• The korean journal of orthodontics
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• v.25 no.1 s.48
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• pp.111-128
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• 1995

This study was investigated to assess the difference of facial height and occlusal plane inclination between pre- and post-treatment in Class I malocclusion group The subjects consisted of 35 extraction patients and 30 nonextraction patient,;, and was subdivided into Group I(overbite<0mm), Group II(04mm) in reference to overbite, and adolescent group and adult group in reference to age. Lateral cephalogram was taken with standard method, traced, and digitized for each subject. The computerized statistical analysis was carried out with SAS program The results wolf as follows. 1. In both groups of extraction and nonextraction group the anterior facial height increased after orthodontic treatment but there was no significant difference(p>0.05) between each goup. 2. There was no statstical significance in change of occlusal plane inclination in adolescent group, but significant difference(p<0.05) among three subgroup in adult group. 3. In adolescent-extraction and adolescent-nonextraction group there was significant increase of anterior facial height and posterior facial height, and was superior to adult groups in posterior facial height increment. 4 In all groups upper and lower molars were uprighted to occlusal plane. This had statistically significant effect.

• Magazine of the Korea Concrete Institute
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• v.7 no.3
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• pp.199-210
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• 1995

We could say that the concrete filled steel tube structure is superior in the vlew of various structure properties as to promote improvement of structural capacity to dtmonstrate heterogeneous material properties interdependently. The compressive strength is increased by putting to tri axial stress because lateral expansion of concrete 1s confined by the steel tube, when concrete conflned by steel tube fall under centric axial load. Also, it have an advantage that decreasr of load carrying capacity 1s small, not occuring section deficiency due to protect falling piienornonon by co~nprrssion fallurc of concrete. So this study investigated for structural behaviors yroprrtiex of concwir. confined by steel tube throughout a series of experlmerit with kcy parxncter, such as diameter-to-thickness(D / t) ratio, strength of concrete as a study on properties of structural behaviors of confined concrete confined by circular steel tube( tri axial stress). Frorn the expcrment results, the obtained results, are surnrnarised as foliow. (1) The restraint effect of concrete by steel tube was presented significantly as the D /t ratio of steel tube and the strength of filled concrete decrease, and the confined concrete by circular steel tube was increased respectively twice as much as 4-7 in deformation capacity at the ultimate strength ,compared with those of non-confined concrete, so expected to increase flexible effect of concrete. (2) The emprical formula to predict the ultimate capacity of confined concrete by steel tube and concrete filled steel tube column using restraint coefficient of concrete were proposed.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.5
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• pp.402-407
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• 2010

Introduction: The planning of implant surgery is an important factor for the implant prosthesis. Stereolithographic (SLA) surgical stents based on a computer simulation are quite helpful for clinicians to perform the surgery as planned. Although many clinical and technical trials have been performed for computed tomography (CT)-guided implant stents to improve the surgical procedures and prosthetic treatment, there are still many problems to solve. We developed a system of a surgical guide based on 3 dimensional (3D) CT for implant therapy and achieved satisfactory results in the terms of planning and operation. Materials and Methods: Fifteen patients were selected and 30 implant fixtures were installed. The preoperative CT data for surgical planning were prepared after obtaining informed consent. Surgical planning was performed using the simulation program, Ondemend3D In2Guide. The stents were fabricated based on the simulation data containing information of the residual bone, the location of the nerve, and the expected design of the prostheses. After surgery with these customized stents, the accuracy and reproducibility of implant surgery were evaluated based on the computer simulation. The data of postoperative CT were used to confirm this system using the image fusion technique and compare the implant fixtures between the planned and implanted. Results: The mean error was 1.18 (${\pm}0.73$) mm at the occlusal center, 1.23 (${\pm}0.67$) mm at the apical center, and the axis error between the two fixtures was $3.25^{\circ}C$ (${\pm}3.00$). These stents showed superior accuracy in maxilla cases. The lateral side error at the apical center was significantly different from the error at the occlusal center but there were no significant differences between the premolars, 1st molars and 2nd molars. Conclusion: SLA surgical stents based on a computer simulation have the satisfactory accuracy and are expected to be useful for accurate planning and surgery if some errors can be improved.

