• Archives of Craniofacial Surgery
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• v.10 no.2
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• pp.81-85
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• 2009

Purpose: The inferior orbital wall is the most vulnerable to injury and inadequate reconstruction of inferior orbital fracture result in postoperative complications include enophthalmos, ocular dystopia and diplopia. Although the anatomical reconstruction of the inferior orbital wall is necessary to prevent these complications, the complexity of inferior orbital wall makes it difficult. We fabricated and remodeled the titanium micro-mesh plate for the anatomical reconstruction of inferior orbital wall. Methods: Twenty-nine patients with inferior orbital wall blow-out fracture were operated and twelve of them presented large extensive fracture. We intraoperatively fabricated and remodeled the Titanium-micro mesh to angulated lazy S shape similar to contralateral uninjured orbit. The preoperative and postoperative facial CT scan verified the 3-dimensional and anatomical reconstruction of the fractures. The mean follow-up was 19.7 months and postoperative complications was evaluated. Results: All cases showed the exact anatomical reconstruction, but there were minor complications in two cases. one patient had postoperative diplopia until 3months after surgery and the other patient had persistent enophthalmos (2 mm), but no further surgical correction was required. Conclusion: The comprehensive understanding of orbital convexity is the most important factor for anatomical reconstruction of inferior orbital fracture. We could prevent postoperative complications after inferior orbital wall reconstruction by intraoperative fabrication and anatomical remodeling of Titanium micro-mesh.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.11
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• pp.4463-4482
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• 2020

Mesh model generated from 3D reconstruction usually comes with lots of noise, which challenges the performance and robustness of mesh simplification approaches. To overcome this problem, we present a novel method for mesh simplification which could preserve structure and improve the accuracy. Our algorithm considers both the planar structures and linear features. In the preprocessing step, it automatically detects a set of planar structures through an iterative diffusion approach based on Region Seed Growing algorithm; then robust linear features of the mesh model are extracted by exploiting image information and planar structures jointly; finally we simplify the mesh model with plane constraint QEM and linear feature preserving strategies. The proposed method can overcome the known problem that current simplification methods usually degrade the structural characteristics, especially when the decimation is extreme. Our experimental results demonstrate that the proposed method, compared to other simplification algorithms, can effectively improve the quality of mesh and yield an increased robustness on noisy input mesh.

• Journal of Korean Neurosurgical Society
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• v.63 no.5
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• pp.631-639
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• 2020

Objective : Traditionally, staged surgery has been preferred in the treatment of compound comminuted depressed fracture (FCCD) after traumatic brain injury (TBI) and involves the removal of primarily damaged bone and subsequent cranioplasty. The main reason for delayed cranioplasty was to reduce the risk of infection-related complications. Here, the author performed immediate reconstruction using a titanium mesh in consecutive patients with FCCD after TBI, reported the surgical results, and reviewed previous studies. Methods : Nineteen consecutive patients who underwent single-stage reconstruction with titanium mesh for FCCD of the skull from April 2014 to June 2018 were retrospectively analyzed. The demographic and radiological characteristics of the patients with FCCD were investigated. The characteristics associated with surgery and outcome were also evaluated. Results : The frequency of TBI in men (94.7%) was significantly higher than that in women. Most FCCDs (73.7%) occurred during work, the rest were caused by traffic accidents. The mean interval between TBI and surgery was 7.0±3.9 hours. The median Glasgow coma scale score was 15 (range, 8-15) at admission and 15 (range, 10-15) at discharge. FCCD was frequently located in the frontal (57.9%) and parietal (31.6%) bones than in other regions. Of the patients with FCCDs in the frontal bone, 62.5% had paranasal sinus injury. There were five patients with fractures of orbital bone, and they were easily reconstructed using titanium mesh. These patients were cosmetically satisfied. Postoperatively, antibiotics were used for an average of 12.6 days. The mean hospital stay was 17.6±7.5 days (range, 8-33). There was no postoperative seizure or complications, such as infection. Conclusion : Immediate bony fragments replacement and reconstruction with reconstruction titanium mesh for FCCD did not increase infectious sequelae, even though FCCD involved sinus. This suggests that immediate single-stage reconstruction with titanium mesh for FCCD is a suitable surgical option with potential benefits in terms of cost-effectiveness, safety, and cosmetic and psychological outcomes.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1564-1569
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• 2007

This study concerns an advanced NURBS surface reconstruction method, which is based on the NURBS surface model fitting to the unstructured point cloud measured from an arbitrary complex shape. The concept of generating a simple triangular mesh model was introduced to generate a quadrilateral mesh model well-representing the topological characteristics of point cloud. The NURBS surface reconstruction processes required the use of the various methodologies such as QEM algorithm, merging scheme of pair-wise triangular mesh, creation algorithm of $G^1$ continuous tensor product NURBS surface patch, and so on. The effectiveness and reliability of the proposed NURBS surface reconstruction method were validated through the simulation results for the geometrically and topologically complex shapes.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.8 s.251
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• pp.906-915
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• 2006

This study concerns an advanced 3D surface reconstruction method that the vertices of surface model can be completely matched to the unstructured point cloud measured from arbitrary complex shapes. The concept of bounding voxel model is introduced to generate the mesh model well-representing the geometrical and topological characteristics of point cloud. In the reconstruction processes, the application of various methodologies such as shrink-wrapping, mesh simplification, local subdivision surface fitting, insertion of is isolated points, mesh optimization and so on, are required. Especially, the effectiveness, rapidity and reliability of the proposed surface reconstruction method are demonstrated by the simulation results for the geometrically and topologically complex shapes like dragon and human mouth.

