• Maxillofacial Plastic and Reconstructive Surgery
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• 제33권1호
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• pp.19-25
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• 2011

Purpose: Addition of platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) to grafting material has become widely accepted additively for bone regeneration because it can raise high expectations on it's clinical potential. The aim of this study was to evaluate the efficacy of PRP and PRF on early bone regeneration of rabbits when used in combination with beta tricalcium phosphate. Methods: In eight rabbits, the calvarium was exposed and the two marrows were penetrated. After then these artificial bone defects were augmented with ${\beta}$-TCP or ${\beta}$-TCP with PRP or ${\beta}$-TCP with PRF and covered. The animals were sacrificed after four and eight weeks. Histologic findings were observed under the light-microscope and histomorphometric analysis was performed by measuring calcified area of new bone formation within the CSD. Results: They demonstrated that new bone formation tended to be produced along the outline of graft materials. More amounts of newly bone was regenerated in ${\beta}$-TCP only and in combination of${\beta}$-TCP with PRF and it was statistically significant. In contrast, there was no significant difference between nothing apply and ${\beta}$-TCP with PRP groups in the relative amounts of newly mineralized bone. Conclusion: Within the limitation of this study, it can be concluded that PRF in combination with ${\beta}$-TCP showed a positive effect on bone regeneration and statistically it was significant.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제44권2호
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• pp.79-85
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• 2018

Objectives: The aim of this study was to evaluate the effects of herbal extracts on bone regeneration. Two known samples were screened. Materials and Methods: We previously established a rat calvaria defect model using a combination of collagen scaffold and herbal extracts. An 8 mm diameter trephine bur with a low-speed dental hand piece was used to create a circular calvaria defect. The experimental group was divided into 4 classifications: control, collagen matrix, Danshen with collagen, and Ge Gan with collagen. Animals in each group were sacrificed at 4, 6, 8, and 10 weeks after surgery, and bone regeneration ability was evaluated by histological examination. Results: Results revealed that both Danshen and Ge Gan extracts increased bone formation activity when used with collagen matrix. All groups showed almost the same histological findings until 6 weeks. However, after 6 weeks, bone formation activity proceeded differently in each group. In the experimental groups, new bone formation activity was found continuously up to 10 weeks. In the Danshen and Ge Gan groups, grafted materials were still present until 10 weeks after treatment, as evidenced by foreign body reactions showing multinucleated giant cells in chronic inflammatory vascular connective tissue. Conclusion: Histological analyses showed that Danshen and Ge Gan extractions increased bone formation activity when used in conjunction with collagen matrix.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권1호
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• pp.86-91
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• 2009

The success of implants essentially depends on a sufficient volume of healthy bone at the recipient site during implant placement. In patients who have the severe alveolar bone resorption or pneumatized maxillary sinus, it should be performed that bone regeneration procedure before implant placement. Development of barrier membrane makes it possible that predictable result of alveolar bone reconstruction. Many kind of materials used for barrier membrane technique are introduced, non-absorbable or absorbable membranes. But, when operation site was ruptured with membrane exposure, bacterias can be grow up at the bone graft site. Then morphology and migration of fibroblast will be changed. It works as a negative factor on healing process of bone graft site. In oral and maxillofacial department of Chonbuk national university dental hospital, we use variable suture technique like as subgingival suture, vertical mattress suture, simple interrupted suture, if need, tenting suture after GBR or block bone graft. Within these suture technique, wound healing was excellent without complication, so now we take a report of suture technique in reconstruction of alveolar bone surgery.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제49권6호
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• pp.354-359
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• 2023

The temporomandibular joint is a unique structure composed of the joint capsule, articular disc, mandibular condyles, glenoid fossa of the temporal bone, surrounding ligaments, and associated muscles. The condyle is one of the major components of a functional temporomandibular joint. Reconstruction of large mandibular defects involving the condyle is a surgical challenge for oral and maxillofacial surgeons. To restore large mandibular defects, there are different options for free flap method such as fibula, scapula, and iliac crest. Currently, the vascularized fibula free flap is the gold standard for reconstruction of complex mandibular defects involving the condyle. In the present report, neocondyle regeneration after mandible reconstruction including the condyle head with fibula free flap was evaluated. In this report, two patients were evaluated periodically, and remodeling of the distal end of the free fibula was observed in both cases after condylectomy or mandibulectomy. With preservation of the articular disc, trapezoidal shaping of the neocondyle, and elastic guidance of occlusion, neocondyle bone regeneration occured without ankylosis. Preservation of the articular disc and maintenance of proper occlusion are critical factors in regeneration of the neocondyle after mandible reconstruction.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제39권
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• pp.8.1-8.8
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• 2017

