• The Academic Congress of Korean Shoulder and Elbow Society
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• 1999.03a
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• pp.69-69
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• 1999

• Archives of Craniofacial Surgery
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• v.11 no.2
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• pp.85-90
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• 2010

Purpose: The goals of a blow-out fracture reconstruction are to restore the osseous continuity, provide support for the orbital contents and prevent functional and anatomic defects. Over the past several years, a range of autogenous and synthetic implants have been used extensively in orbital reconstructions. None of these implants have any absolute indications or contraindications in certain clinical settings. However, in extensive blow-out fractures, it is difficult to restore support of the orbital contents, which can cause more complications, such as enophthalmos. This study examined the clinical outcomes of extensive or comminuted blow-out fractures that were reconstructed by the simultaneous use of a titanium mesh plate and $Medpor^{(R)}$. Methods: Eighty six patients with extensive orbital fractures, who were admitted between March 1999 and February 2007, were reviewed retrospectively. The patients' chart and CT were inspected for review. Twenty three patients were operated on with both a titanium mesh plate (Matrix MIDFACE pre-formed orbital plate, Synthes, USA) and $Medpor^{(R)}$ (Porex, GA, USA). The patients underwent pre-operative CT scans to evaluate the fracture site and measure the area of the fracture. A transconjunctival approach was used, and titanium mesh plates were inserted subperiosteally with screw fixation. $Medpor^{(R)}$ was inserted above the titanium mesh plate. The patients were evaluated post-operatively for enophthalmos, diplopia, sensory disturbances and eyeball movement for a period of at least 6 months. Results: No implant-related complications were encountered during the follow-up period. Enophthalmos occurred in 1 patient, 1 patient had permanent sensory disturbance, and 3 patients complained of ocular pain and fatigue, which recovered without treatment. Although there were no significance differences between groups, the use of 2 implants had fewer complications. Therefore, it can be an alternative method for treating blow out fractures. Conclusion: The use of both a titanium mesh plate and $Medpor^{(R)}$ simultaneously may be a safe and acceptable technique in the reconstruction of extensive blow-out fractures.

• Korean Journal of Optics and Photonics
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• v.8 no.2
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• pp.99-106
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• 1997

In this paper, we demonstrated, through experiment and numerical reconstruction, that the bias and the conjugate image, which are main drawbacks in incoherent holography, can be removed. By using wave plates of the modified triangular interferometer, which was made by adding simple passive devices to the conventional triangular interferometer, we adjusted the relative phase differences of two optical waves traveling in clockwise and counterclockwise. In this way, we obtained four intensity patterns, and then by manipulating the four intensity patterns electronically we obtained the complex hologram without bias and the conjugate image. Comparing numerical reconstruction results of the complex hologram with numerical reconstruction results of the hologram obtained from the conventional triangular interferometer, we demonstrated that bias and the conjugate image can be removed using the modified triangular interferometer.

• Journal of Korean Neurosurgical Society
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• v.41 no.2
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• pp.77-81
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• 2007

Objective : In a variety of thoracolumbar diseases, corpectomy followed by interbody bone graft and anterior instrumentation has allowed direct neural decompression and reconstruction of the weight-bearing column by short segments fusion. In this study, we compared spinal stability of the two different anterior thoracolumbar instruments : Z-plate and Kaneda device representing plate and two-rods type, respectively. Methods : A retrospective review was performed for all the patients with thoracolumbar diseases or traumas treated with anterior corpectomy, autologous iliac bone graft, and fixation with instruments from 1996 to 2000. For the anterior instrumentation, Z-plate or Kaneda device was used for 24 [M:F=5:9, average age=37] and 12 [M:F=9:3, average age=41] patients, respectively. The plain AP and lateral flexion-extension films were taken immediately after surgery and at each follow-up. The sagittal and coronal Cobb's angles at the operation segments were used to observe the change of initial fixation status. The surgical time length and bleeding amount of the two groups were compared. Intra-operative and post-operative instrument associated complications were evaluated. Student t-test was used for statistical analysis and p-value less than 0.05 was considered to be significant. Results : Mean follow-up durations for Z-plate and Kaneda device were 24 and 21 months, respectively. The fusion rate was 91% for Z-plate and 100% for Kaneda device. Two cases of Z-plate group showed instrumentation failure during the follow up period, in which additional surgery was necessary. The mean differences of sagittal Cobb's angles among the AP images immediate after surgery and at follow-up were 7 and 2 degrees for Z-plate and Kaneda device, respectively [p<0.05]. The mean differences of coronal Cobb's angles were 5 and 2 degrees for Z-plate and Kaneda device, respectively [p<0.05]. No Intra-operative complication has occurred in both groups. There was no difference in surgery time and bleeding amount between two groups. Conclusion : We think that Kaneda device [rod type] is stronger than Z-plate [plate type] to keep the spinal stability after anterior thoracolumbar surgery.

