• Journal of Periodontal and Implant Science
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• v.31 no.1
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• pp.163-180
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• 2001

The aim of this study was to evaluate the effects of chitosan coating on the attachment, proliferation, functional and morphological change of periodontal ligament cells. Primary human periodontal ligament cells were cultured in dulbecco's modified Eagle's medium with 10% fetal bovine serum and 1% antibiotics. In experimental group, cells of 4th to 7th passage were inoculated in the multiwell plates coated with chitosan in concentration of 0.22, 0.2, and $2mg/m{\ell}$. Cell counting and MTT assay were done after 0.5, 1.5, 3, 6 and 24 hours of incubation to evaluate the cell attachment, and then after 2 and 7 days of culture to evaluate the cell proliferation. The alkaline phosphatase activity was measured after 4 and 7 days of culture and the ability to produce mineralized modules was evaluated after 21 days of culture. The results were as follows : 1. The morphology of periodontal ligament cells on the chitosan coating was round or spheric. Round cells were aggregated after 6 hours of culture. Aggregated cells on the chitosan coated surface showed nodule-like appearance after 24 hours of culture and not achieved confluency at 7 days. 2. During early period of culture, the attachment of periodontal ligament cells were inhibited by chitosan coating. Inhibition of cell attachment tended to increase with the concentration of chitosan. 3. At the chitosan concentration of 0.02 and $0.2mg/m{\ell}$, periodontal ligament cells were more rapidly proliferated at 7 days, compared to the control group. At the concentration of $2mg/m{\ell}$, the proliferation of periodontal ligament cells was inhibitied(p<0.01). 4. Alkaline phosphatase activity of periodontal ligament cells was increased in chitosan coated group, especially at the concentration of $0.02mg/m{\ell}$after 4 days of culture.5. Periodontal ligament cells produced mineralized nodules on chitosan coated wells without the addition of mineralized nodule forming materials (ascorbic acid, ${\beta}-glycerophosphat$, dexamethasone). With the addition of mineralized nodule forming materials, periodontal ligament cells produced more mineralized nodules at the concentration of $0.02mg/m{\ell}$, compared to the control. In summary, the attachment, proliferation, cell activity, and alkaline phosphatase activity of periodontal ligament cells depended on the concentration of coated chitosan. Chitosan stimulated mineralized nodule formation by periodontal ligament cells. At the appropriate concentration($0.02mg/m{\ell}$), chitosan could increase alkaline phosphatase activity and stimulate the formation of mineralized nodule by periodontal ligament cells. These results suggest that chitosan can be used as an adjunct for bone graft material, and the matrix of tissue engineering for periodontal regeneration, especially bone regeneration.

• Journal of Periodontal and Implant Science
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• v.30 no.2
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• pp.389-405
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• 2000

The purpose of this study is to evaluate the effect of IGF-I for DNA synthetic activity and the mRNA expression of bone matrix protein, type I collagen and osteopontin in prolifetation and differentiation of MC3T3-E1 cells. To evaluate DNA synthetic activity, cells were seeded at $2{\times}10^4cells/ml$ in 24 well plates and to evaluate mRNA of type I collagen and osteopontin cells were seeded at $5{\times}10^5cells/ml$ in 100mm culture dishes. These cells were cultured in alpha-minimum essential medium(${\alpha}-MEM$) containing 10% fetal bovine serum at $37^{\circ}C$, 5% $CO_2$ incubator. For DNA synthetic activity test 1, 10, 100ng/ml IGF-I were added to the cells which had been cultured for 3 days before 24 hours. For type I collagen mRNA expression 1, 10ng/ml IGF-I were added to the cells which had been cultured for 5, 10 days and for osteopontin mRNA expression 0.1, 1, 10ng/ml IGF-I were added to the cells which had been cultured for 5, 15, 20 days. Cell proliferaton was measured by the incorporation of [$^3H$]-thymidine into DNA and expression for type I collagen and osteopontin were measured by northern blot analysis. The results were as follows : DNA synthetic activity were generally higher in experimental group than control group. Expressions of type I collagen mRNA were higher at 5 day group and much lower at 10 day group in the control groups. In the experimental groups, mRNA expressions were slightly increased when 1 ng/ml IGF-I were added to 5 day group and decreased in all experimental 10 day groups. Expressions of osteopontin mRNA were higher at 20 day groups and lower at 15 day groups than the control groups. In the experimental groups, mRNA expressions were incereased when 0.1, 1 ng/ml IGF-I were added to 5 day group and in all the 15 day groups, but decreased when 0.1, 1, 10 ng/ml IGF-I were added to 20 day groups. IGF-I stimulated DNA synthetic activity of MC3T3-E1 cells during proliferation stage significantly, did not greatly changed effects on type I collagen mRNA expression and stimulated osteopontin mRNA expression at 15 day especially. In conclusion, we suggests that IGF-I have a tendency of stimulation effect of DNA synthetic activity but do not stimulate type I collagen mRNA in proliferation stage of MC3T3-E1 cell cultures, and stimulate osteopontin mRNA in differentiation stage of MC3T3-E1 cell cultures.

