RESUMO A displasia fibrosa é uma lesão fibro-óssea benigna em que o osso normal é substituído por tecido conjuntivo fibroso e osso imaturo, podendo afetar um único osso (monostótica) ou vários ossos (poliostótica), ocorrendo principalmente em crianças e adultos jovens. Quando presente nos ossos faciais, a maxila é envolvida com mais frequência que a mandíbula, podendo causar assimetria facial, além de complicações odontológicas. Nos exames por imagem a característica principal da displasia fibrosa é a aparência de vidro despolido. A tomografia computadorizada é o método ideal para avaliação dessa lesão e relação com estruturas adjacentes. A radiografia convencional, devido a sobreposição de estruturas anatômicas, torna difícil a delimitação da extensão da lesão. O presente estudo teve como objetivo apresentar o relato de caso de um paciente do sexo feminino, 10 anos de idade, com presença de displasia fibrosa na maxila, objetivando orientar os cirurgiões-dentistas com relação às principais características imaginológicas dessa lesão.

ABSTRACT Fibrous dysplasia is a benign fibrous-osseous lesion in which normal bone is replaced by fibrous connective tissue and immature bone, affecting only one (monostotic) or several bones (polyostotic) and mainly occurring in children and young adults. When present in facial bones, the maxilla is more frequently involved than the mandible, which can cause facial asymmetry in addition to dental complications. In the image exams, the main characteristic of fibrous dysplasia is its unpolished glass appearance. Computed tomography is the ideal method for evaluating this lesion and its relationship with adjacent structures. The use of conventional radiography, due to the overlapping of anatomical structures, makes it difficult to delineate the extension of the lesion. The present study is aimed at guiding dentist-surgeons on the main imaging characteristics of fibrous dysplasia by describing a case of a female 10-year-old patient presenting with this lesion in the maxilla.

Abstract The purpose of this study was to perform a microcomputed tomographic evaluation of the radioprotective effect of resveratrol on the volume of mandibular incisors of irradiated rats. A second aim was to make a quantitative assessment of the effect of x-ray exposure on these dental tissues. Twenty adult male rats were divided into four groups: control, irradiated control, resveratrol, and irradiated resveratrol. The resveratrol groups received 100 mg/kg of resveratrol, whereas the irradiated groups were exposed to 15 Gy of irradiation. The animals were sacrificed 30 days after the irradiation procedure, and their mandibles were removed and scanned in a microcomputed tomography unit. The images were loaded into Mimics software to allow segmentation of the mandibular incisor and assessment of its volume. The results were compared by One-way ANOVA and Tukey’s post hoc test, considering a 5% significance level. The irradiated groups showed significantly diminished volumes of the evaluated teeth, as compared with the control group (p < 0.05). The resveratrol group presented higher values than those of the irradiated groups, and volumes similar to those of the control group. High radiation doses significantly affected tooth formation, resulting in alterations in the dental structure, and thus lower volumes. Moreover, resveratrol showed no effective radioprotective impact on dental tissues. Future studies are needed to evaluate different concentrations of this substance, in an endeavor to verify its potential as a radioprotector for these dental tissues.

Abstract Aim: To evaluate the relationship between palatal bone height and facial types using cone beam computed tomography (CBCT) images. Methods: The study sample consisted of 110 CBCT images. Subjects aged 18 to 35 years old were classified as brachyfacial, mesofacial and dolichofacial, according to SN.GoGn angle, measured in cephalometric analysis with Nemotec 3D software. Three observers evaluated the bone height of the palate in the anterior region, at the level of the maxillary first premolars. The measurements were performed in sagittal and coronal views, in median and paramedian regions of the palate, also using Nemotec 3D software. Measurements were repeated after 15 days on 25% of the sample to analyse intra and interobserver agreements by CCI test. Analysis of variance was performed to calculate statistical differences between the bone heights of the three facial types, with a significance level of 5%. Results: The correlation level of intra-observer agreement was excellent. No significant differences were observed between the palatal bone height in the region of first premolars and the different facial types (p>0.05). Conclusions: Based on CBCT evaluations, there is no association between palatal bone height and facial morphological patterns.

