• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.42 no.4
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• pp.174-181
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• 2016

Objectives: This retrospective study aims to evaluate the prevalence of maxillofacial trauma in a developing country, along with its pattern, etiology and management. Data for the present study were collected from the Department of Dentistry, ESIC Medical College and Post Graduate Institute of Medical Sciences and Research, Chennai in India. Materials and Methods: The medical records of patients treated for maxillofacial injuries between May 2014 and November 2015 were retrospectively retrieved and analyzed for prevalence, pattern, etiology, and management of maxillofacial trauma. SPSS software version 16.0 was used for the data analysis. Results: Maxillofacial fractures accounts for 93.3% of total injuries. The mean and standard deviation for the age of the patients were $35.0{\pm}11.8$ years and with a minimum age of 5 years and maximum age of 75 years. Adults from 20 to 40 years age groups were more commonly involved, with a male to female ratio of 3:1. There was a statistically significantly higher proportion of males more commonly involved in accident and injuries (P <0.001). Conclusion: The most common etiology of maxillofacial injury was road traffic accidents (RTA) followed by falls and assaults, the sports injuries seem to be very less. In RTA, motorized two-wheelers (MTW) were the most common cause of incidents. The majority of victims of RTA were young adult males between the ages of 20 to 40 years. The malar bone and maxilla were the most common sites of fracture, followed by the mandible. The right side of the zygomatic complex was the predominant side of MTW injury. The majority of the zygomatic complex fractures were treated by conservative management. Open reduction and internal fixation were performed for indicated fracture patients.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.1
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• pp.31-34
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• 2009

Purpose: This study compared the frequency of postoperative infections in patients for a closed mandibular fracture with that without the postoperative antibiotic prophylaxis. Patients and Methods: 48 patients without any specific medical history were divided into two groups depending on whether or not antibiotics had been applied after the surgery. The 24 patients in group 1 received only a second-generation cephalosporin ($Cefotetan^{(R)}$) intravenously from admission to immediate after the surgery. Likewise, 24 patients in group 2 received 1.0g of $Cefotetan^{(R)}$ twice daily longer than the third day after surgery. The mean (SD) duration of antibiotics administration after surgery was 6.9 (${\pm}3.56$). The patients were evaluated after surgery for any postoperative infections according to the criteria: purulent drainage from a wound, spontaneous wound dehiscence accompanied by swelling, pain, and fever around the wound. Results: Postoperative infections were encountered in 2 out of 24 patients in group 1, who received antibiotic medication until shortly after surgery, and in 3 out of the 24 patients in group 2, in whom the medication was continued even after the surgery. There was no sig nificant difference in the incidence of postoperative infections between the two groups. Conclusion: From this study, postoperative use of antibiotics seems to be unnecessary with view of the little significance of the factors that could affect the wound infection.

• Journal of Korean Foot and Ankle Society
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• v.9 no.1
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• pp.105-109
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• 2005

Purpose: We compared the clinical features of the ankle fractures treated by operation between the elderly and the young, and reviewed the principles of treatment of the ankle fractures in the elderly. Materials and Methods: We reviewed 49 cases of the ankle fractures, which were treated by open reduction from August 1991 to July 2002. Patients aged more than 60 were designated as the elderly, and patients aged between 15 and 33 were designated as the young. The average follow-up period was 13.2 months. Using the Lauge-Hansen classification, We defined stage I or II fractures as low stage and stage III or IV fractures as high stage fractures. Results: There were 15 cases of high stage fractures (78.9%) in the elderly and 11 cases (36.7%) in the young. High stage fracture rate was significantly higher in the elderly (P=0.004). Hospital day, period between primary injury and operation, and union time were significantly longer in the elderly (P<0.001). However, there was no statistical difference in immobilization time between the two groups. The results of treatment were satisfactory clinically and radiologically by the Meyer's criteria in both groups. Conclusion: In the elderly, high stage fractures were more common and longer hospitalization and union time were needed than the young. However, the result of surgical treatment was satisfactory.

