• Journal of Periodontal and Implant Science
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• 제29권2호
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• pp.355-373
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• 1999

Many researches have been reported that collagen as cellular stroma, matrix of grafting materials, mediator of agents for the purpose of promoting healing process invivo, but the responses in vivo were seen various. The goal of this experiment is to assess the effect of collagen on bony healing, through histological evaluation of implanted collagen on the calvarial defect in rats. 2-month-old Sprague-Dawley, 24 rats were used and 12 rats assigned to each group of control and test. Defect of 5mm in diameter was made on the calvarial bone with trephine bur. Following thorough saline rinse, defect of control group was left in empty and that of experimental group was filled with fibrillar collagen($COLLATAPE^{(R)}$, COLLA-TEC. INC. U.S.A.) soaked in saline. 3 rats in each group were sacrificed at 3, 7, 14, 21 days after operation respectively, and the tissue blocks were prepared for light microscope with H-E for evaluation of overall healing, with TRAP(tartrate resistant acid phosphatase) for evaluation of osteoclastic activity and with immunohistochemical staining for macrophages. The results were as follows : 1. In the control group, inflammatory responses were disappeared at day 14, but, in the experimental group inflammatory infiltrates were reduced at day 21. Thus, the experimental group showed more severe soft tissue inflammation than control group. 2. Both control and experimental group showed slight appositional growth at day 7 and gradual bony growth to 21th day. But, complete bony healing of the defect was not shown. There was no significant difference in bony healing between control and experimental group 3. Specific response of macrophages for implanted collagen was observed at day 14 in the experimental group. In conclusion, although fibrillar collagen caused inflammation of soft tissue during initial healing period, inflammatory responses by fibrillar collagen didn't inhibit bony regeneration and implanted collagen was biodegradaded by macrophages. Thus, we expect that fibrillar collagen can be used for useful mediator of graft materials or growth factors.

• Journal of Periodontal and Implant Science
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• 제46권4호
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• pp.244-253
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• 2016

Purpose: The aim of this study was to characterize the healing in the grafted calvarial defects of rats after adjunctive hyperbaric oxygen therapy. Methods: Twenty-eight male Sprague-Dawley rats (body weight, 250-300 g) were randomly divided into two treatment groups: with hyperbaric oxygen therapy (HBO; n=14) and without HBO (NHBO; n=14). Each group was further subdivided according to the bone substitute applied: biphasic calcium phosphate (BCP; n=7) and surface-modified BCP (mBCP; n=7). The mBCP comprised BCP coated with Escherichia-coli-derived recombinant human bone morphogenetic protein-2 (ErhBMP-2) and epigallocatechin-3-gallate (EGCG). Two symmetrical circular defects (6-mm diameter) were created in the right and left parietal bones of each animal. One defect was assigned as a control defect and received no bone substitute, while the other defect was filled with either BCP or mBCP. The animals were allowed to heal for 4 weeks, during which those in the HBO group underwent 5 sessions of HBO. At 4 weeks, the animals were sacrificed, and the defects were harvested for histologic and histomorphometric analysis. Results: Well-maintained space was found in the grafted groups. Woven bone connected to and away from the defect margin was formed. More angiogenesis was found with HBO and EGCG/BMP-2 (P<0.05). None of the defects achieved complete defect closure. Increased new bone formation with HBO or EGCG/BMP-2 was evident in histologic evaluation, but it did not reach statistical significance in histometric analysis. A synergic effect between HBO and EGCG/BMP-2 was not found. Conclusions: Within the limitations of this study, the present findings indicate that adjunctive HBO and EGCG/BMP-2 could be beneficial for new bone formation in rat calvarial defects.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제28권4호
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• pp.274-279
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• 2002

The purpose of this study is to evaluate the critical maintenance period of absorbable membrane for guided bone regeneration. Fortynine Sprague-Dawley rats weighing about 300g were divided into seven groups. An 8 mm circular full-thickness defect in calvarial bone was made and then cellular acetate porous filter (Millipore $filter^{(R)}$.) was placed on the calvarial bone defect. The filter was removed at 2, 3, 4, 5, 6, 8 and 11 weeks after placement. Rats were sacrificed at 12 weeks the placement of cellular acetate porous filter. The specimens were stained with Hematoxylin-Eosin and observed under light microscope. The amount of regenerated bone was measured from both margin of calvarial bone defect (unit : mm). The results were as follows. Bone regeneration of each experimental group was increased gradually and the bond defect was almost completely filled with new bone in 5-, 6-, 8-, and 11-week experimental group. Histologic findings showed mild inflammatory response and granulation tissue formation without apparent adverse effects on the healing process. In 11-week experimental group, the bone defect was completely filled with new bone containing abundant osteoid which was oriented to the dural side and contribute to bony thickening. We suggest that non-absorbable membrane and bioabsorbable membrane presumably should remain intact for longer than 5 weeks to be effective.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제18권4호
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• pp.746-757
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• 1996

