• 대한치과보철학회지
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• 제29권2호
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• pp.35-48
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• 1991

Installation periods of implants in Mx. and Mn., is related to pattern of bone formation. The purpose of this study was to observe histologic response in osseointegration at root formed implant-tissue interface at Mx. and Mn., the other is comparison of osseointegration level between Mx. and Mn. at 8 weeks. In this study, unilateral upper & lower molars were extracted in dog. After allowing to heal for 4 months, two kinds of osseointegrated implants Swedevents, Corevents-were inserted in dog. The specimens were treated by conventional method. The interface zones between bone and implant were investiigated using X-rays, light microscope. The following results were obtained from this study. 1. Around titanium implants that were installed in Ma and Mn., Radio lucencies don't exist 2. There are not inflammation and mobility of titanium implants that were installed in Mx. and Mn. Most of implant surface are covered by bony tissued partly by bone-marrow tissues. 3. Titanium implants installed in Mx, in contrast to same implants in Mn., shows more coverage by bone marrow tissue and lack of apposition lamellar bone, which lead to the assumption that bone formation in Mn. is faster than in Mx.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.1078-1080
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• 2002

The pressure variation of interstitial fluid is one of the most important factors in bone physiology. In order to understand the role of interstitial fluid and the biomechanical interactions between fluid and solid constituents within bone, poroelastic theory was applied. The purpose of this study is to describe the behavior of calf vertebral trabecular bone composed of the porous solid trabeculae and the viscous bone marrow by using a commercial finite element analysis program based on the poroelasticity. In this study, the model was numerically tested for 5 different strain rates, i. e., 0.001, 0.01, 0.1, 1.0, and 10 per second. The material properties of the calf vertebral trabecular bone were utilized from the previous experimental study. Two asymptotic poroelastic response, the drained and undrained deformation, were predicted. From the predicted results for the simulated five strain rate, it was found that the pore pressure generation has a linearly increasing behavior when the strain rate is the highest at 10 per second, other wise it showed a nonlinear the strain rate Increased. Based on the results of the present study, it was suggested that the calf vertebral trabecular bone could be modeled as a porous material and its strain rate dependent material behavior could be predicted.

• Imaging Science in Dentistry
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• 제49권3호
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• pp.235-240
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• 2019

Osteosarcoma is the most common primary bone tumor after plasma cell neoplasms. Osteosarcoma has diverse histological features and is characterized by the presence of malignant spindle cells and pluripotent neoplastic mesenchymal cells that produce immature bone, cartilage, and fibrous tissue. Osteosarcoma most frequently develops in the extremities of long bones, but can occur in the jaw in rare cases. The clinical and biological behavior of osteosarcoma of the jaw slightly differs from that of long-bone osteosarcoma. The incidence of jaw osteosarcoma is greater in the third to fourth decades of life, whereas long-bone osteosarcoma mostly occurs in the second decade of life. Osteosarcoma of the jaw has a lower tendency to metastasize and a better prognosis than long-bone osteosarcoma. Radiographically, osteosarcoma can present as a poorly-defined lytic, sclerotic, or mixed-density lesion with periosteal bone reaction response. Multi-detector computed tomography is useful for identifying the extent of bone destruction, as well as soft tissue involvement of the lesion. The current case report presents a fibroblastic osteosarcoma involving the left hemimandible with very unusual radiographic features.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제13권3호
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• pp.265-277
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• 1991

In this study, the healing changes of the implanted bone and its surrounding tissues were examined on the histopathologic basis following implantation of the freeze - dried and radiation - sterilized allogeneic bone in Rectus abdominicus of the rat. This study was performed to see the tissue recations after implantation of the freeze - dried and radiation - sterilized allogeneic bone and whether osteogenesis or osteo - induction or osteo - conduction is happened. And the results were as follows : 1. The shape of the implanted allogeneic bone of the 1, 2 - week group specimen was similar to that of normal bone in light - microscopic finding and the atrophy of cellular organells was found in trans - mission electron - microscopic finding. 2. The implanted allogeneic bone was surrounded with the dense fibroconnective tissues, and infiltration of the chronic inflammatory cells gradually became increased. 3. Hyaline degeneration was observed in the surrounding tissue at the 3, 4, 6 - week group specimen. 4. Light - microscopically the resorption of implanted bone became prominent after 4 - week group and the necrosis of allogeneic bone implant became severe with loss of cell components in lacuna. 5. Electron - microscopically, the osteoclast - like cells ere fond after, 2 - week group. It is summarized that the osteo - conduction potential of the bone is remained just after implanting the freeze - dried and radiation - sterilized allogeneic bone on Rectus abdominicus of the rat, but gradually it disappeared with the gradual increse of chronic inflammatory reaction and osteoclastic activity. So it is suggested that the antigenicity of the freeze - dried and radiation - sterilized bone is remained and it has little osteo - conductive activity when it is implanted in the muscle.

