• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.2
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• pp.97-106
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• 2010

Aim of the study: An alternative source of adult stem cells that could be obtained in large quantities, under local anesthesia, with minimal discomfort would be advantageous. Adipose tissue could be processed to obtain a fibroblast-like population of cells or adipose tissue-derived stromal cells (ATSCs). This study was performed to confirm the availability of ATSCs in bone tissue engineering. Materials amp; Methods: In this study, adipose tissue-derived mesenchymal stem cell was extracted from the liposuctioned abdominal fat of 24-old human and cultivated, and the stem cell surface markers of CD 105 and SCF-R were confirmed by immunofluorescent staining. The proliferation of bone marrow mesenchymal stem cell and ATSCs were compared, and evaluated the osteogenic differentiation of ATSCs in a specific osteogenic induction medium. Osteogenic differentiation was assessed by von Kossa and alkaline phosphatase staining. Expression of osteocyte specific BMP-2, ALP, Cbfa-1, Osteopontin and osteocalcin were confirmed by RT-PCR. With differentiation of ATSCs, calcium concentration was assayed, and osteocalcin was evaluated by ELISA (Enzyme-linked immunosorbant assay). The bone formation by 5-week implantation of HA/TCP block loaded with bone marrow mesenchymal stem cells and ATSCs in the subcutaneous pocket of nude mouse was evaluated by histologic analysis. Results: ATSCs incubated in the osteogenic medium were stained positively for von Kossa and alkaline phosphatase staining. Expression of osteocyte specific genes was also detected. ATSCs could be easily identified through fluorescence microscopy, and bone formation in vivo was confirmed by using ATSC-loaded HA/TCP scaffold. Conclusions: The present results show that ATSCs have an ability to differentiate into osteoblasts and formed bone in vitro and in vivo. So ATSCs may be an ideal source for further experiments on stem cell biology and bone tissue engineering.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.5
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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.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.6
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• pp.461-468
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• 2009

Purpose: Platelet derived growth factor(PDGF)-BB and bone morphogenetic protein(BMP)-2 are well-known representative growth factors. The purposes of this study were to investigate the effect of rhPDGFBB and rhBMP-2 on osseointegration of titanium implants at periimplant bone defects grafted with hydroxyapatite and to evaluate the feasibility of imaging bone structures around screw-type titanium implant with micro-CT. Materials and Methods: The first molar and all premolars in the mandible region of four beagle dogs were extracted. Following a healing period of 4 months, three $8{\times}8{\times}6mm$-sized bony defects were formed and screw-type titanium implants were placed with hydroxyapatite(HA) block and growth factors; Control group, PDGF group and BMP group. Two months post-implantation, the mandible was harvested. Bone volume(BV), bone-to-implant contact(BIC) and bone mineral density(BMD) were analyzed with micro-CT and histology. Results: According to micro-CT analysis, BV and BMD measures of PDGF and BMP group were significantly higher than control group(BV; PDGF group: $p{\fallingdotseq}0.011$, BMP group: $p{\fallingdotseq}0.006$/BMD; PDGF group: $p{\fallingdotseq}0.020$, BMP group: $p{\fallingdotseq}0.011$) and BIC measures of BMP group were significantly higher than PDGF group($p{\fallingdotseq}0.015$). In histologic evaluation, BIC measures of BMP group was significantly higher than PDGF group($p{\fallingdotseq}0.048$). The values of BV in histologic sections were higher than in micro-CT images and the values of BIC in micro-CT images were higher than in histologic sections. Conclusion: The findings of this experimental study indicates that the use of rhPDGF-BB and rhBMP-2 can increase new bone formation in a large bony defect around titanium implant, and rhBMP-2 is more effective than rhPDGF-BB. Micro-CT can be considered useful for assessment as a rapid and nondestructive method for 3-dimensional measurement of bone healing around implants. Further study is necessary, however, to remove metal artifacts around titanium implant and to standardize the method.

• Journal of Periodontal and Implant Science
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• v.49 no.1
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• pp.2-13
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• 2019