<sec><title>Aim:</title><p>To compare the qualitative and quantitative information yielded by imaging modalities on the evaluation of the relationship between the maxillary sinus and the apices of posterior teeth.</p></sec><sec><title>Methods:</title><p>Three oral radiologists examined 109 panoramic radiographs and cone-beam computed tomography (CBCT) images obtained from a digital archive. A total of 1,875 apices were classified according to their topographic relationship in both imaging modalities. Agreements between the two imaging techniques were examined statistically. The evaluation was repeated in 25% of the sample to statistically evaluate the intraobserver agreement, with a 30-day interval.</p></sec><sec><title>Results:</title><p>The values found in the Kappa test for qualitative assessment and the intraclass correlation coefficient (ICC) for quantitative assessment showed nearly perfect and excellent correlation, respectively. Regarding the correlation between the two images, the Kappa test in the quality assessment showed a slight correlation between the palatal roots of the right first molars and second molars. Moreover, the quantitative evaluation by ICC showed poor agreement for the palatal roots of the left first molar and second molar, as well as for the buccomesial of the right second molars and for the buccodistal of the left second molars.</p></sec><sec><title>Conclusions:</title><p>There is low correlation between panoramic radiography and CBCT when roots are in contact or above the maxillary sinus floor. A high level of agreement was observed when roots are below the maxillary sinus floor.</p></sec>

Three-dimensional imaging modalities have been reported to be more accurate than panoramic radiographs (PR) for the assessment of bone components of the temporomandibular joint (TMJ). No exact prior information is available that demonstrates which specific limitations occur in terms of TMJ diagnosis when using PR for this purpose. This study aimed to assess the clinical validity of digital panoramic radiography (DPR) when diagnosing morphological disorders of the TMJ using cone-beam computed tomography (CBCT) images as the gold standard. A sample composed of TMJ images (N = 848), including 212 DPR and 212 CBCT images obtained from the same patient, was used to assess any morphological changes in the TMJ. Four appraisers diagnosed all of the DPR images, whereas the CBCT images were used to establish the gold standard. The reliability of each appraiser’s response pattern was analyzed using the Kappa test (κ), and diagnostic tests were performed to assess each appraiser’s performance using a significance level setting of 5% (α = 0.05). Reliability of each appraiser’s response pattern compared to the gold standard ranged from a slight-to-moderate agreement (0.18 ≤ κ ≤ 0.45); and among the different appraisers, the response pattern showed a fair agreement (0.22 ≤ κ ≤ 0.39). Diagnostic tests showed a wide range among the different possible morphological changes diagnosed. DPR does not have validity when diagnosing morphological changes in the TMJ; it underestimates the radiological findings with higher prevalence, and thus, it cannot be used effectively as a diagnostic tool for bone components within this region.

AIM:To assess which slice inclination would be more accurate in measuring sites for implant placement: the oblique or the orthoradial slice.METHODS: Five regions of eight edentulous mandibles were selected (incisor, canine, premolar, first molar and second molar). The mandibles were scanned with a Next Generation i-CAT CBCT unit. Two previously calibrated oral radiologists performed vertical measurements in all the selected regions using both the oblique and orthoradial slices. The mandibles were sectioned in all the evaluated regions in order to obtain the gold standard. The Wilcoxon signed rank test compared the measurements obtained in the oblique and orthoradial slices with the gold standard.RESULTS:The bone height measurements for the first and second molar regions using the orthoradial slices were statistically different from the gold standard.CONCLUSIONS: Using the orthoradial slices to obtain cross-sectional images may offer insufficient accuracy for implant placement in the posterior region.