• Journal of Periodontal and Implant Science
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• 제30권3호
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• pp.553-569
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• 2000

Many natural medicines have been studied for their capacity and effects of antibacterial, anti-inflammatory and regenerative potential in periodontal tissues. Safflower seed has been traditionally used as a drug for treatment of bone fracture in oriental medicine. The purpose of the present study was to compare the effects of safflower seed extract and bone substitute on bone formation and regeneration in artificial defects in mongrel dogs. The bony defects were made with round bur at mandible and tibia. Extracts of safflower seed and bovine bone were placed directly at each defect for experimental group, and the defect of control group was sutured without any other treatment. Experimental animals were sacrificed at 8 weeks. And then histopathologic reading and histomorphometric study was done. There was not significant differences between control and experimental groups in osteoclastic activity and infiltration of inflammatory cells. However, new capillary proliferation, fibrosis and new bone formation were prominent in safflower seed extract group. The mandibular defects of safflower seed extract group were healed with dense connective and bony tissues, and endochondral bone formation was observed in tibial defect of safflower seed extract group only. New bone area of safflower seed extract group was more significantly increased than that of control and that of bone substitute group. These results indicate that direct local application of safflower seed extracts on bony defects seems to reduces the early inflammatory response and to promotes the bone regeneration.

• 대한치과교정학회지
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• 제24권4호
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• pp.933-943
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• 1994

The present study was undertaken to determine the effect of tensile force on DNA and protein biosynthesis in bone cells, and to identify the cell type(s) which primarily respond to external physical force among the heterogenous bone cell populations. As a prerequisite for this study, two bone cell populations which retain fibroblastic and osteoblastic feature were isolated from fetal rat calvaria with sequential enzyme digestion scheme. Tensile force was delivered to each bone cell population by two acrylic resin plates connected with a orthodontic expansion screw during culture period. Rate of DNA and protein synthesis in each bone cell population were assessed by the incorporated radioactivity of $[^3H]-thymidine$ into DNA and $[^3H]-proline$ into fraction of collagenase-digestible protein and noncollagenous protein, respectively. DNA synthesis of osteoblast-like calvarial cell populations was increased significantly by the application of tensile force for 24 hours. In contrast, no alteration in DNA synthesis of fibroblast-like populations could be observed in response to applied force. Tensile force induced the change in protein synthesis of bone cell populations with the same pattern. Total protein and collagen synthesis were increased whithin 24 hours in osteoblast-like populations, but not in fibroblast-like populations by tensile force application. These findings indicate that physical force can affect cellullar activity of the particular cell population, not all cell Populations residing in bone and osteoblasts respond more sensitively than fibroblasts. So osteoblasts can modulate the behavior of other bone cells including osteoclasts by producing several local regulating factors of bone metabolism. In this context, preferential responsiveness of osteoblasts to applied tensile force observed in this study suggests that osteoblasts may play an important role in regulation of physical force-induced remodelling process.

• Journal of Hospice and Palliative Care
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• 제17권4호
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• pp.207-215
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• 2014

암의 다발성 뼈 전이는 폐암, 유방암, 전립선암, 신장암 등 다양한 암에서 흔히 관찰된다. 뼈 전이는 뼈에 발생한 이차적인 암으로 통증, 골절, 그리고 체중을 지지하는 뼈의 불안정성을 유발할 수 있어 신체활동과 삶의 질을 저하시킨다. 뼈 전이 치료 시 병리조직소견, 환자의 전신 상태, 침범 부위, 그리고 환자의 신경학적 소견등 다양한 요인을 고려하여 진통제, 수술, 항암화학요법 그리고 방사선 치료 등을 시행하게 된다. 외부 방사선 치료는 전통적으로 국소 뼈 전이로 인한 통증의 치료에 이용되어왔지만 특히 유방암이나 전립선암의 다발성 골형성 뼈 전이의 경우 $^{89}Sr$, $^{186}Re$, $^{188}Re$, $^{153}Sm$ and $^{117m}Sn$ 등의 방사성동위원소를 이용한 치료가 시행되고 있는데, 약제 투여의 간편함, 낮은 부작용, 방사능 피폭위험에서의 안전성, 높은 치료 반응 등 다양한 장점을 가진 치료로 임상에서의 유용성이 점차 증가되고 있다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제28권3호
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• pp.205-215
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• 2002

