• 대한두개안면성형외과학회지
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• 제20권1호
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• pp.31-36
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• 2019

Background: After closed reduction, patients are sometimes concerned that their external nasal shapes have changed. The aim of this study was to investigate and explain changes in nasal shape after surgery through objective photogrammetric anthropometry measurements taken through three-dimensional (3D) reformed computed tomography (CT) images. Methods: Our study included 100 Korean patients who underwent closed reduction of isolated nasal bone fracture from January 2016 to June 2017. Using the ruler tool in Adobe Photoshop CS3, we measured preoperative and postoperative nasal base heights, long nostril axis lengths, both nasal alar angles, and amount of nasal deviation through the 3D reformation of soft tissue via CT scans. We then compared the dimension of nose. Results: The amount of postoperative correction for nasal base height was 1.192 mm. The differences in nostril length between each side were found to be 0.333 mm preoperatively and 0.323 mm postoperatively. The differences in the nasal alar angle between each side was $1.382^{\circ}$ preoperatively and $1.043^{\circ}$ postoperatively. The amount of nasal deviation was found to be 5.248 mm preoperatively and 1.024 mm in postoperatively. Conclusion: After the reduction of nasal bone fractures, changes in nasal dimensions were noticeable in terms of nasal deviation but less significant in nasal tips, except for changes in nasal alar angles, which were notable.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제32권4호
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• pp.359-362
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• 2010

The zygoma is second most commonly vulnerable facial bone in fracture, in number only by nasal fractures. It is difficult to evaluate reduction state intraoperatively, because almost surgeons reduce the fractured zygoma by blind method. We suggest the use of orthopedic C-arm intraoperatively. We use plain radiography, CT to evaluate preoperative state. Gilles approach or intraoral approach were used to reduce the fractured zygomatic arch. The C-arm was positioned at chin area, used to evaluate reduction intraoperatively. We got postoperative image by CT or submento-vertex view. There are variable methods to evaluate reduction intraoperatively: palpation, ultrasonography, CT, plain films. C-arm is considered superior diagnostic tool to other methods. The use of intraoperative C-arm was very efficient, it could bring better results.

• Imaging Science in Dentistry
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• 제44권2호
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• pp.89-94
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• 2014

Purpose: Vertical root fracture (VRF) is a common complication in endodontically treated teeth. Considering the poor prognosis of VRF, a reliable and valid detection method is necessary. Cone beam computed tomography (CBCT) has been reported to be a reliable tool for the detection of VRF; however, the presence of metallic intracanal posts can decrease the diagnostic values of CBCT systems. This study evaluated and compared the effects of intracanal stainless steel or titanium posts on the sensitivity, specificity, and accuracy of VRF detection using a NewTom VG CBCT system. Materials and Methods: Eighty extracted single-rooted teeth were selected and sectioned at the cemento-enamel junction. The roots were divided into two groups of 40. Root fracture was induced in the test group by using an Instron machine, while the control group was kept intact. Roots were randomly embedded in acrylic blocks and radiographed with the NewTom VG, both with titanium and stainless steel posts and also without posts. Sensitivity, specificity, and accuracy values were calculated as compared to the gold standard. Results: The sensitivity, specificity, and accuracy of VRF diagnosis were significantly lower in teeth with stainless steel and titanium posts than in those without posts. Interobserver agreement was the highest in teeth without posts, followed by stainless steel posts, and then titanium posts. Conclusion: Intracanal posts significantly decreased the VRF diagnostic values of CBCT. The stainless steel posts decreased the diagnostic values more than the titanium posts.

• 대한족부족관절학회지
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• 제13권1호
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• pp.55-59
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• 2009

Purpose: We tried to evaluate the usefulness of the arthroscopy in the operative treatment of intra-articular calcaneal fracture. Materials and Methods: Between March 2005 and May 2008, 9 patients with intra-articular calcaneal fractures（Tongue type or Sanders type IIC) were treated with arthroscopically assisted percutaneous reduction and screw fixation. American orthopedic foot and ankle society (AOFAS) ankle-hindfoot score, visual analogue scale (VAS), preoperative and postoperative Bohler's angle and the rate of complication were evaluated. Results: AOFAS score at postoperative 1 year was 88.2 (range, 71-92), and mean VAS score was 2.8 (range, 1-4). Bohler angle was improved from preoperative mean $16.2^{\circ}$ to postoperative mean $29.7^{\circ}$. There were no complications such as wound problem, infection or nerve injury. Conclusion: Subtalar arthroscopy provides precise view of posterior facet during the operation. Therefore, it can be a useful tool in treating intra-articular calcaneus fractures, especially tongue type and Sanders type IIC fractures.

