• Maxillofacial Plastic and Reconstructive Surgery
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• 제28권5호
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• pp.404-416
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• 2006

Purpose : This study was to clarify the changes in mandibular condyle after unilateral mandibular distraction osteogenesis throughout histological changes and expression of matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of matrix metalloproteinase-2 (TIMP-2). Materials & Methods : Intraoral distractors were placed via submandibular incision in 8 dogs. Two unoperated animals served as controls. Distraction was performed five days after osteotomy as a rate of 0.5 mm twice per day for 10 days. Two animals were sacrificed on 7, 14, 28, and 56 days after completion of distraction, respectively. Ipsilateral condyles were harvested and processed for histological and immunohistochemical examinations. Results : The condyle cartilage is separated into four layers: fibrous layer, proliferative layer, hypertrophic layer, and calcified layer. At 7 days and 14 days after distraction, the condylar cartilage showed the decreased thickness of the articular cartilage and reduced cellularity. At 28 days after distraction, there was an increase in cellularity of fibrous, proliferative, and hypertrophic layer. However, it demonstrated reduced cellularity compared to the control. At 56 days of after distraction, the articular cartilage was an almost normal histologic structure. Positive Safranin-O staining, indicative of sulfated proteoglycans, was examined in the condylar cartilge of nonloaded control. At 7 days and 14 days after distraction, the sulfated proteoglycans is almost completely depleted from the noncalcified part of the condylar cartilage. At 28 days after distraction, there was an increase in Safranin-O staining intensity. However, the staining intensity of the experimental condyle was weaker than that of the control. At 56 days of after distraction, the condylar cartilage showed almost normal Safranin-O staining pattern. In control condyle, MMP-2 immunostaining was seen in fibrous, proliferative, and hypertrophic layer of condylar cartilage, however, it demonstrated lack of staining in fibrous and proliferative layer. At 7 days and 14 days after distraction, strong MMP-2 immunoreactivity was seen in the fibrous, proliferative and hypertrophic layer of the condylar cartilage. At 28 days after distraction, MMP-2 immunostaining was seen in the fibrous and hypertrophic layer of condylar cartilage, however, their immunoactivity was reduced. At 56 days after distraction, MMP-2 immunoreactivity showed almost normal immunostaining pattern. In control condyle, TIMP-2 immunostaining was primarily seen in fibrous and hypertrophic layer of condylar cartilage, however, it demonstrated lack of staining in proliferative layer. At 7 days after distraction, very weak TIMP-2 immunoreactivity appeared in fibrous, proliferative and hypertrophic layer of the condylar cartilage. At 14 days after distraction, weak TIMP-2 immunoreactivity was seen in the fibrous, proliferative and hypertrophic layer of the condylar cartilage. At 28 days after distraction, TIMP-2 immunoreactivity was increased in the fibrous and hypertrophic layer of condylar cartilage. At 56 days after completion of distraction, TIMP-2 immunoreactivity showed almost normal immunostaining pattern. Conclusions : The results show that short-term outcome of physiologic distraction osteogenesis may lead to degenerative changes in the condylar cartilage. These alterations in the condylar cartilage may be considered as a pressure-related degeneration of the cartilage tissue. However, the long-term results suggest that the condylar cartilage display repair activity after mandibular distraction osteogenesis.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제29권2호
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• pp.123-131
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• 2007

Introduction: Distraction osteogenesis is widely used as for bone lengthening in patients with maxillofacial deformity and alveolar bone atrophy. One of the major problems in distraction osteogenesis is long consolidation period for 2-3 months, in which the devices have to be fixed on the bone to prevent relapse. It results in scar formation on the face, disturbance of mastication and speech. This study was performed to evaluate the stimulating effect of pulsed electromagnetic field on the early bone consolidation in distraction osteogenesis. Materials and methods: Total 10 rabbit were used (5 for control group, 5 for experimental group). A vertical osteotomy in the mandibular body was performed and the distraction device was fixed. After 5 days distraction was done 1mm per a day for 7 days. A pulsed electromagnetic field (38 Gauss, 60 Hz) was applied for 8 hours per day and it continued for 5 days immediately after distraction in the experimental group. Both groups were sacrificed after 2 weeks. Histological specimens with H&E and Masson Trichrome staining were made and histomorphometrically analysed with image analyser. Results: The device for distraction osteogenesis was displaced in one animal for each group, therefore, only four animals in both groups were evaluated. In both groups, a new bone formation was observed in the distracted area after 2 weeks. The bone formation was enhanced in the experimental groups ($31.76{\pm}8.68%$) compared with control group ($9.94{\pm}3.23%$), its difference was statistically significant (p<0.001). Conclusion: This study suggests that electrical stimulation with electromagnectic field may be effective in the early bone formation after distraction osteogenesis. Further studies with large number of animals are needed before clinical application.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제30권5호
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• pp.407-416
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• 2008