Background: For an effective bone graft for reconstruction of the maxillofacial region, an adequate vascular network will be required to supply blood, osteoprogenitor cells, and growth factors. We previously reported that the secretomes of bone marrow-derived mesenchymal stem cells (MSC-CM) contain numerous growth factors such as insulin-like growth factor (IGF)-1, transforming growth factor $(TGF)-{\beta}1$, and vascular endothelial growth factor (VEGF), which can affect the cellular characteristics and behavior of regenerating bone cells. We hypothesized that angiogenesis is an important step for bone regeneration, and VEGF is one of the crucial factors in MSC-CM that would enhance its osteogenic potential. In the present study, we focused on VEGF in MSC-CM and evaluated the angiogenic and osteogenic potentials of MSC-CM for bone regeneration. Methods: Cytokines in MSC-CM were measured by enzyme-linked immunosorbent assay (ELISA). Human umbilical vein endothelial cells (HUVECs) were cultured with MSC-CM or MSC-CM with anti-VEGF antibody (MSC-CM + anti-VEGF) for neutralization, and tube formation was evaluated. For the evaluation of bone and blood vessel formation with micro-computed tomography (micro-CT) and for the histological and immunohistochemical analyses, a rat calvarial bone defect model was used. Results: The concentrations of IGF-1, VEGF, and $TGF-{\beta}1$ in MSC-CM were $1515.6{\pm}211.8pg/mL$, $465.8{\pm}108.8pg/mL$, and $339.8{\pm}14.4pg/mL$, respectively. Tube formation of HUVECs, bone formation, and blood vessel formation were increased in the MSC-CM group but decreased in the MSC-CM + anti-VEGF group. Histological findings suggested that new bone formation in the entire defect was observed in the MSC-CM group although it was decreased in the MSC-CM + anti-VEGF group. Immunohistochemistry indicated that angiogenesis and migration of endogenous stem cells were much more abundant in the MSC-CM group than in the MSC-CM + anti-VEGF group. Conclusions: VEGF is considered a crucial factor in MSC-CM, and MSC-CM is proposed to be an adequate therapeutic agent for bone regeneration with angiogenesis.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제20권4호
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• pp.275-278
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• 1998

Recently, the clinical applications of the autogenous cancellous bone from the proximal tibial metaphysis show satisfactory results in the repair of maxillofacial bony defect or deformity. The proximal tibia has the potential to yield viable cancellous bone with a minimum of morbidity. The purpose of this study was to investigate the regeneration of a full thickness proximal tibial bone defect with covering or uncovering of cortical bone. The follow-up periods were 4, 8, and 12 weeks. Bone defect of right side was uncovered and left side was covered with cortical bone. In the experimental group (uncovered cortical bone) at 12 weeks, the inside of defect was filled to normal marrow tissue. The cortical bone defect was united of inner, outer callus at 4, 8 weeks in both study group. At 12 weeks, the cortical bone defect was remodeled and invaded by osteoclast (giant cell) in experimental group. In the experimental specimen at 12 weeks, the regenerating tissue of bone defect was not differ from the control group.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권2호
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• pp.107-116
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• 2006