• Journal of Korean Foot and Ankle Society
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• v.14 no.2
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• pp.146-150
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• 2010

Purpose: Pilon fracture has several serious complications such as joint stiffness, arthrosis and delayed angular deformity. We report short-term results of new treatment modality using distracted dynamic external fixators and early controlled ankle motion. Materials and Methods: Eight cases of severe pilon fractures for which we tried small plate fixation and additional distracted dynamic external fixators from July 2007 to June 2009 were included. Half passive continuous ankle joint motion was allowed under free hinged ring fixators after the operation. The external fixators were removed after two or three months from the surgery. We investigated joint space by radiograph, joint pain, range of motion, patient's satisfaction of treatment protocol. Results: Joints were distracted when external fixators were applied and mean 28% of space loss developed after removal of external fixators. In most of cases, satisfactory alignments were maintained. Regarding range of joint motion, mean dorsiflexion angle was 15 degrees and mean plantarflexion angle was 32 degree in the condition of wearing external fixators. There was mean 8% reduction of range of motion but no further progression of ankle stiffness after removal of external fixators. Dorsiflexion was not improved after that, but plantarflexion angle was improved 10% even after removal of external fixators. Patients were generally in compliance with the treatment protocols with high level of satisfaction. Conclusion: We got good results with distracted dynamic external fixators and early continuous half-passive joint motion for pilon fractures in terms of joint pain and range of motion. Therefore we suggest this new protocol as an alternative modality for severe pilon fractures.

• Journal of Korean Foot and Ankle Society
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• v.24 no.1
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• pp.19-24
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• 2020

Purpose: Anterolateral minimally invasive plate osteosynthesis (MIPO) was performed to treat patients with distal tibial fractures associated with open fractures or extensive soft tissue injuries, which is limited medial MIPO. The treatment results of the anterolateral MIPO technique were evaluated and analyzed. Materials and Methods: Seventeen patients with distal tibial fractures associated with an open fracture or large bullae formation on the distal tibia medial side were treated with anterolateral MIPO using anterolateral locking plates. Within 24 hours of visiting the emergency room, external fixation was applied, and the medial side wound was managed. After damage control, the anterolateral locking plate was applied using an anterolateral MIPO technique. The union time, nonunion, or malunion were evaluated with regular postoperative radiographs. The ankle range of motion, operative time, blood loss, Iowa score, and wound complications were investigated. Results: Radiological evidence of bony union was obtained in all cases. The mean time to union was 16.7 weeks (12~25 weeks). The mean operation time was 44.0 minutes. Regarding the ankle range of motion, the mean dorsiflexion was 15°, and the mean plantarflexion was 35°. Satisfactory results were obtained in 15 out of 17 cases; five results were classified as excellent, four were good, and six were fair. The mean blood loss was 125.2 mL. Two complications were recorded. Conclusion: In distal tibial fractures with severe medial soft tissue damage caused by high-energy trauma, the staged anterolateral MIPO technique using anterolateral locking plates is a useful alternative treatment to achieving optimal wound care, rapid union with biological fixation, and intra-articular reduction.

• Journal of Korean Foot and Ankle Society
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• v.21 no.4
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• pp.151-155
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• 2017

Purpose: Reducing tenderness or pain on the ankle joint and improving the range of motion are thought to be possible using hyaluronate-based anti-adhesive agents. On the other hand, there are more aspects to be studied regarding the incidence of complications, such as resting pain, tenderness, and stiffness, after surgery. Therefore, the aim of this study was to prove the effectiveness of the agents after ankle fracture surgery. Materials and Methods: Patients, who underwent open reduction and internal fixation surgery due to ankle joint fractures from June 2015 to May 2016, were studied prospectively. Thirty patients of them received a $Guardix^{(R)}$ injection during their surgeries and were included in the injection group. The other 30 patients were included in the control group. Postoperatively, tenderness on the scar, a delay in wound healing, and the active range of motion were evaluated at 2, 6, and 12 weeks after surgery. Results: A significant difference in tenderness on the scar was observed 2 weeks after surgery. On the other hand, there was no significant difference at 6 and 12 weeks after the surgery. The agent-using group showed a 6.7% delay in wound healing and a 93.3% nondelaying. In the non-using group, the delay was 63.3%, while non-delay was 36.7% (p<0.001). The group that underwent $Guardix^{(R)}$ usage showed an effective result in the visual analogue scale, which was statistically significant (p<0.001). The result at 6 and 12 weeks after surgery showed a significant difference. Conclusion: Improvement was observed in the patients who underwent a $Guardix^{(R)}$ injection, regarding the range of motion, visual analog scale, and healing of the wound postoperatively.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.6
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• pp.631-635
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• 2007