Bony defects may be found as a result of congenital anomalies, traumatic injury, automobile collisions and industrial accidents in the maxillofacial area. Such conditions are often associated with severs functional and esthetic problem. Various surgical procedure has been utilized in attempts to repair and reconstruct bony defects. Bone is a complex, living, constantly changing tissue. The architecture and composition of cancellous and cortical bone allow the skeleton to perform its essential mechanical functions. Periosteum covers the external surface of bone and consists of two layers : an outer fibrous layer and an inner more cellular and vascular layer. The inner osteogenic layer or cambium layer can form new bone while the outer layer firms part of the insertions of tendons, ligaments and muscles. This study was under taken to evaluate bone healing process on partial defect of calvarial bone with or without periosteum in rat. We made calvarial defects of different size(4mm, 6mm, 8mm) with periosteum or without periosteum in rat to study the effect of defect size on healing process. Control and experimental groups sacrified at 1, 2, 4, 6, 8 weeks, postoperatively. We examed the specimens by gloss findings, light microscophy, and fluorescent microscophy. The results were as follows. 1. Gloss findings: Control groups are larger bony defects than experimental groups after 2 weeks, and than control groups advanced healing of defected bone but experimental groups are lesser after 4, 6 weeks. After 8 weeks, bone defect has not been identified in control and experimental groups. 2. Light microscope: All defects of control groups are larger bony defects than experimental groups after 2 weeks. And than control groups show smaller defect after 4 weeks. After 8 weeks, the control group reveal pin-point sized, hardly identifiable defect space and the experimental group reveal small, but definite defect space. 3. Fluorescent microscope : Each week, new bone formation of control group is very similar to the experimental group. In this study, Osteogenesis of calvarial bone defects with periosteum or without periosteum was examined for 8 weeks in rats. The replaced periosteum had batter new bone formation than the removed periosteum.

• Journal of Periodontal and Implant Science
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• 제39권3호
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• pp.349-358
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• 2009

Purpose: This study was aimed to evaluate the effect of the Freeze Dried Bone Allograft and Demineralized Bone Matrix on osseous regeneration in the rat calvarial defects. Methods: Eight mm critical-sized calvarial defects were created in the 80 male Sprague-Dawley rats. The animals were divided into 4 groups of 20 animals each. The defects were treated with Freeze Dried Bone Allograft($SureOss^{TM}$), Demineralized Bone Matrix($ExFuse^{TM}$ Gel, $ExFuse^{TM}$ Putty), or were left untreated for sham-surgery control and were evaluated by histologic and histomorphometric parameters following a 2 and 8 week healing intervals. Statistical analysis was done between each groups and time intervals with ANOVA and paired t-test. Results: Defect closure, New bone area, Augmented area in the $SureOss^{TM}$, $ExFuse^{TM}$ Gel, $ExFuse^{TM}$ Putty groups were significantly greater than in the sham-surgery control group at each healing interval(P < 0.05). In the New bone area and Defect closure, there were no significant difference between experimental groups. Augmented area in the $ExFuse^{TM}$ Gel, $ExFuse^{TM}$ Putty groups were significantly greater than $SureOss^{TM}$ group at 2weeks(P < 0.05), however there was no significant difference at 8 weeks. Conclusions: All of $SureOss^{TM}$, $ExFuse^{TM}$ Gel, $ExFuse^{TM}$ Putty groups showed significant new bone formation and augmentation in the calvarial defect model.

• 한국임상수의학회지
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• 제39권6호
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• pp.302-310
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• 2022

Recently, in human medicine and veterinary medicine, interest in synthetic bone graft is increasing. Among them, bone morphogenic protein (BMP) is currently being actively researched and applied to clinical trials. However, BMP has the disadvantage of being expensive and easily absorbed into surrounding tissues. Therefore, BMP requires the use of small amounts and rhBMP (recombinant human bone morphogenetic protein)-2 carriers that can be released slowly. Hydrogel has the property of swelling a large amount of water inside when it is aqueous solution, and when it is, it consists of more than 90 percent water. Using these properties, hydrogels are often used as rhBMP-2 carrier. The scaffold used in this study is a hydrogel made from which keratin is extracted using human hair and based on it. In this study, we wanted to see the effect of bone formation in the calvarial defect model by using keratin-based hydrogel made with human hair as a scaffold. The experiment was conducted by dividing 3 groups a total of 12 mice. Calvarial bone defect is set to all 4 mm diameters. Bone formation was evaluated by using gross evaluation, micro-computed tomography (micro-CT), immunohistochemistry. Groups using keratin-based hydrogel were significantly observed compared to Group 1s, and the most bone formations were found when rhBMP-2 and hydrogel were used. This represents the superiority of the functions of the rhBMP-2 carrier by a new material, keratin-based hydrogel. Through gross evaluation, micro-CT, and immunohistochemistry, we can confirm that keratin-based hydrogel is a useful rhBMP-2 carrier.

