• 한국정밀공학회지
• /
• 제19권4호
• /
• pp.18-24
• /
• 2002

• Imaging Science in Dentistry
• /
• 제31권4호
• /
• pp.199-204
• /
• 2001

Purpose : To assess the relationship between soft tissue asymmetry and bone tissue asymmetry using the standardized photographs and the posteroanterior (PA) cephalometric radiographs in mandibular asymmetric patients. And to clarify that the lack of morphologic balance among different skeletal components can often be masked by compensatory soft tissue contributions. Methods: Experimental group consisted of 58 patients whose chief complaints were facial asymmetry, they were taken with standardized facial photographs and PA cephalometric radiographs. Control group consisted of 30 persons in the normal occlusion. The reproducibility of the facial photograph was confirmed by model test. The differences of fractional vertical heightand horizontal width from standardized facial photographs and PA cephalometric radiographs were compared and analyzed. Results: The difference of fractional vertical bone height was 0.63 and fractional vertical soft height was 0.58 in control group, 3.10 and 2.01 in asymmetric group, respectively. The difference of fractional horizontal bone width was 0.52 and fractional horizontal soft width was 0.70 in control group, 2.51 and 1.70 in asymmetric group, respectively. Both soft and bone tissue showed significant difference between control and asymmetric group (p<0.05). The difference of bone tissue was greater than that of soft tissue (p<0.05) in the experimental group but, not in control group. Conclusions: Soft tissue components may compensate for underlying skeletal imbalances.

• 한국임상수의학회지
• /
• 제34권6호
• /
• pp.410-413
• /
• 2017

Composites of hydroxyapatite (HAp) and chitosan (CS) have been successfully used in bone healing in humans and animals. However, the characteristics of HAp and CS are different. Therefore, the effects of HAp/CS composites on canine bone formation could differ according to their ratio. This study investigated the therapeutic effects of different contents ratios (100, 80:20, 60:40 wt%) on bone defects in a canine model. Thirty intrabony cylindrical defects were created in the humeruses and femurs of 5 beagle dogs, and then the defects were implanted with different composites. The evaluations were performed using radiographs obtained at 10 weeks post-surgery and by histological findings. In radiographic evaluation including the grades of bone filling, periosteal and endosteal reactions, pure hydroxyapatite composite had a significant effect on bone filling, and chitosan containing the composites showed vigorous responses at the periosteum and endosteum. In histological findings, the defect implanted with pure hydroxyapatite had healed completely into mature bony tissue with an obvious osteon structure, and the defect implanted with chitosan containing the composites had the amount of fibrous connective tissue increased significantly within the cortical bone tissue. The results indicate that hydroxyapatite/chitosan composites are therapeutically useful, promoting effective bone healing in defects when the ratio of hydroxyapatite is high and enhanced fibrous connective tissue formation at the periosteum as more chitosan is added.

• Journal of Periodontal and Implant Science
• /
• 제25권2호
• /
• pp.341-356
• /
• 1995

The purpose of this study was to evaluate the effect of demineralized freeze dried bone and demineralized bone gel with guided tissue regeneration treatment around titanium implants with dehisced bony defects and also evaluate space maintaining capacity of demineralized bone gel type and DFDB powder type under e-PTFE membrane. In 3 Beagle dogs, mandibular premolar was extracted and four peri-implant osteotomies were formed for dehiscence. After insertion of implants, the four peri-implant defects were treated as follows. 1) In control group. no graft material and barrier membrane were applied. 2) In experimental group.1, the site was covered only with the e-PTFE membrane. 3) In experimental group 2,received DFDB powder and covered by the e-PTFE membrane. 4) In experimental group 3, demineralized bone gel and e-PTFE membrane were used. By random selection, animals were sacrificed at 4, 8, 12 weeks. The block sectioned specimens were prepared for decalcified histologic evaluation(hematoxylin and eosin staining) and undecalcified histologic evahiation(Von Kossa's and toluidine blue staining) with light microscopy. The results of this study were as follows. 1) In control group, there was a little new bone formation and connective tissue was completely filled in the defect area. 2) Experimental group 1 showed lesser quantity of bone formation as compared to the bone grafted group. Thin vertical growth of new bone formation around implant fixture was shown. 3) Experimental group 2 showed thick bucco-lingual growth of new bone formation and grafted bone particles were almost resorbed in 12 week group. 4) In experimental group 3, most grafted bone particles were not resorbed in 12 week group and thick bucco-lingual bone formation was shown in dehisced defect base area. 5) There was no remarkable differences in space making capacity and new bone formation procedure between demineralized freeze-dried bone powder type and demineralized bone gel type.

• Journal of Periodontal and Implant Science
• /
• 제23권3호
• /
• pp.461-474
• /
• 1993

This study was performed to estimate the effect of plaque control on the progress of the repair pattern of the alveolar bone surface after bone surgery. In this experiment six mongrel dogs were used, four of them were as experimental group and others were as control. In the case of experimental group, dental floss ligature was tied over the neck of crown for permiting of plaque accumulation during one week before surgery and oral hygiene procedures were not performed. In control group, all the surgical intervention was done as same procedure with experimental except oral hygiene program. After surgery plaque was controlled during one week with using the chlorhexidine brushing. Animals were sacrificed at 1,2,4,6 weeks after osseous surgery. The results were as follows : 1. The alveolar bone defects were covered with regenerated epithelium at one week, matrix change of granulation tissue on subcutaneous area was observed, and new bone formation was initiated from the surface of the bone defects. 2. The connective tissue arrangement revealed more dense, new bone formation by osteoblasts was active at 2 weeks and proliferation of gingival epithelium and alveolar bone tissue were evident at 4 weeks, and almostly recovered to normal condition at 6 weeks. 3. In experimental group, inflammatory reaction was persistent in early stage and bone repair was delayed compared to control group. 4. In control group, matrix change of granulation tissue was initiated from one week, regeneration of gingival epithelium and maturation of subcutaneous conective tissue and new bone formation were evident at 2 weeks, so almost normal bone regeneration was observed at 4,6 weeks.