• Journal of the Korean Institute of Intelligent Systems
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• v.9 no.4
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• pp.436-443
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• 1999

Most of the 3D object reconstruction techniques divide the object into multiplane and approximate the surfaces of the object. The Marching Cubes Algorithm which initializes the mesh structure using a given isovalue. and Delaunay Tetrahedrisation are widely used. Deformable models are well-suited for general object reconstruction because they make little assumptions about the shape to recover and they can reconstruct objects *om various types of datasets. Now, many researchers are studying the reconstruction systems based on a deformable model. In this paper, we propose a novel method for reconstruction of 3D objects. This method, for a 3D object composed of curved planes, compresses the 3D object based on the adaptive simplexmesh technique. It changes the pre-defined mesh structure, so that it may approach to the original object. Also, we redefine the geometric characteristics such as curvatures. As results of simulations, we show reconstruction of the original object with high compression and concentration of vertices towards parts of high curvature in order to optimize the shape description.

• 한국전산유체공학회:학술대회논문집
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• 2003.08a
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• pp.31-36
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• 2003

A field reconstruction scheme for a cell centered finite volume method on unstructured meshes is developed. Regardless of mesh quality, this method is exact within a machine accuracy if the solution is linear, which means it has full second order accuracy. It does not have any limitation on cell shape except convexity of the cells and recovers standard discretization stencils at structured orthogonal grids. Accuracy comparisons with other popular reconstruction schemes are performed on a simple example.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.1
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• pp.85-92
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• 2005

Reconstruction of defect in the anterior part of the maxilla to enable implant placement or prothesis is a complicated treatment due to the anatomical position and lack of soft tissues. Two cases are presented in which autogenous iliac PMCB(particulate marrow and cancellous bone) with titanium mesh were used for premaxilla reconstruction and alveolar bone repair of the anterior maxillas prior to denture and implants fixation respectively. Cancellous bone from the anterior iliac crest was compressed and placed against a titanium mesh fixed to the bone of palate in a patient with severe defect of the anterior maxilla. There were no problem in the healing, and the anterior maxillas of two patients had increased height and width during the initial healing and remodeling. The clinical reports describe the use of titanium mesh for reconstruction of premaxilla. Autogenous bone grafts were harvested from the iliac crest and were loaded on a titanium mesh that were left in the patient's maxilla for 6 months before they were removed respectively. The radiographic analysis demonstrated that a 10mm vertical ridge augmentation had been achieved. In guided bone regeneration, the quantity of bone regenerated under the barrier has been demonstrated to be directly related to the amount of the space under the membrane. This space can diminish as a result of membrane collapse. To avoid this problem which involved the use of a titanium mesh barrier to protect the regenerating tissues and to achieve a rigid fixation of the bone segments, were used in association with autologous bone in 2 cases. The aim of this study was to evaluate the capability of a configured titanium mesh to serve as a mechanical and biologic device for restoring a vertically defected premaxilla.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.3
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• pp.63-73
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• 1997

For the practical applications of the EIT technology, it is essential to reconstruct sttic images iwth a higher spatial resolution in a reasonalble amount of processing time. Using the conventional EIT static image reconstruction algorithms, however, the processing time increases exponential with poor convergence characteristics as we try to get a higher spatial resolution. In order to overcome this problem, we developed a recursive mesh grouping method based on the Fuzzy-GA like algorithm. Computational simulation using the well-known improve dewton-raphson method with the proposed recursive mesh grouping algorithm shows a promising result that we can significantly reduce the processing time in the reconstruction of EIT static images of a higher spatial resolution.

• Archives of Plastic Surgery
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• v.33 no.5
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• pp.643-647
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• 2006

Purpose: The transverse rectus abdominis myocutaneous(TRAM) flap has become a mainstay of breast reconstruction. The chief disadvantage of the TRAM flap is its potential to create a weakness in the abdominal wall. Nowadays true hernia is less frequent, but bulging that appears at the muscle donor site, or at the contralateral side, or at the epigastric area is still remained as a problem. To prevent this complications, we have used synthetic mesh as well as abdominal muscle plication. Now we report the result of our methods. Methods: We started to use synthetic mesh and muscle plication as supplementary reinforcement for entire abdominal wall, after TRAM flap harvesting, in an attempt to stabilize it and achieve a superior aesthetic result since 2002. We observed complications of TRAM flap donor site, and compared our results (from January, 2002 to January, 2006) with other operator's result (before 2001) at the same hospital in aspect of incidence of abdominal complications. Results: 42 consecutive patients have been performed routine reinforcement with the extended mesh technique and muscle plication from January, 2002 to January, 2006. Mean patient follow up was 25.2 months. No hernia or mesh related infection were encountered and only one patient had a mild abdominal bulging. Nevertheless the our good results, there were no significant statistical differences were observed between two groups. Conclusion: We recommend the using of synthetic mesh and muscle plication for donor site reconstruction after TRAM flap breast reconstruction to improve strength as well as aesthetic quality of the abdominal wall.