• Clinics in Shoulder and Elbow
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• 제21권3호
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• pp.151-157
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• 2018

Background: Nonunion of lateral humeral condyle fracture causes cubitus valgus deformity. Although corrective osteotomy or osteosynthesis can be considered, there are controversies regarding its treatment. To evaluate elbow joint biomechanics in non-united lateral humeral condyle fractures, we analyzed the motion of elbow joint and pseudo-joint via in vivo three-dimensional (3D) kinematics, using 3D images obtained by computed tomography (CT) scan. Methods: Eight non-united lateral humeral condyle fractures with cubitus valgus and 8 normal elbows were evaluated in this study. CT scan was performed at 3 different elbow positions (full flexion, $90^{\circ}$ flexion and full extension). With bone surface model, 3D elbow motion was reconstructed. We calculated the axis of rotation in both the normal and non-united joints, as well as the rotational movement of the ulno-humeral joint and pseudo-joint of non-united lateral condyle in 3D space from full extension to full flexion. Results: Ulno-humeral joint moved to the varus on the coronal plane during flexion, $25.45^{\circ}$ in the non-united cubitus valgus group and $-2.03^{\circ}$ in normal group, with statistically significant difference. Moreover, it moved to rotate externally on the axial plane $-26.75^{\circ}$ in the non-united cubitus valgus group and $-3.09^{\circ}$ in the normal group, with statistical significance. Movement of the pseudo-joint of fragment of lateral condyle showed irregular pattern. Conclusions: The non-united cubitus valgus group moved to the varus with external rotation during elbow flexion. The pseudo-joint showed a diverse and irregular motion. In vivo 3D motion analysis for the non-united cubitus valgus could be helpful to evaluate its kinematics.

• 대한치과교정학회지
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• 제39권1호
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• pp.43-53
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• 2009

본 연구에서는 NiTi scissors-bite corrector를 세 가지 서로 다른 굵기 $0.018"{\times}0.025",\;0.016"{\times}0.022"$, 0.016"의 NiTi 와이어로 제작하였을 때 각각의 치아 이동 양상을 치아 이동 시뮬레이션 장치인 Calorific machine을 이용하여 3차원적으로 분석하고자 하였다. 가위교합에 이환된 상악 제2대구치 모형을 제작하고 제2소구치와 제1대구치 사이에 교정용 미니 임플랜트(orthodontic mini-implant)를 식립하여 제1대구치에 간접골성고정원을 설계하였다. 세 가지 굵기의 NiTi scissors-bite corrector를 부착하여 실험하였다. 치아의 이동 전후에 실험 모형은 computed tomography(CT)로 촬영하고 3차원 데이터로 변환하여 중첩하였다. 치아 이동 방향과 이동량을 계측하여, NiTi scissors-bite corrector 와이어 굵기에 따른 치아 이동 양상에 관한 통계적 유의성을 검정한 결과, 제2대구치 치관의 설측 이동량은 $0.018"{\times}0.025"$군(2.65 mm)이 가장 많았으며, 0.016"군(1.96 mm)과 통계적으로 유의한 차이를 보였다(p<0.05). 제2대구치 치관의 압하량은 $0.018"{\times}0.025"$군(2.35 mm), $0.016"{\times}0.022"$군(1.18 mm), 0.016"군(1.00 mm)으로 $0.018"{\times}0.025"$군이 나머지 두 군과 유의한 차이를 보였고(p<0.05), 치근의 압하량은 $0.018"{\times}0.025"$군(4.19 mm), $0.016"{\times}0.022"$군(3.29 mm), 0.016"군(2.24 mm)으로 세 군 간 모두 통계적 유의차를 보였다(p<0.05). 치아의 이동 양상을 관찰한 결과, 0.016"군에서는 제2대구치 치근의 협측 이동이 나타나지 않았다. 간접골성고정원으로 사용된 제1대구치의 고정원 소실은 0.2 mm 이하로 나타났다. 이상의 결과를 토대로 $0.018"{\times}0.025"$ NiTi 와이어로 제작한 NiTi scissors-bite corrector를 교정용 미니 임플랜트를 이용한 간접골성고정원과 함께 이용하였을 때, 최소한의 고정원의 소실과 함께 가장 큰 상악 제2대구치의 설측 이동 및 압하가 일어났다고 할 수 있다.