O objetivo neste estudo foi avaliar o efeito radioprotetor da vitamina E sobre glândulas parótidas de ratos por meio de análise morfométrica. Sessenta ratos machos foram divididos em cinco grupos: controle, no qual os animais receberam solução de óleo de oliva; óleo de oliva irradiado, em que os animais receberam óleo de oliva e foram irradiados com uma dose de 15 Gy de radiação gama; irradiado, em que os animais foram irradiados com uma dose de 15 Gy de radiação gama; vitamina E, no qual receberam solução de acetato α-tocoferol; vitamina E irradiado, os quais receberam solução de acetato de α-tocoferol antes da irradiação com uma dose de 15 Gy de radiação gama. Metade dos animais foi eutanasiada em 8 h, e o restante aos 30 dias após a irradiação. Ambas as glândulas parótidas foram removidas cirurgicamente e análise morfométrica das células acinares foi realizada. Os dados foram submetidos à Análise de Variância com 2 fatores e teste de Tukey (α=0,05). A análise morfométrica mostrou uma redução significativa no número de células acinares da glândula parótida aos 30 dias nos grupos óleo irradiado e irradiado. Nos grupos avaliados ao longo do tempo uma redução significativa foi mostrada aos 30 dias nos grupos óleo irradiado e irradiado, indicando que a radiação ionizante causou danos teciduais. O grupo vitamina E/irradiado apresentou mais células acinares que o grupo irradiado, mas diferença estatisticamente significante não foi observada. Em conclusão, a vitamina E parece ter fracassado como um agente radioprotetor nas células acinares das glândulas parótidas de ratos.

The aim of this study was to evaluate the radioprotective effect of vitamin E on rat parotid glands by morphometric analysis. Sixty male rats were divided into 5 groups (n=6): control, in which animals received olive oil solution; olive oil/irradiated, in which animals received olive oil and were irradiated with a dose of 15 Gy of gamma radiation; irradiated, in which animals were irradiated with a dose of 15 Gy gamma radiation; vitamin E, which received α-tocopherol acetate solution; vitamin E/irradiated, which received α-tocopherol acetate solution before irradiation with a dose of 15 Gy gamma rays. Half of the animals were euthanized at 8 h, and the remaining at 30 days after irradiation. Both parotid glands were surgically removed and morphometric analysis of acinar cells was performed. Data were subjected to two-way ANOVA and Tukey's test (α=0.05). Morphometric analysis showed a significant reduction in the number of parotid acinar cells at 30 days in olive oil/irradiated and irradiated groups. In groups evaluated over time a significant reduction was shown at 30 days in olive oil/irradiated and irradiated groups, indicating that ionizing radiation caused tissue damage. The vitamin E/irradiated group presented more acinar cells than the irradiated group, but no statistically significant difference was observed (p>0.05). In conclusion, vitamin E seems to have failed as a radioprotective agent on acinar cells in rat parotid glands.

Esse estudo avaliou a proteção do selênio no processo de reparação óssea em ratas ovariectomizadas após irradiação. Para isso, 80 ratas Wistar foram divididas aleatoriamente em 4 grupos experimentais: ovariectomizado, ovariectomizado/selênio, ovariectomizado/irradiado e ovariectomizado/selênio/irradiado. Foi realizado um defeito ósseo na tíbia de todos os animais 40 dias após ovariectomia. Dois dias após essa cirurgia, os animais dos grupos ovariectomizado/selênio e ovariectomizado/selênio/irradiado receberam 0,8 mg Se/kg. Três dias após a cirurgia, os animais dos grupos ovariectomizado/irradiado e ovariectomizado/selênio/irradiado receberam 10 Gy de radiação X na região de membros inferiores. Os animais foram sacrificados 7, 14, 21 e 28 dias após a cirurgia para avaliação do processo de reparo ósseo, que foi realizado pela análise do número de trabéculas ósseas (coloração Tricrômico de Masson) e pela análise de birrefringência (coloração de Picrosirius). Foi observado atraso no processo de reparo ósseo no grupo ovariectomizado/irradiado e semelhança entre os grupos ovariectomizado, ovariectomizado/selênio e ovariectomizado/selênio/irradiado. Foi possível concluir que o selenito de sódio exerceu efeito radioprotetor no processo de reparação de tíbias em ratas ovariectomizadas sem toxicidade.