• Journal of Periodontal and Implant Science
• /
• 제34권3호
• /
• pp.683-698
• /
• 2004

One of the bone substitutes now in routine use, deproteinized bovine bone mineral(DBBM), is regarded as resorbable and osteoconductive, but some studies refute this. The present study was performed to evaluate the effects of DBBM on guided bone regeneration using titanium membrane on the calvaria of rabbit. At 2 weeks, 4 weeks, 8 weeks, and 12 weeks after surgery, the animal was scrificed. Non-decalcified specimens were produced for histologic analysis. The results of this study were as follows : 1. Titanium membrane was biocompatible and capable of space-maintaining, but there was ingrowth of soft tissue through the pore of titanium membrane. 2. There was no resorption or reduction of DBBM with time. 3. Some of the DBBM particles were combined with newly formed bone. But, apart from host bone, a great part of the particles were surrounded by connective tissue. 4. The bone formation was slight vertically and restricted to superficial area of host bone. Whithin the above results, DBBM dose not appear to contribute to bone formation. DBBM may disturb the migration and proliferation of mesenchymal cell derived from host bone and increase the growth of connective tissue. Therefore, careful caution is needed on selection of bone graft material and surgical protocol at guided bone regeneration for implant placement.

• 대한족부족관절학회지
• /
• 제6권2호
• /
• pp.172-177
• /
• 2002

Objectives: To validate usefulness of the three phase bone scan for the diagnosis of osteomyelitis in the diabetic foot with soft tissue inflammation. Materials and Methods: Fourteen diabetic feet with soft tissue inflammation were included in this study. We took the bone biopsy from the site of hot uptake on the three phase bone scan but no abnormal findings on the plain radiographs. We observed whether the bone has evidence of osteomyelitis on the patholgic findings such as inflammatory cell infiltration within bone, dead bone, new bone formation and fibrosis. Results: Thirteen of fourteen cases (92.8%) were compatible with osteomyelitis on the pathologic criteria. Inflammatory cell infiltration within bone was observed in thirteen cases, dead bone in twelve cases. new bone formation in four cases. fibrosis in eight cases. All of the four findings were observed in three cases. Conclusion: In the diabetic foot with soft tissue inflammation, the osteomyelitis should be included in differential diagnosis if the lesion reveals increased uptake on three phase bone scan, even though the lesion does not show any abnormal findings on the plain radiographs.

• 대한족부족관절학회지
• /
• 제11권1호
• /
• pp.111-114
• /
• 2007

Open calcaneal fracture with more than lateral half of bone loss and soft tissue defect occurred in 17 year-old male patient due to motor vehicle accident. Soft tissue defect included heel pad, peroneal tendon. Bone loss involved mainly most part of inferior tuberosity but not subtalar joint. Open dressing and debridement were done daily in operating room and antibiotics administration was started. After granulation tissue formed, femoral head allograft was performed and fixed with 6.0 mm screws to replace bone defect. Soft tissue defect was covered with latissimus dorsi musculocutaneous free flap. No sign of infection nor major osteolysis was observed in 15 months follow up period. Soft tissue defect was covered with latissimus dorsi musculocutaneous free flap.

• Biomaterials and Biomechanics in Bioengineering
• /
• 제1권3호
• /
• pp.151-162
• /
• 2014

Genetically-modified mesenchymal stem cells (GM-MSCs) have emerged as promising therapeutic tools for orthopedic degenerative diseases. GM-MSCs have been widely reported that they are able to increase bone and cartilage tissue regeneration not only by secreting transgene products such as growth factors in a long-term manner, also by inducing MSCs into tissue-specific cells. For example, MSCs modified with BMP-2 gene increased secretion of BMP-2 protein resulting in enhancement of bone regeneration, while MSCs with TGF-b gene did cartilage regeneration. In this review, we introduce several growth factors for gene delivery to MSCs and strategies for bone and cartilage tissue regeneration using GM-MSCs. Furthermore, we describe strategies for strengthening GM-MSCs to more intensively induce tissue regeneration by co-delivery system of multiple genes.

• 한국수산과학회지
• /
• 제48권1호
• /
• pp.1-15
• /
• 2015

Tissue engineering is an emerging, innovative technology to improve or replace the biological functions of damaged tissues and organs. Scaffolds are important materials for tissue engineering as they support cell attachment, migration, and differentiation. Marine sponges naturally contain scaffolds formed by extracellular matrix proteins (collagen and sponging) and strengthened by a siliceous or calcium carbonate skeleton. Coral skeletons are also derived naturally formed by essential calcium carbonate in the form of aragonite, and are similar to human bone. In addition, collagen extracted from jellyfish is a biosafe alternative to bovine and porcine collagen and gained attention as a potential source for tissue engineering. Moreover, cuttlefish bone is an excellent calcium source and can be used to generate bio-synthetic calcium phosphate. It has become a natural candidate for biomimetic scaffolds. This review describes the use of natural products derived from marine invertebrates for applications in bone tissue engineering based on studies from 2008 to 2014.