• Journal of Dental Rehabilitation and Applied Science
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• v.36 no.2
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• pp.88-94
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• 2020

Purpose: The purpose of this study was to analyze the sagittal root position of maxillary anterior teeth and report the frequency of each classification in Korean for immediate implant placement. Materials and Methods: A retrospective review of cone-beam computed tomography (cone-beam CT) images was conducted on 120 patients (60 male and 60 female) who fulfilled the inclusion criteria. After reorientation of the axis, cone-beam CT images were evaluated and the relationship of the sagittal root position (SRP) of the maxillary anterior teeth to its associated osseous housing was recorded. Class I, II, and III were classified respectively when the root was positioned on the labial, central, and palatal aspect of the alveolar bone. Class IV was the position that at least two thirds of the root is engaging both the labial and palatal cortical plates. Then, the angulation of the root axis and the alveolar bone axis was measured. Descriptive statistics and Kruskal-Wallis test were used to compare the angulation according to the root position and SRP class. Results: The frequency distribution of sagittal root position of maxillary anterior teeth indicated that 81.1%, 10.3%, 1.9%, and 6.7% were classified as Class I, II, III, and IV, respectively. The sagittal angulation at approximately 77.5% of central incisor, lateral incisor, and canine was < 20 degrees, but the angle at more than 42.7% of canine was ≥ 20 degrees. Within the class, the angulation was statistically significantly greater in Class I (16.19) compared to Class II (8.72) and Class III (9.93), and smaller in Class IV (3.79). Conclusion: Within the limitation of this study, a majority of the maxillary anterior roots were positioned close to the buccal cortical plate. However, some roots have very thin alveolar bone and sagittal angulation larger than 30 degrees. Therefore, cone-beam CT analyses of the sagittal root position and the sagittal angulation are recommended for the selection of the appropriate dental implant treatment approach.

• Journal of the korean academy of Pediatric Dentistry
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• v.41 no.2
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• pp.157-165
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• 2014

Skeletal anchorage is recommended as an orthodontic treatment for an impacted immature permanent tooth. Among these methods, C-tube is relatively safe because it is fixed to the cortical bone of interdental and the lower part of the root with several short miniscrews, which causes less damage to the root in patients of early permanent dentition. As it can be easily bent, the traction direction can be adjusted to favorable bone density sites. However, patient cooperation is important and traction based on physiological force in order to gain root and dentoalveolar tissue development in immature permanent teeth is required. Periodic follow-ups should be mandatory.

• Journal of Veterinary Clinics
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• v.27 no.5
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• pp.579-583
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• 2010

An 18-month-old intact male Pomeranian dog was presented because of traumatic head injury from a fall. Based on physical and neurological examination, brain injury was suspected. On plain skull radiographs, bony fragment following fracture was identified in the region of the right occipital bone. On computed tomography (CT) images, there were specific findings associated with an intracranial hemorrhage. The patient expired few hours after diagnosis, and performed necropsy. On gross findings, intracerebral hemorrhage and edema was detected and those were consistent with CT images. This report describes the clinical findings, CT imaging characteristics, necropsy findings, and histopathologic features of severe traumatic brain injury in a dog.

• Journal of the Korean Society of Radiology
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• v.7 no.5
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• pp.313-320
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• 2013

For some patients with joint illnesses such as rheumarthritis or varus deformity, the total knee arthroplasty (TKA) procedures are performed. However, when inserting metal cutting guide for the procedures, due to the femoral shaft bowing, complications such as the cortex of the femoral shaft damages or secondary fractures can be caused. If the central coordinate value of the femoral shaft is known, the metal cutting guide could be inserted into the anatomical center, so such complications can be prevented. In this study, CT images of femoral shafts of 10 individuals in the experiment group who are in need of receiving the total knee arthroplasty procedures and those of 10 individuals in the control group without illness in the femoral shaft have been utilized to locate the 3-dimensional coordinate values. Then, Matlab was utilized to identify the central coordinate value in order to obtain a graph reflecting the anatomical shapes as well as to acquire the 3-dimensional radial curvature values by section. As a result, the average curvature range and standard deviation of femoral shafts of the experiment group was determined to be $758.15{\pm}206.3mm$ whereas the that of the control group was determined to be $1672.97{\pm}395.6mm$. The statistical significance of the measured results was verified through f-distribution analysis. Based on these results, it was verified that the level of curvature of the femoral shaft of the experiment group was higher. If the anatomical central points are located and analyzed using this methodology, it would be helpful in performing orthopedic operations such as the total knee arthroplasty.

