How is the use of digital dental radiology in a developing country? An overview of Brazil / ¿Cómo es el uso de la radiología dental digital en un país en vías de desarrollo? Una visión general de Brasil

Abstract The aim of this study was to assess the use of digital dental radiology in Brazil, by focusing on the use of image receptors, imaging exams and digital image enhancement tools, also assessing the methods of professional image transfer. Questionnaires were distributed in person on dental meetings and digitally via messaging (WhatsApp®) and mailings list. The sample of this cross-sectional study consisted of 478 questionnaires. Most participants were woman (n=315, 65.9%), with average age of 33.8±9.2 years. Descriptive and frequency analysis was performed. Chi-square and Fisher's exact tests were used (α=0.05). Most dentists worked at shared dental clinics (34.7%) and use digital image receptors (51.1%), but a representative percentage (48.9%) still exclusively use radiographic films. Photostimulable phosphor plate is the most used digital image receptor. Among extraoral exams, panoramic radiography (PAN) is the most used. Regarding dental specialties, oral radiologists and oral and maxillofacial surgeons mostly use cone-beam computed tomography (p<0.001). Most dentists who use digital systems make use of digital image enhancement tools (87.8%), mainly contrast, zoom, brightness and measurements. The most common method of professional image transfer (professional-professional and professional-patiens) is by email, with few dentists using online app and social media (26%). Therefore, while most Brazilian dentists use digital imaging systems, a significant percentage still exclusively use radiographic films. The most extraoral imaging exams used is PAN. Regarding image enhancement tools, brightness and contrast adjustments, zoom and measurements are the most applied. Finally, dentists generally use email for professional image transfer.

Resumen El objetivo de este estudio fue evaluar uso de la radiología dental digital en Brasil, centrándose en uso de receptores de imagen, exámenes de imágenes y herramientas de mejora de imagen digital, evaluando también los métodos de transferencia de imagen profesional. Cuestionarios se distribuyeron de forma presencial en reuniones odontológicas y de forma digital a través de mensajería (WhatsApp®) y lista de correo. Muestra de este estudio transversal estuvo compuesta por 478 cuestionarios. Mayoría de los participantes eran mujeres (n=315, 65,9%), con edad promedio de 33,8±9,2 años. Se realizó un análisis descriptivo y de frecuencias. Se utilizaron las pruebas Chi-cuadrado y exacta de Fisher (α=0,05). La mayoría de los odontólogos trabajaban en clínicas dentales compartidas (34,7%) y utilizan receptores de imágenes digitales (51,1%), pero un porcentaje representativo (48,9%) todavía utiliza exclusivamente películas radiográficas. Placa de fósforo fotoestimulable es el receptor de imagen digital más utilizado. Entre los exámenes extraorales, la radiografía panorámica (PAN) es la más utilizada. En cuanto a las especialidades odontológicas, los radiólogos orales y los cirujanos orales y maxilofaciales utilizan mayoritariamente la tomografía computarizada de haz cónico (p<0,001). Mayoría de los odontólogos que utilizan sistemas digitales utilizan herramientas de mejora de imagen digital (87,8%), principalmente contraste, zoom, brillo y medidas. Método más común de transferencia de imágenes profesionales (profesional-profesional y profesional-pacientes) es por correo electrónico, con pocos dentistas que utilizan aplicaciones en línea y redes sociales (26%). Por lo tanto, mientras que la mayoría de dentistas brasileños utilizan sistemas de imágenes digitales, un porcentaje significativo aún utiliza exclusivamente películas radiográficas. Examen de imagen extraoral más utilizado es el PAN. En cuanto a las herramientas de mejora de imagen, los ajustes de brillo y contraste, el zoom y las medidas son las más aplicadas. Finalmente, los dentistas generalmente usan el correo electrónico para la transferencia de imágenes profesionales.

The relationship of articular eminence and mandibular fossa morphology to facial profile and gender determined by cone beam computed tomography.