• The Journal of the Korean bone and joint tumor society
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• v.16 no.2
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• pp.80-86
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• 2010

Purpose: The skeleton is commonly affected by metastatic cancer. The purpose of this study was to evaluate the results of treating metastatic pathologic fractures in lower extremities using locking plates. Materials and Methods: Between 2004 and 2010, we evaluated 12 patients (13 cases) of metastatic pathologic fractures in lower extremities, treated with the locking plate. Mean patient age was 62.2 years (range, 50-81 years), the locations of the fractures were; proximal femur in 2 cases, femoral mid-shaft in 3, distal femur in 3, proximal tibia in 4, and distal tibia in 1 case. The interval to wheelchair ambulation, pain relief and complications were evaluated. Additionally, we assessed operation time and postoperative blood loss. Results: Mean time from operation to wheelchair ambulation was 3.2 days (range, 1-6 days). Mean VAS scores improved from a preoperative score of 8.1 points (range, 7-9 points) to a score of 2.7 points (range, 2-4 points) at 1 week postoperatively. No early complications associated with surgery were encountered. Mean operation time was 88.4 minutes (range, 70-105 minutes), and mean postoperative blood loss was 246.5 ml (range, 130-320 ml). Conclusion: Internal fixation of metastatic pathologic fractures using a locking plate in the lower extremity can be an effective treatment option in the meta- or diaphyseal area of long bones with massive bony destruction or poor bone stock by offering early ambulation, pain relief and low postoperative complications.

• Korean Journal of Veterinary Research
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• v.29 no.2
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• pp.11-18
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• 1989

This study was undertaken to obtain basic data of the sternal development in Korean native cattle from the earliest sternal formation to the ossification using histological and histochemical methods. Thrity three sterna were collected from a series of embryos and fetuses ranging from 11 to 225mm (estimated age 37~120days) in crown rump length. The bilateral sternal bars were observed in the 2nd group(CRL 21~3mm) of Korean cattle embryos. Those bars initiated to be fused in the 3rd group (CRL 31~4mm) and completed in the 7th group(CRL 71~80mm). The ossification centers were detected in the 8th group(CRL 81~90mm) also bilateral ossification centers were found in the same group. The typical epiphyseal plates, endochondral bone and calcium deposit were found in the 9th group(CRL 91~100mm). Osteocytes, osteoblasts, osteoclasts and myeloid cells appeared in ossification centers in the 10th group(more than CRL 101mm). The alcianophility responded markedly in the 9th group that was decreased and showed slightly positive reaction in territorial matrix of the 10th group. Marked positive reaction to PAS was observed in bony trabeculae in the 10th group. The positive reaction to calcium deposit by trichrome stain was observed initially in the hypertrophied zone of epiphyseal plate in the 9th group and was conspicuous in the calcified zone of epiphyseal plate in the 10th group. The 1st positive reaction to the von Kossa stain was observed in the 9th group.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.21 no.3
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• pp.277-283
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• 1999

This study was aimed at furnishing the data of Naso-orbito-ethmoidal fractures and aiding treatmenting Naso-orbito-ethmoidal fractures A 5-year review of Naso-orbito-ethmoidal fractures and concomitant injuries is presented. The patients were treated in the Dept. of Oral and Maxillofacial Surgery of Wankwang University Hospital from Jan. 1, 1993 to Dec. 31, 1997. The results were as followes: Male predominated over female by a ratio of 4.6 : 1. The most common reasons is traffic accident(88.2%). The elapsed time from injury to operation is average 9.2 days, and the mean admission days were 79 days and removal of plates were average 217.3 days. The most associated facial bone fractures is Zygomatico-Maxillary complex fracture(20%). Associated injuries were neurologic injury(29.4%), orthopedic injury(23.5%), opthalmologic injury(17.6%), body injury(5.8%), neuropsychologic injury(5.8%) and otolaryngologic injury(5.8%) in this order. The most injured teeth were upper and lower incisors. The intubation methods for surgery were orotracheal(29.57%), submental(29.5%), and nasotracheal technique(41%). Most patients had complications, that were post-traumatic telecanthus, nasal depression, scar formation. This results suggest that early diagnosis and treatment is prerequisits to satisfactory result. Aggressive management of NOE fracture with direct or bicoronal exposure with aid of CT is now an accepted norm.