• 대한정형외과 초음파학회지
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• 제4권2호
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• pp.66-71
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• 2011

목적: 보존적인 치료를 시행 받은 쇄골 골절 환자 중 단순 방사선학적 검사에서 가골 형성이 관찰 되지 않아 지연유합이나 불유합이 의심되는 경우 초음파 검사가 가골 형성여부를 확인하는 검사로서 유용한 가를 알아보고자 하였다. 대상 및 방법: 쇄골 골절로 진단되어 보존적인 치료를 시행 받았으나, 불유합 또는 지연 유합이 의심되는 여섯 명의 남자와 한 명의 여자 환자(평균 38.3세; 범위: 7~70세)를 대상으로 초음파를 시행하였다. 초음파 검사상 가골 형성이 관찰된 경우는 보존적 치료를 지속하였고, 가골 형성이 관찰 되지 않은 경우는 수술적 치료를 시행하였다. 결과: 초음파 검사상 가골 형성을 관찰 할 수 있었던 6예는 보존적인 치료를 지속하여 최종 추시 단순 방사선 검사상 골유합을 확인 할 수 있었다. 초음파 검사상 가골 형성이 관찰되지 않았던 1예는 수술적 치료를 시행하였으며, 수술소견상 골유합 소견을 관찰할 수 없었다. 결론: 초음파 검사는 보존적 치료를 받는 쇄골 골절 환자에서 임상적 및 방사선학적으로 불유합 또는 지연 유합이 의심되는 경우 가골 형성을 평가하는데 있어 유용한 검사 방법으로 불필요한 수술을 피하는 데 기여할 수 있을 것으로 생각한다.

• 폴리머
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• 제31권2호
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• pp.123-129
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• 2007

세 종류의 폴리올레핀 복합재료의 기계적인 특성과 파괴인성 메커니즘이 연구되었다. 기계적 특성을 조사하기 위해 인장 시험 및 아이조드 충격 시험이 수행되었다. 균열 선단 주위의 파손 메커니즘을 정확히 조사하기 위해 2노치-4점 굽힘 기법이 도입/적용되었다. 광학현미경과 투과형 전자현미경을 이용하여, 폴리올레핀 복합재료의 균열 선단 주변 국부적인 파괴인성 특성들이 관찰되었다. 이를 통한 구체적인 관찰은, 폴리올레핀 복합재료의 균열선단 주변에 전단밴딩, 크레이즈, 입자-수지간 분리, 고무입자의 캐비테이션, 크랙 휭 및 크랙 분기 등과 같은 다양한 파괴인성 메커니즘들이 존재함을 보여주었다. 이러한 파괴인성 메커니즘들은 아이조드 충격 시험에서 보여진 파괴인성 값의 증가에 대한 실질적인 원인으로 보여진다. 본 연구를 바탕으로, 2노치-4점 굽힘 기법은 폴리올레핀 복합재료의 파괴 거동과 그와 관련된 파괴인성 메커니즘을 기술할 수 있는 충분한 정보를 제공하였다.

• 대한한의학회지
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• 제42권2호
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• pp.90-97
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• 2021

DXA로 측정한 요추 부위와 대퇴골경의 골밀도 수치가 2년간 지속적으로 연령대 평균 이하였던 중년의 사무직 남성 환자가 접골탕을 복용하고 골밀도 수치가 개선되었다.

