• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.4
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• pp.250-254
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• 2010

Introduction: This study evaluated the bone regenerative effect of silk fibroin mixed with platelet-rich fibrin (PRF) of a bone defect in rabbits. Materials and Methods: Ten New Zealand white rabbits were used for this study and bilateral round shaped defects were formed in the parietal bone (diameter: 8.0 mm). The silk fibroin mixed with PRF was grafted into the right parietal bone (experimental group). The left side (control group) was grafted only PRF. The animals were sacrificed at 4 weeks and 8 weeks. A micro-computerized tomography (${\mu}$CT) of each specimen was taken. Subsequently, the specimens were decalcified and stained for histological analysis. Results: The average value of plane film analysis was higher in the experimental group than in the control group at 4 weeks and 8weeks after surgery. However, the difference was not statistically significant.(P>0.05) The tissue mineral density (TMD) in the experimental group at 4 weeks after surgery was significantly higher than the control group.(P<0.05) Conclusion: Silk fibroin can be used as a scaffold of PRF for rabbit calvarial defect repair.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.5
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• pp.464-469
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• 2007

The bone graft materials are grossly divided into autogenous bone, allogenic bone, xenogenic bone, and alloplastic material. Among the various allogenic graft materials, hydroxyapatite($Ca_{10}(PO_4)_6(OH)_2$, HA), the main inorganic phase of human hard tissue, is widely used as a repair material for bones. When HA applied to bony defect, however, it may be encapsulated with fibrous tissue and floated in the implanted area by the lack of consolidation. Fluoridated hydroxyapatite($Ca_{10}(PO_4)_6(OH)_2$, FHA), where F- partially replaces the OH- in the hydroxyapatite, is considered as an alternative material for bone repair due to its solubility and biocompatibility. This study was designed to find out the bone healing capacity of FHA newly produced as a nanoscale fiber in the laboratory. We implanted HA and FHA in the rabbit cranium defect and histologically analysed the specimen. The results were as follows. 1. In the 4 weeks, fibrous connective tissue and little bone formation around materials of the experimental group I implanted HA were observed. In the experimental group II implanted FHA, newly formed bone around materials were observed. 2. In the 8 weeks, the amount of newly formed and matured bone of the experimental group II was more than the experimental group I and control group. From the results obtained, we suggest that FHA, newly synthesized, is relatively favorable bone substitute with bioconpatibility and has better bone healing capacity than pure HA.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.3
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• pp.371-377
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• 1996

Bone graft has been used to repair one defect caused by disease and trauma, congenital and acquired deformities. Graft materials are autogenous bone, allogenic bone, xenogenic bone, synthetics. Autogenous bone graft is the most superior to other materials for immunologic reaction, compatibility to host tissue, and revascularization. However, autogenous bone graft is required for additional operation and the amount of taking is limited. Autografts are obtained at own expense and also limited in size, shape. In order to compensate these problems, allogenic bone graft has been used increasingly. But allogenic bone graft encounters immunologic complications. Therefore, it has been used after freezing, lyophilization, or demineralization. Allogenic bone processed by only lyophilization includes potential antigenic properties on its surface, therefore it is demineralized to deplete immunologic reaction. Demineralized bone releases BMP and helps the mesenchymal cells transform to the chondroblast to produce cartilage and bone. This reaction is called osteoinducation. Many authors have reported that mineralized lyophilized bone had less antigenicity clinically and favorable bony consideration with host bone. In our department from 1995 to now, we have used banked allogenic bone graft that has been prepared from Wonkwang Bone Bank in 5 cases and mineralized lyophilized bone graft in 2 cases to reconstruct the maxillofacial bone defect after tumor resection and cyst enucleation and cleft alveolus. We will report with literature review that the result is favorable functionally and esthetically.

• Imaging Science in Dentistry
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• v.39 no.3
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• pp.163-168
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• 2009