• 대한치주과학회:학술대회논문집
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• 대한치주과학회 2001년도 제41회 종합학술대회 연제초록
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• pp.89-90
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• 2001

• Journal of Korean Neurosurgical Society
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• 제58권1호
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• pp.79-82
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• 2015

Cleidocranial dysplasia is a well-documented rare autosomal dominant skeletal dysplasia characterized by hypoplastic/aplastic clavicles, brachycephalic skull, patent sutures and fontanelles, midface hypoplasia, and abnormalities of dentition. Patients with cleidocranial dysplasia often complain about undesirable esthetic appearance of their forehead and skull. Notwithstanding many studies of molecular, genetics and skeletal abnormalities of this congenial disorder, there have been very few written reports of cranioplasty involving cleidocranial dysplasia. Thus, we report a rare case of successful cranioplasty using a modified split calvarial graft technique in patient with cleidocranial dysplasia.

• Journal of Periodontal and Implant Science
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• 제37권3호
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• pp.511-522
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• 2007

Introduction : The purpose of this study was to evaluate the possibility of the acellular dermal matrix (ADM) as a barrier membrane for bone regeneration, and to evaluate the osteogenic effect of ADM as a carrier system for rhBMP-2 in the rat calvarial defect model. Materials and Methods: An 8-mm, calvarial, critical-size osteotomy defect was created in each of 60 male Spraque-Dawley rats(weight $250{\sim}300g$). Three groups of 20 animals, each received either rhBMP-2(0.025mg/ml) in an ADM carrier, ADM only, or negative surgical control. And each group was divided into 2- and 8-weeks healing intervals. The groups were evaluated by histologic and histomorphometric parameters(10 animals/group/healing intervals). Data were expressed as $means{\pm}standard$ deviations($m{\pm}SD$). Comparisons between experimental and control groups were made using two-way ANOVA and post hoc t-test. Comparisons between 2 weeks and 8 weeks were made using paired t-test. The level of statistical difference was defined as P< 0.05. Results : The ADM group and rhBMP-2/ADM group results in enhanced local bone formation in the rat calvarial defect at both 2 and 8 weeks. The amount of defect closure and new bone formation were significantly greater in the rhBMP-2/ADM group relative to ADM group(P<0.05). At 8 weeks, the majority of ADM in the defect was contracted, and integrated with surrounding host tissues. In addition, host cell infiltration and neovascularization of the ADM in the absence of an inflammatory response were observed, and the newly formed bone around ADM showed a continuous remodeling and consolidation. Conclusion : The results of the present study indicated that ADM may be used as a barrier membrane for bone regeneration and that may be employed as a delivery system for BMPs.

• Journal of Periodontal and Implant Science
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• 제38권2호
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• pp.163-170
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• 2008

Purpose: Biphasic calcium phosphates have been of great interest recently. Mixing adequate ratios of hydroxyapatite(HA) and beta-tricalcium phosphate($\beta$-TCP) allowed to control the resorption rate without distorting its osteoconductive property. This study evaluated the bone formation effect of newly developed biphasic calcium phosphate(BCP) in calvarial defect of rabbits. Materials and Methods: 6 male New Zealand rabbits were used. Four defects with 8mm in diameter were created on each animal. BCP with HA/$\beta$-TCP ratio of 7:3 and particle size of $0.5{\sim}1.0\;mm$ was used as the test group and bovine bone with $0.25{\sim}1.0\;mm$ particle size, as the control group. Both test and control group materials were randomly implanted in the calvarial defects and were covered witha polymer membrane. The animals were sacrificed after 12, 24, and 48 weeks of implantation under general euthanasia. Resin blocks were obtained and were stained by masson's trichrome for histological observation. Results: Overall results were uneventful without any defect exposure or inflammation. The amount of new bone formation and bone maturity increased with increase in healing period at both groups. New bone in test group was mostly formed along the material particle surrounded by osteoblasts, and observation of osteoblastic stream was also present. Bone maturity increased as it was closer to thedefect margins. Under the same healing period, the test group showed more bone formation than the control group with more stable bovine bone particles remaining even after 48 weeks, whereas considerable resorption took place in BCP. Almost total defect closure was observed in test group with new bone formation in the central part of the defect. However, limited new bone formation was observed in the control group. Conclusion: Within the limits of the study, the present study reveals the newly developed BCP to be a good osteoconductive material. However, further studies are needed to be conducted in a different study model with a larger sample size.