• 한국기계가공학회지
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• 제19권12호
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• pp.105-112
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• 2020

The increase in the edentulous jaw which occurs in the aged population has led to personal dental health concerns. In the case of dental implant surgery, the duration of a patient's recovery depends on the surgical plan and their physicical ability. A device may be required to assist a physician in controlling vibration reduction of free-hand drilling and prescribing a good treatment plan that is suitable for the patient's condition. In this work, an artificial tooth-root implant assistant manipulator was studied. The structure and the vibration analysis of the dynamic restraint manipulator that is for drilling the alveolar bone in the mandible bone were performed, and the structural stability was analyzed. Further, a virtual prototype of an artificial tooth-root implant assisted manipulator was fabricated and tested. Hence, the state of the Remote Center of Motion (RCM) point and the driving state of the manipulator were confirmed. Furthermore, the drilling experiments were performed by using materials similar to a human jawbone in order to evaluate the performance of the drilling process that is operated using the assistant manipulator.

• Journal of Korean Dental Science
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• 제6권2호
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• pp.50-57
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• 2013

Purpose: Autogenous tooth bone graft is proven to be efficient. We evaluated the bone healing effect and clinical capabilities of autogenous tooth bone materials as a scaffold when growth factor is used together with this material. Materials and Methods: Subjects were those who needed implant placement and bone graft because of missing tooth or alveolar bone defect and who kept their autogenous tooth or needed extraction of other tooth. Group I included autogenous tooth bone graft with growth factor, whereas Group II had only autogenous tooth bone graft. We investigated the bone healing state through computed tomography taken just before surgery and 3 to 4 months after surgery to evaluate the effectiveness of bone graft. Group I had 9 patients, whereas Group II had 5 patients. We compared the pre- and post-operative increase of the Hounsfield unit and bone height by analyzing the computed tomography images. Result: Sinus bone grafts numbered 8 cases, and vertical ridge augmentation was performed together with 3 cases of these. Vertical ridge augmentation was performed in 2 cases, and horizontal ridge augmentation in 1 case alone. Socket graft was done in 3 cases. The post-operative mean value of the Hounsfield unit was 960 in Group I and 836.7 in Group II, but the increase was almost similar, i.e., 636.9 in Group I and 634.7 in Group II on the average. Increase of bone height was 7.6 mm in Group I and 11.1 mm in Group II on the average. This difference was attributable to the fact that most of the cases were sinus bone graft in Group II. Conclusion: In this study, we suggest the possibility of autogenous tooth bone graft materials as a scaffold besides their bone healing ability.

• Archives of Plastic Surgery
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• 제38권6호
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• pp.775-782
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• 2011

Purpose: Nasal bone fracture is most common facial bone fracture. The cause of fractures is mainly trauma such as fighting, automobile accident and fall down, and it commonly involves young males. Very frequently nasal bone fractures are associated with other facial injuries such as orbital bone fracture, maxillary bone fracture and nasal septal deformities. Because of various dynamic directions of power are involved, phenomenon of fractures are also various and treatment cannot be simple. Methods: We studied and analyzed retrospectively 452 cases nasal bone fractures from January 2008 to December 2010. Diagnosis were made with physical examination, Nasal bone X-rays, Facial bone CT and 3D facial bone CT. Four surgeons are involved in treatments of these patients and applied different procedure along patient's condition and deformity. We analyzed the cause of nasal bone fractures, deformities, associate injuries and applied surgical technique, and patient's satisfaction rate. In this study, old nasal bone fractures were excluded. Results: Young male group was most commonly sustained nasal bone fracture and physical violence was most common cause of injury. 64 of 452 patient was involved associate injuries of face. Closed reduction were applied 246 cases and C-arm quide reduction were 167 cases and in 20 cases lateral osteotomy were applied. Approximately, more than 80% of the Patients were satisfied with the outcomes. Conclusion: Diagnosis and treatment of nasal bone fractures are considered simple but because of various deformity and associate injuries, treatment is not always simple and universal. Time to time, we face unsatisfied patient after treatment of nasal bone fractures. For obtaining satisfactory result, cause of injury and state of deformities and associate injuries such as nasal septal deformity should be evaluated properly and proper treatment should be applied.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.182-182
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• 2006

PLLA grafted Hydroxyapatite / polylactide (g-HA/PLA) composites were prepared by three grafting methods. The modified particles (p-HA) were dispersed more uniformly in the PLLA matrix than pure n-HA. The p-HA/PLLA composites exhibited better mechanical properties and thermal stability than the n-HA/PLLA composites. The composites also demonstrated improved cell compatibility due to the good biocompatibility of the HAP nanoparticles and the more uniform distribution of the PLLA-grafted HAP nanoparticles on the film surface. All of these results indicated that the p-HAP/PLLA nano-composites might have a promising medical application in bone repair and in bone tissue-engineering.

