Resumo Este estudo avaliou a centralização da região de interesse (ROI) na aquisição das imagens de TCFC, quando a função scout-view (SV) posicionável livremente é aplicada. Adicionalmente, a dosimetria das imagens adquiridas foi avaliada isoladamente na presença da função SV, bem como após aquisição de imagem tomográfica completa em dois diferentes campos de visão (FOV) (50x50 e 78x150mm). Um dispositivo de três localizações foi criado para acomodar os dosímetros e os espécimes, na localização direita, central e esquerda, durante a aquisição das imagens. Para avaliação da dose, dosímetros termoluminescentes foram irradiados dentro dos campos de visão e analisados em leitor portátil. Para avaliação da ROI, três espécimes de guta percha foram colocados no mesmo aparelho e as tomografias foram adquiridas (CBCT OP 300 Maxio, 90kV, 13mA, 85 μm tamanho de voxel, FOV de 50X50mm), com e sem a SV, em três posições (3-9, 1-7 e 5-11 horas), simulando diferentes regiões da boca. Foram realizadas duas avaliações de imagem, uma objetiva e outra subjetiva. Houve um leve aumento percentual (1,36% para 1,40%) da dose de radiação com o uso de SV. As distâncias foram significativamente maiores nas imagens adquiridas sem SV (p < 0,05). Todas as imagens obtidas com SV foram classificadas como sendo do centro do FOV. Em conclusão, os resultados do presente estudo demonstraram que a função scout view é eficaz para centralizar a ROI no FOV, aumentando a precisão do escaneamento e evitando repetições devido a erros de posicionamento.

Abstract This study evaluated the centralization of the region of interest (ROI) in acquisition of the CBCT images, when the freely positionable scout-view (SV) function is applied. Additionally, the dosimetry of the acquired images was assessed in the SV function alone as well as in complete tomographic image in two different fields of view (FOV) (50x50 and 78x150mm). A three-location device was created to accommodate the dosimeters and the specimens, in the right, middle and left location during image acquisition. For dose assessment, thermoluminescent dosimeters were irradiated within the FOV and analyzed in a portable reader. For ROI evaluation, three specimens of gutta-percha stick were placed on the same device and the CT scans were acquired (CBCT OP 300 Maxio device, 90kV, 13mA, 85 µm voxel size, FOV of 50X50mm), with and without the SV, in three positions (3-9, 1-7 and 5-11 o’clock), simulating different regions of the mouth. Two image evaluations were performed, an objective and subjective. There was a slight percentage increase (1.36% to 1.40%) of the radiation dose with the use of SV. The distances were significantly greater in the images acquired without SV (p < 0.05). Every image obtained with SV was classified as being at the FOV’s center. In conclusion, the results demonstrated that SVs function is effective to centralize the ROI in the FOV, increasing the scan precision and avoiding repetitions due to positioning errors.

Este trabalho tem como objetivo apresentar um caso clínico de adesão do disco da articulação temporomandibular à eminência articular, diagnosticada através da ressonância magnética. Paciente de 37 anos de idade, sexo feminino, com queixa de crises ocasionais de otalgia bilateral, ao longo dos últimos 2 anos. A paciente não referia dor ou ruídos articulares de qualquer natureza. Clinicamente, apresentava limitação de abertura de boca, com desvio à esquerda sem correção da trajetória ao final do movimento mandibular. A impressão diagnóstica foi de deslocamento anterior parcial, com redução, do disco articular direito; e, para o lado esquerdo, deslocamento anterior parcial, com redução, e adesão do disco articular ao componente temporal, com hipomobilidade do côndilo. A particularidade do caso descrito está justamente no fato de que além do deslocamento parcial anterior, bilateral, existia, também, uma adesão do disco no lado esquerdo. Conclui-se que o exame de ressonância magnética da articulação temporomandibular pode ser considerado o método de escolha para avaliação do posicionamento do disco articular e suas alterações morfológicas.

This case report has the aim to present an adhesion of the temporomadibular disc to the articular eminence, diagnosed on magnetic resonance imaging images. A 37-year-old female patient with TMJ (temporomandibular joint) disk adhesion on the left side and complaining of bilateral otalgia over the last 2 years is reported in the present article. The patient did not complain of articular pain or clicking, or any other noises of any nature. Clinical observation showed that the patient had restricted jaw opening, with mandibular deviation the left side without correction during mandibular movement. Our diagnostic impression was of partial anterior disk displacement with reduction of the right side disc; and partial anterior disk displacement with reduction and disc disk adhesion with hypo-mobility of the condyle, on the left temporomandibular joint. The peculiarity of this reported case is the fact that besides the bilateral partial anterior disc displacement, there was also found an adhesion of the disc on the left side. In conclusion, the magnetic resonance imaging exam of the temporomandibular joint can be considered an exam of choice for the evaluation of disc positioning and its morphological alterations.

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.

This study investigated the viability of the cell block technique as an auxiliary method of diagnosing jawbone lesions. Thirty-three clinically diagnosed jawbone lesions with a cystic appearance were subjected to aspiration. The aspirated material was processed by the cell block technique, and the lesions were biopsied and treated. Cytological findings (cell block) and histopathology analyses (gold standard) were compared by the chi-square test. There were associations between cysts and cholesterol crystal clefts, between keratocystic odontogenic tumors (KOT) and epithelial cells, and between KOT and parakeratin. The occurrence of cholesterol crystal clefts in cell block slides was correlated with cystic lesions, and the parakeratin presence was a KOT indicator. The cell block technique proved to be fast, easy-to-handle, and low-cost, making it an attractive auxiliary method for the preliminary diagnosis of jawbone lesions.