Purpose : To assess the clinical findings and hard tissue changes of osteomyelitis of the jaws using computed tomographic (CT) image analysis. Materials and Methods : We reviewed and interpreted the CT images of 163 patients (64 males and 99 females, age range from 10 to 87 years) who visited the Seoul National University Dental Hospital from April 23, 2006 to December 31, 2008 and were diagnosed as osteomyelitis of the jaws through clinical, radiologic, and histopathologic examination. Each CT findings was investigated for frequency, correlation with age and gender. Results : Of the 163 patients, 31 (19.0%) were affected on the maxilla, 135 (82.8%) were affected on the mandible, and 3 (1.8%) were affected on the both jaws simultaneously. The mean age of the patients who were affected on the maxilla was 61.0 years and that of the patients who were affected on the mandible was 56.2 years. On the maxilla, the most frequent site of disease was the posterior area (83.9%) and on the mandible, mandibular body (83.0%), followed by angle (48.1%), ramus (38.5%), condyle (13.3%), incisal area (9.6%), and coronoid process (3.0%). Among the 31 maxillary osteomyelitis, defect in the trabecular bone was observed in 28 (90.3%), osteosclerosis 20 (64.5%), defect in the cortical bone 27 (87.1%), sequestrum 17 (54.8%), and periosteal reaction 2 (6.5%). Among the 135 mandibular osteomyelitis, defect in the trabecular bone was observed in 100 (74.1%), osteosclerosis 104 (77.0%), defect in the cortical bone 116 (85.9%), sequestrum 36 (26.7%), and periosteal reaction 67 (49.6%). Conclusion : Of our cases, the maxillary osteomyelitis was visibly observed more frequently in females than males. The incidence is the highest in seventies (28.8%) and the lowest in teens (3.1%). The osteomyelitis of the jaws was observed more frequently in males than females before the age of 50, and observed more frequently in females after the age of 50. The most noticeable point was that the sequestrum was observed more often on maxillary osteomyelitis and the periosteal reaction was observed more often on mandibular osteomyelitis.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.6
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• pp.481-491
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• 2005

Purpose: The aim of the present study is to evaluate the effect of autogenous bone and allograft material coverd with a bioresorbable membrane on bone regeneration after a simultaneous installation of implant. Materials and methods: Twelve healthy rabbits, weighing about $3{\sim}4$ kg, were used in this experiment. Following impalnt(with 3.25 mm diameter and 8 mm length) site preparation by surgical protocol of $Oraltronics^{(R)}$, artificial bony defect, 5mm sized in height and depth, was created on femoral condyle using trephine drill(with 5 mm diameter and 5 mm length). Then implant was inserted. In the experimental group A, the bony defect was filled with autogenous particulated bone and coverd with $Lyoplant^{(R)}$ resorbable membrane. In the experimental group B, the bony defect was filled with allograft material(Orthoblast $II^{(R)}$) containing demineralized bone matrix and covered with $Lyoplant^{(R)}$. In the control group, without any graft materials, the bony defect was covered with $Lyoplant^{(R)}$. The experimental group A and B were divided into each 9 cases and control group into 3 cases. The experimental animals were sacrificed at 3, 6 and 8 weeks after surgery and block specimens were obtained. With histologic and histomorphometric analysis, we observed the histologic changes of the cells and bone formation after H-E staining and then, measured BIC and bone density with KAPPA Image $Base^{(R)}$ system. Results: As a result of this experiment, bone formation and active remodeling process were examined in all experimental groups and the control. But, the ability of bone formation of the experimental group A was somewhat better than any other groups. Especially bone to-implant contact fraction ranged from 12.7% to 43.45% in the autogenous bone group and from 9.02% to 29.83% in DBM group, at 3 and 8 weeks. But, bone density ranged from 15.67% to 23.17% in the autogenous bone group and from 25.95% to 46.06% in DBM group at 3 and 6 weeks, respectively. Although the bone density of DBM group was better than that of autogenous bone group at 3 and 6weeks, the latter was better than the former at 8 weeks, 54.3% and 45.1%, respectively. Therefore these results showed that DBM enhanced the density of newly formed bone at least initially.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.4
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• pp.325-336
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• 2000

Bone morphogenetic protein-2/4 are members of Transforming Growth Factor-$\beta$(TGF-$\beta$) superfamily and they may induce formation of cartilage and bone in vivo. This study was performed to investigate the cellular target and period of action of BMP-2/4 and understanding of actions of BMP-2/4 at cellular level. The appearance of BMP-2/4 during healing of mandibular and periodontal defect in rat was evaluated immunohistochemically. 40 Sprague-Dawley strain white male rats, each weighing about 300gm were used. Bony defect was performed in the mandible and they were sacrificed at the day of 3rd, 10th, 20th, 30th after operation. The specimens were harvested and examined histologically and immunohistochemically by localization of anti-BMP-2/4. The results were as follows: 1. Woven bone was observed at 10th day and perfect healing of defect with compact bone and periodontal ligment space at 30th day. 2. Osteoprogenitor cells, osteoblastic cells and periosteum were positive reaction to immunohistochemical stain at 10th day. 3. Cells of bone marrow space and surface cells of osteocytes and cementoblasts were positive reaction to immunohistochemical stain at 20th day. 4. Newly formed osteocytes and cementocytes were positive reaction to immunohistochemical stain at 30th day. From the above findings, we could conclude that BMP-2/4 acted significant roles as factors of induction, proliferation and differentiation during bone healing process.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.21 no.1
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• pp.1-12
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• 1999

