• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.6
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• pp.557-564
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• 2000

The bone graft materials can be grossly divided into autogenous bone, allogenic bone, xenogenic bone, and alloplastic material. Much care was given to other bone graft materials away from autogenous bone due to its additional operation for harvesting, delayed resorption and limitation of quantity. Demineralized freeze-dried bone(DFDB) and hydroxyapatite are the representatives of bone graft materials. As resorbable hydroxyapatite is developed in these days, the disadvantage of nonresorbability can be overcome. So we planned to study on the strength and the bone formation at the rats calvarial defects of DFDB graft and those of the composite graft with DFDB and resorbable hydroxyapatite. We used the 16 male rats weighting range from 250 to 300 gram bred under the same environment during same period. After we made the 6mm diameter calvarial defect, we filled the DFDB in 8 rats and DFDB and resorbable hydroxyapatite in another 8 rats. We sacrificed them at the postoperative 1 month and 2 months with the periostium observed. As soon as the specimens were delivered, we measured the compressive forces to break the normal calvarial area and the newly formed bone in calvarial defect area using Instron(Model Autograph $S-2000^{(R)}$, Shimadzu, Japan). The rest of the specimens were stained with H&E(Hematoxylin & Eosin) and evaluated with the light microscope. So we got the following results. 1. In every rats, there was no significant difference between the measured forces of normal bone area and those of the bone graft area. 2. In 1 month, the measured forces at DFDB graft group were higher than those of the DFDB and resorbable hydroxyapatite composite graft group(P<0.05). 3. In 2 months, there was no significant differences between the measured forces of DFDB graft group and those of the DFDB and resorbable hydroxyapatite composite graft group. 4. In lightmicroscopic examination, most of the grafted DFDB were transformed into bone in 1 month and a large numbers of hydroxyapatite crystal were observed in DFDB and resorbable hydroxyapatite composite graft group in 1 month. 5. Both group showed no inflammatory reaction in 1 month. And hydroxyapatite crystals had a tight junction without soft tissue invagination when consolidated with newly formed bone. 6. In both groups, newly formed bone showed the partial bone remodeling and the lamellar bone structures and some of reversal lines were observed in 2 months. From the above results, it is suggested that DFDB and resorbable hydroxyapatite composite graft group had a better resistance to compressive force in early stage than DFDB graft group, but there would be no significant difference between two groups after some period. And it is suggested that the early stage of bone formation procedure of DFDB and resorbable hydroxyapatite composite graft group was slight slower than that of DFDB graft group, but there would be no significant difference between two groups after some period.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.2
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• pp.232-247
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• 2005