This studyevaluated protection by selenium (Se) in the bone repair process in ovariectomized rats after irradiation. For such purpose, 80 ovariectomized female Wistar rats were randomly divided into 4 experimental groups: ovariectomized (Ov), Ov/Se, Ov/irradiated (Irr) and Ov/ Se/Irr. A bone defect was created on the tibia of all animals 40 days after ovariectomy. Two days after surgery, only the Ov/Se and Ov/Se/Irr rats received 0.8 mg Se/kg. Three days after surgery, only the Ov/Irr and Ov/Se/Irr rats received 10 Gy of x-rays on the lower limb region. The animals were euthanized at 7, 14, 21 and 28 days after surgery to assess the repair process, which was evaluated by analysis of trabecular bone number (Masson Trichrome) and birefringence analysis (Picrosirius). It was possible to observe a delay in the bone repair process in the ovariectomized/irradiated group and similarity between the ovariectomized, Ov/Se and Ov/Se/Irr groups. In conclusion, sodium selenite exerted a radioprotective effect in the bone repair of tibia of ovariectomized rats without toxicity.

O objetivo deste estudo foi avaliar a aplicabilidade da inversão da escala de cinza na realização de mensurações endodônticas lineares digitais. Quarenta dentes unirradiculares humanos extraídos foram radiografados com limas K tamanho 15 posicionadas no canal radicular em diferentes comprimentos, usando o sistema digital CDR Wireless®. Todas as imagens foram tratadas com Positive, uma ferramenta digital que inverte os valores da escala de cinza. Oito radiologistas mediram a distância entre o limite inferior do stop de borracha e a ponta da lima endodôntica nas imagens originais e positivas. Após quinze dias, eles repetiram esse procedimento em 50% da amostra. A concordância intra- e interobservador foi analisada pelo teste de correlação intraclasse e a comparação entre os dois grupos de imagem e os valores reais, pelo teste t-Student (α=0,05). A análise intra- e interobservador apresentou elevada reprodutibilidade (r>0,95) das imagens original e Positive. Não foi encontrada diferença (p>0,05) entre as medidas realizadas nas imagens original e positiva, mas ambas diferiram dos valores reais (p<0,05). A inversão da escala de cinza tem baixa aplicabilidade na realização de mensuração endodôntica, considerando que as medidas não se apresentaram mais acuradas

The aim of this study was to assess the applicability of gray scale inversion in performing digital linear endodontic measurements. Standardized digital images were taken of 40 extracted human permanent single-rooted teeth with K-files size 15 placed at different lengths in the root canal, using the CDR Wireless® digital system. All images were treated with Positive, a digital tool that inverts the grayscale value. Eight radiologists measured the distance between the lower limit of the rubber stop and the tip of the file on both original and positive images. After 15 days, they repeated this procedure in 50% of the image samples. The intra- and inter-examiner agreement was analyzed by intraclass correlation test, and the comparison between the two image groups and the actual lengths by the Student's t-test (α=0.05). Intra- and inter-examiner evaluation showed high reproducibility (r>0.95) of both original and positive images. No statistically significant differences (p>0.05) were found between measurements performed on original and positive images, but both differed significantly from the actual lengths (p<0.05). Gray scale inversion has low applicability in measuring endodontic files, since it did not improve the accuracy of measurements.

O objetivo deste estudo foi avaliar a precisão no diagnóstico de lesões iguais-à-cárie secundárias simuladas em restaurações estéticas de materiais diferentes, mudando o ângulo vertical de incidência (AVI) do feixe de raios-x. Vinte dentes humanos foram submetidos a preparo cavitário inlay MOD. No grupo experimental (n=10), no soalho da caixa de proximal, foi confeccionada uma cavidade esférica para simular lesões iguais-a-cárie. Todos os dentes foram restaurados com 3 resinas compostas (Charisma, Filtek-Z250, TPH-Spectrum), em três tempos diferentes. Duas imagens radiográficas foram adquiridas com 0 e 10 graus de AVI o feixe de raios-x. Dez observadores avaliaram as imagens usando uma escala de confiança de 5-pontos. A reprodutibilidade intra- e inter- observador foi analisada com o coeficiente de correlação interclasse e a precisão do diagnóstico foi avaliada usando a área sob a curva ROC (Az), o teste de Friedman e de Wilcoxon (α=0,05). Os mais altos valores de precisão (p>0,05) foram observados com o AVI em 10º (Filtek-Z250 Az=0,66>TPH-Spectrum Az=0,56) comparado com 0º (Charisma Az=0,55>TPH-Spectrum Az=0,37), porém, sem diferenças estatisticamente significantes (p>0,05). A detecção de lesões iguais-à-cárie secundárias simulada em restaurações estéticas de diferentes materiais não foi influenciada pela mudança de AVI do feixe de raios-x.