Purpose:Maxillay sinus grafting is an effective treatment procedure to improve bone height in the posterior maxillar area for implant installation. Beta-tricalciumphosphate(${\beta}$-TCP) was introduced to be grafting substitute material, providing a reasonable bio-degradation time, no need for harvesting procedure. The purpose of this study is to evaluate bone healing & regeneration phase using histomorphometric and immunohistochemical analysis. Material & Methods:Sixteen rabbits were divided into 4 groups. Bi-lateral maxillary sinus membranes were elevated at each rabbits, ${\beta}$-TCP was augmented in left sinus, autogenous bone was augmented in right sinus. The rabbits were sacrificed at 2, 4, 8 and 12 weeks. We investigated the bone regeneration & growth factor expression. Results: 1. The mean new bone volume formation was 28.99${\pm}$6.55%, 49.54${\pm}$5.47%, 69.09${\pm}$8.90% in autogenous grafted area, and 22.86${\pm}$5.56%, 24.00${\pm}$4.09%, 34.11${\pm}$3.37% in ${\beta}$-TCP area at 4, 8, 12 weeks. Therefore, new bone formation in autogenous bone was significantly higher than ${\beta}$-TCP (p<0.05). 2. The BMP 2/4 expression in autogenous bone grafted area was higher at 4, 8 weeks. 3. There was no difference in expression pattern of BMP-7/PDGF/VEGF during grafted bone regeneration. Conclusion:The authors we conclude that the autogenous bone graft was faster than ${\beta}$-TCP in bone regeneration, and the BMP 2/4 were more important in graft bone regeneration.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권5호
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• pp.380-390
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• 2004

Bone healing plays an important role in orthognathic and craniofacial surgery. Bone tissue repair and regeneration are regulated by an array of growth and morphogenetic factors. Bone formation and remodeling require continuous generation of osteoprogenitor cells from bone marrow stromal cells, which generate and respond to a variety of growth factors with putative roles in hematopoiesis and mesenchymal differentiation. In this study, the efficacy of a single application of hepatocyte growth factor to promote bone regeneration in 5-mm experimental calvarial defects of adult male rats was assessed histologically and immunohistochemically. The result of the experimental site were compared with those of the contralateral contral side. None of the control and experimental bone defects demonstrated complete bone closure. Bone regeneration was found close th the margine and central part of the defects. At 1, 2 weeks, there were found much significant cellural mitotic activity and many inflammatory cells and osteoblasts on the experimental site than control site. At 4, 6 weeks, new bone apposition was founded in both site but, more apposition was seen at experimental site. At 8, 12 weeks, also, some differences was found that more apposition of new bone and collagen fiber was seen on experimental site. Our results have some possibility that HGF do a early positive role to repair the bone defect. More study will be needed.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제43권6호
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• pp.373-387
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• 2017

Objectives: The purpose of this study was to introduce our three experiments on bone morphogenetic protein (BMP) and its carriers performed using the critical sized segmental defect (CSD) model in rat fibula and to investigate development of animal models and carriers for more effective bone regeneration. Materials and Methods: For the experiments, 14, 16, and 24 rats with CSDs on both fibulae were used in Experiments 1, 2, and 3, respectively. BMP-2 with absorbable collagen sponge (ACS) (Experiments 1 and 2), autoclaved autogenous bone (AAB) and fibrin glue (FG) (Experiment 3), and xenogenic bone (Experiment 2) were used in the experimental groups. Radiographic and histomorphological evaluations were performed during the follow-up period of each experiment. Results: Significant new bone formation was commonly observed in all experimental groups using BMP-2 compared to control and xenograft (porcine bone) groups. Although there was some difference based on BMP carrier, regenerated bone volume was typically reduced by remodeling after initially forming excessive bone. Conclusion: BMP-2 demonstrates excellent ability for bone regeneration because of its osteoinductivity, but efficacy can be significantly different depending on its delivery system. ACS and FG showed relatively good bone regeneration capacity, satisfying the essential conditions of localization and release-control when used as BMP carriers. AAB could not provide release-control as a BMP carrier, but its space-maintenance role was remarkable. Carriers and scaffolds that can provide sufficient support to the BMP/carrier complex are necessary for large bone defects, and AAB is thought to be able to act as an effective scaffold. The CSD model of rat fibula is simple and useful for initial estimate of bone regeneration by agents including BMPs.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제46권5호
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• pp.361-366
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• 2020

Guided bone regeneration (GBR) is a surgical procedure that utilizes bone grafts with barrier membranes to reconstruct small defects around dental implants. This procedure is commonly deployed on dehiscence or fenestration defects ≥2 mm, and mixing with autogenous bone is recommended on larger defects. Tension-free primary closure is a critical factor to prevent wound dehiscence, which is critical cause of GBR failure. A barrier membrane should be rigidly fixed without mobility. If the barrier is exposed, closed monitoring should be utilized to prevent secondary infection.