin embargo, su análisis en las técnicas radiográficas convencionales, en la mayoría de las veces, no se presenta de forma clara. Con la evolución de las técnicas radiográficas, la tomografía computarizada pasó a ser un examen de gran importancia en el diagnóstico de las anquilosis temporomandibulares. En vista de ello, el presente trabajo se propone mostrar y describir imágenes tomográficas de la anquilosis de esta articulación, presentando dos casos clínicos, utilizando diversos planos, como el axial y el coronal, además del uso de la reconstrucción sagital y en 3D, con la finalidad de orientar una correcta indicación e interpretación de este examen, el cual representa una valiosa herramienta para los profesionales de la Odontología.Ankylosis of the temporomandibular joint is characterized by restriction or limitation of mandibular movement. It presents as a classic symptom a limited range of motion on opening. Radiographically, ankylosis presents features that facilitate the diagnosis. However, its visualization is not clear in most of the cases involving conventional radiographic techniques. With the evolution of radiographic techniques, computed tomography (CT) became an important examination in the diagnosis of the ankylosis of temporomandibular joint. Due to the increasing use of the CT and its importance in the diagnosis of this disease, the aim of this paper is to present and describe tomographic images of ankylosis of this joint by presenting two clinical cases, using several slices as axial, coronal, and three-dimensional reformatted images

Computed tomography of the TMJ in diagnosis of ankylosis : two case reports

Ankylosis of the temporomandibular joint is characterized by restriction or limitation of mandibular movement. It presents as a classic symptom a limited range of motion on opening. Radiographically, ankylosis presents features that facilitate the diagnosis. However, its visualization is not clear in most of the cases involving conventional radiographic techniques. With the evolution of radiographic techniques, computed tomography (CT) became an important examination in the diagnosis of the ankylosis of temporomandibular joint. Due to the increasing use of the CT and its importance in the diagnosis of this disease, the aim of this paper is to present and describe tomographic images of ankylosis of this joint by presenting two clinical cases, using several slices as axial, coronal, and three-dimensional reformatted images