• Imaging Science in Dentistry
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• v.43 no.4
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• pp.261-266
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• 2013

Purpose: This study was performed to investigate the bone thickness of the infrazygomatic crest area by computed tomography (CT) for placement of a miniplate as skeletal anchorage for maxillary protraction in skeletal Class III children. Materials and Methods: CT images of skeletal Class III children (7 boys, 9 girls, mean age: 11.4 years) were taken parallel to the Frankfurt horizontal plane. The bone thickness of the infrazygomatic crest area was measured at 35 locations on the right and left sides, perpendicular to the bone surface. Results: The bone was thickest (5.0 mm) in the upper zygomatic bone and thinnest (1.1 mm) in the anterior wall of the maxillary sinus. Generally, there was a tendency for the bone to be thicker at the superior and lateral area of the zygomatic process of the maxilla. There was no clinically significant difference in bone thickness between the right and left sides; however, it was thicker in male than in female subjects. Conclusion: In the infrazygomatic crest area, the superior and lateral area of the zygomatic process of the maxilla had the most appropriate thickness for placement of a miniplate in growing skeletal Class III children with a retruded maxilla.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.6
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• pp.485-493
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• 2007

Introduction: Although several types of calcium-phosphate coumpound have been frequently applied to osseous defects at maxillofacial area for many years, there is a controversy about its efficiency on bone conductivity comprared to xenograft bone substitute. Alloplastic carbonapatite has been introduced to improve disadvantages of hydroxyapatite and to mimic natural bone containing carbon elements. However, a preclinical study about its efficiency of osteoconductivity has not been reported. This study was performed to evaluate the early osteoconductive potential of synthetic carbonapatite with multiple pores relative to anorganic bovine xenograft. Materials and methods: Total 5 beagle dogs were used for maxillary augmentation model. The control (anorganic bovine xenograft) and experimental groups (synthetic carbonapatite) were randomly distributed in the mouth split design. After bone graft, all animals were sacrificed 4 weeks after surgery. Histological specimens with Masson Trichrome staining were made and histomorphometrically analysed with image analyser. The statistical analysis was performed using paired t-test. Results: In both groups, all animals had no complications. The experimental group showed relatively much new bone formation around and along the bone substitutes, whereas it was clearly reduced in the control group. The ratios of new bone area to total area, to material area and to the residual area excluding materials were higher in the experimental group ($0.13{\pm}0.03,\;0.40{\pm}0.13,\;0.20{\pm}0.06$ respectively) than in the control group ($0.01{\pm}0.01,\;0.03{\pm}0.02,\;0.03{\pm}0.03$, respectively). And the differences between both groups were statistically significant (p<0.001, <0.01, <0.01, respectively), while the ratio of material area to total area in two groups was not significant. Conclusion: Carbonapatite showed a high osteoconductivity in the early stage of bone healing compared to bovine derived anorganic bone substitute. This study suggests that this bone materials can be applied as a reliable bone substitute in the clinical treatment.

• Imaging Science in Dentistry
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• v.30 no.1
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• pp.33-48
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• 2000

Purpose : To investigate osseointergration of titanium implants into the tibia of rabbits, which were fed a low calcium diet and irradiated. Materials and Methods : To prepare the experimental model, control group was fed a normal diet and experimental group was fed a low calcium diet for 4 weeks. And then, titanium implants were inserted into the tibia of each rabbit. Experimental group was subdivided into two groups; low calcium diet/non-irradiation group and low calcium diet/irradiation group. The low calcium diet/irradiation group was irradiated with a single absorbed dose of 15 Gy at the 5th postoperative day. At 12, 19, 33, 47, and 61 days after implantation (1, 2, 4, 6, and 8 weeks after irradiation), the bone formation in the bone-implant interface area was examined by light microscopy and fluorescent microscopy. Results and Conclusions: 1. In the control group, there began to form woven bone in the bone-implant interface area at 12 days after implantation. As the experimental time was going on, the amount of bone which was in contact with the implant was increased. 2. In the low calcium diet/non-irradiation group, there began to form woven bone in the bone-implant interface area at 19 days after implantation. Although the amount of bone which was in contact with the implant was increased as the experimental time was going on, the extent of increased bone was weak as compared with control group. 3. In the low calcium diet/irradiation group, there began to form woven bone incompletely in the bone-implant interface area at 19 days after implantation, but there were vascular connective tissues in the bone-implant interface area over the entire experimental period. 4. In the control group and low calcium diet/non-irradiation group, bone labeling bands were observed at 33 days after implantation, which suggests that the bone formation and remodeling was in process, but interstitial bone remodeling was not observed in the low calcium diet/irradiation group.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.3
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• pp.362-374
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• 2007

