• The korean journal of orthodontics
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• v.38 no.3
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• pp.187-201
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• 2008

Objective: The aim of this study was to determine whether cortical punching stimulates the expression of matrix metalloproteinase-1, -8, and -13 in orthodontic tooth movement in rats. Methods: A total of 32 male sprague-dawley rats at 15 weeks old were divided into two groups of 16 rats each, to form the tooth movement with cortical punching (TMC) group and tooth movement only (TM) group. A total of 20 gm of orthodontic force was applied to rat incisors to cause experimental tooth movement. Cortical punching was performed on the palatal side near the central incisor with a 1.0 mm width microscrew in the TMC group. The duration of tooth movement was 1, 4, 7, and 14 days. Results: Measurements of the mRNA expression were selected as the means to determine the identification of expression of MMP-1, -8, and -13. In the TMC group, the expression of collagen type I was greater than that of the TM group from day 4 to day 14. Expression of TIMP-1 in the TM group was greater than that of the TMC group in the pressure side of PDL and alveolar bone cell at day 4. In the TMC group, TIMP-1 was expressed at the osteoclast, but not at the tooth surface of the TM group at day 14, Maximum induction of the mRNA of MMP-1 was observed on day 4 in the TMC group, but it was observed on day 7 in the TM group. MMP-8 mRNA of the TMC group was twice greater than that of the TM group at f days. In the TMC group, maximum induction of MMP-13 mRNA was observed on day 1. Conclusions: These findings suggested that cortical punching can stimulate remodeling of PDL and alveolar bone connective tissues during experimental orthodontic tooth movement in rats.

• The Journal of the Korean bone and joint tumor society
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• v.10 no.2
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• pp.71-78
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• 2004

Purpose: The purpose of this study is to investigate the characteristic of recurred giant cell tumor after bony curettage and cementation, and to review a way to prevent the recurrence. Materials and Methods : Thirty seven cases were analyzed, which were pathologically diagnosed giant cell tumor after diagnostic biopsy or surgical excision, followed by curative curettage, burring and cementation. Location, character, and time interval to recurrence were reviewed. Results: Thirteen out of thirty seven analyzed cases(35%) showed recurrence after primary curettage and cementation. The mean interval to recurrence was sixteen months(5 months to 43 months). Most of recurrence happened within the first two years except two cases. Among the recurred cases, eleven showed recurrence in the vicinity of window area. Two cases recurred in the depth of bone marrow, where cementation was made. The advantage of curettage and cementation is the immediate stability of the operation site, early rehabilitation, and early detection of recurrence. Furthermore, cementation is beneficial in that the cement-producing heat can eradicate the residual tumor burden. In this study, 85% of cases with insufficient curettage (for example, in cases where too small surgical window was made, or where there were anatomical difficulty in approaching the target tumor burden) showed recurrence. Conclusion: Bony curettage, burring and cementation is widely used as the primary curative modality for giant cell tumor. A few other modalities such as chemical cautery using phenol and $H_2O_2$; cryotherapy; and anhydroalcohol have also been introduced, but the benefit of these are still questionable. For some cases that relatively small surgical window was made due to anatomically complicated structures (such as ligament insertion or origin site) over the target tumor burden, unsatisfactory curettage and burring was made. This study showed high chance of recurrence after unsatisfactory curettage, and 85% of recurrence developed in the vicinity of the small window area. Most of the recurrence occurred within the first two years. It is concluded that sufficient window opening, extensive curettage and eradicative burring are key factors to prevent recurrence. Also, it should be reminded that careful and close observation should be made for at least the first two years after initial treatment for early detection of recurrence.

• Investigative Magnetic Resonance Imaging
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• v.3 no.1
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• pp.66-72
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• 1999