The purpose of this study was to evaluate the tissue response in various bone grafting materials, especially xenogenous bone materials in vivo, compare of bone formation capacity of various bone grafting materials on rat skull defects and evaluate the effect of Hyaluronic acid on healing of human Demineralized Freezed Dried Bone allogenous graft (DFDBA) materials in rat calvarial defects. 30 Sprague-Dawly rats were divided into 4 groups. $7{\times}7mm$ size bony defect were artificially prepared in the calvaria (both parietal bone) of all 30 rats and follwed group grafting of autogenous bone graft on right side and allogenic DFDBA on left side bone graft (rat DFDB) in 15 control group, but in 15 experimental group, xenograft (human DFDB) on left side, hyaluronic acid treated with xenograft on right side. Sequential sacrifices was performed at 1, 2, 4, 6, 8 weeks of experiment. These specimens were stained with H&E and MT stain, and then histologic analysis under light microscope was carried out. There were inflammatory reaction in all graft material during early stage. Autogenous and Allogenous DFDBA graft group observed inflammatory reaction at 1 week. Xenograft group persistant inflammatory reaction until 4 weeks, but in HA treated xenograft group inflammatory reaction was decreased at 2 weeks. Osteoblastic activity in control group was begun at 2 week, xenograft group was delayed at 6 weeks, however HA treated xenograft group was begun at 4 weeks. At 2 week, mild osteoclastic activity were observed in all xenograft group not in concerned to HA, but there was no difference each group after 4 weeks. There are most activated angiogenesis around graft mateirals in xenograft group at 2 weeks, but in HA treated xenograft group, decreased angiogenesis was observed at same time. Bone formation and bone maturation of xenograft group, there was no difference in HA treatment, was less than control group. Fibrosis around xenograft materials were observed until 6 weeks, there was no difference between xenograft and HA treated groups.

• Imaging Science in Dentistry
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• 제53권1호
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• pp.1-9
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• 2023

Purpose: The aim of this study was to evaluate 3-dimensional cone-beam computed tomography (CBCT) images of alveolar bone changes in patients who underwent minimally invasive periodontal surgery-namely, the pinhole surgical technique (PST). Materials and Methods: Alveolar bone height was measured and compared on CBCT images of 254 teeth from 23 consecutive patients with Miller class I, II, or III recession who had undergone PST. No patient with active periodontal disease was selected for surgery. Two different methods were used to assess the alveolar bone changes postoperatively. In both methods, the distance between the apex of the tooth and the mid-buccal alveolar crestal bone on pre- and post-surgical CBCT studies was measured. Results: An average alveolar bone gain >0.5 mm following PST was identified using CBCT(P=0.05). None of the demographic variables, including sex, age, and time since surgery, had any significant effect on bone gain during follow-up, which ranged from 8 months to 3 years. Conclusion: PST appears to be a promising treatment modality for recession that results in stable clinical outcomes and may lead to some level of resolution on the bone level. More long-term studies must be done to evaluate the impact of this novel technique on bone remodeling and to assess sustained bone levels within a larger study population.

• 대한치과보철학회지
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• 제9권1호
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• pp.53-57
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• 1969

Trauma from occlusion causes apparent changes in the blood vessels of the periodontal ligament. The initial response is primarily mechanical, due to compression, and secondarily characterized by necrotic changes. Recently, many investigators are concerned with vascular changes in relation to the loss of the alveolar bone. Author observed vascular changes of the periodontium in the experimental trauma from occlusion on rats. The results were observed as follows.: 1) There were no remarkable changes in the gingiva. 2) The blood vessels that normally occupied a position closer to the bone surface showed a displace-ment toward the cemental surface due to trauma from occlusion. 3) There were no appreciable changes of the alveolar bone in the initial period of trauma from occlusion, whereas there was excessive resorption of the alveolar bone in the long range.