• Clinics in Shoulder and Elbow
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• v.20 no.4
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• pp.217-221
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• 2017

Background: The purpose of this study was to evaluate the clinical and radiographic outcomes of internal fixation with locking T-plates for osteoporotic fractures of the proximal humerus in patients aged 65 years and older. Methods: From January 2007 through to December 2015, we recruited 47 patients aged 65 years and older with osteoporotic fractures of the proximal humerus. All fractures had been treated using open reduction and internal fixation with a locking T-plate. We classified the fractures in accordance to the Neer classification system; At the final follow-up, the indicators of clinical outcome-the range of motion of the shoulder (flexion, internal rotation, and external rotation) and the presence of postoperative complications-and the indicators of radiographic outcome-the time-to-union and the neck-shaft angle of the proximal humerus-were evaluated. The Paavolainen method was used to grade the level of radiological outcome in the patients. Results: The mean flexion was $155.0^{\circ}$ (range, $90^{\circ}-180^{\circ}$), the mean internal rotation was T8 (range, T6-L2), and the mean external rotation was $66.8^{\circ}$ (range, $30^{\circ}-80^{\circ}$). Postoperative complications, such as plate impingement, screw loosening, and varus malunion were observed in five patient. We found that all patients achieved bone union, and the mean time-to-union was 13.5 weeks of the treatment. The mean neck-shaft angle was $131.4^{\circ}$ at the 6-month follow-up. According to the Paavolainen method, "good" and "fair" radiographic results each accounted for 38 and 9 of the total patients, respectively. Conclusions: We concluded that locking T-plate fixation leads to satisfactory clinical and radiological outcomes in elderly patients with proximal humeral fractures by providing a larger surface area of contact with the fracture and a more rigid fixation.

• Clinics in Shoulder and Elbow
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• v.20 no.4
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• pp.222-229
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• 2017

Background: The purpose of this study was to investigate the outcomes after fixation using a 3.5-mm locking compression plate (LCP) hook plate for isolated greater tuberosity (GT) fractures of the proximal humerus. Methods: We evaluated the postoperative radiological and clinical outcomes in nine patients who were followed up at least 1 year with isolated GT fractures. Using the deltopectoral approach, we fixed the displaced GT fragments with a 3.5-mm LCP hook plate (Synthes, West Chester, PA, USA). Depending on the fracture patterns, the hook plate was fixed with or without augmentation using either tension suture or suture anchor fixation. Results: All the patient showed successful bone union. The mean time-to-union was 11 weeks. The radiological and clinical outcomes at the final follow-up were generally satisfactory. The mean visual analogue scale for pain, the University of California at Los Angeles score, the American Shoulder and Elbow Surgeons score, and the subjective shoulder value were 1.4, 30.3, 84.3, and 82.2%, respectively. The mean active forward flexion, abduction, external rotation, and internal rotation of the shoulder were $156.7^{\circ}$, $152.2^{\circ}$, $61.1^{\circ}$, and the 10th thoracic vertebral level, respectively. Only one patient presented with a postoperative complication of shoulder stiffness. The patient was treated through arthroscopic capsular release on the 5th postoperative month. Conclusions: We conclude that fixation using 3.5-mm LCP hook plates for isolated GT fractures of the proximal humerus is a useful treatment method that provides satisfactory clinical and radiological outcomes.

