• 대한치과교정학회지
• /
• 제9권1호
• /
• pp.111-115
• /
• 1979

The author intended to observe the developmental pattern in mandibular bone and condyle following the loss of function of molar with 5 week-old rats b y means of removing the crown of molar. The bjects were observed everyweek during six weeks. The results were as follows ; 1. Bone apposition was observed at the root apex and interadicular area of alveolar bone. 2. Development of bone substance in mandible tended to increase in the narrow bone trabeculae and fibrous bone substance. 3. Development of condylar head showed little difference from that of control group and development of calcified zone appeared more or less poorly.

• 대한예방한의학회지
• /
• 제7권1호
• /
• pp.55-66
• /
• 2003

Osteoporosis is characterized by bone loss and mobidity with osteoporotic fracture. This study was performed to evaluate the effect of on the bone mass and its related factors in estrogen-deficient animal model. The model rats of osteoporsis showed a significant decrease in bone density, bone ash density, calcium content of femur bone. At the 14th day after ovariectomy-surgery, rats were administered with DBE, extract of Dioscorea batatas, per orally, and continued for 10 weeks. And osteoporosis related parameters were determined to investigate the effect of DBE. Osteoporetic rats showed lower serum estrogen level, higher body weight than normal rats, and showed atrophy of uterine horns. DBE showed inhibitory effect on bone loss in osteoporetic condition, and reduced the increase of ALP activity and osteocalcin level in serum, and reduced the increase of OH-proline level in urine. But, DBE had no effect on cell proliferation and ALP activity in rat calvarial cell culture.

• Applied Microscopy
• /
• 제32권3호
• /
• pp.285-290
• /
• 2002

홍화씨는 한방 및 민간에서 뼈에 우수한 작용이 있는 것으로 알려져 오랫동안 복용되어 왔다. 최근 고령화 사회를 맞이하면서 골다공증 문제는 사회적인 문제로 인식되고 있으며 저자들이 기존에 실시한 실험결과에 의하면 홍화씨 분말은 난소를 적출한 rat에서 골다공증의 예방효과를 나타내었다. 그러나 아직까지 골다공증이 유발된 rat에서 홍화씨 분말이 미치는 효과에 관한 실험적 자료가 제시된 것은 별로 없다. 이에 저자들은 홍화씨 분말이 골다공증의 치료에 미치는 효과를 알아보기 위하여 본 실험을 실시하였다. 실험동물은 체중 230 g의 12주령의 Sprague-Dawley Rats를 사용하였으며, 양쪽 난소제거 후 7주부터 홍화씨 분말을 매일 0.3 g씩 복용시키면서 1, 3 및 5주 후에 경골을 채취하여 관찰하였다. 채취된 조직은 통상적인 주사전자현미경 시료제작법으로 고겅과정을 거친 후 10% 질산으로 12시간 탈회하여 뼈의 단면을 노출시키고 탈수, 건조 및 금도금 과정을 거쳐 주사전자현미경(Hitachi, S-450)으로 관찰하여 촬영하였다. 관찰결과 대조군은 골수강에서 피질골까지의 두께의 감소와 골수강의 확장이 심하였으나, 홍화씨 분말을 투여한 실험군에서는 1주에서 5주까지 거의 같은 소견을 나타내었다. 이상의 결과를 종합해보면 홍화씨 분말은 여성호르몬 결핍으로 인한 골다공증의 치료에 효과가 있는 것으로 사료된다.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제38권
• /
• pp.29.1-29.9
• /
• 2016

Background: The objective of this study was to evaluate xenograft degradation velocity when treated with 4-hexylresorcinol (4HR). Methods: The scapula of a cow was purchased from a local grocery, and discs (diameter 8 mm, thickness 1 mm) were prepared by trephine bur. Discs treated with 4HR were used as the experimental group. Untreated discs were used as the control. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), antibacterial test, endotoxin test, and scanning electron microscopy (SEM) were performed on the discs. In vivo degradation was evaluated by the rat calvarial defect model. Results: The XRD and FT-IR results demonstrated successful incorporation of 4HR into the bovine bone. The experimental disc showed antibacterial properties. The endotoxin test yielded results below the level of endotoxin contamination. In the SEM exam, the surface of the experimental group showed needle-shaped crystal and spreading of RAW264.7 cells. In the animal experiments, the amount of residual graft was significantly smaller in the experimental group compared to the control group (P = 0.003). Conclusions: In this study, 4HR was successfully incorporated into bovine bone, and 4HR-incorporated bovine bone had antibacterial properties. In vivo experiments demonstrated that 4HR-incorporated bovine bone showed more rapid degradation than untreated bovine bone.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제30권5호
• /
• pp.368-379
• /
• 2004