Purpose. The purposes of this investigation were to discover the possibility of clinical application in the areas of dental implants and bone grafts by investigating the bone formation histologically around specimen which was depending on the intensity of magnetic field of neodymium magnet inside of the specimens. Material and method. 1. Measurement of magnetic intensity - placed the magnet inside of the specimen, and measured the intensity of magnetic field around the 1st thread and 3rd thread of specimen 20 times by using a Gaussmeter(Kanetec Co., Japan). 2. Surgical Procedure - Male rabbit was anesthetised by constant amount of Ketamine (0.25ml/kg) and Rompun (0.25ml/kg). After incising the flat part of tibia, and planted the specimens of titanium implant, control group was stitched without magnet, while experimental groups were placed a magnedisc 500(Aichi Steel Co., Japan) or magnedisc 800(Aichi Steel Co., Japan) into it, fixed by pattern resin and stitched. 3. Management after the surgery - In order to prevent it from the infection of bacteria and for antiinflammation, Gentamycin and Ketopro were injected during 1 week from operation day, and dressed with potadine. 4. Preparation of histomorphometric analysis - At 2, 4 and 8 weeks after the surgery, the animals were sacrificed by excessed Ketamine, and then, specimens were obtained including the operated part and some parts of tibia, and fixed it to 10% of PBS buffer solution. After embedding specimens in Technovit 1200 and B.P solution, made a H-E stain. Samples width was 75$\mu$m . In histological findings through the optical microscope and using Kappa image base program(Olympus Co. Japan), the bone contact ratio and bone area ratio of each parts of specimens were measured and analyzed. 5. Statistical analysis - Statistical analysis was accomplished with Mann Whitney U-test. Results and conclusion. 1. In histomorphometric findings, increased new bone formation was shown in both control & experimental groups through the experiment performed for 2, 4 & 8 weeks. After 4 weeks, more osteoblasts and osteoclasts with significant bone remodeling were shown in experimental groups. 2. In histomorphometric analysis, the bone contact ratios were 38.5% for experimental group 1, 29.5% for experimental group 2 and 11.9% for control group. Experimental groups were higher than control group(p<0.05) (Fig. 6, Table IV). The bone area ratios were 60.9% for experimental group 2, 46.4% for experimental group 1 and 36.0% for control group. There was no significantly statistical difference between experimental groups and control group(p<0.05) (Fig. 8, Table VII) 3. In comparision of the bone contact ratios at each measurement sites according to magnetic intensity, experimental group 2(5.6mT) was higher than control group at the 1st thread (p<0.05) and experimental group 1 (1.8mT) was higher than control group at the 3rd thread(p<0.05) (Fig. 7, Table V, VI). 4. In comparision of the bone area ratios at each measurement sites according to magnetic intensity, experimental group 2(5.6mT) was higher than control group and experimental group 1 (4.0mT) at the 1st thread(p<0.1) and experimental group 2(4.4mT) was higher than experimental group 1 (1.8mT) at the 3rd thread(p<0.1) (Fig. 9, Table IX, X). Experiment group 2 was largest, followed by experiment group l and control group at the 3rd thread of implant. There was a significant difference at the 1st thread of control group & experiment group 2, and at 1st thread & 3rd thread of experiment group 1 & 2, and not at control group experiment group 1.(p<0.1)

• Archives of Plastic Surgery
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• v.38 no.1
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• pp.77-80
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• 2011

Purpose: We report a patient with DiGeorge syndrome who was later diagnosed as mild metopic synostosis and received anterior 2/3 calvarial remodeling. Methods: A 16-month-old boy, who underwent palatoplasty for cleft palate at Chungnam National University Hospital when he was 12 months old of age, visited St. Mary's Hospital for known DiGeorge syndrome with craniosynostosis. He had growth retardation and was also diagnosed with hydronephrosis and thymic agenesis. His chromosomal study showed microdeletion of 22q11.2. On physical examination, there were parieto-occipital protrusion and bifrontotemporal narrowing. The facial bone computed tomography showed premature closure of metopic suture, orbital harlequin sign and decreased anterior cranial volume. The interorbital distance was decreased (17 mm) and the cephalic index was 93%. Results: After the correction of metopic synostosis by anterior 2/3 calvarial remodeling, the anterior cranial volume expanded with increased interorbital distance and decreased cephalic index. Fever and pancytopenia were noted at 1 month after the operation, and he was diagnosed as hemophagocytic lymphohistiocytosis by bone marrow study. He however, recovered after pediatric treatment. There was no other complication during the 12 month follow up period. Conclusion: This case presents with a rare combination of DiGeorge syndrome and metopic synostosis. When a child is diagnosed with DiGeorge syndrome soon after the birth, clinicians should keep in mind the possibility of an accompanying craniosynostosis. Other possible comorbidities should also be evaluated before the correction of craniosynostosis in patients as DiGeorge syndrome. In addition, postoperative management requires a thorough follow up by a multidisciplinary team of plastic surgeons, neurosurgeons, ophthalmologists and pediatricians.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.3
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• pp.291-297
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• 2015