• Journal of Korean Neurosurgical Society
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• v.30 no.4
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• pp.493-500
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• 2001

Objective : Anterior cervical locking plates are the devices for achieving anterior cervical spinal fusion. This study was conducted to evaluate the locking plate system regarding its long-term advantages and disadvantages in the view of interbody fusion rate, hardware-related failures, vertebral change close to the fusion segment and postoperative complications. Method : Eight-six patients, operated from Jan., 1996 to Jun. 1998, were followed-up for more than two years. All of the cases were fused with iliac bone graft and ORION locking plate(Sofamor Danek USA, Inc., Memphis, TN) fixation. The patients were discharged or transferred to rehabilitation department 2-7 days after operation. A comprehensive evaluation of the interbody fusion state, instrument failure, vertebral change and postoperative complications were made by direct interview and cervical flexion-extension lateral plain films. Results : There were 55 male and 31 female with a mean age of 45 years(18-75 years). The mean follow-up period was 29 months(24-43 months). Various disorders that were operated were 40 cervical discs, 6 cervical stenosis including OPLL, 2 infections, and 38 traumas. Fusion level was single in 59 cases, two levels of each disc space in 15 cases, and two levels after one corpectomy in 12 cases. There was no instrument failure. Pseudoarthrosis was observed in two cases(2%) without radiological instability. The other patients(98%) showed complete cervical fusion with stable instrument. Mild settling of interbody graft with upward migration of screws was found in 12 cases(14%). Anterior bony growth at the upper segment was found in 5 cases(6%). Postoperative foreign body sensation or dysphagia was observed in 12 cases(4%), and disappeared within one month in 7 cases and within six months in 4 cases. One patient complained for more than six months and required reoperation to remove paraesophageal granulation tissue. Conclusion : The results show that Orion cervical locking plate has some disadvantages of upward migration of screws, anterior bony growth at the upper segment, or possibility of esophageal compression even though it has advantages of high interbody fusion rate or low instrument failure. Author believe that anterior cervical locking plate in the future should be thinner, and should have short end from the screw hole, and movable screw with adequate stability.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.5
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• pp.271-275
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• 2012

Objectives: This study evaluated a range of fixation methods to determine which is best for the postoperative stabilization of a mandibular osteotomy using three-dimensional finite element analysis of the stress distribution on the plate, screw and surrounding bone and displacement of the lower incisors. Materials and Methods: The model was generated using the synthetic skull scan data, and the surface model was changed to a solid model using software. Bilateral sagittal split ramus osteotomy was performed using the program, and 8 different types of fixation methods were evaluated. A vertical load of 10 N was applied to the occlusal surface of the first molar. Results: In the case of bicortical screws, von-Mises stress on the screws and screw hole and deflection of the lower central incisor were minimal in type 2 (inverted L pattern with 3 bicortical repositioning screws). In the case of plates, von-Mises stress was minimal in type 8 (fixation 5 mm above the inferior border of the mandible with 1 metal plate and 4 monocortical screws), and deflection of the lower central incisor was minimal in types 6 (fixation 5 mm below the superior border of the mandible with 1 metal plate and 4 monocortical screws) and 7 (fixation 12 mm below the superior border of the mandible with 1 metal plate and 4 monocortical screws). Conclusion: Types 2 and 6 fixation methods provide better stability than the others.

• Clinics in Shoulder and Elbow
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• v.6 no.1
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• pp.44-49
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• 2003

Purpose: Many different operative technique of mid-shaft clavicle fracture have been reported. The aim of this prospective study was to compare the results of anterior or anterior-inferior plating with superior plating on the acute mid-shaft fracture of clavicle Materials and Methods: From February1997 to February 2002, thirty-eight consecutive open reduction and internal fixation with reconstruction plates were performed in thirty-eight patients. from August 1999, anterior or anterior-inferior plating was mainly used, prospectively. The duration of follow-up averaged 17 months (range,23 to 43 months). The mean age was 38 years old (range,21 to 57 years old) on anterior or anterior-inferior plating group and 35 years old (range,24 to 55 years old) on superior plating group. The physician progress note, VAS patient complement score, Roentgenogram and ASES score was evaluated. Results: Four patients were lost to follow-up. There was no statistical difference on mean radiological bone union time （8.7 weeks vs. 8.6 weeks) and ASES score (92 vs 94) at inferior and superior plating groups (P > 0.05). VAS patient complement score was very good or excellent on anterior or anterior-inferior group, average score was 1.1 (ranger,0 to 2) compare with superior plating group (P < 0.05). There were two cases of infection, 1 case of failed fixation on superior plating group and 1 case of delayed union on anterior inferior plating group. Conclusion: Anterior inferior plating on acute clavicle midshaft fracture results in excellent patient complement score compare with conventional superior reconstruction plate.