Purpose : To evaluate the usefulness of Dual Echo in Steady State(DESS) image in the diagnosis of chondromalacia of the knee compared with turbo spin-echo MR images Materials and Methods : We included 26 patients with chondromalacia of the knee. MR imaging was obtained with a 1.5T imager. Sagittal and coronal double echo T2 weighted images(TR/TE 3000-4200/16-96msec, FOV $140-160{\times}140-160mm$, matrix size $180{\times}256$, slice thickness 4.0mm, interslice gap 0.5mm), and sagittal DESS image(TR/TE 25.4/9.0msec, flip angle $35-45^{\circ}$, FOV $150-160{\times}150-160mm,{\;}matrix{\;}size{\;}192{\times}256$, effective slice thickness 1.5mm) were obtained. Cartilage lesions were staged according to a modified scheme proposed by Outerbirdge: grade 0, normal; grade 1, softening or/and swelling; grade 2, mild surface fibrillation or/and less than 50% of cartilage thickness; grade 3, severe surface fibrillation or/and loss of more than 50% of cartilage thickness but without exposure of subchondral bone; and grade 4, complete loss of cartilage with subchondral bone exposure. Gradings were determined by two readers with consensus, and patellofemoral, medial and lateral tibiofemoral compartments were evaluated. Results : Arthroscopic findings revealed grade 1 in seven cases, grade 2 in 21 cases, grade 3 in six cases, and grade 4 in 18 cases. Sensitivity of turbo spin-echo MR image was as follows; 0%, 14%, 0%, 61% in each grade, and sensitivity of DESS image was as follows; 0%, 33%, 50%, 67%, in each grade(p=0.001). In the detection of chondromalacic lesions regardless of gradings, sensitivity, specificity and accuracy of conventional MR image were 59.6% 88.6% 78.8%, and of DESS image, 73.1% 88.4%, 82.2%(p=0.007). Conclusion : For chondromalacia of knee joints, DESS images showed higher sensitivity than turbo spin-echo MR images. Therefore, DESS images will be helpful for diagnosis of chondromalacia of knee joints.

• Journal of the Korean Arthroscopy Society
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• v.5 no.1
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• pp.17-21
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• 2001

Purpose : To analyze changes of the anterior translation, MRI findings and associated injuries at scarring of the torn ACL in the chronic ACL rupture. Materials & Method : From Dec. 1996 to May 2000, 19 patients who were diagnosed as the chronic ACL rupture were studied. We analyzed KT-2000 side to side difference of maximal manual anterior displacement(MMAD), MRI findings and associated injuries. Results : There was statistically significant difference in the average MMAD between the 7 cases$(37\%)$ with scar formation$(2.78{\pm}2.41mm)$ and the 12 cases without scarring$(5.75{\pm}2.52mm)$. The chronic ACL rupture without scarring had more meniscal injuries$(67\%)$ than with scarring$(28\%)$. MRI showed that relatively straight bands toward expected insertion site with single large fragment(5 cases) and continuous band with focal angulation(2 cases). Conclusion : If relatively straight bands toward expected insertion site with single large fragment or continuous band with focal angulation on MR imaging is showed in the patient without significant anterior translation at arthrometer, the possibility of the scar formation of the torn ACL should be considered. We think that the chronic ACL rupture with scarring had less meniscal injuries than without scarring will give additional information on the natural history of ACL injuries.

• Journal of the Korean Arthroscopy Society
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• v.5 no.1
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• pp.1-6
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• 2001

Purpose : The purpose of this study was to compare the postoperative success and stability of arthroscopically assisted anterior cruciate ligament(ACL) reconstructions using central one third bone-patellar-tendon bone(BPB) autograft versus quadrupled semitendinos-us(ST) autograft as the medium term review. Materials and Methods : Eighty patients(40 BPBs,40 STs) with isolated ACL injury were available for a mean follow up of 49.4 months(BPB) and 48.8 months(ST). There was no significant difference between the two groups with respect to age and sex. We compare the final results between two groups with respect to subjective Lysholm score, objective laxity including anterior drawer test, Lachman test, pivot shift test, KT-2000 measurements and International Knee Documentation Committee(IKDC) evaluation system. Results : Postoperatively, positive anterior drawer test was found in $22.5\%\;and\;27.5\%$, positive Lachman test was found in $30.0\%$ and $25.0\%$ and positive pivot shift test was found in $15\%\;and\;20\%$ of the ST and BPB group, respectively(p>0.05). Mean side to side difference of KT-2000 at 20 lbs was 2.2 mm for the ST group and 2.1 mm for the BPB group. There was no significant difference between the two groups about Lysholm score(>0.05). Anterior knee pain was knee common in the BPB group. Eighty-three percent of the patients were nearly normal according to the IKDC grade in both groups. Conclusion : We consider that autogenous semitendinosus tendon is a good alternative subsititute in ACL reconstruction together with the bone-patellar tendon-bone autograft.