Purpose: The aim of the present study is to evaluate the effect of repetitive distraction and compression on new bone formation during distraction period. Materials and methods: Sixteen healthy rabbits, weighing about 2.5kg, were used in this experiment. A unilateral mandibular osteotomy was performed in the left mandible and the distractor(Track 1 $plus^{(R)}$, Gebruder Martin $GmbH^{(R)}$, Germany) was fixed with four screws (Cross driver screw $TI^{(R)}$, Gebruder Martin $GmbH^{(R)}$, Germany). After 4 days, the mandibles were distracted at a rate of 0.6mm/day for 10 days to obtain the amount of 6mm distraction in the control group(n=4). In the experimental group A(n=6), they were distracted at a rate of 1.2mm/day for 5 days and then compression of 0.6mm length and distraction of 0.6mm per 12 hours were carried out as counter direction for 5 days, relatively. In the experimental group B(n=6), distraction of 1.2mm length and compression of 0.6mm length per 12 hours were repeated for 10 days to obtain the amount of 6mm distraction finally. The experimental animals were sacrificed at 2 and 4 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 and Masson- Trichrome staining and then, measured Bone Deposition Rate with TOMORO $ScopeEye^{TM}$ ver. 3.5(Olympus, Japan), Results: Histologically, new bone formation was 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. On the histomorphometric analysis, Bone Deposition Rate was higher in the experimental group A$(50.67{\pm}4.36%)$ than in the control group$(45.94{\pm}3.97%)$ and in the experimental group B$(42.68{\pm}5.70%)$. These data showed significant differences statistically(p<0.05). Conclusion: These results show that the distraction osteogenesis using repetitive compression and distraction force in the early consolidation period may be effective for new bone formation.

• 대한치과교정학회지
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• 제38권2호
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• pp.121-132
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• 2008

양악 수술 시 상악골의 상방이동을 시행하였을 경우에 상기도의 공간적 구조변화를 평가하기 위하여, 술전, 술후, 술후 6개월 후의 간격으로 두부규격방사선사진을 촬영하여 그 변화량을 분석해 보았다. 술전 교정치료를 시행하여 상악은 Le Fort I 골절단술로 상방이동 시행하였고 동시에 하악은 후방이동 시키는 수술을 시행 받은 24명을 대상으로 하였다 (평균 연령22세 1개월, 남자 9명 여자 15명). 상악골 상방이동에 대한 상기도 공간의 변화와 그에 따른 관련성을 조사한 결과, PAS (R)부위는 술후 (T1) 감소하였으나 (p<0.01) 술후 6개월 후(T2)에는 다시 증가하여 술전과 비교 시, 크기 변화를 관찰할 수 없었고, PAS (NL) 부위는 술후(T1)와 술후 6개월 후(T2)에서 유의성 있는 크기 증가를 보였다. PAS (OL)의 경우, 술후 (T1)증가를 보이다가 술후 6개월 이후(T2)에서 감소하였다. 연구개의 두께는 술후 (T1) 증가를 보이다가 6개월 이후 (T2) 처음과 같거나 약간 감소하는 것으로 나타났으며 FH-uvular 각도는 술후 6개월 이후 증가하였다. 또한 상악골 상방이동에 대한 상기도 공간의 변화를 회귀분석 시행한 결과 양악수술 시 평균 $4.40{\pm}1.14mm$의 상악골 상방이동은 양악 수술 후 상기도 공간의 변화에 큰 영향을 미치지 않는 것으로 나타났다.

