• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권4호
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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.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권6호
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• pp.620-627
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• 2000

The purpose of this study is to investigate the clinical and histologic changes in distraction osteogenesis according to different distraction rates in the rat's tibia. Eighteen adult rats underwent open osteotomy and attachment of an external unilateral distraction device in the middle of left tibia. Latency was allowed for 7 days before distracton began. The distraction device was activated with varying distraction rates of 0.5mm, 1mm, 2mm and same rhythm of twice a day until 5mm length gain was achieved. The animals were sacrificed at post-distraction 4, 8 weeks to observe the bony healing states. At each group, clinical, radiographic and histologic studies were done. The results obtained from this study were as follows: 1. The 0.5mm group showed excellent osteogenesis than other groups. The new bone was formed by intramembranous bone formation mostly and endochondral bone formation partly. 2. The 1mm group showed delayed osteogenesis and incomplete bony healing at 8 weeks. 3. The 2mm group showed weak osteogenesis and fibrous union or nonunion at 8 weeks. From these results, it could be stated that distraction rate of 0.5mm per day was most useful in rat's tibia. The rate of 1mm showed delayed bony healing and needed more consolidation period. Distraction osteogenesis is a excellent clinical method for regenerating local bone deficiencies in limbs and craniofacial area. The more studies needed for the higher animals and human about distraction rates and other biomechanical factors on the basis of this study.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권3호
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• pp.305-309
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• 2000

The basal cell nevus syndrome is a well recognized entity, the major symptoms of which are basal cell nevi, multiple jaw cysts, skeletal anomalies, and ectopic calcification. The syndrome follows a hereditary pattern, which is characterized by a highly penetrant, autosomal dominant gene with multiple and variable effects. The patient often has a characteristic face, with frontal and temporoparietal bossing, which results in an increased cranial circumference. The eyes may appear widely separated, and 40 percent of patients have true ocular hypertelorism. Jaw cysts are one of the most constant features of the syndrome and are present in at least 75 percent of the patients. The cysts are odontogenic keratocysts and frequently multiple. Radiographically, the cysts in patients with basal cell nevus syndrome do not differ significantly from isolated keratocysts. The cysts in patients with this syndrome are often associated with the crowns of unerupted teeth; on radiographs they may mimic dentigerous cysts. We report a case of multiple odontogenic keratocysts associated with basal cell nevus syndrome with the literature of review.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권5호
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• pp.481-489
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• 2000

This research was focused on overall examination of tissue alteration, wound healing promotion. After the hair on the dorsal surface was shaved, $5{\times}5mm$ oval skin defect was formed. Experimental wounds of right side were irradiated on every day for 90 second with Ga-Al-As semi-conductor laser. Left side wounds served as control group. The rats were sacrificed on the 1st, 3rd, 5th, 7th, 14th, 21th day. For light microscopically, parafin section were stained with H&E, MT. The outcomes were as follows : 1. On 1st day, experimental and control group were seen acute inflammatory cell infiltration, edema. 2. On the 3rd days, both groups were seen crust development, collagen, blood vessel proliferation. 3. On the 5th days, experimental group were reduced edema and inflammatory cell infiltration than control group. 4. On the 7th days, both groups were observed edema, inflammatory cell infiltration disappearance and keratinocytes motility from wound defect. 5. On the 14th days, experimental group appeared collagen, blood vessel proliferation and hair follicle than control group. 6. On the 21th days, both groups were seen normal status re-epithelization. According to the above results, The wound-healing stimulated by laser radiation involves an increased rate of epithelial growth. LLLT was confirmed that it has fibroblast, blood vessel proliferation, influence initial wound healing process.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권5호
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• pp.507-513
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• 2000

Objective : The purpose of this study is to evaluate the vitality of the teeth in and adjacent to the mandibular fracture line according to variable conditions of fracture and to establish the protocol of treatment of fracture line teeth. Materials and Methods : The vitality of 97 teeth in fracture line and 104 teeth adjacent to fracture line of 52 patients were invested preoperatively. Of these, 66 teeth in fracture line and 72 teeth adjacent to fracture line were monitored at least 6 months after operation. An electric pulp tester was used to measure pulpal response. The relationships between the vitality of teeth in variable time(preoperation, immediate post-operation; within 1 week after operation, and 6 months after operation) and variable conditions of fracture(horizontal, vertical gap of fracture line, the number of fracture line)were evaluated statistically. Result : The vitality of fracture line teeth in the 6 months after operation statistically differed by the vertical gap of fracture line and the number of fracture line. The vitality of fracture line adjacent teeth in the immediate post-operation only statistically differed by the vertical gap of fracture line. There were statistically differences between preoperative EPT value and vitality of fracture line teeth on 6 months after operation. There were 5 cases of complications including periapical and periodontal abscess. Of these, only one tooth was extracted and the others were well treated with endodontic treatment and subgingival curettage. Conclusion : It is recommended to retain teeth and to monitor the vitality of teeth in and adjacent to fracture line, unless there is an absolute indication for extraction.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제29권5호
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• pp.282-292
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• 2003

