• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.45 no.5
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• pp.285-293
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• 2019

Objectives: This study examined the effects of plasma-rich growth factors (PRGF) on accelerating bone regeneration/repair in fresh extraction sockets, and determined the quality and quantity of bone by assessing the bone density using cone-beam computed tomography (CBCT). Materials and Methods: Twenty patients, who had undergone bilateral extractions, were included in this study. In one extraction socket, PRGF was used and covered with an autologous fibrin plug. Nothing was used in the opposite side extraction socket. Thirteen weeks post extraction, the level of bone regeneration was evaluated on both sides with CBCT. Results: At the end of the study, the mean bone density according to the Hounsfield units (HU) in the control group and PRGF group was 500.05 HU (type III bone type) and 647.95 HU (type II bone type), respectively. Conclusion: This study recommends the use of PRGF in post extraction sites to accelerate the rate of bone regeneration and improve the quality of regenerated bone. The technique to process PRGF was simple compared to previously mentioned techniques used for platelet-rich plasma (PRP) preparation. PRP preparation requires a two-cycle centrifugation procedure, leading to a longer processing time.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.45 no.3
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• pp.121-122
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• 2019

• Maxillofacial Plastic and Reconstructive Surgery
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• v.37
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• pp.16.1-16.7
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• 2015

Background: This study aimed to investigate new bone formation using recombinant human bone morphogenetic protein 2 (rhBMP-2) and locally applied bisphosphonate in rat calvarial defects. Methods: Thirty-six rats were studied. Two circular 5 mm diameter bony defect were formed in the calvaria using a trephine bur. The bony defect were grafted with $Bio-Oss^{(R)}$ only (group 1, n = 9), $Bio-Oss^{(R)}$ wetted with rhBMP-2 (group 2, n = 9), $Bio-Oss^{(R)}$ wetted with rhBMP-2 and 1 mM alendronate (group 3, n = 9) and $Bio-Oss^{(R)}$ wetted with rhBMP-2 and 10 mM alendronate (group 4, n = 9). In each group, three animals were euthanized at 2, 4 and 8 weeks after surgery, respectively. The specimens were then analyzed by histology, histomorphometry and immunohistochemistry analysis. Results: There were significant decrease of bone formation area (p < 0.05) between group 4 and group 2, 3. Group 3 showed increase of new bone formation compared to group 2. In immunohistochemistry, collagen type I and osteoprotegerin (OPG) didn't show any difference. However, receptor activator of nuclear factor ${\kappa}B$ ligand (RANKL) decreased with time dependent except group 4. Conclusion: Low concentration bisphosphonate and rhBMP-2 have synergic effect on bone regeneration and this is result from the decreased activity of RANKL of osteoblast.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.3
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• pp.188-195
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• 2002

The purpose of this investigation was to evaluate the relationship between the hydration time of demineralized freeze-dried bone (DFDB) and early new bone formation in rat calvarial defects filled with DFDB. Rats (n = 43) were divided into 4 experimental groups. Standard, transosseous circular defects of the calvaria were made midparietally. In experimental group 1, the defect was grafted immediately after soaking the DFDB. In experimental group 2, the defects were grafted with DFDB after soaking the DFDB for 10 minutes. In experimental groups 3 and 4, the defects were filled after soaking the DFDB for 30 and 60 minutes, respectively. Graft sites were analyzed histologically after healing periods of 1, 2, or 4 weeks. Each group showed similar bone regeneration at each time point by histological analysis. The results of this study were as follows: 1. After 1 week, a significant amount of inflammation, granulation tissue, and edema were found. A small amount of bone was seen, but the amount of bone did not differ between groups. 2. After 2 weeks, a small amount of new bone formation and DFDB resorption were observed. 3. After 4 weeks, a greater amount of new bone formation was observed. The greatest amount of bone formation occurred in experimental group 4 after 4 weeks. We conclude that the hydration time of DFDB does not affect new bone formation and that it is very important to control inflammation in bone grafting.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.47 no.6
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• pp.480-483
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• 2021

Tissue regeneration is one of the ultimate goals of maxillofacial surgery and various types of tissue engineering technologies have been utilized in clinics. Healthy resources of host cells and growth factors are essential for the tissue engineering, therefore autologous blood-derived cell therapy was introduced. In this article, clinical applications of the autologous platelet concentrates and stem cell separation therapy will be summarized and evaluated for their efficacy and feasibility in the current maxillofacial clinics.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.6
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• pp.648-653
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• 2007

This case study investigated the clinical effect of guided bone regeneration(GBR) using $Regenaform^{(R)}\;and\;Ossix^{(R)}$ membrane and the histology of the new bone that formed just under the membranes. $Regenaform^{(R)}$ transplantation and covering with $Ossix^{(R)}$ membrane were performed to repair bone defects around implants after implantation in three patients. After $3{\sim}4$ months, the membranes were removed in a second operation, and a biopsy was taken under the membrane. The biopsies showed a bone density of $23{\sim}42%$, and subsequent prosthetic treatments were successful in all cases.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.19 no.1
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• pp.15-24
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• 1997