• Journal of Nutrition and Health
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• 제37권4호
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• pp.291-301
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• 2004

We studied the effects of soy isoflavones supplementation with exercise on bone mineral density and the urinary excretion of deoxypyridinoline as an index of bone resorption rates in postmenopausal women. A total of 67 postmen-opausal women were assigned to Isoflavone (90 mg/day) or placebo groups. These group were further divided into groups that undergone a regular exercise or a rather sedentary state performing daily activity only. Four groups were Placebo-control group (n = 16), Placebo-exercise group (n = 16), Isoflavone-sedentary group (n = 19) and Isofla-vone-exercise group (n = 16). After the intervention, we compared anthropometric mesurement, dietary recall, bone mineral density (femoral neck, lumbar spine), urinary deoxypyridinoline between the groups and between the pre and post studies. There were no significant differences between the four groups in terms of average age, height, weight, period after menopause at the baseline. The average age of the subjects were 55.2 yrs, average height, weight, period after menopause were 154.7 cm, 59.3 kg, 5.58 yrs, respectively. After eight week intervention period, there were no significant differences between the four groups in bone mineral density, but urinary deoxypyridinoline excretion was significantly decreased both in Isoflavone-sedentary and Isoflavone-Exercise groups. These results suggest that Isofla-vone supplementation alone or with exercise may be preventive measures through the decrease of bone reabsorption rate in post-menopausal subjects. Whereas exercise alone did not appear to be an effective measure in bone loss with these subjects.

• Corrosion Science and Technology
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• 제7권3호
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• pp.162-167
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• 2008

Degradable implants have been in use for bone surgery for decades. However, degradable metal implants are one of the new research areas of biomaterials science. Magnesium has good biocompatibility due to its low toxicity, and it is a corroding, i.e. dissolvable, metal. Furthermore, magnesium is needed in human body, and naturally found in bone tissue. There have been some published reports also asserting the potential bone cell activation or bone healing effect of high magnesium ion concentrations. The classic method for achieving intertransverse process fusion involves autogenous iliac crest bone graft. Several investigations have been performed to enhance this type of autograft fusion. However, there is no research which has been undertaken to investigate the efficiency of pure magnesium particles in posterolateral spinal fusion. In this study, corrosion behavior of magnesium metal at the bone interface, the possibility of new bone cell formation and the degree of effectiveness in producing intertransverse process lumbar fusion in a sheep model have been investigated. Cortical bone screws were machined from magnesium alloy AZ31 extruded rod and implanted to hip-bones of sheep via surgery. Three months after surgery, the bone segments carrying these screws were removed from the sacrificed animals. Samples were sectioned to reveal Mg/bone interfaces and investigated using optical microscope, SEM-EDS and radiography. Optical and SEM images showed that there was a significant amount of corrosion on the magnesium screw. The elemental mapping results indicate, due to the presence of calcium and phosphorus elements, that there exists new bone formation at the interface. Furthermore, sixteen sheep were subjected to intertransverse process spinal fusions with pedicle screw fixation at various locations along their spines. Each animal was treated with 5cc autograft bone at one fusion level and 1cc magnesium+5cc autograft bone at the other. Six months after surgery, bone formation was evaluated by gross inspection and palpation, and radiological, histological, scanning electron microscopic and x-ray diffraction analyses. It may be stated that the potential for using useful corrosion of magnesium alloys in medical applications is expected to be significant.

• 한국산학기술학회논문지
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• 제10권11호
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• pp.3405-3411
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• 2009

본 논문은 일개 농촌주민들을 대상으로 신체구성, 운동(과거 운동여부), 체력상태, 골밀도를 조사하고, 골밀도와의 관련된 요인을 파악하여 농촌 주민들의 골다공증 예방을 위한 기초자료를 제시하고자 143명을 대상으로 연구하였고, 결과로서 조사대상자들 연령이 증가할수록, 교육수준이 낮을수록 골밀도가 낮았으며(p<0.05), 만성질환이 있는 경우는 없는 경우보다 골밀도가 낮았다(p<0.05). 그리고, 체중 BMI 체지방량 제지방량이 많이 나가는 경우가 낮은 경우보다 골밀도가 유의하게 높았으며(p<0.01), 과거 운동을 했던 경우와 기초 대사량이 높은 경우, 근육량이 많은 경우 골밀도가 높았다(p<0.01). 또한, 악력 윗몸일으키기 팔굽혀펴기 등 체력이 좋은 경우 골밀도가 높았으며(p<0.01), 골밀도 수치를 종속변수로 한 다중 회귀분석결과 연령, 만성질환 유무, 과거 운동유무가 유의한 변수로 나타났다.