• The korean journal of orthodontics
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• v.29 no.3 s.74
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• pp.339-347
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• 1999

The purpose of this study was to investigate the variations of the skeletal and dentoalveolar dimensions in relation to vertical facial patterns. Lateral cephalogram of 200 cases (100 cases of male and 100 cases of female, average age of which was 23.2 years) were traced and some measurements of skeletal and dentoalveolar dimensions were measured. The ratio of UAFH/LAFH was employed to classify the samples into groups of excess and short lower anterior facial height. And the comparison between two groups were taken statistacally. The following results were obtained. 1. The dentoalveolar height, lower anterior facial height, lower genial angle, and FMA in the excess-lower-anterior-facial-height group were significantly larger than those in short-lower-anterior-facial-height group. 2. The dentoalveolar height, facial height, ramus height, and Jarabak ratio in the male subjects were significantly larger than those in the female subjects. 3. The UAFH/LAFH ratio showed a significant correlation to upper, lower facial height, AUDH, PUDH, ALDH, PLDH, Lower gonial angle, FMA, and $Bj\"{o}rk's$ Sum.

• Clinics in Shoulder and Elbow
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• v.11 no.2
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• pp.150-157
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• 2008

Purpose: We wanted to evaluate the results of surgical treatment for fracture of the scapular body. Materials and methods: The subjects of this study were seven patients with fracture of the scapular body and all these patients were managed surgically. We considered the operative indications as being 100% translation of the lateral border, or $25^{\circ}$ of angular deformity of the glenoid, or 1cm medialization or the variant of the double disruption of the superior scapular suspensory complex. There were five males and two females, and their ages ranged between 40 and 58 years (mean age: 49) with average follow up of 11 months (6~24 months). Two patients sustained multiple fractures of the ribs and spines. The surgical results were evaluated according to the subjective satisfaction, the UCLA score and the Korean shoulder score. Results: The mean UCLA score was 29 (17~33) and the mean Korean shoulder score was 86 (63~94). The self assessment for subjective satisfaction was 7.7 (4~9). There were two complications; one case of screw pull-out without the loss of the fracture fixation and the other case with screw penetration of the glenoid cavity. Conclusion: Surgical treatment may be effective for the management of severely displaced fracture of the scapular body in order to prevent the impairment of the shoulder function caused by the altered glenohumeral and scapulothoracic kinematics.

• Radiation Oncology Journal
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• v.36 no.1
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• pp.54-62
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• 2018

Purpose: To investigate set-up errors, suggest the adequate planning target volume (PTV) margin and image-guided radiotherapy frequency in head and neck (H&N) cancer treated with intensity-modulated radiotherapy (IMRT) assessed by kV cone-beam computed tomography (CBCT). Methods: We analyzed 360 CBCTs in 60 patients with H&N cancer treated with IMRT. The target delineation was contoured according to ICRU62. PTVs were generated by adding a 3-5 mm margin in all directions to the respective clinical target volumes. The kV CBCT images were obtained at first three days of irradiation and weekly thereafter. The overall mean displacement, range, systematic (${\Sigma}$) and random (${\sigma}$) errors were calculated. Adequate PTV margins were calculated according to the van Herk formula ($2.5{\Sigma}+0.7r$). Results: The mean of set-up errors was less than 2 mm in any direction. The overall frequency of set-up displacements greater than 3 mm was 3.9% in medial-lateral (ML) direction, 8% in superior-inferior (SI) direction, and 15.5% in anterior-posterior (AP) direction. The range of translations shifts was 0-9 mm in ML direction, 0-5 mm in SI direction and 0-10 mm in AP direction, respectively. After systematic set-up errors correction, the adequate margin to overcome the problem of set-up errors was found to be less than 3 mm. Conclusion: Image-guided kV CBCT was effective for the evaluation of set-up accuracy in H&N cancer. The kV CBCT at first three fractions and followed-by weekly appears adequate for reducing significantly set-up errors in H&N cancer treated with IMRT technique. Finally, 3-5 mm PTV margins appear adequate and safe to overcome the problem of set-up errors.

• Journal of Korean Neurosurgical Society
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• v.29 no.8
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• pp.985-994
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• 2000