• 대한소아치과학회지
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• 제32권4호
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• pp.709-716
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• 2005

구순구개열 환자에서는 이른 시기에 시행된 수술로 인한 구순이나 구개부의 반흔 형성으로 섭식장애나 발음장애를 동반한 상악의 열성장이 나타나게 된다. 때로는 집중적인 교정치료 후에도 심한 상악골 저형성증을 보이며 이러한 경우성장이 완료 된 후에 골이식을 동반한 악교정 수술로 상악골을 전방이동시켜 안모의 개선을 도모하기도 한다. 그러나 이러한 상악골의 전방이동은 연조직의 과도한 신장으로 인한 술후회귀현상, 추가적인 골이식이 필요하다는 한계를 가지고 있다. 골신장술은 이러한 한계점을 극복하는 최신 치료방법으로 구순구개열 환자, 두개골 융합증을 나타내는 환자 등에서 상악골을 포함한 두개 안면골의 개선에 많이 이용되고 있다. 특히 구외장치를 이용하는 골신장술은 골신장기간 중에 견인 방향의 조절이 보다 쉬우며, 충분한 양의 골신장이 가능하여 보다 좋은 결과를 얻을 수 있다. 본 증례는 상악 열성장을 보이는 구순구개열 6세 7개월의 여자 환아로, 변형된 구내 르포씨 1형 골절단술(modified Le Fort I osteotomy) 후 두개골을 고정원으로 이용하는 견고 구외 골신장술을 통해 상악골을 전진시켜 양호한 결과를 얻었기에 이를 보고하는 바이다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제28권6호
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• pp.531-548
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• 2006

The purpose of this study was to investigate the biomechanical, histologic findings of distracted regenerate and TMJ response in modified distraction osteogenesis (DO) technique combined with compression force as biomechanical stimulation method which has been suggested in 2002, and developed thereafter by authors. This study was performed with two experiments. First experiment was designed to explore the optimal ratio of compression force versus distraction force for the new DO technique. Second experiment was planned to evaluate the reaction of TMJ tissue, especially condyle, disc after application of the DO technique with compression force. Total 52 New Zealand adult male-rabbits with 3.0kg body weight were used for the study. For the first study, 30 adult male-rabbits underwent osteotomy at one side of mandibular body and a external distraction device was applied on each rabbit with same manner. In the control group of 10 rabbits, final 8 mm of distraction with 1 mm rate per day was done with conventional DO technique after 5 latency days. For the experimental group of 20 rabbits, a compression force with 1 mm rate per day was added to the distracted mandible on 3-latency day after over-distraction (over-lengthening). As the amount of the rate of compression versus distraction, experimental subgroup I (10 rabbits) was set up as 2 mm compression versus 10 mm distraction (1/5) and experimental subgroup II (10 rabbits) was set up as 3 mm compression versus 11 mm distraction (about 1/3). All 30 rabbits were set up to obtain final 8 mm distraction and sacrificed on postoperative 55 day to analysis on biomechanical, and histologic findings of the bone regenerates. For second study, 22 adult male-rabbits were used to evaluate TMJ response after the DO method application with compression force. In the control group, 10 rabbits was used to be performed with conventional DO method, on the other hand, in a experimental group of 10 rabbits, 10 mm distraction with 2 mm compression (1/5 ratio) was done. The remaining 2 rabbits served as the normal control group. Histomorphologic examinations on both condyle, histological studies on condyle, disc were done at 1, 2, 3, 4, 7 weeks after distraction force application. The results were as follows: 1. On the bone density findings, the experimental group II (force ratio - 1/3) showed higher bone density than the other experimental group (force ratio - 1/5) and control group (control group - $0,2906\;g/cm^2$, experimental group I - $0.2961\;g/cm^2$, experimental group II - $0.3328\;g/cm^2$). 2. In the histologic findings, more rapid bone maturation like as wide lamellar bone site, more trabeculae formation was observed in two experimental groups compared to the conventional DO control group. 3. In morphologic findings of condyle, there were no differences of size and architecture in the condyle in the control and experimental groups. 4. In histologic findings of condyles, there were thicker fiberous and proliferative layers in experimental group than those of control group until 2 weeks after distraction with compression force. But, no differences were seen between two groups on 3, 4, 7 weeks after compression. 5. In histologic findings of disc, more collagen contents in extracellular matrix, more regular fiber bundles, and less elastin fibers were seen in experimental group than control group until 2 weeks after distraction with compression. But, no differences were seen between two groups on 3, 4, 7 weeks after distraction with compression. From this study, we could identify that the new distraction osteogenesis technique with compression stimulation might improve the quality of bone regeneration. The no remarkable differences on TMJ response between control and experimental groups were seen and TMJ tissues were recovered similarly to normal TMJ condition after 3 weeks.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제32권4호
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• pp.299-305
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• 2010