• 대한의용생체공학회:의공학회지
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• 제42권3호
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• pp.71-79
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• 2021

Currently, the naked eyes-based diagnosis of bone metastases on CT images relies on qualitative assessment. For this reason, there is a great need for a state-of-the-art approach that can assess and follow-up the bone metastases with quantitative biomarker. Radiomics can be used as a biomarker for objective lesion assessment by extracting quantitative numerical values from digital medical images. In this study, therefore, we evaluated the clinical applicability of non-invasive and objective bone metastases computer-aided diagnosis using radiomics-based biomarkers in CT. We employed a total of 21 approaches consist of three-classifiers and seven-feature selection methods to predict bone metastases and select biomarkers. We extracted three-dimensional features from the CT that three groups consisted of osteoblastic, osteolytic, and normal-healthy vertebral bodies. For evaluation, we compared the prediction results of the classifiers with the medical staff's diagnosis results. As a result of the three-class-classification performance evaluation, we demonstrated that the combination of the random forest classifier and the sequential backward selection feature selection approach reached AUC of 0.74 on average. Moreover, we confirmed that 90-percentile, kurtosis, and energy were the features that contributed high in the classification of bone metastases in this approach. We expect that selected quantitative features will be helpful as biomarkers in improving the patient's survival and quality of life.

• 대한치과교정학회지
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• 제42권4호
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• pp.159-168
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• 2012

Objective: The aims of this study were to investigate mandibular deformation under clenching and to estimate its effect on the stability of orthodontic mini-implants (OMI). Methods: Three finite element models were constructed using computed tomography (CT) images of 3 adults with different mandibular plane angles (A, low; B, average; and C, high). An OMI was placed between #45 and #46 in each model. Mandibular deformation under premolar and molar clenching was simulated. Comparisons were made between peri-orthodontic mini-implant compressive strain (POMI-CSTN) under clenching and orthodontic traction forces (150 g and 200 g). Results: Three models with different mandibular plane angles demonstrated different functional deformation characteristics. The compressive strains around the OMI were distributed mesiodistally rather than occlusogingivally. In model A, the maximum POMI-CSTN under clenching was observed at the mesial aspect of #46 (1,401.75 microstrain [${\mu}E$]), and similar maximum POMI-CSTN was observed under a traction force of 150 g (1,415 ${\mu}E$). Conclusions: The maximum POMI-CSTN developed by clenching failed to exceed the normally allowed compressive cortical bone strains; however, additional orthodontic traction force to the OMI may increase POMI-CSTN to compromise OMI stability.

• Imaging Science in Dentistry
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• 제50권3호
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• pp.199-208
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• 2020

Purpose: This study was performed to introduce an in vivo hybrid multimodality technique involving the coregistration of micro-computed tomography (micro-CT) and high-resolution magnetic resonance imaging (HR-MRI) to concomitantly visualize and quantify mineralization and vascularization at follow-up in a rat model. Materials and Methods: Three adult female rats were randomly assigned as test subjects, with 1 rat serving as a control subject. For 20 weeks, the test rats received a weekly intravenous injection of 30 ㎍/kg zoledronic acid, and the control rat was administered a similar dose of normal saline. Bilateral extraction of the lower first and second molars was performed after 10 weeks. All rats were scanned once every 4 weeks with both micro-CT and HR-MRI. Micro-CT and HR-MRI images were registered and fused in the same 3-dimensional region to quantify blood flow velocity and trabecular bone thickness at T0 (baseline), T4 (4 weeks), T8 (8 weeks), T12 (12 weeks), T16 (16 weeks), and T20 (20 weeks). Histological assessment was the gold standard with which the findings were compared. Results: The histomorphometric images at T20 aligned with the HR-MRI findings, with both test and control rats demonstrating reduced trabecular bone vasculature and blood vessel density. The micro-CT findings were also consistent with the histomorphometric changes, which revealed that the test rats had thicker trabecular bone and smaller marrow spaces than the control rat. Conclusion: The combination of micro-CT and HR-MRI may be considered a powerful non-invasive novel technique for the longitudinal quantification of localized mineralization and vascularization.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제41권
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• pp.43.1-43.5
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• 2019

