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OBJECTIVE: To determine the influence of the radius of Monson's sphere, the number of posterior laterotrusive, mediotrusive, and protrusive contacts, and the chewing rate on food comminution. DESIGN: Sixty healthy dentate subjects, aged 21.22 ± 2.30 years, were selected. The three-dimensional coordinates of the cusp tips of the lower canine, premolar, and molar teeth were identified from the subjects' digital models. Monson's sphere was designed using the simplex method for function minimisation by adjusting the coordinates on its surface. The contacts were verified using 12 µm metal strips in jaw excursions at 0.5, 1.0, 2.0, and 3.0 mm. The masticatory performance and efficiency, swallowing threshold, and chewing rate were assessed through particle size fractionation. Data were analysed with multiple linear regression (α = 0.05). RESULTS: The sphere's radius, laterotrusive and protrusive contacts at 0.5 mm, and chewing rate were found to be negative predictor variables for masticatory performance until 20 chewing cycles (R2 = 0.429). For 40 cycles, the radius and total contacts (0.5 mm) were also explanatory factors (R2 = 0.223). Only the radius (R2 = 0.176) and the chewing rate (R2 = 0.082) were found to be significant for 60 cycles and swallowing threshold, respectively. Masticatory efficiency was influenced by masticatory performance until 40 and 60 cycles, as well as the radius and total contacts at 2.0 and 3.0 mm (R2 = 0.958). CONCLUSION: A larger radius of Monson's sphere and a greater number of posterior excursive contacts were found to be related to better masticatory function.

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As fraturas nasais são de grande incidência dentre as fraturas faciais, podendo envolver também outras estruturas da face. O diagnóstico é baseado no exame físico, o qual muitas vezes é dificultado devido ao edema formado na região. A palpação dos contornos ósseos, verificação de presença de crepitação nasal, alterações de permeabilidade e assimetrias locais são algumas das alterações sugestivas de fraturas nasais. Além disso, a inserção do ligamento cantal medial pode ser perdida devido ao trauma ou devido ao deslocamento ósseo em que ele se encontra inserido. Exames de imagem, como radiografias e Tomografias Computadorizadas, são utilizados para a visualização das fraturas ósseas e planejamento cirúrgico. A redução aberta dos ossos nasais é indicada para fraturas de maior complexidade e cominuição, tendo em vista o adequado reposicionamento dos ossos, cartilagens e ligamentos deslocados. Assim, o objetivo deste estudo é relatar a redução aberta de uma fratura dos ossos nasais com perda de inserção do ligamento cantal medial direito, sob anestesia geral... (AU)

Nasal fractures are of great incidence among facial fractures, and may also involve other facial structures. The diagnosis is based on physical examination, which is often hampered due to the edema formed in the region. Palpation of bone contours, checking for the presence of nasal crackling, changes in permeability and local asymmetries are some of the changes suggestive of nasal fractures. In addition, the insertion of the medial canthal ligament may be lost due to trauma or due to the bone displacement in which it is inserted. Imaging exams, such as radiographs and CT scans, are used for visualizing bone fractures and surgical planning. The open reduction of the nasal bones is indicated for fractures of greater complexity and comminution, in view of the appropriate repositioning of the bones, cartilage and dislocated ligaments. Thus, the aim of this study is to report the open reduction of a fracture of the nasal bones with loss of insertion of the right medial canthal ligament, under general anestesia... (AU)

Las fracturas nasales son de gran incidencia entre las fracturas faciales, y también pueden involucrar otras estructuras faciales. El diagnóstico se basa en el examen físico, que a menudo se ve obstaculizado por la inflamación que se forma en la región. La palpación de los contornos óseos, confirmación de la presencia de crepitantes nasales, alteraciones de la permeabilidad y asimetrías locales son algunas de las alteraciones sugestivas de fracturas nasales. Además, la inserción del ligamento cantal medial puede perderse debido a un traumatismo o al desplazamiento del hueso en el que se inserta. Las pruebas de imagen, como las radiografías y las tomografías computadorizadas, se utilizan para visualizar las fracturas óseas y planificar la cirugía. La reducción abierta de los huesos nasales está indicada para las fracturas de mayor complejidad y conminución, en vista del reposicionamiento adecuado de los huesos, cartílagos y ligamentos dislocados. Así, el objetivo de este estudio es relatar la reducción abierta de una fractura de los huesos nasales con pérdida de inserción del ligamento cantal medial derecho, bajo anestesia general... (AU)

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