Purpose: Adipose tissue is located beneath the skin, around internal organs, and in the bone marrow in humans. Its main role is to store energy in the form of fat, although it also cushions and insulates the body. Adipose tissue also has the ability to dynamically expand and shrink throughout the life of an adult. Recently, it has been shown that adipose tissue contains a population of adult multipotent mesenchymal stem cells and endothelial progenitor cells that, in cell culture conditions, have extensive proliferative capacity and are able to differentiate into several lineages, including, osteogenic, chondrogenic, endothelial cells, and myogenic lineages. Materials and Methods: This study focused on endothelial cell culture from the adipose tissue. Adipose tissues were harvested from buccal fat pad during bilateral sagittal split ramus osteotomy for surgical correction of mandibular prognathism. The tissues were treated with 0.075% type I collagenase. The samples were neutralized with DMEM/and centrifuged for 10 min at 2,400 rpm. The pellet was treated with 3 volume of RBC lysis buffer and filtered through a 100 ${\mu}m$ nylon cell strainer. The filtered cells were centrifuged for 10 min at 2,400 rpm. The cells were further cultured in the endothelial cell culture medium (EGM-2, Cambrex, Walkersville, Md., USA) supplemented with 10% fetal bovine serum, human EGF, human VEGF, human insulin-like growth factor-1, human FGF-$\beta$, heparin, ascorbic acid and hydrocortisone at a density of $1{\times}10^5$ cells/well in a 24-well plate. Low positivity of endothelial cell markers, such as CD31 and CD146, was observed during early passage of cells. Results: Increase of CD146 positivity was observed in passage 5 to 7 adipose tissue-derived cells. However, CD44, representative mesenchymal stem cell marker, was also strongly expressed. CD146 sorted adipose tissue-derived cells was cultured using immuno-magnetic beads. Magnetic labeling with 100 ${\mu}l$ microbeads per 108 cells was performed for 30 minutes at $4^{\circ}C$ a using CD146 direct cell isolation kit. Magnetic separation was carried out and a separator under a biological hood. Aliquous of CD146+ sorted cells were evaluated for purity by flow cytometry. Sorted cells were 96.04% positivity for CD146. And then tube formation was examined. These CD146 sorted adipose tissue-derived cells formed tube-like structures on Matrigel. Conclusion: These results suggest that adipose tissue-derived cells are endothelial cells. With the fabrication of the vascularized scaffold construct, novel approaches could be developed to enhance the engineered scaffold by the addition of adipose tissue-derived endothelial cells and periosteal-derived osteoblastic cells to promote bone growth.

• 대한치과보철학회지
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• 제51권1호
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• pp.11-19
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• 2013