Background: Reconstructive surgery is often required for tumors of the oral and maxillofacial region, irrespective of whether they are benign or malignant, the area involved, and the tumor size. Recently, three-dimensional (3D) models are increasingly used in reconstructive surgery. However, these models have rarely been adapted for the fabrication of custom-made reconstruction materials. In this report, we present a case of maxillary reconstruction using a laboratory-engineered, custom-made mesh plate from a 3D model. Case presentation: The patient was a 56-year-old female, who had undergone maxillary resection in 2011 for intraoral squamous cell carcinoma that presented as a swelling of the anterior maxillary gingiva. Five years later, there was no recurrence of the malignant tumor and a maxillary reconstruction was planned. Computed tomography (CT) revealed a large bony defect in the dental-alveolar area of the anterior maxilla. Using the CT data, a 3D model of the maxilla was prepared, and the site of reconstruction determined. A custom-made mesh plate was fabricated using the 3D model (Okada Medical Supply, Tokyo, Japan). We performed the reconstruction using the custom-made titanium mesh plate and the particulate cancellous bone and marrow graft from her iliac bone. We employed the tunneling flap technique without alveolar crest incision, to prevent surgical wound dehiscence, mesh exposure, and alveolar bone loss. Ten months later, three dental implants were inserted in the graft. Before the final crown setting, we performed a gingivoplasty with palate mucosal graft. The patient has expressed total satisfaction with both the functional and esthetic outcomes of the procedure. Conclusion: We have successfully performed a maxillary and dental reconstruction using a custom-made, pre-bent titanium mesh plate.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제34권6호
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• pp.622-627
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• 2008

In orthognathic surgery, precise analysis and diagnosis are essential for successful results. In facial asymmetric patient, traditional 2D image analysis has been used by lateral and P-A Cephalometric view, Skull PA, Panorama, Submentovertex view etc. But clinicians sometimes misdiagnose because they cannot find exact landmark due to superimposition, moreover image can be magnified and distorted by projection technique or patient's skull position, when using these analysis and method. For overcome these defects, analysis by using of 3D CT has been introduced. In this way we can analysis precisely by getting the exact image free of artifact and finding exact landmark with no interruption of superimposition. So we want to review of relationship between various skeletal landmarks of mandible or cranial base and facial asymmetry by predictable analysis using 3D CT. We select the cases of the patients who visited our department for correction of facial asymmetry during 2003-2007 and who were taken image of 3D CT for diagnosis. 3D CT images were reconstructed to 3D image by using V-Work program (Cybermed Inc., Seoul, Korea). And we analysis the relationship between facial asymmetry and various affecting factor of skeletal pattern. The mandibular ramus hight difference between right and left was most affecting factor that express facial asymmetry. And in this research, there was no relationship between cranial base and facial asymmetry. The angulation between facial midline and mandibular ramus divergency has significant relationship with facial asymmetry

• Imaging Science in Dentistry
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• 제36권2호
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• pp.89-94
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• 2006

Purpose : To evaluate clinical usefulness of facial soft tissue thickness measurement using 3D computed tomographic images. Materials and Methods : One cadaver that had sound facial soft tissues was chosen for the study. The cadaver was scanned with a Helical CT under following scanning protocols about slice thickness and table speed; 3 mm and 3 mm/sec, 5 mm and 5 mm/sec, 7 mm and 7 mm/sec. The acquired data were reconstructed 1.5, 2.5, 3.5 mm reconstruction interval respectively and the images were transferred to a personal computer. Using a program developed to measure facial soft tissue thickness in 3D image, the facial soft tissue thickness was measured. After the ten-time repeation of the measurement for ten times, repeated measure analysis of variance (ANOVA) was adopted to compare and analyze the measurements using the three scanning protocols. Comparison according to the areas was analyzed by Mann-Whitney test. Results : There were no statistically significant intraobserver differences in the measurements of the facial soft tissue thickness using the three scanning protocols (p>0.05). There were no statistically significant differences between measurements in the 3 mm slice thickness and those in the 5 mm, 7 mm slice thickness (p>0.05). There were statistical differences in the 14 of the total 30 measured points in the 5 mm slice thickness and 22 in the 7 mm slice thickness. Conclusion : The facial soft tissue thickness measurement using 3D images of 7 mm slice thickness is acceptable clinically, but those of 5 mm slice thickness is recommended for the more accurate measurement.