Distraction osteogenesis is a biologic process of new bone formation between the surfaces of bone segments that are gradually separated by incremental traction. Distraction osteogenesis is clinically applied as a new treatment modality of mandibular hypoplasia or bony defect area in maxillofacial area by many studies of distraction devices and method. But disadvantage of distraction osteogenesis shows unfavorably long consolidation period and relapse tendency. Therefore. this experiment was designed to investigate the effectiveness of combined application of distraction and compression force for improving of bone quality and shortening of treatment period during distraction osteogenesis. Twenty-one Sprague-Dawley rats with $300{\sim}350gm$ were used. These were divided into two group as distraction group and combination group was applied with compression force in the consolidation period. The rat were sacrificed for gross finding, radiographic and histologic findings. at 2, 4 weeks after distraction. The result were follow : 1. On radiographic finding, all experimental groups appeared more radiopacity than control groups both at 2, 4 weeks after distraction. 2. On histologic finding, trabeculae of bone and mature lamellar bone were showed increasingly in experimental group. Ossification occured rapidly. From this study, we may suggest that compression force application in consolidation period during distraction osteogenesis can be useful method improve bone quality and to shorten the treatment period. But more experimental and clinical studis are necessitated on effects of compression force application during distraction osteogenesis.

• Imaging Science in Dentistry
• /
• 제34권2호
• /
• pp.81-89
• /
• 2004

Purpose: To investigate the histopathological changes in the temporomandibular joint in streptozotocin-induced diabetic rat following irradiation. Materials and Methods : Sprague-Dawley rats weighing about 250 gm were divided into three groups: control, diabetic, and diabetic-irradiated groups. Diabetes mellitus was induced in the rats by injecting streptozotocin. Rats in the control group were injected with citrate buffer only. After 5 days, the head and neck region of the rats in diabetic-irradiated group were irradiated with single absorbed dose of 10 Gy. The rats were killed at 1, 3, 7, 14, 21, and 28 days after irradiation. The specimen including the temporomandibular joint were sectioned and observed using a histopathological method. Results : In the diabetic group, severe bone resorption in the mandibular condyle was observed throughout the period of experiment. Necrosis of bone marrow and trabeculae was observed at 28 days after diabetic state. Atrophy and fibrosis in the retrodisca] tissue was gradually progressed during the time of the experiment. In the diabetic-irradiated group, severe bone resorption in the mandibular condyle was observed during the early experimental phases, but regeneration of bone marrow was initiated at ]4 days after diabetic state and irradiation. A]so, calcification of abnormal trabeculae was observed at 28 days after diabetic state and irradiation. The retrodisca] tissue was degenerated in the early experimental phases, but it had been gradually regenerated during the experimental time. Conclusion: This experiment suggests that bone resorption and degeneration in the mandibular condyle are caused by the induction of diabetes, and abnormal bone formation is induced after irradiation in diabetic state.

• The Journal of Advanced Prosthodontics
• /
• 제5권4호
• /
• pp.374-381
• /
• 2013

PURPOSE. The purpose of this study was to evaluate the effect of alendronates on bone remodeling around titanium implant in the maxilla of rats. MATERIALS AND METHODS. The maxillary first molars were extracted and customized-titanium implants were placed immediately in thirty male Sprague-Dawley rats. The rats were divided into experimental (bisphosphonate) group and control group. At 4 weeks after implantation, the rats in the bisphosphonate group were subcutaneously injected with alendronate three times a week for 6 weeks where as the rats in control group were injected with saline. The rats were sacrificed at 1, 2, 3, 4, or 6 weeks after starting of injection and maxillary bones were collected subsequently. Alveolar bone remodeling around the implants were evaluated by radiographic and histologic analysis. Microarray analysis and immunohistomorphologic analysis were also performed on one rat, sacrificed at 6 weeks after starting of injection, from each group. Statistical analysis was performed using repeated measures analysis of variance and independent t test at a significance level of 5%. RESULTS. There was no statistically significant difference in the bone area (%) around implant between the bisphosphonate group and the control group. However, the amount of empty lacuna was significantly increased in the bisphosphonate group, especially in the rats sacrificed at 4 weeks after starting of injection compared to that of the corresponding control group. The bisphosphonate group showed the same level of TRAP positive cell count, osteocalcin and angiopoietin 1 as the control group. CONCLUSION. Alendronate may not decrease the amount of osteoclast. However, the significantly increased amount of empty lacuna in the bisphosphonate group may explain the suppression of bone remodeling in the bisphosphonate group.