• 대한의생명과학회지
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• 제9권1호
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• pp.9-13
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• 2003

Currently bone biochemical markers are considered to be the best indicators of present and the future state of bone turnover. A recent study has reported that chlorella increases the bone mineral density (BMD) on postmenopausal women, but presently there are no studies on bone biochemical markers treated with chlorella dietary supplementation. The purpose of the present study was to assess the bone biochemical markers for the short term and long term treatment groups, and non-treatment group as a control. Twenty two postmenopausal woman were treated for four months and eighteen for one year with 4 gm of chlorella dietary supplementation per day, and then assessed bone biochemical markers from serum and urine samples. Bone turnover rates calculated with Osteocalcin (OC), bone specific alkaline phosphatase (BAP) as a bone formation markers and deoxypyridinoline (DP), cross-linked N-telopeptides of type I collagen (NTx) as a bone resorption markers, showed 1131$\pm$87% for control group, 61$\pm$11% for short term treated group and 190$\pm$101% for long term treated group. We conclude that chlorella dietary supplementation enhances the bone formation, and NTx as a single markers, OC/Dp as a single markers of bone turnover rate were very useful tools for determine the effectiveness of chlorella dietary supplementation (or the postmenopausal women.

• 한국임상수의학회지
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• 제15권2호
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• pp.442-449
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• 1998

Freeze-dried cortical bones of the goat were transplanted to the experimental fibular defect of 10 dogs for valuating the possibility of xenogeneic bone implantation and the specificity of BM(Bone Morphogenetic Protein). The . freeze-dried cortical bone eliminated antigens and defatted with chloroform and methanol were freeze-dried at $-80{\circ}C$ for preservation of BMP and then sterilized with 50 gas and storaged in room temperature. Ten freeze-dried cortical implants of the goat were transplanted in experimentally defected regions of bilateral fibula of 5 dogs in clinically normal. The transplanted region had been radiographed for observing state of bone union and BALPOone Alkaline Phosphatase) in the serum of the host was measured for valuating activity of oteoblast per 2 week-interval after transplant procedures. New bone formation had been observed early in one of ten regions around implants about the same time as autoimplant regions. It was incorporated with its host bone during 4-12 weeks after transplantation. In another 2 cases of 2 dogs, new bone formation and absorption of implant had been observed from 4 weeks but they were not incorporated completely until 20 weeks. The rest of the freeze-dried bone implants, 7 cases of 4 dogs had not been observed new bone formation nor absorption of implants. The freeze-drying method for implants means to not influence bone incorporation. Although less of union percentages the union form of this experiment were similar to alloimplantation and it may mean to block immunity reaction that disturbs the bone induction by BMP. It demonsknted that the possibility of the xenogenous bone implantation is recognized by reason of the low specificity of BMP between goat and dog.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제48권6호
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• pp.371-381
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• 2022

Objectives: This study determined the effect of platelet-rich fibrin (PRF) on extraction socket bone regeneration and assessed the patterns and determinants of bone regeneration after the surgical extraction of impacted mandibular third molars. Materials and Methods: This prospective study randomly allocated 90 patients into two treatment groups: A PRF group (intervention group) and a non-PRF group (control group). After surgical extractions, the PRF group had PRF placed in the extraction socket and the socket was sutured, while the socket was only sutured in the non-PRF group. At postoperative weeks 1, 4, 8, and 12, periapical radiographs were obtained and HLImage software was used to determine the region of newly formed bone (RNFB) and the pattern of bone formation. The determinants of bone regeneration were assessed. Statistical significance was set at P<0.05. Results: The percentage RNFB (RNFB%) was not significantly higher in the PRF group when compared with the non-PRF group at postoperative weeks 1, 4, 8, and 12 (P=0.188, 0.155, 0.132, and 0.219, respectively). Within the non-PRF group, the middle third consistently exhibited the highest bone formation while the least amount of bone formation was consistently observed in the cervical third. In the PRF group, the middle third had the highest bone formation, while bone formation at the apical third was smaller compared to the cervical third at the 8th week with this difference widening at the 12th week. The sex of the patient, type of impaction, and duration of surgery was significantly associated with percentage bone formation (P=0.041, 0.043, and 0.018, respectively). Conclusion: Placement of PRF in extraction sockets increased socket bone regeneration. However, this finding was not statistically significant. The patient's sex, type of impaction, and duration of surgery significantly influenced the percentage of bone formation.