1,721,293 research outputs found
Cloud-based Collaboration Platform for Orthognatic Surgical Planning
No full textMany medical departments use several multi-disciplinary technologies to support the planning of the surgery. For complex operations a collaboration between different experts can improve
the success rate, but the tools are mostly on-premises software and limit the good cooperation. In this case, the orthognathic and dental surgery uses 3D and CT scans to plan the surgery beforehand by making use of 3D image processing, visualization and planning tools. We researched the possibility to create an online cloud-based platform to run the currently used surgical planning tools to improve the collaboration between several experts. We achieved multiple two-factor authentication user logins for security, simultaneous surgical planning sessions for collaboration and lightweight multi-platform support for existing technologies
Cloud-based Collaboration Platform for Orthognatic Surgical Planning
No full textMany medical departments use several multi-disciplinary technologies to support the planning of the surgery. For complex operations a collaboration between different experts can improve
the success rate, but the tools are mostly on-premises software and limit the good cooperation. In this case, the orthognathic and dental surgery uses 3D and CT scans to plan the surgery beforehand by making use of 3D image processing, visualization and planning tools. We researched the possibility to create an online cloud-based platform to run the currently used surgical planning tools to improve the collaboration between several experts. We achieved multiple two-factor authentication user logins for security, simultaneous surgical planning sessions for collaboration and lightweight multi-platform support for existing technologies
Anaesthesia of the inferior alveolar and lingual nerves following subcondylar fractures of the mandible
No full textAbstractA retrospective chart review of 387 patients with condylar and subcondylar fractures revealed 2 cases of inferior alveolar nerve (IAN) and lingual nerve (LN) anaesthesia following the subcondylar fracture. Only 5 cases have been reported previously. The mechanism of action remains unknown but a review of the literature and an analysis of 120 dry human skulls supported the hypothesis that compression of the mandibular nerve at a high level, close to the foramen ovale, could cause anaesthesia. This complication is rare, because it requires compression at a particular angle. The antero-median angulation of the condyle must be close to the foramen ovale, and the fracture must be a unilaterally displaced fracture. The presence of an enlarged lateral pterygoid plate appeared to enhance the risk of compression. The IAN and LN anaesthesia could be resolved after open reduction of the fracture and IAN and LN anaesthesia constitute a strict indication for an early open fracture reduction
Cloud-based orthognathic surgical planning platform
No full textMulti-disciplinary technologies are currently involved in orthognathic and dental surgery. By using 3D and CT scans, the surgery can be planned beforehand by making use of 3D image processing, visualization and planning tools. With 3D printing, accurate splints and wafers can be generated for the surgery. Nowadays, these tools are on-premises software and this makes it very hard for collaboration between several specialists. Therefore, we researched the possibility to create an online cloud-based platform to run the currently used surgical planning tools. We achieved multiple two-factor authentication user logins, simultaneous surgical planning sessions and lightweight multi-platform support.The research in this paper was partly funded by the bilateral FWOMOST (Belgian Research Council research cooperation contract
G.0524.13
A simple method to estimate the linear length of the orbital floor in complex orbital surgery
No full textBACKGROUND: The orbital floor (OrF) and infraorbital rim (IOR) repair in cases of complete destruction is challenging mainly due to the fact that the defect length cannot be measured. The aim of the current study is to develop a method of calculating the Orf length by using the gender and the lengths of the medial, superior and lateral orbital walls (OrW) of the same orbit. MATERIAL AND METHODS: Ninety-seven (59 male and 38 female) European adult dry skulls were classified according to age: 20-39, 40-59 and 60 years and above. The length of each OrW was measured by using the direct distance between the optic foramen and a landmark in each orbital rim. RESULTS: A side asymmetry was detected for the lengths of the inferior, superior and medial OrW. Although a gender dimorphism was detected, no correlation with the age was found. Using the Stepwise multiple regression analysis two formulas were developed, one for the right and one for the left OrF with coefficient of determination R2 0.43 and 0.57, respectively. CONCLUSIONS: The proposed formulas represent a simple, applicable and individualized method to calculate the OrF linear length in cases of complete destruction of the IOR and OrF, with accuracy and without the use of expertise material. Such data may improve the surgery planning of orbital floor fractures and complex orbital reconstructions.status: Publishe
Expression Pattern of Basal Markers in Human Dental Pulp Stem Cells and Tissue
Full text linkDental pulp stem cells (DPSC) have been characterized as a multipotent stem cell population, with the ability to differentiate into mesodermal and neural cell lineages. Although 'de novo' expression of neural markers after differentiation is mostly considered as proof of differentiation, expression of these markers in undifferentiated DPSC is not well described. Therefore, an immunocytochemical analysis was performed to evaluate the neural marker expression of undifferentiated human DPSC (hDPSC) in in vitro cultures. Undifferentiated hDPSC uniformly expressed neural markers β-III-tubulin, S100 protein and synaptophysin. A subset of the population showed a positive immune-reactivity for galactocerebroside, neurofilament and nerve growth factor receptor p75. Furthermore, the location of possible stem cell niches, present in young dental pulp tissue, was determined by means of immunohistochemistry based on mesenchymal and neural marker expression. The results demonstrated the presence of a perivascular niche and a second stem cell niche at the cervical area. In adult dental pulp, only a perivascular niche could be observed. Based on the expression of neural markers in naïve DPSC, it has to be taken into account that not only the marker expression upon neural differentiation must be analyzed, but an ultrastructural analysis of the morphological changes and functional studies must also be performed to confirm a successful differentiation.sponsorship: The authors of the manuscript are very grateful to Marc Jans and Jeanine Santermans for their dedicated technical assistance. A.B. received a postdoctoral grant from the Fonds voor Wetenschappelijk Onderzoek-Vlaanderen. (Fonds voor Wetenschappelijk Onderzoek-Vlaanderen)status: Publishe
Haptic Collision Detection on Highly Complex Medical Data Structures
No full textNowadays, the planning procedure for orthognathic surgery consists of a manual workflow which relies on cost and time consuming tasks. The burden that this procedure has on the surgeon and the medical staff can be reduced by substituting
the current procedure with a digital workflow. In the novel
workflow the surgeon uses a haptic feedback device to mimic
the haptic information perceived from the manual procedure.
