Evaluation of the microstructure, chemical composition, and image quality of different PSP receptors.

This study aimed to assess the microstructure, chemical composition, and image quality of different photostimulable phosphor plates (PSP). Four PSP systems, Express®, Digora®, VistaScan®, and Apixia,® were assessed. Five radiographs of a homogeneous acrylic phantom were obtained with the PSP of each system, to acquire a total of 20 images. The images were objectively evaluated for uniformity using mean grey and standard deviation (SD) of their grey values. PSP receptors were analyzed using scanning electron microscopy (SEM) to determine the thickness of the granule layer and the size of the granules. The chemical composition of the PSP receptors was analyzed using total reflection X-ray fluorescence (TXRF). VistaScan showed more uniform and higher density images than the other tested systems (p < 0.05), as well as the lowest SD of grey values (p < 0.05). Regarding the microstructure of the receptors, Digora and VistaScan had thicker granule layers than Express and Apixia, and VistaScan had smaller granules than Digora and Express (p < 0.05). Fourteen chemical elements were detected in the receptors, with barium being the element with the highest concentration in all PSP systems. The microstructure, chemical composition, and image quality varied among all four PSP receptors studied. VistaScan receptors showed the smallest variation in granule size, one of the thickest granule layers, and the most uniform and least noisy images.

Evaluation of the microstructure, chemical composition, and image quality of different PSP receptors

Abstract This study aimed to assess the microstructure, chemical composition, and image quality of different photostimulable phosphor plates (PSP). Four PSP systems, Express®, Digora®, VistaScan®, and Apixia,® were assessed. Five radiographs of a homogeneous acrylic phantom were obtained with the PSP of each system, to acquire a total of 20 images. The images were objectively evaluated for uniformity using mean grey and standard deviation (SD) of their grey values. PSP receptors were analyzed using scanning electron microscopy (SEM) to determine the thickness of the granule layer and the size of the granules. The chemical composition of the PSP receptors was analyzed using total reflection X-ray fluorescence (TXRF). VistaScan showed more uniform and higher density images than the other tested systems (p < 0.05), as well as the lowest SD of grey values (p < 0.05). Regarding the microstructure of the receptors, Digora and VistaScan had thicker granule layers than Express and Apixia, and VistaScan had smaller granules than Digora and Express (p < 0.05). Fourteen chemical elements were detected in the receptors, with barium being the element with the highest concentration in all PSP systems. The microstructure, chemical composition, and image quality varied among all four PSP receptors studied. VistaScan receptors showed the smallest variation in granule size, one of the thickest granule layers, and the most uniform and least noisy images.

Differential diagnosis for an unusual calcification in the maxillary sinus: case report / Diagnóstico diferencial para calcificação incomum em seio maxilar: relato de caso

ABSTRACT The aim of this study was to report a rare case of an asymptomatic calcification of unusual size and shape, inside the maxillary sinus identified on a cone beam computed tomography exam and to discuss the importance of knowledge of the anatomy of maxillary sinus and its changes carefully evaluating the entire volume of the images, regardless of the region of interest. An 83-year-old female patient underwent a cone beam computed tomography exam for other diagnostic purposes in the maxillofacial region. When analyzing the entire volume, an image of unusual limits, hyperdense and calcified was found in the right maxillary sinus, close to the anterior and medial wall, with a rounded and homogeneous shape, occupying approximately one third of the maxillary sinus. There was no lytic or erosive lesions on the maxillary sinus wall. The main diagnostic hypotheses raised were giant anthrolith, mucous retention phenomenon and osteoma. Due to the anatomical complexity of the maxillary sinus, diagnosis in this region becomes a challenge. Considering the limitations of 2D exams, the cone beam computed tomography exam can be used to evaluate these structures. Knowledge of differential hypotheses is extremely important for the case to be conducted correctly, but it does not replace biopsy and histopathological examination.