OBJECTIVE: The aim of this study was to evaluate the relationship of the morphology of the articular eminence and mandibular fossa to facial profile and sex by using cone beam computed tomography (CBCT) images. STUDY DESIGN: CBCT examinations of 76 patients were conducted, and the patients were classified according to facial profile as dolichocephalic, mesocephalic, or brachycephalic. The inclination and height of the articular eminence and the inclination of the mandibular fossa of 152 temporomandibular joints were measured. Comparisons between these measurements and facial profile and gender were performed by 2-way analysis of variance with Tukey's post hoc test. Significance was established at α = 0.05. RESULTS: Males with brachycephaly presented significantly greater values of eminence inclination compared with those with other facial types and greater values than patients with dolichocephaly for the measurements of eminence height and inclination of the fossa posterior wall (P ≤ .05). Females with brachycephaly presented significantly greater eminence height values compared with those with other facial profiles (P ≤ .05). No significant differences were observed between males and females. CONCLUSIONS: The morphology of the articular eminence and the mandibular fossa is associated with facial profile, with males with brachycephaly showing greater inclination of the eminence and mandibular fossa. Articular eminence height in brachycephaly was greater in both sexes.

Morphological Evaluation of the Nasopalatine Canal in Patients With Different Facial Profiles and Ages.

PURPOSE: To evaluate the influence of facial profile and age on the morphology of the nasopalatine canal. MATERIALS AND METHODS: One hundred thirty-two cone-beam computed tomograms were classified according to facial profile-mesofacial, brachyfacial, and dolichofacial-and divided into the following age groups: 21 to 30, 31 to 40, 41 to 50, and 51 to 60 years. Measurements were obtained for openings of the incisive and nasopalatine foramina, alveolar bone thickness, and the full length, most constricted region, and volume of the nasopalatine canal. Intra- and inter-examiner agreements were calculated using the intraclass correlation coefficient. After exploratory and descriptive analysis, data were subjected to 2-way analysis of variance and Tukey test for comparisons between facial profiles and age groups. The significance level was 5% (α = 0.05). RESULTS: Intra- and inter-examiner reproducibilities were excellent for all measurements. Patients older than 50 years presented a significantly larger nasopalatine canal than patients 21 to 30 years old for all facial profiles (P ≤ .05). Linear measurements obtained from the nasopalatine canal showed no significant difference between facial profiles and age groups (P > .05). CONCLUSIONS: The nasopalatine canal was not influenced by facial profile but did exhibit an increased volume with aging, particularly after 50 years of age.

Influence of scan mode (partial/full rotations) and FOV size in the formation of artefacts in cone beam CT.

OBJECTIVE: To evaluate the influence of rotation degree and field of view (FOV) size on the amount of artefacts produced in cone beam CT (CBCT) images. METHODS: A cylindrical wax utility phantom, with a metallic sample in its interior, was scanned with two FOV sizes (100 x 100 and 40 x 40 mm) and in full (360°) and partial (~180°) rotations. After the acquisitions, images were objectively assessed in the ImageJ software, obtaining the standard deviation in areas around the metal sample. The influence of artefacts produced by the several FOVs and rotation degrees was compared by two-way analysis of variance (α = 0.05). RESULTS: The images obtained with a large FOV presented a higher amount of noise compared to a restricted FOV, both for partial (p = 0.0037) and full (p = 0.0023) rotation degrees. For images obtained with a restricted FOV, full rotation resulted in images with less noise (p = 0.0259). For images obtained with large FOV, there was no statistically significant difference (p = 0.1494) in noise for both rotation protocols. CONCLUSIONS: As there were no significant differences in the amount of artefacts in rotation protocols for large FOVs, the partial rotation can be indicated due to its lower exposure to radiation. For acquiring images with restricted FOVs, the full rotation is recommended.

Monostotic fibrous dysplasia: a case report with cone-beam computed tomography findings / Displasia fibrosa monostótica: relato de caso por meio de achados de tomografia computadorizada de feixe cônico

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.

