Clinical and imagiological findings of central giant cell lesion and cherubism

Cone beam computed tomography (CBCT) is the best examination for bone lesions of the maxilla, allowing the dentist to evaluate precisely the behavior and components of the lesion and their relationship to the surrounding structures. Central giant cell lesion and cherubism are histologically very similar lesions. Therefore clinical and radiological examinations are fundamentally important for the diagnosis. The aim of this paper is to report two cases diagnosed as central giant cell lesions and cherubism using CBCT. This imaging modality was very important for the diagnosis of the lesions presented in the current study. It also allowed observing precisely the limits of the lesions, the components, the behavior and the exact relationship to adjacent structures.

A tomografia computadorizada de feixe cônico (TCFC) é o melhor exame para lesões ósseas da maxila, permitindo que o dentista possa avaliar com mais confiabilidade o comportamento, os componentes da lesão, e sua relação com estruturas adjacentes. A Lesão central de células gigantes e o querubismo são patologias muito semelhantes histologicamente, portanto, exames clínicos e radiológicos são de fundamental importância para o diagnóstico. O objetivo deste trabalho é relatar dois casos diagnosticados usando TCFC, um de lesões centrais de células gigantes e um de querubismo. Esta modalidade de imagem foi muito importante para o diagnóstico das patologias apresentadas neste estudo. Também permitiu observar com mais confiabilidade os limites das lesões, os componentes, o comportamento e a relação exata com as estruturas adjacentes.

Influence of dental metallic artifact from multislice CT in the assessment of simulated mandibular lesions

OBJECTIVE: This study evaluated the influence of metallic dental artifacts on the accuracy of simulated mandibular lesion detection by using multislice technology. MATERIAL AND METHODS: Fifteen macerated mandibles were used. Perforations were done simulating bone lesions and the mandibles were subjected to axial 16 rows multislice CT images using 0.5 mm of slice thickness with 0.3 mm interval of reconstruction. Metallic dental restorations were done and the mandibles were subjected again to CT in the same protocol. The images were analyzed to detect simulated lesions in the mandibles, verifying the loci number and if there was any cortical perforation exposing medullar bone. The analysis was performed by two independent examiners using e-film software. RESULTS: The samples without artifacts presented better results compared to the gold standard (dried mandible with perforations). In the samples without artifacts, all cortical perforation were identified and 46 loci were detected (of 51) in loci number analysis. Among the samples with artifacts, 12 lesions out of 14 were recognized regarding medullar invasion, and 40 out of 51 concerning loci number. The sensitivity in samples without artifacts was 90 percent and 100 percent regarding loci number and medullar invasion, respectively. In samples with artifacts, these values dropped to 78 percent and 86 percent, respectively. The presence of metallic restorations affected the sensitivity values of the method, but the difference was not significant (p>0.05). CONCLUSIONS: Although there were differences in the results of samples with and without artifacts, the presence of metallic restoration did not lead to misinterpretation of the final diagnosis. However, the validity of multislice CT imaging in this study was established for detection of simulated mandibular bone lesions.

Influência do nível de experiência doexaminador na interpretação de radiografias obtidas através da técnica convencional e da subtração radiográfica digital (srd) / Influence of the examiner level of experience in diagnostic of radiographies taken by both

Este estudo propôs-se a avaliar através de técnica radiográfica convencional e SRD, a influência do nível de experiência do examinador no diagnóstico de lesões infra-ósseas. Quarenta e oito defeitos foram confeccionados nas cristas ósseas, utilizando-se brocas esféricas de diferentes diâmetros. O processamento automatizado das películas foi seguido da digitalização das imagens (500 dpi / 8bits). A técnica de SRD foi realizada utilizando-se o programa de computador AxionVisionv 4.3. As películas radiográficas e as imagens subtraídas foram codificadas. Quatro examinadores com diferentes níveis de experiência diagnosticaram as lesões (presente ou ausente), com intervalo de 15 dias entre os exames. Foram calculados os valores de sensibilidade (S) e especificidade (E), associação (testequi-quadrado) entre resultados e concordância inter-examinadores (teste Kappa). A técnica convencional mostrou valores médios de S = 13,28% e E = 93,46%,, enquanto que a SRDrevelou S = 37,61% e E = 91,22%. Conclui-se que a experiênciado examinador teve maior influência sobre a técnica convencionale que a SRD foi capaz de melhorar a S de diagnóstico, independentemente do nível de experiência do examinador sendo mais sensível para a detecção de pequenas lesões periodontais.