RESUMO O objetivo desse estudo foi relatar um caso raro de uma calcificação assintomática de tamanho e formato incomum, no interior do seio maxilar, diagnosticado em um exame de tomografia computadorizada de feixe cônico, além de discutir a importância do conhecimento da anatomia do seio maxilar e suas alterações, avaliando cuidadosamente todo o volume das imagens, independentemente da região de interesse. Paciente do sexo feminino, 83 anos de idade, realizou uma tomografia computadorizada de feixe cônico para outros fins de diagnóstico na região bucomaxilofacial. Ao analisar todo volume da tomografia encontrou-se uma imagem de limites incomuns, hiperdensa e calcificada, no seio maxilar direito, próximo a parede anterior e medial, com formato arredondado e homogêneo, ocupando aproximadamente um terço do seio maxilar, com as suas paredes intactas e sem nenhuma lesão lítica ou erosiva. As principais hipóteses diagnosticas levantadas foram antrólito gigante, fenômeno de retenção mucoso e osteoma. Devido a complexidade anatômica do seio maxilar, o diagnóstico nessa região se torna um desafio. Considerando as limitações dos exames 2D, a tomografia computadorizada de feixe cônico pode ser empregada para a avaliação dessas estruturas. O conhecimento do raciocínio diagnóstico e das hipóteses diferenciais são de extrema importância para o que o caso seja conduzido corretamente, porém não substituem a biópsia e o exame histopatológico.

What has Changed in the Daily Practice of the Dental Imaging Center During the COVID-19 Pandemic?

ABSTRACT: A new type of RNA coronavirus (SARS-CoV-2) related to acute respiratory syndrome (SARS) and responsible for COVID-19 disease has spread around the world, resulting in an unprecedented pandemic. COVID-19 has become an international public health emergency and countless people and sectors have been affected. In this context, individual and collective protection measures were taken, mainly in health care. Dentistry, considered a high risk area, had to undergo changes in relation to biosecurity, including in radiological clinical practice. Thus, this letter aims to comment on these changes during visits to dental imaging centers.

RESUMEN: Un nuevo tipo de coronavirus de ARN (SARS-CoV-2) relacionado con el síndrome respiratorio agudo (SARS) responsable de la enfermedad COVID-19 se ha extendido por todo el mundo y ha provocado una pandemia sin precedentes. COVID-19 se ha convertido en una emergencia de salud pública internacional y un sinnúmero de personas y sectores se han visto afectados. En este contexto, se tomaron medidas de protección individual y colectiva, principalmente en el ámbito de la salud. La atención dental, considerada de alto riesgo, tuvo que sufrir cambios en relación con la bioseguridad, incluida la práctica clínica radiológica. Así, esta carta tiene como objetivo comentar estos cambios durante los atendimientos a los centros de imagenología dental.

Biosecurity Perspectives in Oral and Maxillofacial Radiology in Times of Coronavirus disease (COVID-19): a Literature Review

ABSTRACT: The aim of this work was to report biosecurity measures in the Oral and Maxillofacial Radiology (OMR) clinic in the current context of COVID-19, based on a literature review. An electronic search for scientific papers was perform ed using PubMed, Embase, Web of Science, and Scopus database. Although the literature related to care in the OMR clinic regarding COVID-19 is still scarce, this unprecedented scenario created by the pandemic generated an urgent need for measures to prevent the transmission of the virus. Dentists are at maximum risk of contagion and, although the practice of OMR generally does not produce aerosols, radiologists and technicians are continually in contact with body fluids, such as saliva. In additio n, imaging exams are often indispensable for emergency or elective dental diagnosis and treatment. Training in infection control practices during major outbreaks of infectious diseases should be quickly reinforced and dental settings have unique characteristics that warrant specific infection control considerations. Some recommendations have been proposed and were discussed, which cover patient flow, equipment handling and environment, radiographic technique and processing, personal protective equipment and preparation and issuance of radiological reports and access to exam results. Due to the COVID-19 pandemic, biosecurity measures in the routine of the OMR clinic are indispensable to enable emergency dental care and the perspectives of returning to elective treatment. Biosecurity measures and staff training at the OMR clinic should be instituted immediately, since imaging exams are an important and often indispensable part of dental diagnosis and treatment.

