RESUMO
The mouth opening is an important indication of the functionality of the temporomandibular joint (TMJ). Mouth opening is usually evaluated by asking the patient to open their mouth as wide as possible and measuring the distance between the edges of the frontal incisors with a ruler or caliper. With the advancement of technology, new techniques have been proposed to record mandibular movement. The aim of this work is to present a novel technique based on 3D electromagnetic articulography and data postprocessing to analyze the mouth opening considering distances, trajectories, and angles. A maxilla-mandible phantom was used to simulate the mouth opening movement and fixed position mouth opening. This was recorded using the AG501 3D EMA (Carstens Medizinelektronik GmbH, Bovenden, Germany). The collected data was processed using Matlab (Mathworks, Natick, MA, USA). Fix and mobile mouth opening of 1, 2, 3 and 4 cm were simulated. It was possible to evaluate the mandibular opening through the vertical distance, the Euclidean distance, the trajectory, and the opening angle. All these values were calculated and the results were consistent with expectations. The trajectory was the highest value obtained while the vertical distance was the lowest. The angle increased as the mouth opening increased. This new technique opens up new possibilities in future research since oral opening can be analyzed using multiple variables without the need to use different devices or depending on the researcher's experience. This will make it possible to establish which parameter presents significant differences between groups of patients or between patients who have undergone some treatment.
RESUMO
Resumo Em 1930, o engenheiro Theodoro Ramos publicou pela livraria francesa Albert Blanchard seu livro sobre cálculo vetorial. Este artigo apresenta o contexto de edição da obra, a casa editorial onde foi impressa, o mercado para livros desse tipo na França e o aparecimento desse tema na história do cálculo. Compara conteúdos e aspectos materiais de várias obras similares editadas no período com o livro aqui estudado de maneira a evidenciar tanto suas inovações quanto adesões em relação a esse corpus de livros. Além de seus aspectos intrinsecamente matemáticos, procura capturar as representações, às vezes conflituosas, que a obra recebeu em seu percurso entre São Paulo e a Europa, seja em meio a especialistas ou a seus alunos.
Abstract In 1930, the engineer Theodoro Ramos published a book on vector calculus through the French publisher Albert Blanchard. The context of is publication, the publishing house where it was printed, the market for books of this kind in France, and the appearance of this topic in the history of calculus are discussed. Some of the contents and material aspects of several works of a similar nature published in the same period are compared with a view to bringing to light the innovations and consistencies of the book in question vis-à-vis this bibliographic corpus. Alongside its intrinsically mathematical aspects, the sometimes conflicting representations of the book by specialists and students in its trajectory between São Paulo and Europe are observed.