The purpose of this study was to evaluate the healing process of the calvarial defect filled with hydroxylapatite(HA) and $TGF-{\beta}$ in Rat. 72 Sprague-Dawly rats were divided into 3 groups, control and two experimental groups. Bony defect were artificially prepared in the calvaria of all 72 rats and followed by implantation of HA (experimental group of 24 rats) and HA+$TGF-{\beta}$(another experimental group of 24 rats) into the defects. Sequential sacrifice was performed at 1, 2, 4, 6, 8, 12 weeks of experiment. Obtained specimen was stained with Hematoxylin and Eosin, Masson's Trichrome and Immunohistochemistry. The results were as follows, 1. Granulation tissue was prominent on control group in 1 and 2 weeks. Bony defects were filled with dense fibrous tissue through the whole experimental period and osteoinduction could not be observed in all groups. 2. Inflammatory cell infiltration was prominent on control group in 1 and 2 weeks and osteoclastic activity was high in HA implanted experimental group at 1 and 2 weeks. 3. Inflammatory cell infiltration was less and maturation of fibrous tissue could be found on HA+$TGF-{\beta}$ implanted experimental group at 1 and 2 weeks. 4. Osteoconduction activity was high in HA+$TGF-{\beta}$ implanted experimental group at 2 and 4 weeks but there was no difference after 6 weeks among 3 groups. 5. In grafted site of HA+$TGF-{\beta}$ implanted group, osteonectin expression was slightly increased from 1 week to 6 weeks. In the host site, it was increased from 1 to 4weeks. 6. In grafted site of HA+$TGF-{\beta}$ implanted group, osteocalcin expression was high at 4 weeks. In the host site, we could find the difference among 3 groups. From above results, the HA with mixture of $TGF-{\beta}$ has the potentiality of promoting bone formation in the bony defect area in the rat.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.1
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• pp.9-15
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• 2010

Aim of the study: As an injectable scaffold, MPEG-PCL diblock copolymer was applied in bone tissue engineering. In vivo bone formation was evaluated by soft X-ray, histology based on the rat calvarial critical size defect model. Materials and Methods: New bone formation was evaluated with MPEG-PCL diblock copolymer in rat calvarial critical size bone defect. No graft was served as control. 4, 8 weeks after implantation, gross evidence of bone regeneration was evaluated by histology and soft X-ray analysis. Results: The improved and effective bone regeneration was achieved with the BMP-2 and osteoblasts loaded MPEG-PCL diblock copolymer. Conclusion: It was confirmed that MPEG-PCL temperature sensitive hydrogels was useful as an injectable scaffold in bone regeneration.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.4
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• pp.361-365
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• 2007

The reconstruction of perioral defects following resection of cancer on the perioral region has been a challenge for oral and maxillofacial surgeons. Surgical management of oral squamous cell carcinoma (SCC) typically involves resection of the carcinoma with a 1cm margin of normal appearing tissue. A large surgical defect is often encountered. The goals of perioral reconstruction are esthetics and function, with oral competence and good lip control. Abbe described the operation that bears his name in 1898, when he reported on the repair of a "conspicuous deformity" in a 21-year-old man born with bilateral cleft lip and palate. Since that time, Abbe flap reconstruction has been used more frequently for repair following resection of malignancies. Large defects of the lips have been repaired with recent modifications of the Abbe flap. The technique has been popularized by Estlander for reconstruction of the lower lip. We have treated 70-year-old male patient with SCC on lower lip using Abbe-Estlander flap. Postoperatively the results showed good prognosis. So we report the result of its treatment and case with review of literatures.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.6
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• pp.466-472
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• 2012

The loss of mandibular continuity due to trauma, neoplasm, or infection results in major esthetic and biologic compromise. The reconstruction of the mandibular bone defect still poses a challenge to oral and maxillofacial surgeons. There have been a number of variety graft materials. Among them, free block bone graft with rigid fixation has been widely used. However, cases using free block bone grafts may lead to a marked invasion of the donor site, mal-union, and absorption of the block bone. In this respect, particulate cortical bone using a titanium mesh tray can be an effective alternative option in order to achieve a proper bone contour and good oral rehabilitation. We have developed an intraoral approach for the mandibular reconstruction method using a titanium mesh tray with autogenous particulate cortical bone graft.