Purpose: The classic technique for open reduction of subcondylar fractures is the submandibular approach. The aim of this study was to evaluate clinical result of retromandibular approach to displaced subcondylar fractures. Material and methods: During a period of 24months we perfomed a prospective study with a retromandibular approach in 23 patients with displaced subcondylar fractures. In this article we describe clinical result in 23 patients with follow ups for 3 months after surgery. Preoperatively all patients had malocclusion and radiology demonstrated displacement. Result: The retromandibularl approach for ORIF was good in all case. Mouth opening(M/O) was 49mm. Occlusion was good too. Permanent facial nerve palsy was not detected. Conclusion: Our findings indicate that the retromandibular approach is a safe technique for subcondylar fractures.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.3
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• pp.505-512
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• 1988

Since the propagation of a short fatigue crack is directly related to the large crack which causes the fracture of bulk specimen, the detailed study on the propagation of the short crack is essential to prevent the fatigue fracture. However, a number of recent studies have demonstrated that the short crack can grow at a low applied stress level which are predicted from the threshold condition of large crack. In present study, the threshold condition for the propagation of short fatigue crack is examined with respect to the microstructure and cyclic loading history. Specimens employed in this study were decarburized eutectoid steels which have various decarburized ferrite volume fraction. Rotating bending fatigue test was carried out on these specimens with the special emphasis on the '||'&'||'quot;critical non-propagating crack length.'||'&'||'quot; It is found that the reduction of the endurance limit of their particular microstructures can be due to the increase of the length of critical non-propagating crack, and the quantitative relationship between the threshold stress .DELTA. .sigma. $_{th}$ and the critical non-propagating crack length Lc can be written as .DELTA. .sigma. $_{th}$, Lc=C where m, C is constant. Further experiments were carried out on the effect of pearlitic structure and cyclic loading history on the length of critical non-propagating crack. It is shown that the length of critical non-propagating crack is closely related to both pearlite interlamellar spacing and cyclic loading history.ory. cyclic loading history.

• Journal of the Korean Wood Science and Technology
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• v.39 no.5
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• pp.451-458
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• 2011

Adhesives derived from renewable resources allow wood panel producers to make lower cost alternatives to formaldehyde-based adhesive resins. Among them, adhesive components extracted from industrial by-products or wastes are the most important research fields in the efficient utilization of waste and cost reduction. In our study, the rapeseed flour, which is a by product from the production of biodiesel extracted from rapeseed, was introduced to develop alternative adhesives for the production of wood flooring. The rapeseed flour was hydrolyzed with 1% sodium hydroxide solution and PF prepolymers were prepared with 3-molar ratios, 1.8, 2.1 and 2.4. The linear fracture mechanics was introduced to evaluate the glue bond quality in wood flooring composed of fancy-veneered and plywood, and the formaldehyde emission and adhesive penetration were also investigated. The formaldehyde emissions of wood flooring met the requirement of the standard of $SE_0$ specified in the KS standard. The rapeseed flour adhesive penetrated sufficiently into the vessel elements and lumens in fancy veneer and plywood and gave strong bond quality to the wood flooring. The fracture mechanics was introduced to evaluate the adhesive joint between fancy veneer and plywood. The critical stress intensity factor ($K_{IC}$) of boliva overlayed wood flooring was increased with increasing molar ratio and this was the same tendency in oak overlayed wood flooring. From the results, the formulated adhesives were efficiently used to bond fancy veneer onto the plywood to make wood flooring and showed a potential to be used as a component of environmentally friendly adhesive resin systems for production of flooring.

• Journal of the Microelectronics and Packaging Society
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• v.8 no.4
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• pp.25-33
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• 2001

Sn-3.5Ag-xBi alloys with five different levels of Bi (0, 2.5, 4.8, 7.5, 10 wt%) were prepared for evaluating creep properties. Cast alloys were roiled and heat treated to provide stable microstructures during the subsequent creep tests, which were conducted under constant load using dog-bone specimens. For the Bi containing alloys, creep strength showed the maximum around 2.5 wt%Bi and tended to decrease with increasing Bi content. The stress exponent of the alloy was around 4, suggesting typical dislocation creep, but the exponent was 2 for the 10 wt%Bi alloy, suggesting creep assisted by grain boundary Sliding. For the Bi containing alloys, the brittle fracture mode appeared showing small amount of reduction of area, while the ductile fracture mode was true for the Bi free alloy. Microstructural examination of ruptured specimens showed cavitations on grain boundaries normal to the load axis, and a significant of grain boundary sliding for the Bi containing alloys.