Statement of problem. The intial stability for osseointegration of implant has been an interesting factor. Especially, in the case of poor bone quality or immediately loaded implant, various strategies have been developed focusing on the surface of materials to improve implant fixation to bone. The microscopic properties of implant surfaces play a major role in the osseous healing of dental implants. Purpose. The aims of this study are to perform a histologic and histomorphometric comparison of the healing characteristics of three different surfaces and the comparison of resonance frequency analysis (RFA) values measured by $Osstell^{TM}$ and perio-test values (PTV) measured by Periotest. Material and methods. A total of 24 screw titanium implants (Dentium Co., Seoul, Korea) with 6mm in length and 3.4mm in diameter, were placed in the mandible of 4 beagle dogs. Implants were divided into three groups following the surface treatment methods: Group I is machined(control group). Group II is anodically oxidized. Group III is coated 500nm in thickness with hydroxyapatite(HA) by ion beam assisted deposition(IBAD) on the anodized oxidization. Bone blocks from 2 dogs were caught after 3 weeks of covered healing and another blocks from 2 dogs after 6 weeks. RFA values and PTV were measured right after insertion and at 3 and 6weeks. Histomorphometric analysis was made with Kappa Image Base System to calculate bone-to-implant contact (BIC) and bone area inside the threads. Pearson's correlation analyses were performed to evaluate the correlation between RFA and PTV, BIC and bone area ratio of three different surfaces at 3 and 6 weeks. Results. 1) In all surface treatment methods, the RFA values decreased and the PTV values increased until 6 weeks in comparison to initial values. 2) At 3 weeks, no significant difference was found from bone-to-implant contact ratio and bone area ratio of three different surface treatment methods(P>0.05). However, at 6 weeks, different surface treatment methods showed significantly different bone-toimplant contact ratio and bone area ratio(P<0.05). 3) In the implants with the IBAD on the anodic oxidization, significant difference was found between the 3 weeks and the 6 weeks bone area ratio(P<0.05). 4) Correlation was found between the RFA values and the bone area ratio at 3 and 6 weeks with significant difference(P<0.05). Conclusions. These results indicate that the implants with the IBAD on the anodic oxidization may have a high influence on the initial stability of implant.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.5
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• pp.375-379
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• 2011

Introduction: This study examined the effect of autogenous tooth bone used as a graft material for bone regeneration in an artificial bony defect of minipigs. Materials and Methods: Four healthy minipigs, weighing approximately 35-40 kg, were used. Four standardized artificial two-walled bony defects, 5 mm in length and depth, were made on the bilateral partial edentulous alveolar ridge on the mandible of minipigs, and autogenous tooth bone was augmented in the right side as the experimental group. On the other hand, only alloplastic bone graft material HA was grafted with the same size and manner in the left side as the control group. All minipigs were sacrificed at 4 weeks after a bone graft and evaluated histologically by Haematoxylin-eosin staining. The specimens were also evaluated semi-quantitatively via a histomorphometric study. The percentage of new bone over the total area was evaluated using digital software for an area calculation. Results: All specimens were available but one in the left side (control group) and two in the right side (experimental group) were missing during specimen preparation. The amount of bone formation and remodeling were higher in all experimental groups than the control. The mean percentage area for new bone in the experimental and control groups was $43.74{\pm}11.96%$ and $30.79{\pm}2.93%$, respectively. Conclusion: Autogenous tooth bone is a good alternative to autogenous bone with the possible clinical feasibility of an autogenous tooth bone graft in the reconstruction of bony defects.