Purpose: The aim of this study was to conduct a histologic evaluation of irradiated calvarial defects in rats 4 weeks after applying fibroblast growth factor-2 (FGF-2) with hyaluronan or biphasic calcium phosphate (BCP) block in the presence or absence of adjunctive hyperbaric oxygen (HBO) therapy. Methods: Twenty rats were divided into HBO and non-HBO (NHBO) groups, each of which was divided into FGF-2 and BCP-block subgroups according to the grafted material. Localized radiation with a single 12-Gy dose was applied to the calvaria of rats to simulate radiotherapy. Four weeks after applying this radiation, 2 symmetrical circular defects with a diameter of 6 mm were created in the parietal bones of each animal. The right-side defect was filled with the materials mentioned above and the left-side defect was not filled (as a control). All defects were covered with a resorbable barrier membrane. During 4 weeks of healing, 1 hour of HBO therapy was applied to the rats in the HBO groups 5 times a week. The rats were then killed, and the calvarial specimens were harvested for radiographic and histologic analyses. Results: New bone formation was greatest in the FGF-2 subgroup, and improvement was not found in the BCP subgroup. HBO seemed to have a minimal effect on new bone formation. There was tendency for more angiogenesis in the HBO groups than the NHBO groups, but the group with HBO and FGF-2 did not show significantly better outcomes than the HBO-only group or the NHBO group with FGF-2. Conclusions: HBO exerted beneficial effects on angiogenesis in calvarial defects of irradiated rats over a 4-week healing period, but it appeared to have minimal effects on bone regeneration. FGF-2 seemed to enhance new bone formation and angiogenesis, but its efficacy appeared to be reduced when HBO was applied.

• Archives of Plastic Surgery
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• v.40 no.4
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• pp.397-402
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• 2013

Background Fracture-dislocation of the proximal interphalangeal (PIP) joint is a relatively common injury. Various treatments for fracture-dislocation of the PIP joint have been reported. In the present study, we performed open reduction through a midlateral incision using absorbable sutures to reduce the small bone fragments and performed volar plate repair. Methods We treated nine patients with fracture-dislocation of the PIP joint with small fractured bone fragments too small for pinning or screw fixation. Patients with volar plate injury were treated with open reduction and volar plate repair at the periosteum of the middle phalangeal bone base by the modified Kessler method using absorbable sutures. All patients were placed in a dorsal aluminum extension block splint, which maintained the PIP joint in approximately 30 degrees of flexion to avoid excessive tension on the sutured volar plate. Results At a mean final follow-up of postoperative 9 months, all patients were evaluated radiographically and had adequate alignment of the PIP joint and reduction of the displaced bone fragments. Range of motion was improved and there were no complications. Conclusions This technique is an excellent alternative to the current method of treating patients with fracture-dislocations that include small fragments that are too small for pinning or screw fixation. It is a less invasive surgical method and enables stable reduction and early exercise without noticeable complications.

• Imaging Science in Dentistry
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• v.50 no.3
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• pp.217-226
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• 2020

Purpose: The purpose of this study was to analyze the quantity and quality of the mandibular anterior alveolar bone in terms of alveolar width, density, and total alveolar height (TAH) based on dental status, gender, and age. Additionally, this study aimed to quantitatively evaluate the available alveolar height for graft harvesting (AHGH) and examine its variability based on the aforementioned factors. Materials and Methods: This retrospective cone-beam computed tomographic study included a total of 100 subjects. On the basis of gender, dental status, and age, the scans were divided into 3 primary groups and 8 subgroups. The mandibular alveolar width and density were measured 5 mm mesial to the mental foramen bilaterally and at the midline. The TAH was measured at the midline, and the AHGH was measured as the midline distance between 5 mm apical to the root of the canines and 5 mm superior to the lower border. Results: The mandibular alveolar width was statistically similar between dentulous and edentulous patients (P>0.05). A significantly greater density was observed at the midline in edentulous patients (P<0.05). The TAH was significantly greater in edentulous male patients than in edentulous female patients (P<0.05). Dentulous and male patients had significantly greater AHGH than edentulous and female patients, respectively (P<0.05). Conclusion: Based on the data evaluated in this study, it can be concluded that the mandibular symphyseal area has adequate bone quality and quantity for bone graft harvesting for dental implant therapy.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.21 no.4
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• pp.376-381
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• 1999

A variety of materials and procedures such as sinus floor elevation, sinus-lift graft, inlay bone graft using Le Fort I osteotomy, and onlay graft have been used to create adequate bone volume in the maxillary sinus for placement of endosseous implants in the posterior atrophic maxilla. Because of the frequent lack of bone in the posterior maxilla, sinus lift procedure has become a commonly practiced treatment modality. The 138 endosseous implants of 36 patients with sinus augmentation procedures performed in Korea University Hospital from January 1991 to December 1998 were summarized and analysed. The result of this study were as follows: 1. Age ranged from 39 to 57, with a mean of 50.7. 2. The mean survival rate for 138 implants with maxillary sinus lift procedure was 80.4%. 3. There was no corelationship between the fixture length, width and the survival rate. 4. The result showed that the healing period for 8-12 months was necessary if the residual alveolar bone height was less than 5mm. 5. Autogenous iliac corticocancellous block graft showed the most favorable survival rate(95%).

