• Journal of Chest Surgery
• /
• v.24 no.4
• /
• pp.390-396
• /
• 1991

From July 1984 to September 1990, 316 patients of congenital heart diseases were operated and 15 patients died. Hospital mortality was 4.75%. Five patients of 73 PDA had residual shunt after operation: 4 were ligated under support of Dacron patch, 1 was closed through the pulmonary arteriotomy under CPB. 3 patients were reoperated. No patient had residual shunt or reopening among the patients of simple ligation or division and suture. During the ligation of PDA, Dacron patch for protection from tearing may disturb the complete interruption of shunt. If the tissue around the ductus arteriosus looks weak or fragile, division and suture may be more reliable other than ligation with supporting patch. If the septal leaflet of tricuspid valve is adherent around the VSD, remained opening of VSD may be closed with simple suture directly. In these cases, the incidence of postoperative residual shunt is as high as the incidence of more large VSD closed with patch [10.9%: 9.6%]. During the direct closure of remained opening of VSD, another leaking route should be looked for carefully beneath the septal leaflet of tricuspid valve.

• Structural Engineering and Mechanics
• /
• v.55 no.1
• /
• pp.65-78
• /
• 2015

In recent years, implants have gained growing importance in all areas of medicine. The success of the treatment depends on many factors affecting the bone-implant, implant-abutment and abutment-prosthesis interfaces. In this paper, static and dynamic behaviors of the dental prosthesis are investigated. Three-dimensional finite element models of dental prosthesis were constructed. Dynamic loads in 5 sec applied on occlusal surface. Therefore, FEA was selected for use in this study to examine the effect of the static and dynamic loads on the stress distribution for an implant-supported fixed partial denture and supporting bone tissue.

• The korean journal of orthodontics
• /
• v.41 no.5
• /
• pp.371-378
• /
• 2011

Transposition is defined as a dental anomaly manifested by a positional interchange of 2 adjacent teeth within the same quadrant of the dental arch. Maxillary canine-first premolar [Mx4-3] transposition is the most frequent tooth transposition reported in the literature. In this case report, an orthodontic correction of a transposition of the maxillary left canine and first premolar with the help of palatally located mini-implant anchorage is described. Esthetic and occlusal evaluations suggested alignment of the transposed teeth to their correct anatomic positions in the dental arch. The clinical result at the end of the treatment was satisfactory. Alignment was obtained, and intercuspation was adequate. Nevertheless, the maxillary canine showed facial recession, probably because it was initially positioned buccally. Supporting tissue was examined after treatment and no alveolar bone damage was observed.

• Korean Journal of Computational Design and Engineering
• /
• v.11 no.5
• /
• pp.351-358
• /
• 2006

Recently, the development of new structural model in fixed partial denture system is required to be started from the conceptual design with low cost, high performance and quality. In this point, a FEM based design of partial denture is used to investigate stress distribution on the durable shape. In this paper, the structural performances of partial dentures were analyzed under three biting forces. The periodontal embedding model is introduced on behalf of the detailed supporting tissue, which is composed of dentin, cortical bone, cancellous bone and periodontal ligament. Using topology optimization, the optimal reinforcement layout of connector was obtained and the detail shape in the fixed partial denture was designed.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.20 no.10
• /
• pp.38-43
• /
• 2021

Photocurable hydrogels are widely used as 3D printing materials in tissue engineering (e.g., scaffold fabrication) as well as optical fibers (or optical sensors) materials. Photocurable hydrogels can control optical and mechanical properties such as chemical or fabrication conditions. In previous research, we introduced a new 3D printing method to fabricate a freestanding overhanging hydrogel structure without supporting structure. This study was measured and analyzed the difference of the mechanical properties of the photocurable hydrogel according to the light intensity using a micro tensile tester. In practically, it was difficult to perform a direct tensile test on a micro (less than 1 mm) size fiber. In this study, the tensile test of the hydrogel fibers could be measured simply and repeatedly using a paper carrier.

• Proceedings of the PSK Conference
• /
• 2003.10b
• /
• pp.235.1-235.1
• /
• 2003

With an aim of obtaining high efficacy in cartilage regeneration, implantable polymeric rods were fabricated. These rod-type matrices were anticipated to perform structural tissue supporting activity and enhance extracellular matrix (ECM) formation by releasing specific agent, DHEA-S, in controlled manner. It is expected that application for the drilling operation on the articular cartilage of OA patients as the implants may promote regeneration of their cartilage. Osteoarthritis (OA) is a degenerative joint disease characterized by progressive loss of articular cartilage, subchondral bone remodeling, spur formation, and synovial inflammation. (omitted)

• Applied Microscopy
• /
• v.32 no.3
• /
• pp.213-222
• /
• 2002

Histology and ultrastructure of the mantle epidermis in the ark shell, Scapharca broughtonii are described using light and electron microscopy. The mantle of the ark shell is composed of outer epidermis, connective tissue and inner epidermis. Both epidermis are simple and consists of supporting cells, ciliated cells and secretory cells. Connective tissue is composed of mainly collagen and muscle fibers. The supporting cells in the inner epidermis are usually columnar and covered with microvilli. The ciliated cell have cilia and microvilli on the free surface, and numerous tubular mitochondria are observed in the apical cytoplasm. Secretory cells are mainly observed in the outer epidermis, and it can be divided into four types of A, B, C and D with morphological features of the secretory granules. Type A cells of mucous cell are found in the marginal and central mantle. And these cells contains numerous secretory granules of non-bounded and low electron density. Type B cells contains numerous rough endoplasmic reticula, well-developed Golgi complex and secretory granules of membrane-bounded and high electron density. Secretory granules of type C cells are divided into fibrous core layer and homogeneous peripheral layer. Type D cells are found in the outer epidermis of the central and umbonal mantle. And secretory granules of these cells are divided into homogeneous core layer and granular peripheral layer. This results suggest that the outer and inner epidermis of the mantle are related with shell formation and cleaning of the mantle cavity, respectively.