The principle of guided tissue regeneration (GTR), as applied to bone healing, is based on the prevention of connective tissue from entering the bony defect during the healing phase. This allows the slower bone producing cells to migrate into and reproduce bone within the defect. GTR has demonstrated a level of success in regenerating bone defect. Several types of membrane barrier have been utilized to apply this principle in bone regeneration. The purpose of this study was to evaluate whether improved bone regeneration can be achieved with different membrane barriers ($Gore-Tex^{TM}$membrane, $COLLACOTE^{(R)}$). In the 10 NewZealand white rabbits, full-thickness bone defects on three sites of each rabbit calvaria were made. Experimental group 1 was covered with $COLLACOTE^{(R)}$, and group 2 was covered with $Gore-Tex^{TM}$membrane. Macroscopic, microscopic examinations were made serially on 1, 2, 3, 6, 12 weeks after operation. The results were as follows : 1. Macroscopically, both of experimental group 1, 2 were filled with bone-like mass but the defects of experimental group 1 disclosed markedly thinner than the original bone. 2. Microscopically, the defect of experimental group 1, 2 was filled with bony trabeculae without infection and adverse reaction. But multinucleated giant cell infiltration around $COLLACOTE^{(R)}$ was seen till 6th week. 3. Resorption of $COLLACOTE^{(R)}$ started from 3rd week and it was completely resorped on the 12th week.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.4
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• pp.290-301
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• 2002

The purpose of this study was to evaluate new bone formation and healing process in rat calvarial bone defects using $BioMesh^{(R)}$. membrane and DFDB. Forty eight rats divided equally into 4 groups of 1 control group and 3 experimental groups. Standardized transosseous circular calvarial defects (8 mm in diameter) were made midparietally. In the control group, the defect was only covered with the soft tissue flap. In the experimental group 1, it was filled with DFDB only, in the experimental group 2, it was covered $BioMesh^{(R)}$. membrane only, and in the experimental group 3, it was filled DFDB and covered with membrane. At the postoperative 1, 2, 4, 8 weeks, rats were sacrificed and histologic and histomorphometric analysis were performed. These results were as follows. In histomorphometric analysis, It showed the greatest amount of new bone formation through experimental in the experimental group 3 (P<0.001). The amount of new bone formation at the central portion of the defect was greater in the experimental group 3 than experimental group 2. $BioMesh^{(R)}$. membrane began to resorb at 1 week and resorbed almost completely at 8 weeks after operation. The collapse of membrane into the defect was observed through the experimental periods in the experimental group 2. In the area of collapsed membrane, new bone formation was restricted. These results suggest that maintenance of some space for new bone to grow is required in the use of $BioMesh^{(R)}$. membrane alone in the defect. It is also thought that use of the membrane may promote new bone growth in DFDB graft.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.1
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• pp.18-24
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• 2013

Purpose: This study is performed to determine the effects of titanium cap with various sizes of pores on bone formation during guided bone regeneration (GBR). Methods: Calvaria from 10 adult male rabbits were chosen as the recipient sites. A trephine bur with a diameter of 10 mm was used to form one round groove on each side of sagittal suture of the cranium, and a round bur with a diameter of 1.5 mm was used to form 6 small holes on the inner circles of round grooves to induce bleeding. In the control group, bone graft was not conducted, and closed titanium cap was fixed in the round groove. Bone graft was not performed in groups 1 and 2, but fixed on titanium caps with 0.2 mm, and 0.5 mm sized pores, respectively. For groups 3, 4, and 5, a synthetic bone graft material (${\beta}$-tricalcium phosphate, Cerasorb$^{(R)}$, Germany) was transplanted, and titanium caps without pore, with 0.2 mm and 0.5 mm sized pore were fixed, respectively. The animals were sacrificed 4 weeks after, and clinical, radiographical, and histomorphometrical evaluation of bone regeneration was performed. Results: In all groups, there were no clinical signs of infection, inflammation or wound dehiscence. Radiographic evaluation revealed well-defined semi-circular radiopacity inside the titanium cap of groups 3, 4, and 5. Histologically, the inner surface of the hemisphere was evenly lined with newly formed bone tissue, as well as grafted bone material in the group 3. In groups 4 and 5, the insertion of connective tissue was observed along the inner surface. However, the overall surface area between the grafts with different holes yielded no statistical significance in the histomorphometrical evaluation. Conclusion: Although the total area of newly formed bone showed no significant difference, excellent bone formation tendency was observed histologically when closed caps were used with bone graft was accompanied.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.4.1-4.10
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• 2019

Background: The mandibular third molar (M3) is typically the last permanent tooth to erupt because of insufficient space and thick soft tissues covering its surface. Problems such as alveolar bone loss, development of a periodontal pocket, exposure of cementum, gingival recession, and dental caries can be found in the adjacent second molars (M2) following M3 extraction. The specific aims of the study were to assess the amount and rate of bone regeneration on the distal surface of M2 and to evaluate the aspects of bone regeneration in terms of varying degree of impaction. Methods: Four series of panoramic radiographic images were obtained from the selected cases, including images from the first visit, immediately after extraction, 6 weeks, and 6 months after extraction. ImageJ software^® (NIH, USA) was used to measure linear distance from the region of interest to the distal root of the adjacent M2. Radiographic infrabony defect (RID) values were calculated from the measured radiographic bone height and cementoenamel junction with distortion compensation. Repeated measures of analysis of variance and one-way analysis of variance were conducted to analyze the statistical significant difference between RID and time, and a Spearman correlation test was conducted to assess the relationship between Pederson's difficulty index (DI) and RID. Results: A large RID (> 6 mm) can be reduced gradually and consistently over time. More than half of the samples recovered nearly to their normal healthy condition (RID ≤ 3 mm) by the 6-month follow-up. DI affected the first 6 weeks of post-extraction period and only showed a significant positive correlation with respect to the difference between baseline and final RID. Conclusions: Additional treatments on M2 for a minimum of 6 months after an M3 extraction could be recommended. Although DI may affect bone regeneration during the early healing period, further study is required to elucidate any possible factors associated with the healing process. The DI does not cause any long-term adverse effects on bone regeneration after surgical extraction.