• 한국결정성장학회지
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• 제8권1호
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• pp.111-116
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• 1998

질화규소는 고경도, 고인성 세라믹 재료이기 때문에, 기계적 가공성은 매우 나쁘며, 또한 질화규소는 높은 전기 저항을 갖는다. 매우 높은 전기저항을 띠는 질화규소에 30wt% 이상의 TiN 분말이 첨가되었을 때 전도성 세라믹 복합체가 된다. 높은 전기 전도도를 가질 때 세라믹을 방전가공방법(EDM)을 이용하여 정밀한 가공을 할 수 있다. 높은 전기 전도도를 갖는 $Si_3N_4-TiN$ 세라믹 복합체는 EDM 방법을 이용하여 금속 가공 tool을 만드는데 이용되며, 이러한 tool 재료들은 산화뿐만 아니라 심각한 마모문제를 갖는다. 상압소결후 post HIP 소결방법으로 $Si_3N_4-TiN$ 복합체를 만들었으며, TiN의 양의 변화에 따른 $Si_3N_4$ 복합체의 마모특성을 상온의 대기중에서 조사하였다. 경도, 파괴인성, 강도값을 마모량과 비교하였다. 마모흔의 SEM 관찰로 $Si_3N_4-TiN$ 복합체의 마모기구를 설명하였다.

• Imaging Science in Dentistry
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• 제51권1호
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• pp.55-62
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• 2021

Purpose: This study evaluated the influence of a metal artifact reduction (MAR) tool in a cone-beam computed tomography (CBCT) device on the diagnosis of vertical root fractures (VRFs) in teeth with different root filling materials. Materials and Methods: Forty-five extracted human premolars were classified into three subgroups; 1) no filling; 2) gutta-percha; and 3) metallic post. CBCT images were acquired using an Orthopantomograph 300 unit with and without a MAR tool. Subsequently, the same teeth were fractured, and new CBCT scans were obtained with and without MAR. Two oral radiologists evaluated the images regarding the presence or absence of VRF. Receiver operating characteristic (ROC) curves and diagnostic tests were performed. Results: The overall area under the curve values were 0.695 for CBCT with MAR and 0.789 for CBCT without MAR. The MAR tool negatively influenced the overall diagnosis of VRFs in all tested subgroups, with lower accuracy (0.45-0.72), sensitivity (0.6-0.67), and specificity (0.23-0.8) than were found for the images without MAR. In the latter group, the accuracy, sensitivity, and specificity values were 0.68-0.77, 0.67-083, and 0.53-087, respectively. However, no significant difference was found between images with and without MAR for the no filling and gutta-percha subgroups (P>0.05). In the metallic post subgroup, CBCT showed a significant difference according to MAR use (P<0.05). Conclusion: The OP 300 MAR tool negatively influenced the detection of VRFs in teeth with no root canal filling, gutta-percha, or metallic posts. Teeth with metallic posts suffered the most from the negative impact of MAR.

• 대한골대사학회지
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• 제25권4호
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• pp.195-211
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• 2018

Background: To develop guidelines and recommendations to prevent and treat glucocorticoid (GC)-induced osteoporosis (GIOP) in Korea. Methods: The Korean Society for Bone and Mineral Research and the Korean College of Rheumatology have developed this guideline based on Guidance for the Development of Clinical Practice Guidelines ver. 1.0 established by the National Evidence-Based Healthcare Collaborating Agency. This guideline was developed by adapting previously published guidelines, and a systematic review and quality assessment were performed. Results: This guideline applies to adults aged ${\geq}19years$ who are using or plan to use GCs. It does not include children and adolescents. An initial assessment of fracture risk should be performed within 6 months of initial GC use. Fracture risk should be estimated using the fracture-risk assessment tool (FRAX) after adjustments for GC dose, history of osteoporotic fractures, and bone mineral density (BMD) results. All patients administered with prednisolone or an equivalent medication at a dose ${\geq}2.5mg/day$ for ${\geq}3months$ are recommended to use adequate calcium and vitamin D during treatment. Patients showing a moderate-to-high fracture risk should be treated with additional medication for osteoporosis. All patients continuing GC therapy should undergo annual BMD testing, vertebral X-ray, and fracture risk assessment using FRAX. When treatment failure is suspected, switching to another drug should be considered. Conclusions: This guideline is intended to guide clinicians in the prevention and treatment of GIOP.