An oral environment is constantly exposed to environmental factors and microorganisms. The periodontal ligament (PDL) fibroblasts within this environment are subject to bacterial infection and allergic reaction. However, how these condition affect PDL fibroblasts has yet to be elucidated. PDL fibroblasts were isolated from healthy donors. We examined using reverse transcription-polymerase chain reaction and measuring the intracellular $Ca^{2+}$ concentration ($[Ca^{2+}]_i$). This study investigated the receptors activated by exogenous bacterial pathogens (Lipopolysaccharide and peptidoglycan) and allergens (German cockroach extract and house dust mite) as well as these pathogenic mediators-induced effects on the intracellular $Ca^{2+}$ signaling in human PDL fibroblasts. Moreover, we evaluated the expression of pro-inflammatory cytokines (interleukin (IL)-$1{\beta}$, IL-6, and IL-8) and bone remodeling mediators (receptor activator of NF-${\kappa}B$ ligand and osteoprotegerin) and intracellular $Ca^{2+}$-involved effect. Bacterial pathogens and allergic mediators induced increased expression of pro-inflammatory cytokines, and these results are dependent on intracellular $Ca^{2+}$. However, bacterial pathogens and allergic mediators did not lead to increased expression of bone remodeling mediators, except lipopolysaccharide-induced effect on receptor activator of NF-${\kappa}B$ ligand expression. These experiments provide evidence that a pathogens and allergens-induced increase in $[Ca^{2+}]_i$ affects the inflammatory response in human PDL fibroblasts.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.5
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• pp.478-483
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• 2010

Bisphosphonates are synthetic analogue and have high affinity on bone remodeling site. Since they have a long half-reduction time, they accumulate at bone and act for a long time. They are widely used in osteo-porosis derived from imflammatory bowel disease or postmenopausal osteoporosis patient for bone mineral density improvement. In addition, they neutralize hypercalcemia owing to bone metastasis of malignancy. However, a jaw bone necrosis was recently reported in some patients who have taken bisphosphonates for a long time. It is called Bisphosphonate Related Osteonecrosis of Jaws (BRONJ). It can come spontaneous-ly, but more often after oral surgery including tooth extraction. In this case, a 80-year-old woman was treated with bisphosphonate (sodium alendronate) for 2 years to improve bone mineral density. She had her left lower second molar tooth extracted at local clinic. After extraction, she had inflammatory symptoms like a pain, a cheek swelling, and a discharge of pus. She was referred to our clinic for treatment. We treated meticulously from dressing to surgery. After following up about 1.5 years, the jaw lesion was successfully healed. So we report this case.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.36 no.1
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• pp.25-29
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• 2014

The purpose of this study is to report on five cases treated with bone graft using recombinant human bone morphogenetic protein-2 (rhBMP-2) on jaw defects after cyst enucleation. We performed bone graft with BMP (rhBMP-2+${\beta}$-tricalcium phosphate/hydroxyapatite) wrapped with a collagen sponge on jaw defects after cyst enucleation. Postoperative panoramic radiographs were taken periodically. After 1 to 12 months, bone remodeling was observed in the jaw defect area. In our cases, there were few signs or symptoms of recurrence of the cyst during the follow-up period.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.40 no.6
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• pp.291-296
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• 2014

Objectives: Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a side effect of bisphophonate therapy that has been reported in recent years. Osteoclastic inactivity by bisphosphonate is the known cause of BRONJ. Bone morphogenetic protein-2 (BMP-2) plays an important role in the development of bone. Recombinant human BMP-2 (rhBMP-2) is potentially useful as an activation factor for bone repair. We hypothesized that rhBMP-2 would enhance the osteoclast-osteoblast interaction related to bone remodeling. Materials and Methods: Human fetal osteoblast cells (hFOB 1.19) were treated with $100{\mu}M$ alendronate, and 100 ng/mL rhBMP-2 was added. Cells were incubated for a further 48 hours, and cell viability was measured using an MTT assay. Expression of the three cytokines from osteoblasts, receptor activator of nuclear factor-${\kappa}B$ ligand (RANKL), osteoprotegerin (OPG), and macrophage colony-stimulating factor (M-CSF), were analyzed by real-time polymerase chain reaction and enzyme-linked immunosorbent assay. Results: Cell viability was decreased to $82.75%{\pm}1.00%$ by alendronate and then increased to $110.43%{\pm}1.35%$ after treatment with rhBMP-2 (P<0.05, respectively). OPG, RANKL, and M-CSF expression were all decreased by alendronate treatment. RANKL and M-CSF expression were increased, but OPG was not significantly affected by rhBMP-2. Conclusion: rhBMP2 does not affect OPG gene expression in hFOB, but it may increase RANKL and M-CSF gene expression.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.36 no.3
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• pp.103-110
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• 2014