The aim of this study was to evaluate the accuracy on the diagnosis of secondary caries-like lesions simulated on esthetic restorations of different materials, changing the incidence vertical angle (IVA) of the x-ray beam. Twenty human teeth received MOD inlay preparations. In the experimental group (n=10), a round cavity was made in the floor of the proximal box to simulate the caries-like lesion. All teeth were restored with 3 composite resins (Charisma, Filtek-Z250 and TPH-Spectrum) at 3 moments. Two radiographic images were acquired with 0º and 10º IVA. Ten observers evaluated the images using a 5-point confidence scale. Intra- and interobserver reliability was analyzed with the Interclass Correlation Coefficient and the diagnostic accuracy was evaluated using the area under the ROC curve (Az), Friedman test and Wilcoxon test (α=0.05). Higher accuracy values were obtained with 10º IVA (Az=0.66, Filtek-Z250>Az=0.56, TPH-Spectrum) compared to 0º (Az=0.55, Charisma>Az=0.37, TPH-Spectrum), though without statistically significant difference (p>0.05). The detection of secondary caries-like lesions simulated on esthetic restorations of different materials suffered no negative influence by changing the IVA of the x-ray beam.

OBJECTIVE: The aim of this study was to establish which materials afford better simulation of soft tissues in Oral Radiology studies. MATERIAL AND METHODS: The sample was composed of four materials in eleven different thicknesses to simulate the soft tissues of the face. The mean values of the relative amounts of radiographic contrast of the materials were determined and compared to a gold standard value, which was obtained from 20 patients who were referred to have periapical radiographs taken of the left mandibular molars. Data were subjected to statistical analysis with Dunnett's test (p<0.05). RESULTS: The mean value of the relative amounts of contrast encountered in the patients was 0.47, with a range between 0.36 and 0.64 for all 44 material/thickness combinations. The majority of the tested materials showed values close to those of the patients' tissues, without statistically signifcant differences among them. The values of only three materials/thickness combinations differed statistically from those of the patients' tissues. CONCLUSIONS: Based on the results of the present study, it may be concluded that except for utility wax (4 mm and 8 mm) and water (4 mm), all materials tested at different thickness could be used as soft tissue substitute materials in Oral Radiology studies.

O objetivo na presente pesquisa foi determinar o tamanho, forma e posição da camada de imagem por meio da avaliação da formação da imagem radiográfica em diferentes posições anatômicas. Foi construído um phantom constituído por uma placa acrílica de 14 cm² e 0,3 cm de espessura, com sua superfície contendo perfurações a cada 0,5 cm dispostas em linhas e colunas. O phantom foi posicionado no local do apoio de mento do aparelho panorâmico, com sua superfície paralela ao plano horizontal. Esferas metálicas de 0,315 cm foram inseridas nas perfurações, e executadas radiografias panorâmicas. Cada coluna de cada quadrante foi individualmente preenchida pelas esferas para a execução das radiografias, em três planos horizontais diferentes: alturas orbital, oclusal e mentual. As imagens das esferas foram medidas com o uso de um paquímetro digital e a camada de imagem localizada. Os dados foram analisados estatisticamente utilizando-se o teste T Student, ANOVA e teste de Tukey (?=0,05). Quando o tamanho das esferas nos eixos horizontal e vertical foi comparado, diferenças estatisticamente significativas (p<0,05) foram observadas em todas as áreas da camada de imagem, porções e alturas do plano horizontal avaliado. Na porção central da camada de imagem diferenças no tamanho das esferas foram observadas somente no eixo horizontal (p<0,05), enquanto que no eixo vertical nenhuma diferença foi observada (p>0,05). A metodologia utilizada determinou com precisão o tamanho, forma e posição da camada de imagem, e diferenças de ampliação foram observadas tanto no eixo horizontal quanto vertical.