• Journal of Periodontal and Implant Science
• /
• 제25권2호
• /
• pp.210-221
• /
• 1995

The purpose of this study was performed to investigate the mineralization and differentiation of osteobalsts for bone regeneration in vitro and the effect of rate of the composition in periodontal cells on mineralization. For this study, healthy gingival tissues were surgically obtained from the patients during 1st premolar extraction for the purposes of orthodontic treament. Gingival tissue was washed several time with Phosphate buffered saline contained high concentration of antibiotics and antifungal agent, and cultured in Dulbecco's Modified Eagle's Medium(DMEM, Gibco, U.S.A.). Every cell were cultured in state at $37^{\circ}C$, 100% of humidity, 5% of $CO_2$ incubator. Bone marrow stromal cells were isolated from 5-clay-old rat femur with using medium irrigation mathod by syringe. Cell suspension medium were centrifuged at 1500 rpm for 5 min and then cultured in the petri dish. Two kinds of cell were freezed and stocked in the liquid nitrogen tank until experiment. Cell were incubated into the 24 multi-well plate with $5{\times}10^4$cell/well of medium at $37^{\circ}C$, 100% of humidity 5% $CO_2$ incubator for 24 hours. After discarded of the supernatent of medium, O.5ml of medium were reapplied and incubated. And counted the number of cell using the hemocytometer and inverted light microscope. We have measured the number of mineralized nodule with using Alizarin red S. staining in microscope. Furthermore every cell were observed the morphological change between every rate of co-culture of the two kinds of cell. The results were as follows; The rate of proliferation of co-culture cell revealed high rate tendency compared the bone marrow stromal cell only and low growth rate to compared with gingival fibroblast only. The tendency of formation of the mineralized nodule were observed dose-depend pattern of bone marrow stromal cell. It is concluded that the gingival fibroblast may inhibit the formation of mineralized nodule in the culture of the bone marrow stromal cell.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제35권3호
• /
• pp.137-145
• /
• 2009

As an efficient controlled release system for rhBMP-2, a functional nanoparticle-hydrogel complex, incorporated with matrix metalloproteinase(MMP) sensitive peptide cross-linker, was developed and used as a bone transplant. In vivo bone formation was evaluated by soft x-ray, histology, alkaline phosphatase(ALP) activity and mineral contents analysis, based on the rat calvarial critical size defect(8mm in diameter) model. Significantly, effective bone regeneration was achieved with the rhBMP-2 loaded MMP sensitive hyaluronic acid(HA) based hydrogel-Nanoparticles(NP) complex, as compared to only MMP HA, the MMP HA-NP without rhBMP-2, or even with the rhBMP-2. These improvements included the formation pattern of bone and functional marrow, the degree of calcium quantification, and the ALP activity. These results indicate that the MMP sensitive HA with nano-particle complex can be a promising candidate for a new bone defect replacement matrix, and an enhanced rhBMP-2 scaffold.

• Journal of Periodontal and Implant Science
• /
• 제30권1호
• /
• pp.91-104
• /
• 2000

Many synthetic bone materials have been studied for their potential of regenerative effects in periodontal tissue. Safflower seeds have been traditionally used as a drug for the treatment of fracture and blood stasis in oriental medicines. The purpose of this study was to assess and compare the osseous responses in rat calvarial defects between bone substitutes such as calcium carbonate and bovine-derived hydroxyapatite and feeding of safflower seeds. The calvarial defects were made with 8 mm trephine bur in 24 Sprague-Dawley rats. Two graft materials were implanted in each experimental groups, whereas the control and safflower seed feeding groups were sutured without any other treatment. And then the rats of safflower seed feeding group were supplied with 3 g/day of safflower seeds. Each group was sacrificed at 4 weeks and 8 weeks. To study a histopathology related to bone healing and regeneration, Goldner's Masson Trichrome stain was done at each weeks. The tissue response was evaluated under light microscope. There were more osteoblastic activity, new bone formation, dense bony connective tissues in bovine-derived hydroxyapatite group compared to other groups at 8 weeks. The osseous defect area of safflower seed feeding group was filled with prominent fibrous tissues, where less inflammatory infiltration and new capillary proliferation. In the early phase of bone healing, safflower seed feeding reduces the inflammatory response and promotes the proliferation of connective tissue. These results suggest that natural bovine-derived HA and safflower seed feeding could enhance the regenerative potential in periodontal defects.