Several agents are in use to promote new bone formation during bone graft procedures in maxillofacial region. Among them, we have used crude BMP, PRP, and P-15 for experimentally created defects with accompanying graft materials in the rabbit model. The aim of this study is to analyze the effect of above mentioned agents on bone formation using histologic and histomorphometrical methods, thus to provide experimental support for clinical application of these agents. Six rabbits were used as experimental animals. Four surgical defects were created on the distal femoral heads of each animal using trephine drill. The defects were filled with each agents with accompaning graft materials as experimental groups and particulate corti-co-cancellous autogenous graft as control. For histomorphometric analysis, fluorescent dye was injected at 2week and 1week before sacrifice. Then, the animals were sacrificed at 2, 4 and 8weeks after surgery and histologic and histomorphometric examinations were achieved. At two weeks after bone graft, bone formation and active remodeling process were examined in all experimental groups and the control. But the intensity of such activities of the experiments were somewhat weaker than that of the control. In BMP group, the amount of newly formed osteoid was increased constantly and the amount was preserved constantly in PRP group. But in P-15 group, the amount of newly formed osteoid was decreased with time to 8week after surgery. Histologic findings showed superior bony quantity and quality in PRP group than that of P-15 group. MAR(Mineralization Apposition Rate) of all experimental groups were slower than that of control group. In P-15 group, constant foreign body reaction was observed at all periods and the graft material showed inwardly destroyed characteristics rather to mature. The data from this study provide the basis for future studies for evaluating the long-term remodeling process and foreign body reactions observed in P-15 group and clinical study for predictable use of these agents.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제29권5호
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• pp.293-297
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• 2003

Florid cemento-osseous dysplasia (FCOD) is a benign, non-neoplastic lesion characterized by multiple sclerosing masses only within jawbones. It is frequently confused with chronic diffuse sclerosing osteomyelitis (CDSO) in previous literatures. In our study, two cases of FCOD were examined to know the characteristics of their calcifying tissues. The first case was non-infected, while the second case was severely infected, displaying the typical features of CDSO in clinico-radiologic findings. The infected FCOD case showed a lot of bacterial colonies in the main lesion with relatively rare inflammatory reaction. The globular cementum-like materials of FCOD showed woven bone pattern and was positive for Alcian blue stain, and also positive for the antibodies of ameloblastin, bone morphogenetic protein (BMP) -2 and -4. On the other hands, in the immunostains of matrix metalloproteinase (MMP) -3, -9, -10, and $TNF-{\alpha}$, macrophage infiltrated in the FCOD lesion was rarely observed. These data suggest that the cementum-like materials of FCOD contain various matrix proteins, and that the cementum-like materials are relevant to the overgrowth of the bacterial colonies by inhibition of the regional inflammatory reactions.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권4호
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• pp.282-291
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• 2004

Pure-phase beta-tricalcium phosphate(${\beta}$-TCP) proved to be a bone regeneration material, providing the patient with vital bone at the defect site in a reasonable time, making a second surgical procedure for bone harvesting unnecessary. This study compares bone healing and BMP 2/4 expression in cranial defects in rabbits grafted with autogenous bone and ${\beta}$-TCP. Thirty New Zealand White rabbits was divided into 3 group of 10 animals each. Bilateral calvarial defects were made in the parietal bones of each animal. ${\beta}$-TCP placed in one defect and the other defects was filled with autogenous bone. The animal were sacrificed at 4, 8 and 12 weeks. Immunohistochemical analysis was used to investigate the expression of BMP 2/4. 1. The new bone formation around autogenous bone from 4 weeks and ${\beta}$-TCP from 8 weeks. 2. In autogenous bone graft, BMP 2/4 expression was decreased from 4 to 12 weeks. 3. In ${\beta}$-TCP graft, BMP 4 expression was increased from 8 to 12 weeks. But, BMP 2 was observed from 12 weeks. This study showed that bone healing, regeneration and, BMP 2/4 expression are delayed in grafted ${\beta}$-TCP than autogenous bone.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제29권2호
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• pp.135-139
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• 2003

저자 등은 본과에 내원하여 함치성 낭종으로 진단된 5명의 소아 환자에서 보존적인 조대술을 이용하여 매복된 영구치를 발거하지 않고 이차 치유를 유도하였다. 술 후 병소는 신생골로 치유되었으며 매복 영구치도 정상적인 위치로 맹출하였다. 이와 같이 소아에서 함치성 낭종의 경우 주기적인 예후 관찰이 가능하다면 보다 보존적인 조대술 등을 이용시에는 영구치의 정상적인 유도와 낭종의 치유를 유도할 수 있으리라 사료된다. 또한 인접치아의 경사 등에 의한 정상적인 치아의 맹출이 어려운 경우에는 교정치료와 병행시에 정상적인 영구 치열을 확보할 수 있을 것으로 사료되어 문헌고찰과 함께 보고하는 바이다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권4호
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• pp.316-322
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• 2004

A low molecular weight component named bone morphogenetic protein(BMP) chemically isolated from the organic matrix of bone, induce postfetal connective tissue cells surrounding small blood vessels to differentiate into cartilage and bone. The end product of BMP is a spherical ossicle of lamella bone filled with red bone marrow for the functional loading. This is a important point that the graft material is embedded the defect site during the implant surgery. Because present knowledge of the relationship between BMP and bone regeneration arises mainly from studies of induced bone formation in heterotopic sites, it would be helpful to determine whether BMP plays any part in the process of bone healing. The BMPs have been shown to play crucial roles in normal skeletal development as well as bone healing and are able to activate transcription of genes involved in cellular migration, proliferation, and differentiation. The delivery of BMP on matrices has been efficacious in the treatment of defect bone in implant surgery. The purpose of the histologic study was to evaluate the effect of DLB(demineralized lyophilized bone) coated with purified human BMP(hBMP-I) in immediate implant surgery with bony defect to obtain the functional structure of implant asap. The ability of a graft of hBMP-I to accelerate bony defect repair provides a rationale for its use in immediate implant surgery that have large bone defect in edentulous area.