• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.2
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• pp.197-203
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• 2000

Maxillary defect may be induced by trauma, inflammation, cyst, tumor and surgical procedure. In case of limited wall defect, free bone graft has been preferred. But it has some problems such as postoperative bone resorption and soft tissue inclusion to recipient site. And we can not use free bone in the case who has inflammation in the donor site. So we used the micro-titanium mesh as reconstructive material for the maxillary wall defect. We had operated 8 patients who were diagnosed as maxillary partial defects from June 1997 to September 1998 in the Chin-Hae military hospital. They were 1 case of antral wall defect, 1 case of palatal wall defect, 5 cases of infra-orbital wall defects and 1 case of oroantral fistula case. As a result, the micro-titanium mesh has shown the morphological stability and biocompatibility and it could be used in case who has infection. And mesh structure could prevent soft tissue ingrowth to bony defect area. Thus it can be used to the case of maxillary partial defect successfully.

• Archives of Plastic Surgery
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• v.41 no.4
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• pp.355-361
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• 2014

Background A blow-out fracture is one of the most common facial injuries in midface trauma. Orbital wall reconstruction is extremely important because it can cause various functional and aesthetic sequelae. Although many materials are available, there are no uniformly accepted guidelines regarding material selection for orbital wall reconstruction. Methods From January 2007 to August 2012, a total of 78 patients with blow-out fractures were analyzed. 36 patients received absorbable mesh plates, and 42 patients received titanium-dynamic mesh plates. Both groups were retrospectively evaluated for therapeutic efficacy and safety according to the incidence of three different complications: enophthalmos, extraocular movement impairment, and diplopia. Results For all groups (inferior wall fracture group, medial wall fractrue group, and combined inferomedial wall fracture group), there were improvements in the incidence of each complication regardless of implant types. Moreover, a significant improvement of enophthalmos occurred for both types of implants in group 1 (inferior wall fracture group). However, we found no statistically significant differences of efficacy or complication rate in every groups between both implant types. Conclusions Both types of implants showed good results without significant differences in long-term follow up, even though we expected the higher recurrent enophthalmos rate in patients with absorbable plate. In conclusion, both types seem to be equally effective and safe for orbital wall reconstruction. In particular, both implant types significantly improve the incidence of enophthalmos in cases of inferior orbital wall fractures.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.6
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• pp.307-317
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• 2002

In this paper we propose a new mesh reconstruction scheme that produces a displaced subdivision surface directly from unorganized points. The displaced subdivision surface is a new mesh representation that defines a detailed mesh with a displacement map over a smooth domain surface, but original displaced subdivision surface algorithm needs an explicit polygonal mesh since it is not a mesh reconstruction algorithm but a mesh conversion (remeshing) algorithm. The main idea of our approach is that we sample surface detail from unorganized points without any topological information. For this, we predict a virtual triangular face from unorganized points for each sampling ray from a parameteric domain surface. Direct displaced subdivision surface reconstruction from unorganized points has much importance since the output of this algorithm has several important properties: It has compact mesh representation since most vertices can be represented by only a scalar value. Underlying structure of it is piecewise regular so it ran be easily transformed into a multiresolution mesh. Smoothness after mesh deformation is automatically preserved. We avoid time-consuming global energy optimization by employing the input data dependant mesh smoothing, so we can get a good quality displaced subdivision surface quickly.

• Journal of Chest Surgery
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• v.10 no.1
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• pp.7-17
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• 1977

The increasing frequency of post-tracheostomy stenosis parallels the increase in the incidence of tracheostomy. The development of stenosis of trachea following the operation of tracheal tumor or tracheostomy is a very serious complication. The continuing need for an adequate tracheal substitute has not been answered, despite the necessities of excision and reconstruction of the trachea to keep for effective ventilation. Experimental tracheal reconstuction, with a prosthesis of heavy Marlex mesh and pericardium, _ vas performed in twelve dogs. Five to six tracheal ring circumferential defects were created and were bridged with heavy Marlex mesh fashioned into a tube of suitable diameter. Group A: A prepared cylinder of Marlex mesh was anastomosed outside the cut ends of the trachea. Group B: The external surface of the prepared cylinder of Marlex mesh was completely covered with suitably sized patch of pericardium and overlapped all margin of the Marlex mesh by 2 to 3 mm in each direction. Group C: The internal surface of the prepared cylinder of Marlex mesh was covered with suitably sized patch of pericardium and overlapped all margin of the Marlex mesh by 2 to 3 mm in each direction. The results of this exepriment were as follow: 1. In group A and B, the graft was well bridged with new granulation and fibrous tissue, and the lumen of trachea kept good patency for effective ventilation.. The interstices of Marlex became uniformly infiltrated with young well vasculated connective tissue. Epithelization has not yet occurred at 4 weeks in each group, but there were evidences of new growing mucosa at grafted site in 6 weeks. The remainder of the prosthesis was completely covered with glistening epithelium and the underlying fibrous tissue became more matured with little inflammation. These findings were more striking in group B than group A. 2. In group C, the covered pericardium was necrotized with stenosis of the lumen of grafted site due to poor blood supply.