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.

Cone beam computed tomography in the diagnosis of dens invaginatus: case report / Tomografía computarizada de haz cónico en el diagnóstico de diente invaginado: presentación de un caso

The aim of this report is to present a case of dens invaginatus asymptomatic discovered after exam cone beam computed tomography. A 20-year-old patient attended the clinic Radiology to perform tomography to fracture research at the root of the tooth 15. However, the examination was observed the presence of a conoid supernumerary tooth between the tooth located roots 11 and 12, which had a hyperdense line to the apex of the root, representing the invagination of the enamel, dens invaginatus feature. It was also observed extensive hypodense image in the periapical region, with areas of external resorption both in supernumerary tooth as we ll as the roots of teeth 11 and 12. The treatment consisted of surgery for dens invaginatus extraction. The dentists should be aware of the imaginological characteristics of the anomalies that can affect the teeth/jaws, which can be discovered in tests for routine imaging and proper conduct for the treatment of patients.

El objetivo de este trabajo fue presentar un caso dedens invaginatusasintomático descubierto en una tomografía computarizada de haz cónico. Un paciente de 20 años de edad acudió a la clínica radiológica para realizarse una tomografía producto una fractura radicular del diente 15. Sin embargo, en el exámen se observó la presencia de un diente supernumerario cónico localizado entre las raíces de los dientes 11 y 12, observando además una línea hiperdensa hacia el ápice de la raíz, que representa la invaginación del esmalte, característica propia de undens invaginatus.También se observó un área hipodensa en la región periapical, con áreas de reabsorción externa tanto en el diente supernumerario como en las raíces de los dientes 11 y 12. El tratamiento consistió en cirugía de extracción deldens invaginatus. Los dentistas deben conocer las características imagenológicas de las anomalías que pueden afectar a los dientes, las cuales pueden ser descubiertas en exámenes de rutina y también el protocolo adecuado de tratamiento de éstas.

Behavior and perceptions of hand hygiene practices among dental students / Comportamento e percepção de práticas de higiene das mãos entre os estudantes de Odontologia

ABSTRACT Objective: To investigate behavior and perception of hand hygiene practices among undergraduate students in a School of Dentistry. Methods: The study adopted a qualitative technique called Collective Subject Discourse (CSD). The sample comprised students enrolled in a Public School of Dentistry, in Sao Paulo State, Brazil (n=54). Semi-structured interviews were recorded in a digital voice recorder. Data analysis was carried out by means of a quali-quantitative approach with the help of Qualiquantisoft(r) software. Results: Students showed adequate knowledge regarding guidelines about hand hygiene practices. However, they considered their procedure gloves as an effective way to avoid crossed-infection, and mentioned inadequate infrastructure of sinks and sometimes lack of consumables undermined their adherence to hand hygiene practices. They reported health professionals and professors at the Institution as being reckless with handwashing, especially before donning gloves or after removal. Students reported the school properly guided them in relation to teaching hand hygiene practices, but they stated they were careless with the recommendations. Students were very concerned if they would hypothetically be treated by professionals who did not wash their hands. Conclusion: This study identified some of the hand hygiene compliance failures among dental students. Educational strategies by means of an increase in motivation to perform hand hygiene properly, and by adjusting professor's practices in front of the students would be crucial to improve adherence. Additionally, the improvement on the infrastructure in this institution by means of new washbasins and more available consumables would benefit hand hygiene adherence.