• Applied Microscopy
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• v.32 no.3
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• pp.223-230
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• 2002

Vitamin D is one of important factors involved in the regulation of bone metabolism. In osteoporosis, the therapeutic effect of vitamin D on the healing process has still been controversial. To confirm the effects of $1{\alpha},\;25\;Dihydroxyvitamin\;D_3$ on the osteoporosis, the change of bone mineral density and the histologic changes of osteoporotic femur were examined comparatively in normal control group (positive control), CFA control group (negative control), CFA+$1{\alpha}$, 25 dihydroxyvitamin $D_{3}\;0.01{\mu}g/kg$ group (Vit $D_{3}L$) and CFA+$1{\alpha}$, 25 dihydroxyvitamin $D_{3}\;0.1{\mu}g/kg$ group (Vit $D_{3}H$) after osteoporosis was induced by single injection of complete Freund's adjuvant (CFA) in rats. The value of bone mineral density and bone mineral content of femur was increased in both Vit $D_{3}L$ and Vit $D_{3}H$ than CFA control, and the increase rate of that was higher in Vit $D_{3}H$ than Vit $D_{3}L$. In CFA control, the size of the bone marrow cavities significantly increased and the width from the bone marrow cavity and cortex significantly decreased than normal control. In Vit $D_{3}H$ and Vit $D_{3}L$, the increase rate of the size of bone marrow cavity and the decrease rate of the width from the bone marrow cavity and cortex was depressed than CFA control. These results suggest that $1{\alpha},\;25\;Dihydroxyvitamin\;D_3$ has therapeutic effect on adjuvant-induced osteoporosis in rats.

• Journal of the Korean Society of Radiology
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• v.85 no.1
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• pp.240-246
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• 2024

Epithelioid angiosarcoma is a rare variant of angiosarcoma characterized by an epithelioid morphology that mimics carcinoma. Therefore, multicentric epithelioid angiosarcoma is easily misdiagnosed as bone metastasis from carcinoma and has an aggressive clinical course. Here, we present a rare case of a 61-year-old male with multicentric epithelioid angiosarcoma of the bone. Plain radiography, CT, and MRI revealed multiple osteolytic lesions in both femurs; some lesions showed soft tissue extension with cortical bone destruction. Interestingly, PET-CT revealed that the lesions were only distributed along the bones of the lower extremities, including the pelvic bones, femurs, and tibiae. Despite histological analysis initially suggesting metastatic carcinoma, after additional immunohistological staining, including that for vascular markers (CD31 and ERG), the final diagnosis was epithelioid angiosarcoma. A better understanding of the clinicoradiological features of this disease may help eliminate diagnostic confusion and provide better management.

• The Journal of the Korean bone and joint tumor society
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• v.9 no.1
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• pp.52-60
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• 2003

Purpose: To analyse their end results and also to differentiate the single or multiple giant cell tumor(GCT) of tendon sheath in hand. Materials & Methods: Total 21 cases with GCT of tendon sheath in hand were treated surgically and analyzed their end results with clinically, radiologically and pathologically to allowed for average 16 months after surgical excision. Results: The finger flexor tendons, especially on index and ring finger, involving distal interphalangeal joint and mid-phalanges in fourth decades (average age of 47 years old) were frequently involved, and the mass was not exceed than 2 cm in size, fixed on tendon sheath with rubbery hard tenderness but rare bony involvements except 4 cases of bony erosion and cortical perforation. The three cases with multiple GCT of hand was also combined with familial hypercholesterolemia, and are commonly involved the extensor tendons as well as achilles tendons bilaterally, treated with partial excision because of multiplicity. Average 16 months after surgical excision for single GCT cases was followed and showed the recurrence in 3 cases(3/18,16.7%), treated with wide excision. The single and multifocal GCT are similar in pathologic changes but different soft tissue tumors in their pathogenesis, treatment and prognosis. Conclusion: Incomplete excision of GCT of tendon sheath in hand are thought to be the cause of recurrence, especially in cases with incomplete lesional excision, in multilobular and bony involvement etc. So careful wide excision is necessary to prevent the recurrence.