The aim of this study was to determine size, shape and position of the image layer by evaluation of the radiographic image formation in different anatomic positions. A customized phantom was made of a rectangular acrylic plate measuring 14 cm² and 0.3 cm thick, with holes spaced 0.5 cm away and arranged in rows and columns. Each column was separately filled with 0.315 cm diameter metal spheres to acquire panoramic radiographs using the Orthopantomograph OP 100 unit. The customized phantom was placed on the mental support of the device, with its top surface kept parallel to the horizontal plane, and was radiographed at three different heights from the horizontal plane, i.e., the orbital, occlusal and mandibular symphysis levels. The images of the spheres were measured using a digital caliper to locate the image layer. The recorded data were analyzed statistically by the Student'-t test, ANOVA and Tukey' test (?=0.05). When the image size of spheres in horizontal and vertical axes were compared, statistically significant differences (p<0.05) were observed in all areas, portions of the image layer and heights of horizontal plane evaluated. In the middle portion of the image layer, differences in the image size of spheres were observed only along the horizontal axis (p<0.05), whereas no differences were observed along the vertical axis (p>0.05). The methodology used in this determined the precise size, shape and position of the image layer and differences in magnification were observed in both the horizontal and vertical axes.

OBJECTIVE: This study aimed to evaluate the possibility of any correlation between disc displacement and parameters used for evaluation of skull positioning in relation to the cervical spine: craniocervical angle, suboccipital space between C0-C1, cervical curvature and position of the hyoid bone in individuals with and without symptoms of temporomandibular dysfunction. MATERIAL AND METHODS: The patients were evaluated following the guidelines set forth by RDC/TMD. Evaluation was performed by magnetic resonance imaging for establishment of disc positioning in the temporomandibular joints (TMJs) of 30 volunteer patients without temporomandibular dysfunction symptoms and 30 patients with symptoms. Evaluation of skull positioning in relation to the cervical spine was performed on lateral cephalograms achieved with the individual in natural head position. Data were submitted to statistical analysis by Fisher's exact test at 5% significance level. To measure the degree of reproducibility/agreements between surveys, the kappa (K) statistics was used. RESULTS: Significant differences were observed between C0-C1 measurement for both symptomatic (p=0.04) and asymptomatic (p=0.02). No statistical differences were observed regarding craniocervical angle, C1-C2 and hyoid bone position in relation to the TMJs with and without disc displacement. Although statistically significant difference was found in the C0-C1 space, no association between these and internal temporomandibular joint disorder can be considered. CONCLUSIONS: Based on the results observed in this study, no direct relationship could be determined between the presence of disc displacement and the variables assessed.

This study aimed at investigating the effect of the partial erasing of DenOptix® system storage phosphor plates on the image quality of digital radiographs. Standardized digital radiographs were acquired of a phantom mandible, using size 2 intraoral DenOptix® storage phosphor plates (n = 10). Subsequently, the active areas of the plates were placed in a viewing box with a constant light intensity of 1,700 lux for 130 seconds to achieve complete erasing (control plate), as well as for 0, 5, 10, 15, 20, 25, 34, 66, and 98 seconds, to compose the experimental group of partially erased plates. The same exposure settings were repeated using the control and experimental plates, which were scanned at a resolution of 300 dpi. Five radiologists independently examined the pairs of digital radiographs obtained with the control and partially erased plates, in random order, and indicated the best image for oral diagnosis. Cochran-Mantel-Haenszel’s chi-square test, at a significance level of 5%, was used to compare the percentages of superior quality images in each combination of control and partially erased plates, subjectively assessed. No significant differences were found between radiographic images acquired with control and partially erased plates, except for the combination of 0 second (30%) versus 130 seconds (70%), p = 0.0047. It can be concluded that, under adequate light intensity conditions, erasing intraoral DenOptix® storage phosphor plates may require time intervals of as little as 5 seconds.