• Journal of Korean Orthopaedic Sports Medicine
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• v.9 no.2
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• pp.98-103
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• 2010

Purpose: We reported the results of arthroscopically assisted lateral release and medial imbrication for the recurrent patella dislocation. Materials and Methods: Twenty patients (20 knees) underwent arthroscopically assisted surgery for the recurrent patella dislocation. There were 4 males and 16 female. The average age was 20.2 years. All patients had definite trauma history and average follow-up period was 19 months. The surgical results were evaluated according to the Lysholm knee score and the Kujala score. The congruence angle and lateral patellofemoral angle were measured on plain radiograph and the tibial tubercle-trochlear groove distance was calculated on computerized tomography. Results: The median value of preoperative congruence angle was $16.5^{\circ}$ (range, $0.0{\sim}+34^{\circ}$) and the average final follow-up was $-6.4^{\circ}$ (range, $-19{\sim}10^{\circ}$) with statistically significant improvement (p=0.025). The median value of preoperative Lysholm knee score was 70 (range, 63~81) and the final follow-up score had changed to 88 (range, 80~95) with statistically significant improvement (p=0.0341). The median value of preoperative Kujala score was 72 (range, 65~80) and the average final follow-up score showed 87 (range, 80~92) with statistically significant improvement (p=0.024). Recurrent dislocations after surgery occurred in 2 cases, one case which showed positive "thumb to forearm test" had been treated with medial patellofemoral ligament reconstruction. Conclusion: Arthroscopically assisted lateral release and medial imbrication for recurrent patella dislocation without bony malaligmenent showed the effective treatment, but would be inappropriate for the patients with the generalized joint laxity.

• The korean journal of orthodontics
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• v.28 no.4 s.69
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• pp.563-580
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• 1998

This study was designed to analysis the displacement and stress distribution of individual tooth by orthodontic force during distal on masse movement of the maxillary dentition. In this study, three dimensional finite element analysis was used. Author made the finite element model of maxillary teeth, periodontal ligament, alveolar bone and bracket with anatomic and physiologic characteristics on computer. Author analysed and evaluated the displacement and stress distribution of individual tooth when extraoral force, Class II intermaxillary elastics, ideal arch wire, MEAW and tip back bend were used for distal on masse movement of the maxillary dentition. These analyses were also applied in the case of the maxillary second molar were not extracted. Author compared the results of the cases which maxillary second molar were extracted or not. The results were expressed quantitatively and visually. Author obtained following results, 1. When anterior headgear was applied, the posterior translation, posterior tipping, and vertical displacement of teeth were produced more in the anterior segment of the dentition. 2. When Class II intermaxillary elastics were applied in the ideal arch wire, the teeth displacement were usually produced in the anterior segment. But when tip back bend were added in the ideal arch wire, the orthodontic force produced by elastics were transmitted to the posterior segment. As increasing the tip back bend, posterior translation and lingual tipping of anterior teeth were decreased, posterior translation and tipping displacement of posterior teeth were increased, and extrusion of anterior teeth by Class II elastics were decreased 3. When MDAW and Class II elastics were applied, the teeth movement were sir flu with the case of ideal arch wire and Class II elastics, but more small and uniform teeth displacement were produced Compared with the ideal arch wire, posterior tipping of the posterior segment were more produced than lingual tipping displacement of the anterior segment. 4. When the maxillary second molar without orthodontic appliance existed, the displacement of maxillary first molar were decreased.

• Journal of the Korean Arthroscopy Society
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• v.12 no.1
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• pp.1-6
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• 2008