• The Journal of Korean Academy of Prosthodontics
• /
• v.22 no.1
• /
• pp.109-122
• /
• 1984

The purpose of this study was to analyze the magnitude and mode of the stress distribution induced in the supporting alveolar bone and periodontal ligament and, to determine the displacement of abutment teeth and telescope denture base by applying chewing force to the telescope denture quantitatively and qualitatively. Two finite element models of telescope denture that were restored the missing mandibular second molar with two abutment teeth which were constructed. In two different models, parallel and tapering type telescope crowns were constructed. These finite element models of two cases used for these experiment were a two-dimensional mesiodistal section of the mandibular second bicuspid and first molar. Chewing force of 25Kg that was devided in the ratio of 45/155 (29%) in bicuspid and 55/155 (35.5%) in molars was applied to telescope denture and abutment teeth respectively. The displacement of the telescope denture base and abutment teeth and the stress distribution in the periodontal ligament and alveolar bone were analized to investigate the influence of chewing force acting on the telescope denture and abutment teeth. The results were as follows: 1. Abutment teeth displaced mesially and the magnitude of displacement of abutment teeth in vertical direction were more than that of horizontal direction in two cases. The displacement of abutment teeth on the telescope denture treated with tapering type telescope crown were less than that of the parallel type crown. 2. The displacement of the telescope denture base that were treated with parallel type telescope crown were less than that of treated with tapering type telescope crown. 3. The stress induced in the alveolar bone and periodontal ligament on abutment teeth that treated with parallel type telescope crown were more than that of treated with tapering type telescope crown and more stress induced in the alveolar bone than in the periodontal ligament. 4. In the telescope denture, the magnitude of displacement of abutment teeth and stress induced in the periodontal ligament and alveolar bone were within physiologic limit.

• The Journal of Korean Academy of Prosthodontics
• /
• v.31 no.3
• /
• pp.351-384
• /
• 1993

Complete denture occlusion must be developed to function efficiently and with the least amount of trauma to the supporting tissues. For the preservation of supporting tissues, it is imperative to reduce to a minimum the functional stress induced by dentures. The magnitude of the horizontal component of functional stress contributed by various occlusal teeth forms has not been studied. This study was aimed to investigate the influence of different occlusal teeth forms on the mode of distribution of the stresses in the mandibular tissue, and the displacement of lower dentures during the variant functional movement of mandible for this study three dimensional finite element analysis was used. FEM models were created using commercial software Super Sap for IBM 32 bit computer. The model was composed of 3380 brick elements and 4346 nodes. The results were as follows. 1. The magnitude of stress was similar between two models in centric occlusion, in the case of anatomic model, the stress was concentrated on the buccal side of alveolar ridge beneath the bicuspids. 2. During the protrusive movement, the increasing of stress from the posterior to anterior part of mandible was seen in the case of anatomic model. 3. During the lateral movement, the stress of anatomic model was greater than that of nonanatomic model. 4. The stress of anatomic model was concentrated on the anterior region of residual ridge during the lateral movement. 5. In the case of anatomic model the anterior part of denture was displaced severely at the centric and lateral position, but the denture of nonanatomic model was displaced minutely at the protrusive and lateral position.

• Science of Emotion and Sensibility
• /
• v.7 no.2
• /
• pp.179-186
• /
• 2004

Acute spinal cord injury can produce neurologic injury with many physical, psychological and social ramifications. It has been shown that two separate components combine to produce neurologic damage in acute spinal cord injury : the primary and secondary injuries. The primary mediators of spinal cord injury include the actual mechanical tissue disruption which is a passive process that occurs immediately following the trauma. A secondary injury cascade follows which appears mediated by cellular and molecular processes working through complex mechanisms. Both the primary and secondary injury cascades produce cell death both in neuronal and supporting cell tissues. Recovery from central nervous system(CNS) disorders is hindered by the limited ability of the vertebrate CNS to regenerate injured cells, replace damaged myelin sheath, and re-establish functional neuronal connections. Of many CNS disorders including multiple sclerosis, stroke, and other trauma, spinal cord injury is one of the important diseases because of the direct association with the functional loss of the body. Previous studies suggest that substantial recovery of function might be achieved through regeneration of lost neuronal cells and remyelination of intact axon in spinal cord injury which is occurred frequently. As a therapeutic approach in spinal cord injury, recently, cell transplantation provides a potential solution for the treatment of spinal cord injury. This review describes the characteristics of spinal cord injury and presents some evidence supporting functional recovery after cell transplantation following spinal cord injury.