• Journal of Periodontal and Implant Science
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• v.25 no.2
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• pp.418-437
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• 1995

The effect of the hydroxyapatite coatings on Titanium implants has been the subject of recent investigations. So far, the use of HA coating remains substantially controversial.This study was aimed to evaluate histologically the bone healing patterns around titanium plasm sprayed(TPS) amd HA-coated implant after implantation into the femur neck of ten adult dogs. After implantation, animals were sacrificed at the intervals of 2,4,6,8 and 12 weeks.The fluorescent dyes were injected on the postoperative 4th and 12th week into the animals supposed to be killed at the 12th week. The morphology and direction of new bone formation was similar in both TPS and HA-coated implants.There was a tendency toward more bone formation in the cortical bone area than in the cancellous bone area. Histologically,in the interface of the HA-coated implants, bone response and bone maturation was faster, compared to the TPS implants in the 2nd and 4th week. By fluorescent microscopy, new bone formation was active in the 4th week around both implants and was directed from the periosteum overlying cortical bone to the cancellous bone. These results suggest that the bone formation and maturation is faster during the early healing stage in the interface of the HA-coated implant and where the cortical bone quality is poor, HA coated implant is superior to the TPS implant in the early phase of new bone formation.

• Imaging Science in Dentistry
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• v.44 no.2
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• pp.129-135
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• 2014

Purpose: The objective of this study was to assess the trabecular bone changes that occurred around functional endosseous dental implants by means of radiographic image analysis techniques. Materials and Methods: Immediate preoperative and postoperative periapical radiographs of de-identified implant patients at the University Dental Hospital of Manchester were retrieved, screened for specific inclusion criteria, digitized, and quantified for structural elements of the trabecular bone around the endosseous implants, by using image analysis techniques. Data were analyzed using SPSS version 11.5. P values of less than 0.05 were considered statistically significant. Results: A total of 12 implants from 11 patients were selected for the study, and 26 regions of interest were obtained. There was a significant increase in the bone area in terms of the mean distance between nodes (p=0.006) and a significant decrease in the marrow area in terms of the bone area (p=0.006) and the length of marrow spaces (p=0.032). Conclusion: It appeared that the bone around the implant underwent remodeling that resulted in a net increase in bone after implant placement.

• Journal of Microbiology and Biotechnology
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• v.18 no.5
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• pp.975-982
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• 2008

We investigated whether transplantation of osteogenically differentiated bone marrow-derived mesenchymal stem cells (BMMSCs) and the use of an hydroxyapatite (HAp) scaffold can enhance the in vivo bone formation efficacy of human BMMSCs. Three months after implantation to the subcutaneous dorsum of athymic mice, transplantation of osteogenically differentiated human BMMSCs increased the bone formation area and calcium deposition to 7.1- and 6.2-folds, respectively, of those of transplantation of undifferentiated BMMSCs. The use of the HAp scaffold increased the bone formation area and calcium deposition to 3.7- and 3.5-folds, respectively, of those of a polymer scaffold. Moreover, a combination of transplantation of osteogenically differentiated BMMSCs and HAp scaffold further increased the bone formation area and calcium deposition to 10.6- and 9.3-folds, respectively, of those of transplantation of undifferentiated BMMSCs seeded onto polymer scaffolds. The factorial experimental analysis showed that osteogenic differentiation of BMMSCs prior to transplantation has a stronger positive effect than the HAp scaffold on in vivo bone formation.

• BMB Reports
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• v.53 no.3
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• pp.154-159
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• 2020

We investigated the effects of physalin A, B, D, and F on osteoclastogenesis induced by receptor activator of nuclear factor κB ligand (RANKL). The biological functions of different physalins were first predicted using an in silico bioinformatic tool (BATMAN-TCM). Afterwards, we tested cell viability and cell apoptosis rate to analyze the cytotoxicity of different physalins. We analyzed the inhibitory effects of physalins on RANKL-induced osteoclastogenesis from mouse bone-marrow macrophages (BMMs) using a tartrate-resistant acid phosphatase (TRAP) stain. We found that physalin D has the best selectivity index (SI) among all analyzed physalins. We then confirmed the inhibitory effects of physalin D on osteoclast maturation and function by immunostaining of F-actin and a pit-formation assay. On the molecular level, physalin D attenuated RANKL-evoked intracellular calcium ([Ca(2+)](i)) oscillation by inhibiting phosphorylation of phospholipase Cγ2 (PLCγ2) and thus blocked the downstream activation of Ca2+/calmodulin-dependent protein kinases (CaMK)IV and cAMP-responsive element-binding protein (CREB). An animal study showed that physalin D treatment rescues bone microarchitecture, prevents bone loss, and restores bone strength in a model of rapid bone loss induced by soluble RANKL. Taken together, these results suggest that physalin D inhibits RANKL-induced osteoclastogenesis and bone loss via suppressing the PLCγ2-CaMK-CREB pathway.

• 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.