Search results for " Skeleton"
showing 10 items of 62 documents
Approximation of Pore Space with Ellipsoids: A Comparison of a Geometrical Method with a Statistical one
2018
We work with tomographic images of pore space in soil. The images have large dimensions and so in order to speed-up biological simulations (as drainage or diffusion process in soil), we want to describe the pore space with a number of geometrical primitives significantly smaller than the number of voxels in pore space. In this paper, we use the curve skeleton of a volume to segment it into some regions. We describe the method to compute the curve skeleton and to segment it with a simple segment approximation. We approximate each obtained region with an ellipsoid. The set of final ellipsoids represents the geometry of pore space and will be used in future simulations. We compare this method …
Imaging Evaluation of Facial Complex Strut Fractures
2012
High-resolution multidetector computed tomography with multiplanar reformations and 3-D postprocessing often provides the detail necessary for preoperative assessment of facial injuries. Maxillofacial fractures are classified in the following manner: upper face fractures, midface fractures (the most frequent), Le Fort fractures, and lower face or mandible fractures. The facial skeleton is a framework of vertical and horizontal buttresses that ensures a better resistance to trauma, but serves also as reference for maxillofacial surgery to restore facial size and shape. Radiologists should know how to diagnose and report the main types of facial fracture.
Remplacement total de l’articulation temporo-mandibulaire par prothèse
2013
Summary Introduction The temporomandibular joint (TMJ) may be the location for tumoral, post-traumatic, degenerative, inflammatory, or congenital diseases requiring a prosthetic replacement. We present a technical note for total TMJ replacement with a Biomet ® Microfixation prosthesis (Jacksonville, FL, USA). Technical note The preoperative data includes dental panoramic X-ray, MRI of the TMJ, and CT-scan (or cone beam) of the facial skeleton. The last two mentioned examinations allow three-dimensional reconstructions and stereo-lithographic models required for surgical planning. The prosthetic device includes a temporal ultra-high density polyethylene component and a mandibular chrome-coba…
Using skeleton and Hough transform variant to correct skew in historical documents
2020
International audience; As a main part of several document analysis systems, Skew estimation represents one of the major research challenges, particularly in case of historical documents exploration. In this paper, we propose an original skew angle detection and correction technique. Morphological Skeleton is introduced to considerably diminish the amount of data by eliminating the redundant pixels and preserving only the central curves of the image components. Next, the proposed method uses Progressive Probabilistic Hough Transform (PPHT) to find image lines. At the end, a specific procedure is applied in order to measure the global skew angle of the document image from these identified li…
Regulación de las modificaciones óseas en la madre durante la gestación
2015
El embarazo constituye un modelo donde se produce el desarrollo del esqueleto fetal en un corto lapso de tiempo. Este logro se lleva a cabo bajo la tutela del propio feto, que gobierna este proceso a través de las señales generadas en la denominada unidad feto-placentaria. El organismo materno sufre un proceso de adaptación donde se produce un drástico reajuste en mecanismos implicados en el recambio óseo. Entre los cambios más evidentes detectables en sangre materna están los incrementos con la edad gestacional de los niveles de calcitriol, de la hormona de crecimiento de origen placentario, del factor de crecimiento similar a la insulina tipo I (IGF-1), de estrógenos, y de prolactina. Tam…
Beyond the functional matrix hypothesis: a network null model of human skull growth for the formation of bone articulations.
2014
Craniofacial sutures and synchondroses form the boundaries among bones in the human skull, providing functional, developmental and evolutionary information. Bone articulations in the skull arise due to interactions between genetic regulatory mechanisms and epigenetic factors such as functional matrices (soft tissues and cranial cavities), which mediate bone growth. These matrices are largely acknowledged for their influence on shaping the bones of the skull; however, it is not fully understood to what extent functional matrices mediate the formation of bone articulations. Aiming to identify whether or not functional matrices are key developmental factors guiding the formation of bone articu…
Magnesium deprivation affects development and biomineralization in the sea urchin arba-cia lixula
2018
Skeletogenesis is a key morphogenetic event in the life of marine invertebrates. Marine calcifiers secrete their calcareous skeletons taking up ions from seawater. Marine biominerals include aragonite and calcite, the latter of which in some taxa (e.g. echinoderms, coralline algae) can have a substantial magnesium (Mg) component. Echinoderms have an extensive endoskeleton composed of high magnesian calcite and occluded matrix proteins1. As biomineralization in sea urchin larvae is sensitive to the Magnesium:Calcium ratio of sea water, we investigated the effects of magnesium deprivation on development and skeletogenesis in the Mediterranean sea urchin Arbacia lixula. Microscopic inspection …
The face of conflict: Significant sharp force trauma to the mid-facial skeleton in an individual of probable 16th–17th century date excavated from By…
2016
A variety of injuries have always been associated with violence, consequences of which people had to deal with. In this paper we present a complex of craniofacial and dental injuries resulted from sharp force trauma. The basis of our study was historical skeletal material excavated from archeological site in Byczyna (11th–17th century), Poland. An individual whose skeleton was exhumed from the grave No. 610 exhibited healed, oblique trauma of the left maxilla, damage to the crowns of right central and lateral incisors and concomitant luxation of the right maxillary central incisor. We describe the mechanism of this trauma and complications that resulted from damage to the masticatory appara…
Giovanni Filippo Ingrassia: A five-hundred year-long lesson.
2010
Giovanni Filippo Ingrassia was born five centuries ago in Regalbuto, a small town in the center of Sicily. After his medical course in Padua, under the guidance of Vesalius and Fallopius, he gained international fame as a physician and was recruited as a Professor of human anatomy in Naples and later in Palermo. He is remembered as "the new Galen" or "the Sicilian Hippocrates." He contributed to the knowledge of human anatomy through the description of single bones rather than the whole skeleton. In particular, he was the first to describe the "stapes," the "lesser wings of the sphenoid" and various other structures in the head (probably the pharyngotympanic tube) as well as in the reproduc…
Simulation study of transcatheter heart valve implantation in patients with stenotic bicuspid aortic valve
2019
Bicuspid aortic valve (BAV) anatomy has routinely been considered an exclusion in the setting of transcatheter aortic valve implantation (TAVI) because of the large dimension of the aortic annulus having a more calcified, bulky, and irregular shape. The study aims to develop a patient-specific computational framework to virtually simulate TAVI in stenotic BAV patients using the Edwards SAPIEN 3 valve (S3) and its improved version SAPIEN 3 Ultra and quantify stent frame deformity as well as the severity of paravalvular leakage (PVL). Specifically, the aortic root anatomy of n.9 BAV patients who underwent TAVI was reconstructed from pre-operative CT imaging. Crimping and deployment of S3 fram…