Objective : There are some advantages of trigeminal evoked potential(TEP) recording compared to other somatosensory evoked potential(SSEP) recordings. The trigeminal sensory pathway has a pure sensory nerve branch, a broader receptive field in cerebral cortex, and a shorter pathway. Despite these advantages, there is little agreement as to what constitutes a normal response and what wave forms truly characterize the intraoperative TEP. This study presents the normative data of TEP recorded on the epidural surface of the rat with a platinum ball electrode. Materials & Methods : Under general anesthesia with urethane, the adult Sprague-Dawley male rats(300-350g) were given electrical stimulation with two stainless steel electrodes which were inserted into the subcutaneous layer of the area around whiskers. A reference electrode was positioned in the temporalis muscle ipsilateral to the recording site. Results : TEPs were recorded in the Par I area of somatosensory cortex and recorded most apparently on the point of 2mm posterior from the bregma and 6mm lateral from the midline. The typical wave form consisted of 5 peaks (N1-P1-N2-P2-N3 according to emerging order, upward negativity). Each latency to corresponding peaks was not influenced by the different intensities of stimulation, especially from 1 to 5mA. Average latencies of 5 peaks were in the following order ; 7.7, 11.1, 15, 22.3, 29.4ms. There was also no significant difference between latencies before and after administration of muscle relaxant(pancuronium). For the electrophysiological localization of recorded waves, the action potential of a single unit was recorded with glass microelectrode(filled with 2M NaCl, $3-5M{\Omega}$) in the thalamus of rat. A sharp wave was recorded in the VPM nucleus, in which the latency was shorter than that of N1. This suggests that all 5 peaks were generated by neural activities in the suprathalamic pathway. Conclusion : In terms of recording near-field potentials, our data also suggests that TEP in the rat may be superior to other SSEPs. In overall, these results may afford normative data for the studies of supratentorial lesions such as hydrocephalus or cerebral ischemia which can have an influence on near-field potentials.

• Journal of Yeungnam Medical Science
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• v.11 no.2
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• pp.284-292
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• 1994

In transtrochanteric rotational osteotomy to treat osteonecrosis of the femoral head, the necrotic superior anterior femoral head is rotated anteriorly around the longitudinal neck axis so that the weight bearing force is transferred to the intact posterior surface. The ratio of transposed intact articular surface of the femoral head to the weight-bearing surface of the acetabulum on postoperative anteroposterior view of the hip roentgenograph is the most important indicator of the prognosis. During the period from December 1992 to June 1994, we treated 31 hips in 28 patients who were indicated for the anterior rotational osteotomy among the patients of osteoncrosis of the femoral head. Among the patients, male were 27 and female was one. Age distribution was from 13 to 62 years old and mean age was 44.3. According to the Ficat and Arlet classification, II A was most in number as 16 II B was 7 and III was 8. As their etiolgic factors, alcohol was most in number as 18, steroid was 3, idiopathic was 5 and trauma was 2. The mean rate of the intact area of the posterior part of the femoral head to the total articular surface on the preoperative lateral view of the hip roentgenograph was 41.8%, The mean ratio of transposed intact articular surface of the femoral head to the weight bearing surface of the acetabulum was 53.8%, Fixation devices were screws or dynamic hip screw.

• Journal of Korean Society of Steel Construction
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• v.28 no.6
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• pp.467-476
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• 2016

For the connections between modular units in modular buildings, the bolted joints with connector plates are used commonly. The strength of structure is determined by the weakest part of structure and the connections may be weaker than the members being joined. Therefore, to check the safety of modular building, the structural performance of connections between modular units as well as that of beam-to-column connections should be evaluated. In this study, the behavior of module to module connection with straight and cross shaped connector plates is investigated by lateral cyclic tests according to KBC2009 0722.2.4 which shall be conducted by controlling the story drift angle in the width and the longitudinal direction respectively. All of test results generally show the stable ductile behavior up to 0.04rad drift levels and the tests in longitudinal direction show a superior energy dissipation per cycle in each of the load steps. However, the straight shaped connector plates have the degradation of stiffness with cyclic loading and the larger drift angle of column than the cross shaped connector plates.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.19 no.1
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• pp.123-136
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• 1989

The purpose of this study was to decide the diagnostic value of transmaxillary and transcranial projection in the evaluation of mandibular condyles. Five dry skulls with intact anatomic structure were selected for this study and the artificial osteophytes were attached to 9 different are as of the mandibular condyle. Ninety transcranial and forty-five transmaxillary radiographs were taken and then the radiographs were evaluated three times. The results were as follows; In transcranial radiographs, superocentral osteophyte was easily observed in closing state than in opening state (p<0.05). But there were no significant differences in other locations (p>0.05). The osteophytes on the medial and central portion easily observed at the transmaxillary projection than transcranial projection (p<0.05), but there was no significant difference on the lateral portion (p>0.05). The osteophytes on the superior (p<0.01) and posterior (p<0.01.) portion were easily observed at the transmaxillary projection than transcranial projection, but there was no significant difference on the anterior portion (p >0.05). The more laterally located osteophytes (p<0.01) at the transcranial projections were easily observed. The more posteriorly located osteophytes (p<0.05) at the transmaxillary projections were easily observed.