• Archives of Plastic Surgery
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• v.40 no.6
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• pp.728-734
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• 2013

Background Absorbable materials offer many advantages in the reconstruction of orbital walls; however, the possibility of postoperative enophthalmos after complete absorption cannot be excluded. We evaluated the postoperative results of absorbable mesh plates used as onlay implanting on the medial orbital wall to determine whether they are suitable for medial orbital wall reconstruction. Methods The study included 20 patients with medial orbital wall fractures who were followed up for more than 2 years postoperatively. We used absorbable mesh plates in all of the patients. We measured the following: the changes in the expanded orbital volume by comparing the preoperative and postoperative computed tomography (CT) scans and the degree of clinical enophthalmos. Results There were no major complications associated with the use of absorbable materials such as infection, migration, or extrusion of mesh plates during the long-term follow-up. The orbital volumetric changes between the preoperative and postoperative CT scans were not statistically significant. However, the expanded orbital volume was not related to the degree of clinical enophthalmos. Conclusions The reconstructed orbital wall may provide supportive scar tissue to the orbital contents even after the absorbable materials have dissolved completely. Absorbable mesh plates could be another option for the reconstruction of the medial orbital wall.

• Journal of KIISE:Computer Systems and Theory
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• v.36 no.6
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• pp.511-520
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• 2009

In this paper, we present a new iso-density surface reconstruction scheme based on a hierarchy on the input volume data and the output mesh data. From the input volume data, we construct a hierarchy of volumes, called a volume pyramid, based on a 3D dilation filter. After constructing the volume pyramid, we extract a coarse base mesh from the coarsest resolution of the pyramid with the Cell-boundary representation scheme. We iteratively fit this mesh to the iso-points extracted from the volume data under O(3)-adjacency constraint. For the surface fitting, the shrinking process and the smoothing process are adopted as in the SWIS (Shrink-wrapped isosurface) algorithm[6], and we subdivide the mesh to be able to reconstruct fine detail of the isosurface. The advantage of our method is that it generates a mesh which can be utilized by several multiresolution algorithms such as compression and progressive transmission.

• 한국전산유체공학회:학술대회논문집
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• 2008.03a
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• pp.334-336
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• 2008

A novel adaptive mesh refinement (AMR) strategy based on the Moment-of-Fluid (MOF) method for volume-tracking dynamic interface computation is presented. The Moment-of-Fluid method is a new interface reconstruction and volume advection method using volume fraction as well as material centroid. The mesh refinement is performed based on the error indicator, the deviation of the actual centroid obtained by interface reconstruction from the reference centroid given by moment advection process. Using the AMR-MOF method, the accuracy of volume-tracking computation with evolving interfaces is improved significantly compared to other published results.

• 한국전산유체공학회:학술대회논문집
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• 2008.10a
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• pp.334-336
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• 2008

A novel adaptive mesh refinement (AMR) strategy based on the Moment-of-Fluid (MOF) method for volume-tracking dynamic interface computation is presented. The Moment-of-Fluid method is a new interface reconstruction and volume advection method using volume fraction as well as material centroid. The mesh refinement is performed based on the error indicator, the deviation of the actual centroid obtained by interface reconstruction from the reference centroid given by moment advection process. Using the AMR-MOF method, the accuracy of volume-tracking computation with evolving interfaces is improved significantly compared to other published results.

• Journal of computational fluids engineering
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• v.14 no.1
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• pp.18-23
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• 2009

A novel adaptive mesh refinement(AMR) strategy based on the Moment-of-Fluid(MOF) method for volume-tracking dynamic interface computation is presented. The Moment-of-Fluid method is a new interface reconstruction and volume advection method using volume fraction as well as material centroid. The adaptive mesh refinement is performed based on the error indicator, the deviation of the actual centroid obtained by interface reconstruction from the reference centroids given by moment advection process. Using the AMR-MOF method, the accuracy of volume-tracking computation with evolving interfaces is improved significantly compared to other published results.

• Journal of Institute of Convergence Technology
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• v.10 no.1
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• pp.7-12
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• 2020

We describe a efficient surface reconstruction method that reconstructs a 3D manifold polygonal mesh approximately passing through a set of 3D oriented points. Our algorithm includes 3D convex hull, octree data structure, signed distance function (SDF), and marching cubes. The 3D convex hull provides us with a fast computation of SDF, octree structure allows us to compute a minimal distance for SDF, and marching cubes lead to iso-surface generation with SDF. Our approach gives us flexibility in the choice of the resolution of the reconstructed surface, and it also enables to use on low-level PCs with minimal peak memory usage. Experimenting with publicly available scan data shows that we can reconstruct a polygonal mesh from point cloud of sizes varying from 10,000 ~ 1,000,000 in about 1~60 seconds.