Purpose: The current gold standard for clinical jawbone formation involves autogenous bone as a graft material. In addition, demineralized dentin can be an effective graft material. Although demineralized dentin readily induces heterotopic bone formation, conventional decalcification takes three to five days, so, immediate bone grafting after extraction is impossible. This study evaluated the effect of vacuum ultrasonic power on the demineralization and processing of autogenous tooth material and documented the clinical results of rapidly processed autogenous demineralized dentin (ADD) in an alveolar defects patient. Methods: The method involves the demineralization of extracted teeth with detached soft tissues and pulp in 0.6 N HCl for 90 minutes using a heat controlled vacuum-ultrasonic accelerator. The characteristics of processed teeth were evaluated by scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). Bone grafting using ADD was performed for narrow ridges augmentation in the mandibular area. Results: The new processing method was completed within two hours regardless of form (powder or block). EDS and SEM uniformly demineralized autotooth biomaterial. After six months, bone remodeling was observed in augmented sites and histological examination showed that ADD particles were well united with new bone. No unusual complications were encountered. Conclusion: This study demonstrates the possibility of preparing autogenous tooth graft materials within two hours, allowing immediate one-day grafting after extraction.

• Molecules and Cells
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• v.37 no.11
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• pp.827-832
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• 2014

The balance between bone formation by osteoblasts and destruction of mineralized bone matrix by osteoclasts is important for bone homeostasis. The increase of osteoclast differentiation by RANKL induces bone diseases such as osteoporosis. Recent studies have shown that insulin is one of main factors mediating the cross-talk between bone remodeling and energy metabolism. However, the systemic examination of insulin-induced differential gene expression profiles in osteoclasts has not been extensively studied. Here, we investigated the global effects of insulin on osteoclast precursors at the level of gene transcription by microarray analysis. The number of genes that were up-regulated by ${\geq}1.5$ fold after insulin treatment for 6 h, 12 h, or 24 h was 76, 73, and 39; and 96, 83, and 54 genes were down-regulated, respectively. The genes were classified by 20 biological processes or 24 molecular functions and the number of genes involved in 'development processes' and 'cell proliferation and differentiation' was 25 and 18, respectively, including Inhba, Socs, Plk3, Tnfsf4, and Plk1. The microarray results of these genes were verified by real-time RT-PCR analysis. We also compared the effects of insulin and RANKL on the expression of these genes. Most genes had a very similar pattern of expressions in insulin- and RANKL-treated cells. Interestingly, Tnfsf4 and Inhba genes were affected by insulin but not by RANKL. Taken together, these results suggest a potential role for insulin in osteoclast biology, thus contributing to the understanding of the pathogenesis and development of therapeutics for numerous bone and metabolic diseases.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.6
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• pp.391-397
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• 2012

Purpose: The purpose of this study was to evaluate the effectiveness of the platelet-rich fibrin (PRF) used in combination with the porcine cancellous bone as a scaffold, in promoting bone regeneration in the bone defects ofthe rabbit calvaria. Methods: Ten rabbits were used in the study. Three round-shaped defects (diameter 8.0 mm) were created in the rabbit calvaria and were filled with nothing (control group), porcine cancellousbone (Experimental Group 1, porcine bone) and PRF-mixed porcine cancellous bone (Experimental Group 2). TS-GBB is a xenogenic bone-substitute product comprised of a high heat-treated mineralized porcine cancellous bone. Animals were sacrificed at 6 weeks and 12 weeks for the histological and radiographic evaluations. Results: In the micro computed tomography and histological results, the experimental groups 1 and 2 showed more bone formation, remodeling, and calcification than the control group. The new bone formation ratio showed theGroup 2 to be larger than Group 1 at6 and 12 weeks. However, there was no significant difference between the experimental groups 1 and 2 in the new bone formation area, at the 6 and 12 weeks (P>0.05). Conclusion: The PRF-mixed group showed more bone formation than the porcine cancellousbonegroup (TS-GBB), butthere was a no significant difference. The PRF may not lead to enhanced bone healing when grafted with the porcine cancellous bone.