Purpose: The purpose of this study is to compare the results of the arthroscopic reconstruction of ACL using autologous hamstring tendon and autologous bone-patellar tendon-bone. Materials and Methods: From January, 2000 to December, 2004, 120 patients underwent arthroscopic ACL reconstruction using autologous hamstring tendon(60 cases) and autologous bone-patellar tendon-bone(BPTB)(60 cases). The mean followed up period of hamstring tendon group was 42 months(range $24{\sim}69$ months) and patellar tendon group was 52 months(range $24{\sim}84$ months). At the time of the final follow up, sixty patients in each group were evaluated the results of physical examination, activity level, patients' satisfaction, functional status, and objective anteriror stability using KT-2000 arthrometer. Results: At the time of the final follow up we compared the two groups who had ACL reconstruction using either autologous hamstring tendon or BPTB, and the final results of the Lachman test showed negative, or mildly positive in 85%(51 cases) of the hamstring tendon group and 90%(54 cases) of the BPTB group. Pivot shift test indicated positive in both groups, 8%(5 cases) and 5%(3 cases) respectively and showed no statistically significant difference. The evaluation of the anterior laxity using the KT-2000 arthrometer revealed no significant difference in the hamstring and BPTB groups: differences less than 3 mm compared to the healthy side were 85%(51 cases) and 90%(54 cases)(p>0.05). The Lysholm score improved from a preoperative score of 51 to a postoperative score of 79.1 in the hamstring groups and from 52 to 82.2 in the BPTB groups. According to the IKDC rating system, 87%(52 cases) were normal or near normal in the hamstring group. In the BPTB group, 83%(50 cases) were normal or near normal. The Tegner score for the hamstring groups was 4.8 preoperatively and 7.1 at the final follow up, and the Tegner score for the BPTB groups was 4.5 preoperatively and 7.3 after the last follow-up. The anterior knee pain was found in 7%(4 cases) in the hamstring tendon group and 10%(6 cases) in the patellar tendon group. Conclusion: Arthroscopic ACL reconstruction using both the autologous hamstring tendon and the patellar tendon during their mid term follow up period demonstrated excellent results. However, the final results during their last follow up showed no statistically significant difference between the two groups.

• The korean journal of orthodontics
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• v.28 no.2 s.67
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• pp.297-310
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• 1998

The purpose of this study was to investigate the initial tissue change, to repair on the teeth & surrounding tissue under the intrusive orthodontic forces by use of elastic chain, through the microscopic findings. For this study, three young adult mongrel dogs were used, and were divied into three group : the control group was deliveried only casting crown and the experimental group 1 was equipped with energy chain during 1 week and experimental 2 group was deliveried using energy chain during 1 week and 3 weeks observation. All experimental groups and control groups were sacrificed to make the samples for microscopic findings on premolar teeth. All samples were examed and compared the histologic changes through the microscopic with H-E stain. The obtained results were as follows. 1. In hematoxylin-eosin stain of the control group, the periodontal ligament was constant width from apical third to cervical third of the root, and the periodontal fiber arrangement was horizontal or oblique in cervical third, oblique in middle and apical third of the root. 2. In Masson Trichrome stain of the control group, osteoblast and osteoclast appeared in cervical third of root, and bone resorption and new bone formation was observed in middle and apical third of the root. 3. In experimental 1, osteoclasts were increased highly, and hyperemia of blood vessels and new bone formation and bone resorption by reversal line in apical third of the root were seen. PDL width was increased apprarently from crest to apex of the root and more in apical third. 4. In experimental 2, osteoclasts and hyperemia of blood vessels were more increased than control material in apical third of the root. PDL width was increased more than control group in root apex, and was seen less than experimental 1. PDL arrangement was similar to experimental 1 and was mixed only in root apex. Therefore, in premolar intrusion of the young adult dog, there were increased osteoclast, hyperemia and dilation of blood vessel, resorption of alveolar bone and cementum and different arrangement of PDL in initial tissue change. There was not observed complete repair after remove intrusive force.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.2
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• pp.213-230
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• 2008

The aim of this study was to analyze the initial movement and the stress distribution of each tooth and periodontal ligament during the lingual lever-arm retraction of 6 maxillary incisors using FEA. Two kinds of finite element models were produced: 2-properties model (simple model) and 24-properties model (multi model) according to the material property assignment. The subject was an adult male of 23 years old. The DICOM images through the CT of the patient were converted into the 3D image model of a skull using the Mimics (version 10.11, Materialise's interactive Medical Image Control System, Materialise, Belgium). After series of calculating, remeshing, exporting, importing process and volume mesh process was performed, FEA models were produced. FEA models are consisted of maxilla, maxillary central incisor, lateral incisor, canine, periodontal ligaments and lingual traction arm. The boundary conditions fixed the movements of posterior, sagittal and upper part of the model to the directions of X, Y, Z axis respectively. The model was set to be symmetrical to X axis. Through the center of resistance of maxilla complex, a retraction force of 200g was applied horizontally to the occlusal plane. Under this conditions, the initial movements and stress distributions were evaluated by 3D FEA. In the result, the amount of posterior movement was larger in the multi model than in the simple model as well as the amount of vertically rotation. The pattern of the posterior movement in the central incisors and lateral incisors was controlled tipping movement, and the amount was larger than in the canine. But the amount of root movement of the canine was larger than others. The incisor rotated downwardly and the canines upwardly around contact points of lateral incisor and canine in the both models. The values of stress are similar in the both simple and multi model.