• Clinics in Shoulder and Elbow
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• v.26 no.2
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• pp.131-139
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• 2023

Background: Massive rotator cuff tears (RCTs) are complicated by muscle atrophy, fibrosis, and intramuscular fatty degeneration, which are associated with postoperative tendon-to-bone healing failure and poor clinical outcomes. We evaluated muscle and enthesis changes in large tears with or without suprascapular nerve (SN) injury in a rat model. Methods: Sixty-two adult Sprague-Dawley rats were divided into SN injury (+) and SN injury (-) groups (n=31 each), comprising tendon (supraspinatus [SSP]/infraspinatus [ISP]) and nerve resection and tendon resection only cases, respectively. Muscle weight measurement, histological evaluation, and biomechanical testing were performed 4, 8, and 12 weeks postoperatively. Ultrastructural analysis with block face imaging was performed 8 weeks postoperatively. Results: SSP/ISP muscles in the SN injury (+) group appeared atrophic, with increased fatty tissue and decreased muscle weight, compared to those in the control and SN injury (-) groups. Immunoreactivity was only positive in the SN injury (+) group. Myofibril arrangement irregularity and mitochondrial swelling severity, along with number of fatty cells, were higher in the SN injury (+) group than in the SN injury (-) group. The bone-tendon junction enthesis was firm in the SN injury (-) group; this was atrophic and thinner in the SN injury (+) group, with decreased cell density and immature fibrocartilage. Mechanically, the tendon-bone insertion was significantly weaker in the SN injury (+) group than in the control and SN injury (+) groups. Conclusions: In clinical settings, SN injury may cause severe fatty changes and inhibition of postoperative tendon healing in large RCTs. Level of evidence: Level Basic research, controlled laboratory study.

• The Korean Journal of Pain
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• v.33 no.2
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• pp.138-143
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• 2020

Background: Severe pain associated with proximal femur fractures makes the positioning for regional anesthesia a challenge. Systemic administration of analgesics can have adverse effects. Individually, both the fascia iliaca block (FIB) and femoral nerve blocks (FNB) have been studied. However, there is little evidence comparing the two. The aim of this study was to compare the overall efficacy of the two blocks in patients with proximal femur fracture before positioning for spinal anesthesia. Methods: ASA (American Society of Anesthesiologists) class I, II, and III patients scheduled for elective and emergency surgery with the diagnosis of proximal femur fracture between October 2018 and June 2019 were included in the study. The patients were assigned to two groups by convenience nonprobability sampling of 35 each. Results: Our study showed a reduction in visual analogue scale scores at 3, 4, and 5 minutes after administration of the FIB being 5.1 ± 1.1, 4.1 ± 1.3, and 2.8 ± 0.8, and those after the FNB as 4.4 ± 1.1, 3.3 ± 1.1, and 2.1 ± 1.4 with P < 0.05, which was statistically significant. The mean first rescue analgesia time for the FIB was 7.1 ± 2.1 hours, while for the FNB it was 5.2 ± 0.7 hours. The P value was less than 0.001, which was significant. Conclusions: Both ultrasound guided FNB and FIB techniques provide sufficient analgesia for patient's positioning before spinal anesthesia. However, the duration of postoperative analgesia provided by FIB was greater than that of the FNB.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.4
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• pp.331-339
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• 2007

Background: Distraction osteogenesis(DO) is a useful method for treating cases demanding the generation of new bone. During DO, the angiogenic activity is crucial factor in the new bone formation. The aim of this study was to detect the autocrine growth activity in the cellular components of the distracted bone with observation of the co-expression of vascular endothelial growth factor(VEGF) and its receptors following the mandibular DO. Materials and methods: Unilateral mandibular distraction(0.5 mm twice per day for 10 days) was performed in six mongrel dogs. Two animals were killed at 7, 14, and 28 days after completion of distraction, respectively. Immediately after the animals were killed, the right mandibles were harvested en block. Immunohistochemical staining was processed for observation of the VEGF expression, and double immunofluorescent staining was also processed for detection of the co-expression of osteocalcin and VEGF's two distinct receptors(VEGFR-1 and VEGFR-2). Results: At 7 and 14 days after distraction, the expressions of VEGF were significantly increased in the osteogenic cells of the distracted bone. Up to 28 days after distraction, VEGF was still expressed moderate in the osteoblastic cells of distracted bone. The co-expressions of osteocalcin/VEGFR-1 and osteocalcin/VEGFR-2 were observed in the distracted bone at 7 and 14 days after distraction. In the double immunofluorescent staining, the co-expression' s level of osteocalcin/VEGFR-1 was more than that of osteocalcin/VEGFR-2. Conclusion: Taken together, this study suggested that VEGF plays an important role in the osteogenesis, and these osteoblastic cell-derived VEGF might act as autocrine growth factor during distraction osteogenesis. In the other word, the cellular components, such as osteoblasts and immature fibroblast-like cellsor mesenchymal cells in the distracted bone, might have autocrine growth activity during distraction osteogenesis.