• Restorative Dentistry and Endodontics
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• v.34 no.4
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• pp.324-332
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• 2009

The purpose of this study was to investigate the effect of rigidity of post core systems on stress distribution by the theoretical technique, finite element stress-analysis method. Three-dimensional finite element models simulating an endodontically treated maxillary central incisor restored with a zirconia ceramic crown were prepared and 1.5 mm ferrule height was provided. Each model contained cortical bone, trabecular bone, periodontal ligament, 4 mm apical root canal filling, and post-and-core. Six combinations of three parallel type post (zirconia ceramic, glass fiber, and stainless steel) and two core (Paracore and Tetric ceram) materials were evaluated, respectively. A 50 N static occlusal load was applied to the palatal surface of the crown with a $60^{\circ}$angle to the long axis of the tooth. The differences in stress transfer characteristics of the models were analyzed. von Mises stresses were chosen for presentation of results and maximum displacement and hydrostatic pressure were also calculated. An increase of the elastic modulus of the post material increased the stress, but shifted the maximum stress location from the dentin surface to the post material. Buccal side of cervical region (junction of core and crown) of the glass fiber post restored tooth was subjected to the highest stress concentration. Maximum von Mises stress in the remaining radicular tooth structure for low elastic modulus resin core (29.21 MPa) was slightly higher than that for high elastic modulus resin core (29.14 MPa) in case of glass fiber post. Maximum displacement of glass fiber post restored tooth was higher than that of zirconia ceramic or stainless steel post restored tooth.

• Journal of the Korean Arthroscopy Society
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• v.9 no.2
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• pp.222-231
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• 2005

Purpose: This article describes a double-bundle ACL reconstruction technique using a five-strand hamstring tendon autograft with conventional anteromedial bundle reconstruction and additional posterolateral bundle reconstruction. Operative technique: For the tibial tunnel, the conventional single tunnel technique is performed and for the femoral tunnel, the double tunnel technique is performed with the anteromedial and posterolateral bundle. After minimal notchplasty, the anteromedial femoral tunnel is prepared with leaving one milimeter of posterior femoral cortex within the over-the-top, which if positioned at the 11-o'clock orientation for the right knee or at the 1-o'clock position for the left knee. The posterolateral femoral tunnel that is located 5 to 7 mm superior to the inner margin of the lateral meniscus anterior horn at $90^{\circ}$ of flexion is prepared with tile outside-in technique using a 4.5 cannulated reamer. The graft material for the double bundle reconstruction is made of the conventional four-strand hamstring autograft in the anteromedial bundle and of a single-strand semitendinosus tendon in the posterolateral bundle. The anteromedial bundle is fixed with using a rigid fix system on the femoral side and the posterolateral bundle is fixed to tie with the miniplate from the outside femur. Then, with the knee in $10^{\circ}\;to\;20^{\circ}$ of flexion, a bioabsorbable screw is simultaneously applied to achieve tibial fixation with tensioning of both bundles. Conclusion: A double bundle reconstruction with five-strand hamstring autograft, which is designed with a favorable conventional anteromedial bundle and an additional posterolateral bundle to restore rotation stability, seems to be a very effective method for the treatment for ACL instabilities.

• Journal of the Korean Arthroscopy Society
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• v.7 no.2
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• pp.189-195
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• 2003

Purpose : To evaluate the clinical results after anterior cruciate ligament (ACL) reconstruction with hamstring tendon and Ligament Anchor (LA) screw Materials and Methods : 103 patients (104 cases) who were followed up at least more than 2 years after ACL reconstruction were included in this study. The average period of follow-up was 36 months. The clinical results such as physical examination and Lysholm knee score and instrumented anterior laxity test with Telos were evaluated. Results : The Lysholm knee score was 57.9 in average preoeratively and improved to 95.2 in average at follow up. On the Lachman test, there were mild (+) instability in 46 cases $(45\%)$, moderate (++) in 33 $(31\%)$, severe (+++) in 25 $(24\%)$ preoperatively. 90 cases $(87\%)$ were converted to negative and 14 $(13\%)$ to mild at follow up. On Pivot-shift test, there were negative (-) instability in 22 cases $(22\%)$, mild (+) in 62 $(59\%)$, moderate (++) in 12 $(11\%)$ and severe in 8 $(8\%)$ preoperatively. 87 cases $(84\%)$ were converted to negative and 17 $(16\%)$ to mild at follow up. On instrumented anterior laxity test with $Telos^{\circledR}$, side to side difference on 20 lb was $13.4{\pm}5.6$ (7-25) mm in average preoperatively, and was decreased to $3.6{\pm}1.5$ (1-6) mm in average at follow-up. Complications were quadriceps muscle atrophy in 27 $(30.0\%)$, saphenous nerve paresthesia in 19 $(18.3\%)$, anterior knee crepitus in 13 $(12.5\%)$ and over-penetration of screw through lateral femoral cortex in 5 cases $(4.8\%)$. Conclusion : ACL reconstruction with hamstring tendon and LA screw was one of the choice of graft and fixatives in restoring knee stability and in improving clinical results with little complications such as anterior knee pain.