However, highly complex 3D medical scan models of the upper
and lower jaw are needed to reproduce a realistic feeling. These
complex models stress the need for an efficient collision detection algorithm to obtain the necessary update rate of at least 1 kHz for haptic feedback devices. In this paper the potential of the Inner Sphere Tree (IST) data structure is analyzed for application in the orthognathic surgery digital planning workflow. An open-source C++ program is developed on the CHAI3D platform for the implementation and evaluation of the IST. For the evaluation, the detection speed, but also the accuracy of the collision detection, in terms of the error introduced by the proximity of the minimum
distance between bounding volume hierarchies (BVHs), are taken
into consideration. Various tree traversal algorithms, distance
and backtracking, are implemented and evaluated. Finally, a
multi-point tree traversal algorithm is developed to find multiple contact-points between two ISTs. Due to the added optimizations and by using these tree traversal algorithms, the required update speed is reached.FW
Analysis of collision detection using Implicit Sphere Tree in haptic interaction environments for maxillofacial surgery applications
No full textFacial malformations such as overbite or underbite
can be treated by maxillofacial surgery where the mandibula (i.e.
the lower jaw) and/or maxilla (i.e. the upper jaw) is repositioned
to obtain a preferential occlusion. These treatments need to be
carefully planned prior to the actual operation. The planning of
such surgery is an intensive and time consuming procedure in
which the experience and knowledge of the surgeon plays a major
role. As part of a CAD-based surgery planning, haptic interaction
using 3D virtual models of the mandibula and maxilla, haptic
feedback can make planning and surgery much more efficient.
Haptic devices bridge the gap between the virtual environment
and the physical world. An important step in such haptics based
workflow is the collision detection between the two models at an
update frequency of at least 1000 Hz. In this paper the possibility
of the Implicit Sphere Tree algorithm as a collision detection
algorithm tailored for this specific application is presented
Haptic Collision Detection on Highly Complex Medical Data Structures
No full textNowadays, the planning procedure for orthognathic surgery consists of a manual workflow which relies on cost and time consuming tasks. The burden that this procedure has on the surgeon and the medical staff can be reduced by substituting
the current procedure with a digital workflow. In the novel
workflow the surgeon uses a haptic feedback device to mimic
the haptic information perceived from the manual procedure.
However, highly complex 3D medical scan models of the upper
and lower jaw are needed to reproduce a realistic feeling. These
complex models stress the need for an efficient collision detection algorithm to obtain the necessary update rate of at least 1 kHz for haptic feedback devices. In this paper the potential of the Inner Sphere Tree (IST) data structure is analyzed for application in the orthognathic surgery digital planning workflow. An open-source C++ program is developed on the CHAI3D platform for the implementation and evaluation of the IST. For the evaluation, the detection speed, but also the accuracy of the collision detection, in terms of the error introduced by the proximity of the minimum
distance between bounding volume hierarchies (BVHs), are taken
into consideration. Various tree traversal algorithms, distance
and backtracking, are implemented and evaluated. Finally, a
multi-point tree traversal algorithm is developed to find multiple contact-points between two ISTs. Due to the added optimizations and by using these tree traversal algorithms, the required update speed is reached.FW
Ultrastructural evidence for multi-lineage differentiation of human dental pulp stem cells
No full textMesenchymal stemm cells (MSCs) are one of the most promising stem cell types due to their availability and relatively simple requirements for in vitro expansion and genetic manipulation. Besides the well-characterized MSCs derived from bone marrow, there is growing eveidence suggesting that dental pulp and the umbilical cord matrix both contain a substantial amount of cells having propertes similar to those of MSCs. In order to assess the potential of dental pulp-derived MSCs(DPSC) and umbilical cord-derived MSCs(UCSC) in future clinical applications, it is essential to gain more insight into their differentiation capacity and to evaluate the tissues formed by these cells. In the present study, the morphological and ultrastructural characteristics of DPSC and UCSC induced towards osteogenic, adipogenic, and chondrogenic lineages were investigated. Cultured DPSC and UCSC showed a similar expression pattern of antigens characteristic of MSCs including CD105, CD29, CD44, CD146, and STRO-1. Under appropriate culture conditions, both DPSC and UCSC showed chondrogenic and osteogenic potential. Adipogenesis could be only partially induced in DPSC resulting in the de novo expression of fatty acid binding protein (FABP), whereas UCSC expressed FABP combined with a very high accumulation of lipid droplets in the cytoplasm. Our results demonstrate, at the biochemical and ultrastructural level, that DPSC display at least bilineage potential, whereas UCSC, which are developmentally more primitive cells, show trilineage potential. We emphasize that transmission electron microscopical analysis is useful to elucidate detailed structural information and provides indisputable evidence of differentiation. These findings highlight their potential therapeutic value for cell-based tissue engineering
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