연구 목적: 본 연구에서는 수술가이드를 이용한 무피판 임플란트 술식에서 임플란트 드릴링이 열발생에 미치는 효과를 측정하였으며 드릴링 방법에 따른 온도 차이를 측정하고자 하였다. 연구 재료 및 방법: 하악 양측 제 1 대구치와 제 2 대구치가 없는 실험 모델에서 피판을 거상하는 임플란트 수술(실험A군)과 수술가이드를 이용한 무피판 임플란트 수술(실험B군), 그리고 핸드피스의 상하 수직 움직임을 제한한 후 수술가이드를 이용하여 무피판 임플란트 수술(실험C군)을 각각 진행하여 온도 측정을 하였다. 임플란트 드릴링 시 온도 측정은 thermocouple과 열전식 온도 기록계(Yokogawa, Tokyo, Japan)를 이용하여 측정하였다. 온도 측정 위치는 최종 임플란트 드릴(직경 3.8 mm)의 경계부에서 0.5 mm 떨어진 곳에서 3 mm 깊이(설측)와 6 mm 깊이(협측)로 하였다. 측정된 온도 값을 이용하여 종속변수인 온도가 정규분포 하는지를 검정하기 위해 Kolmogorov-Smirnov test를 거쳐 확인한 후 세 수술 방법 간의 평균 온도 차이를 검정하기 위해 independent t-test로 분석하였다. 결과: 피판을 거상하고 드릴링을 한 수술군(실험A군)에서 평균 온도는 $27.2^{\circ}C$($SD{\pm}2.1^{\circ}C$)를 보였고 피판을 거상하지 않고 드릴링을 한 수술군(실험B군)에서 평균 $27.5^{\circ}C$($SD{\pm}2.3^{\circ}C$)를 나타냈다. 이들 두 수술 방법 간 온도비교에서는 통계학적으로 유의한 차이를 보이지 않았다. 수술가이드를 이용하여 무피판 수술 시 상하 수직 움직임(upand-down pumping motion)이 없이 드릴링을 시행한 수술군(실험C군)에서 평균온도는 $37.0^{\circ}C$($SD{\pm}3.4^{\circ}C$)을 보였다. 이를 상하 수직 움직임으로 드릴링을 한 무피판 임플란트 수술군(실험B군)과 비교 시 통계학적으로 유의한 온도 차이를 보였다. 결론: 수술가이드를 이용하여 무피판 임플란트 수술 시 핸드피스를 상하 수직 움직임으로 드릴링을 시행하면 피판을 거상하여 수술할 때와 온도차이가 발생하지 않으나, 상하 수직 움직임 없이 드릴링을 시행하면 드릴링 시 높은 온도 상승을 보인다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권5호
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• pp.403-414
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• 2005

The purpose of this study was to identify the effectiveness of the modified distraction osteogenesis (DO) method with the concept of overdistraction and compression stimulation which have been previously suggested by the authors in 2002 and to explore the optimal distraction-compression ratio and appropriate latency period for the compression force application during consolidation. The experimental specimens were assessed with radiography, histologic findings, and dual energy x-ray absorptiometry (DEXA) after the conventional DO method and the modified DO technique had been applied on rat mandibles. Total 60 rats were used for the study. In experimental group of 54 adult rats, mandibular osteotomies between the first and second molar areas were performed and customized external distractors were applied. The surgeries on 6 rats of control group also were done with same osteotomy technique and DO device application. Final amount of distraction was set-up as 2 mm on both groups. But, in a experimental group of 54 rats, distraction osteogenesis with a compression force were performed with the different distraction-compression ratio and variant latency periods for compression. The three ratio-subgroups were made as distraction 4 mm group with compression 2 mm, distraction 3 mm group with compression 1 mm, and distraction 2.5 mm group with compression 0.5 mm. In addition, The three subgroups with 3, 7, 11 days latency period prior compression were allocated on each ratio-subgroups. Total 9 subgroups consisted of 6 rats on each subgroup. In control group of 6 rats, conventional distraction technique were routinely performed. The rats of control groups were sacrificed on postoperative 3, 6 weeks after 2 mm distraction. The rats in the experimental groups also were sacrificed on the same euthanasia days of control groups to compare the wound healing. Final available specimens were 55 rats except 5 due to osteomyelitis, device dislodgement. Distraction-compression combined group on 6 weeks generally had showed increased bone mineral density than the same period group of conventional distraction technique on the DEXA study. More matured lamellar bone state and extended trabecular pattern in the combined group than those of control group were also observed in the histologic findings on 6 weeks. In the distraction-compression combined groups, the bone density of 2.5 mm distraction subgroups with 0.5 mm compression showed the highest value on the DEXA study among various force ratio groups. In the distraction-compression combined groups, the bone density of 3 day latency period subgroups showed the highest value on the DEXA study among various latency period groups for the compression application. From this study, we could deduce that 1/5 force ratio for the compression versus distraction, 3 day latency period prior compression application would be the most effective condition if modified distraction osteogenesis technique might be applicable. The modified DO method with a compression force may improve the quality of bone regenerate and shorten total treatment period in comparison with conventional DO technique clinically.