RESUMO Objetivo: Investigar o comportamento e a percepção sobre a prática da higiene das mãos entre acadêmicos de um Curso de Odontologia. Métodos: Este estudo adotou a técnica qualitativa Discurso do Sujeito Coletivo (DSC). A amostra foi composta por estudantes matriculados numa Faculdade Pública de Odontologia do Estado de São Paulo, Brasil (n=54). Entrevistas semiestruturadas foram registradas em um gravador digital. A análise dos dados foi realizada por meio de abordagem quali-quantitativa com auxílio do programa Qualiquantisoft(r). Resultados: Estudantes mostraram conhecimento adequado quanto às diretrizes sobre a prática de higiene das mãos. Porém, consideraram que as luvas de procedimento seriam efetivas para evitar a contaminação cruzada e afirmaram que a infraestrutura inadequada de pias e a falta de materiais de consumo minavam a adesão. Relataram que o comportamento em higiene das mãos de profissionais e de alguns professores era negligente quanto à higiene das mãos, especialmente antes de calçarem luvas e após retirarem. Relataram que a faculdade oferecia ensino para correto treinamento, mas atribuíram a si próprios a postura negligente. Entretanto, apresentaram-se muito preocupados de serem hipoteticamente atendidos por profissionais que não lavassem as mãos. Conclusão: Algumas falhas quanto à conformidade com a higiene das mãos entre estudantes de Odontologia foram identificadas. Estratégias educativas, por meio da motivação e do ajuste da conformidade da prática pelos professores seriam fundamentais para aumento da adesão. Adicionalmente, melhorias na infraestrutura nessa instituição, por meio de novas pias e disponibilidade irrestrita de material de consumo beneficiaria a adesão à higiene das mãos.

Fontes de carbono de baixo custo para a produção de xilanase termoestável por Aspergillus niger / Low-cost carbon sources for the production of a thermostable xylanase by Aspergillus niger

A strain of the filamentous fungus Aspergillus niger was isolated and shown to possess extracellular xylanolytic activity. These enzymes have biotechnological potential and can be employed in various industries. This fungus produced its highest xylanase activity in a medium made up of 0.1% CaCO3, 0.5% NaCl, 0.1% NH4Cl, 0.5% corn steep liquor and 1% carbon source, at pH 8.0. A low-cost hemicellulose residue (powdered corncob) proved to be an excellent inducer of the A. niger xylanolytic complex. Filtration of the crude culture medium with suspended kaolin was ideal for to clarify the extract and led to partial purification of the xylanolytic activity. The apparent molecular mass of the xylanase was about 32.3 kDa. Maximum enzyme activity occurred at pH 5.0 and 55-60ºC. Apparent Km was 10.41 ± 0.282 mg/mL and Vmax was 3.32 ± 0.053 U/mg protein, with birchwood xylan as the substrate. Activation energy was 4.55 kcal/mol and half-life of the crude enzyme at 60ºC was 30 minutes. Addition of 2% glucose to the culture medium supplemented with xylan repressed xylanase production, but in the presence of xylose the enzyme production was not affected.

Uma linhagem do fungo filamentoso Aspergillus niger foi isolada e apresentou atividade xilanolítica extracelular. Estas enzimas possuem grande potencial biotecnológico e podem ser aplicadas em diversas indústrias. O fungo produziu sua maior atividade de xilanase em um meio contendo CaCO3 0,1%, NaCl 0,5%, NH4Cl 0,1%, 0,5% água de maceração de milho e 1% de fonte de carbono, em pH 8,0. Um resíduo lignocelulósico de baixo custo (sabugo de milho em pó) mostrou ser um excelente indutor do complexo xilanolítico em A. niger. A filtração do extrato cru com caulim foi ideal para a clarificação do extrato e levou à purificação parcial da enzima. A massa molecular aparente da xilanase foi de 32,3 kDa. A máxima atividade da enzima ocorreu em pH 5,0 e a 55-60ºC. O Km aparente foi de 10,41 ± 0,282 mg/mL e a Vmax foi de 3,32 ± 0,053 U/mg proteína, utilizando-se xilana birchwood como substrato. A energia de ativação foi de 4,55 kcal/mol, e a meia-vida da enzima a 60ºC foi de 30 minutos. A adição de 2% de glicose ao meio de cultura suplementado com xilana reprimiu a produção de xilanase, mas em presença de xilose a produção da enzima não foi afetada.