• Journal of Advanced Navigation Technology
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• v.2 no.2
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• pp.126-131
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• 1998

In optical scanning holography, 3-D holographic information of an object is generated by 2-D active optical scanning. The optical scanning beam can be a time-dependent Gaussian apodized Fresnel zone plate. In this technique, the holographic information manifests itself as an electrical signal which can be sent to an electron-beam-addressed spatial light modulator for coherent image reconstruction. This technique can be applied to 3-D optical remote sensing especially for identifying flying objects. In this paper, we first briefly review optical scanning holography and analyze the resolution achievable with the system. We then present mathematical expression of real and virtual image which are responsible for holographic image reconstruction by using Gaussian beam profile.

• Smart Structures and Systems
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• v.20 no.6
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• pp.759-767
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• 2017

Wear and aging associated damage is a severe problem for safety and maintenance of engineering structures. To acquire structural operational state and provide warning about different types of damage, research on damage identification has gained increasing popularity in recent years. Among various damage identification methods, the Lamb wave-based methods have shown promising suitability and potential for damage identification of plate-type structures. In this paper, a comprehensive study was presented to elaborate four remarkable aspects regarding the Lamb wave-based damage identification method for plate-type structures, including wave velocity, signal denoising, image reconstruction, and sensor layout. Conclusions and path forward were summarized and classified serving as a starting point for research and application in this area.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.28 no.1
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• pp.47-58
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• 1998

The purpose of this study was to investigate an influence of the change of central panoramic curves on the image reconstruction in the dental implant CT. The author designed three experimental groups according to the location of central panoramic curve. In group A, central panoramic curve was determined as the curve connecting the center of roots from the first premolar to the first molar. In group B, central panoramic curve was determined as the line connecting the lingual cortical plate at the level of the mesial aspect of the first premolar with the buccal cortical plate at the level of the mesial aspect of the first molar. In Group C, central panoramic curve was determined as the line connecting the buccal cortical plate at the level of the mesial aspect of the first premolar with the lingual cortical plate at the level of the mesial aspect of the first molar. Twenty four reformatted CT images was acquired from four mandibles embedded in the resin block and twenty four contact radiographs of dog specimens were acquired. Each Image was processed under Adobe Photoshop program analysed by MSPA(mandible/maxilla shape pattern analysis) variables such as MXVD, MXHD, UHD, MHD, and LHD. The obtained results were as follows ; 1. The mean of MXVD variable was 19.9, 20.2, and 20.0 in group A, B, and C, respectively, which were smaller than actual value 20.5. But, there was no significant difference among 3 groups (p>0.05). 2. The mean of MXHD, UHD, MHD, and LHD variables in group A, B, and C was 11.9, 12.2, and 12.3; 9.3, 9.5, and 9.6; 10.0, 10.3, and 10.3; 9.2, 9.3, and 9.4 respectively which were equal to or greater than the actual value 11.8, 9.3, 10.0, and 9.2. But, there was no significant difference among 3 groups (p>0.05). 3. The number of noneffective observations with difference over or under 1 mm with comparison to the actual value was 24(20％), 58(48.3％), and 52(43.3％), respectively, in group A, B, and C. 4. In group A, the number of observations over 1 mm and under 1 mm was 9 and 15, respectively, but in group Band C, the number of observations over 1 mm was more than under 1 mm.

• Journal of the Society of Naval Architects of Korea
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• v.53 no.1
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• pp.69-75
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• 2016

Fabrication of the hull plate demands a lot of man-hour and a high degree of technology. In recent years, commercial shipping orders have been fallen because of intensifying competition with low price of order and labor cost. In order to solve this problem, a countermeasure such as a cost reduction is required. In this study, we are dealing with the method of supplying the forming information of the hull to the production site. We reviewed studies of hull forming that have been proposed so far to develop a method for providing hull forming information. On the basis of given production plans from the production site of shipyard, we discuss how to convert shell plate to production plan. Then, we will discuss the efficiency of the distribution method through the network about the method of hull forming. Thus, we have modified the distribution method which was proposed before. Finally, we will introduce the enhanced method for providing fabrication information of the hull plate to the small and medium-sized shipyards.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.40 no.3
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• pp.135-139
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• 2014

This following case report describes the open reduction, internal fixation and the reconstruction of an extensive comminuted mandibular fracture with bilateral condylar fractures in a 19-year-old male patient with an intellectual disability and autistic disorder. He suffered fall trauma, resulting in shattered bony fragments of the alveolus and mandibular body between both mandibular rami, the fracture of both condyles and the avulsion or dislocation of every posterior tooth of the mandible. The patient underwent open reduction and internal fixation between both mandibular rami using a reconstruction plate, open reduction and internal fixation of the shattered fragments using miniplates and screws, and the closed reduction of the bilateral condylar fractures.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.5
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• pp.229-236
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• 2023

Since 3D printed medical implant parts usually have surface defects, it is necessary to inspect the surface after manufacturing. In order to automate the surface inspection, it is effective to 3D scan the implant and reconstruct it as a scan model such as a point cloud. When constructing a scan model, the characteristics of the shape and material of the implant must be considered because it has characteristics different from those of general 3D printed parts. In this paper, we present a method to reconstruct the 3D scan model of a 3D printed metal bone-plate that is one kind of medical implant parts. Multiple partial scan data are produced by multi-view 3D scan, and then, we reconstruct a scan model by alignment and merging of partial data. We also present the process of the scan model reconstruction through experiments.