RESUMEN: El objetivo de este trabajo fue reportar las medidas de bioseguridad en la clínica de Radiología Oral y Maxilofacial (OMR) en el contexto actual del COVID-19, a partir de una revisión de la literatura. Se realizó una búsqueda electrónica de artículos científicos utilizando PubMed, Embase, Web of Science y la base de datos Scopus. Si bien la literatura relacionada con la atención en la clínica OMR respecto al COVID- 19 aún es escasa, este escenario inédito creado por la pandemia generó una urgente necesidad de medidas para prevenir la transmisión del virus. Los dentistas tienen el máximo riesgo de contagio y, aunque la práctica en la OMR generalmente no produce aerosoles, los radiólogos y técnicos están continuamente en contacto con fluidos corporales, como la saliva. Además, los exámenes por imágenes a menudo son indispensables para el diagnóstico y el tratamiento dental de emergencia o electivo. La capacitación en prácticas de control de infecciones durante brotes importantes de enfermedades infecciosas debe reforzarse rápidamente y los entornos dentales tienen características únicas que justifican consideraciones específicas de control de infecciones. Se han propuesto y discutido algunas recomendaciones que cubren el flujo de pacientes, el manejo y el entorno del equipo, la técnica y el procesamiento radiográfico, el equipo de protección personal y la preparación y emisión de informes radiológicos y el acceso a los resultados de los exámenes. Debido a la pandemia de COVID-19, las medidas de bioseguridad en la rutina de la clínica OMR son indispensables para posibilitar la atención dental de emergencia y las perspectivas de volver al tratamiento electivo. Las medidas de bioseguridad y la capacitación del personal en la clínica OMR deben instituirse de inmediato, ya que los exámenes por imágenes son una parte importante y, a menudo, indispensable del diagnóstico y tratamiento dental.

A comparative study of the accuracy between two computer-aided surgical simulation methods in virtual surgical planning.

OBJECTIVE: The aim of this retrospective and observational study was to compare the accuracy of two different virtual surgical planning (VSP) protocols, namely, the CASS method and the modified CASS method. MATERIALS AND METHODS: The patients underwent bimaxillary orthognathic surgery, planned using either the CASS method or the modified CASS method. Linear and angular discrepancies between the VSP outcome and postoperative outcome for both groups were compared for maxilla, mandible, and chin segments. Aside from the comparison between both groups, additional criteria were used to determine the accuracy of the protocol based on a linear and angular difference between planned and actual outcomes of less than 2 mm and 4°, respectively. The intergroup comparisons were performed by one-way ANOVA, with the level of significance set at 5%. RESULTS: A total of 21 patients, of both genders, were assigned into group I (n = 11), planned with the CASS method, and group II (n = 10), planned with the modified CASS method. Both the CASS and modified CASS methods presented similar accuracy with regard to linear differences for the maxilla, mandible, and chin segments, except for ΔX for the mandibular segment, where the modified CASS method showed slightly better accuracy. However, there was a statistically significant difference with regard to angular differences in the chin segment, with the CASS method shown to be the more accurate. Aside from Δpitch for the chin segment, no linear or angular differences exceeded 2 mm or 4°. CONCLUSION: Although statistically significant differences were found with regard to angular measurements in the chin segment, the accuracy of the modified CASS method for virtual planning can be considered as clinically equivalent, with a performance comparable to that of the CASS method.

Analysis of the deterioration of photostimulable phosphor plates.

OBJECTIVES: To assess, objectively to determine the deterioration of the photostimulable phosphor plates (PSPs) after several acquisitions. METHODS: Two new PSPs without preliminary use were exposed with an intraoral X-ray unit, and the EXPRESS® (Instrumentarium Imaging, Tuusula, Finland) unit was used for scanning of the PSPs. A 12-stepwedge aluminum scale were used superimposed with the PSPs during the X-rays exposures to perform the objective analyses. Objective analysis was carried out by mean gray values using the Image J software through a region of interest (ROI) of 0.1 × 0.1 mm, and the data were analyzed statistically using ANOVA. RESULTS: For each, the Express® PSP a total of 1800 images were acquired during 60 days. The objective analysis showed loss of the mean gray values between the initial and final images. Besides, the percentage of mean gray values' loss was between 0.7%, for the thickest step, and 8.4%, for the lowest thickness step. CONCLUSION: After many X-ray exposures of the Express® PSP a singular deterioration in the mean gray values could be observed.