• Imaging Science in Dentistry
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• 제38권2호
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• pp.81-87
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• 2008

Purpose: To investigate the relationship between 3D bone architectural parameters and direction-related elastic moduli of cancellous bone of mandibular condyle. Materials and Methods: Two micro-pigs (Micro-$pig^R$, PWG Genetics Korea) were used. Each pig was about 12 months old and weighing around 44 kg. 31 cylindrical bone specimen were obtained from cancellous bone of condyles for 3D analysis and measured by micro-computed tomography. Six parameters were trabecular thickness (Tb. Th), bone specific surface (BS/BV), percent bone volume (BV/TV), structure model index (SMI), degree of anisotropy (DA) and 3-dimensional fractal dimension (3DFD). Elastic moduli of three orthogonal directions (superior-inferior (SI), medial-lateral (ML), andterior-posterior (AP) direction) were calculated through finite element analysis. Results: Elastic modulus of superior-inferior direction was higher than those of other directions. Elastic moduli of 3 orthogonal directions showed different correlation with 3D architectural parameters. Elastic moduli of SI and ML directions showed significant strong to moderate correlation with BV/TV, SMI and 3DFD. Conclusion: Elastic modulus of cancellous bone of pig mandibular condyle was highest in the SI direction and it was supposed that the change into plate-like structure of trabeculae was mainly affected by increase of trabeculae of SI and ML directions.

• Radiation Oncology Journal
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• 제28권3호
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• pp.177-183
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• 2010

목 적: 유방암 치료를 위한 방사선치료계획에 전산화단층촬영을 이용한 모의치료가 널리 이용되고 있다. 이는 환자 개개인의 해부학적 특징에 기반하여 종양 표적과 정상 조직을 정의할 수 있다. 본 연구는 일반적으로 유방 크기가 작은 한국인 유방암 환자에서 적용하는 방사선치료계획 방법에 따라 치료용적 및 치료범위에 차이가 있는지를 알아보기 위해 시행하였다. 대상 및 방법: 2008년 11월부터 2009년 1월까지 조기유방암으로 유방보존술을 시행 받은 25명의 환자를 대상으로 통상적인 접면조사의 이차원치료 계획과 전산화단층촬영을 기반으로 한 삼차원치료계획을 시행하였다. 이차원 치료계획에서 방사선조사영역의 경계는 유방실질을 촉지하여 결정하였고 위쪽으로는 쇄골의 바로 아래, 내측은 몸의 정중선, 외측은 중심 액와선 그리고 아래쪽은 유방밑주름에서 2 cm 아래에 표시하였다. 삼차원치료계획에서 임상표적체적은 모든 유선 조직을 포함하였고 계획용 표적체적은 임상표적체적에서 피부 쪽을 제외한 모든 방향으로 1 cm의 여유를 두어 결정하였다. 이차원과 삼차원치료계획 간의 조사영역의 경계 차이 및 동등조사영역의 차이를 확인하고 신체질량지수, 폐경 여부 및 유방크기의 관련성을 평가하였다. 그리고 선량분포로 지정한 유방조사량과 삼차원 선량분포에 기반하여 측정된 조사된 폐용적과 심장용적을 평가하였다. 결 과: 2명의 환자를 제외하고 계획용표적체적(PTV)은 삼차원치료계획이 이차원치료계획보다 모든 방향에서 표시한 방사선조사영역을 감소시켰고 위쪽 경계에서 그 차이값이 가장 컸다. 동등조사영역크기는 한 명을 제외하고 삼차원치료계획에서 이차원치료계획에서보다 작았으며(평균 0.9 cm), 신체질량지수, 폐경 여부 및 유방크기(브래지어 사이즈)와의 관련성은 보이지 않았다. 조사된 폐용적은 삼차원치료계획에서 유의하게 감소하였고, 심장용적 또한 감소하였지만 통계적으로 유의한 차이는 보이지 않았다. 결 론: 통상적인 치료계획과 비교하여 전산화단층촬영을 기반으로 한 삼차원치료계획이 작은 유방을 가진 환자에서 방사선조사영역 및 손상위험장기의 조사량을 줄이면서 수술 후 변화를 포함하여 더 정확한 종양치료가 가능할 수 있음을 보여주었다. 그러나 앞으로 임상표적체적의 정의에 대한 추가적인 연구 및 일반적인 합의가 필요하다.