Exuberant manifestation of neurofibromatosis type 1 affecting 3 generations: delayed diagnosis and the importance of the multidisciplinary approach.

Neurofibromatosis type 1 (NF1) is an autosomal dominant inherited disorder caused by mutations of chromosome 17. The NF1 clinical diagnosis is based on pre-established criteria, including the presence of cutaneous neurofibromas, café au lait spots, and iris (Lisch) nodules. Early detection and a multidisciplinary approach are essential for the prevention of complications, including problems of function, aesthetics, and self-esteem, as well as the occurrence of malignant transformation. This study reports a case of an exuberant NF1 manifestation diagnosed by a dental surgeon, whose investigation of a family led to the diagnosis of NF1, with different expressivities, in 3 generations.

Three-dimensional alterations in pharyngeal airspace, soft palate, and hyoid bone of class II and class III patients submitted to bimaxillary orthognathic surgery: A retrospective study.

INTRODUCTION: The aim of this retrospective study was to evaluate changes in pharyngeal airway space (PAS), soft palate, and hyoid bone position after bimaxillary orthognathic surgery in skeletal Class II and Class III patients. METHODS: Patients were divided into Group 1: Class III patients who underwent maxillary osteotomies and mandibular setback surgery (N = 43); and Group 2: Class II patients who underwent maxillomandibular advancement surgery (N = 36). Cone beam computed tomography (CBCT) images were acquired one month before and six to eight months after orthognathic surgery. PAS area, volume and minimum axial area (MAA), soft-palate morphology, and hyoid bone position measurements obtained before and after orthognathic surgery were compared using the Gamma family test (p ≤ 0.10). RESULTS: In Class II group the maxillomandibular advancement surgery significantly increased the PAS area, volume, and MAA and significantly affected hyoid bone position and soft-palate morphology. In Class III group, maxillary osteotomies and mandibular setback also showed increase in PAS area, however without statistically significant values for most of the evaluated measurements. CONCLUSION: The results of the present study indicate that PAS and related structures are expected to be improved in Class II patients submitted to bimaxillary surgery, and they are not negatively affected by bimaxillary surgery in Class III patients.

Enxerto gengival misto: uma alternativa para tratamentos de retrações gengivais e falta de gengiva queratinizada / The mixed soft tissue graft technique: an alternative treat recession and the lack of keratinized gingival tissues

Um dos principais objetivos da cirurgia plástica periodontal é solucionar problemas associados com a falta de gengiva inserida, tanto em volume quanto em altura. No entanto, em alguns casos, apenas uma cirurgia de enxerto de tecido conjuntivo com um reposicionamento coronal do retalho não é suficiente para sanar o problema. Isso se deve ao fato de que, para realizar um recobrimento, é necessário um mínimo de quantidade de gengiva queratinizada. Desta forma, foi introduzido na prática clínica um procedimento no qual o tecido conjuntivo e uma faixa de tecido epitelial são removidos da área doadora e posicionados na área receptora, com o intuito de aumentar a área de tecido queratinizado ao redor do dente e realizar o recobrimento radicular em apenas uma cirurgia, diminuindo custos e morbidade do paciente. Desta forma, o objetivo deste trabalho foi relatar um caso clínico no qual o tratamento de escolha foi a técnica do enxerto misto.

One of the main issues on plastic periodontal surgery is to solve the lack of volume and height for attached keratinized gingiva. However, in some cases, only the connective tissue graft and coronal flap positioning are not sufficient because some local attached gingiva needs to exist before root coverage. In this way, a procedure is introduced where the connective tissue and an epithelial layer are harvested at the donor site and grafted to increase the keratinized gingiva and to cover the exposed surfaces in one surgical maneuver. This paper describes a clinical case using the mixed soft tissue graft technique.