• Journal of Biomedical Engineering Research
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• v.28 no.3
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• pp.397-409
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• 2007

Owing to needs of biomechanical comprehension and analysis to obtain various medical treatment designs which are related with the spine in order to cure and diagnose LBP patients, the FE modeling and nonlinear analysis of lumbosacrum including a partial ilium and iliolumbar ligaments, were carried out. First, we investigated whether the geometrical configuration of vertebrae displayed by DICOM slice files is regular and normal condition. After constructing spinal vertebrae including a partial ilium, a sacrum and five lumbars (from L1 to L5)with anatomical shape reconstructed using softwares such as image modeler and CAD modeler, we added iliolumbar ligaments, lumbar ligaments, discs and facet joints, etc.. And also, we assigned material property and discretized the model using proper finite element types, thus it was completely modeled through the above procedure. For the verification of each segment, average sagittal ROM, average coronal ROM and average transversal ROM under various loading conditions(${\pm}10Nm$), average vertical displacement under compression(400N), ALL(Anterior Longitudinal Ligament) and PLL(Posterior Longitudinal Ligament) force at L12 level, strains of seven ligaments on sagittal plane at L45 level and maximal strain of disc fibers according to various loading conditions at L45 level, etc., they were compared with experimental results. For the verification of multilevel-lumbosacrum spine including partial ilium and iliolumbar ligaments, the cases with and without iliolumbar ligaments were compared with ROM of experiment. The results were obtained from analysis of the verified FE model as follows: I) Iliolumbar ligaments played a stabilizing role as mainly posterior iliolumbar ligaments under flexion and as both posterior and anterior iliolumbar ligaments of one side under lateral bending. 2) The iliolumbar ligaments decreased total ROM of 1-8% in total model according to various motion conditions, which changed facet contact forces of L5S level by approximately 0.8-1.4 times and disc forces of L5S level by approximately 0.8-1.5 times more than casewithout ilioligaments, under various loading conditions. 3) The force of lower discs such as L45 and L5S was bigger than upper discs under flexion, left and right bending and left and right twisting, except extension. 4) It was predicted that strains of posterior ligaments among iliolumbar ligaments would produce the maximum 16% under flexion and the maximum 10% under twisting. 5) It's expected that this present model applies to the development and design of artificial disc, since it was comparatively in agreement with the experimental datum.

• The korean journal of orthodontics
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• v.39 no.2
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• pp.120-129
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• 2009

Objective: To estimate dental maturity using the Demirjian Index for the mandibular third molar and investigate the relationships between dental maturity and skeletal maturity among growing children. Methods: The samples were derived from panoramic, lateral cephalometric and hand-wrist radiographs of 270 female subjects registered as patients at the orthodontic department, dental hospital, Yonsei University. Dental maturity [Demirjian Index (DI)] and skeletal maturity [skeletal maturation indicators (SMIs)] and cervical vertebrae maturation indicators (CVMIs)] were estimated from these radiographs. Results: There was a significant correlation (r = 0.64) between SMIs and DI, and a similar correlation (r = 0.59) was observed between CVMIs and DI (p < 0.001). If DI was above Stage E, then the SMI was above Stage 10 and the CVMI was above Stage 5. There was a weak correlation (r = 0.26) between age at menarche and DI (p < 0.001). There was no significant difference in DI among Class I, II or III malocclusions. Conclusions: Dental maturity evaluation using the mandibular third molar will be an adjunctive tool in combination with cervical vertebrae and hand-wrist maturity evaluations.

• Korean Journal of Ichthyology
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• v.19 no.1
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• pp.57-65
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• 2007

A new species of the rajid genus Okamejei is described from a single specimen (295 mm TL) from off Shantou, Gwangdong in the South China Sea. The new species differs from all other congeners in the following combination of characters: snout pointed, dorsal head length 6.7 times interorbital width, tail moderately wide and long, its length 48.5% TL, interdorsal distance less than length of first dorsal fin base, postdorsal tail short as 5.8% TL, small evenly distributed dark brownish spots, without ocelli on dorsal surface of disc, pores of ampullae of Lorenzini on ventral surface distributed from snout tip to distal end of metapterygium, scapulocoracoid high, its height about 1.4 times rear corner height, trunk vertebrae 23, predorsal tail vertebrae 50 and pectoral fin radials 96.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.2
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• pp.243-258
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• 2008

The purpose of this study was to investigate the relationship between the stages of calcification of various teeth and skeletal maturity stages among Korean individuals. The study subjects consisted 154 female and 179 male ranging from 7 years to 16 years of age. A total of 333 hand-wrist, cephalo-lateral and panoramic radiographs were obtained and analyzed. The tooth development of the mandibular canines, first, second premolars, and second molars were assessed according to the Dermijian's system. Skeletal maturity stages were determined from hand-wrist radiographs by using the SMI system and cephalo-lateral radiographs by using the CVMS, respectively. The results were as follows. 1. The mean ages of each stage of skeletal maturity were consistently younger in female subjects. 2. There was a high correlation between skeletal maturity of hand-wrist and cervical vertebrae in the both sexes. 3. There was a high correlation between skeletal maturity and dental calcification stage of mandibular canines, first premolar, second premolars, and second molar. 4. The mandibular second molar was tooth showing the highest correlation. 5. Percent distributions of the relationship between calcification stages of individual teeth and stages of skeletal maturity were obtained in both sexes. In summary, this suggests that tooth calcification stages from panoramic radiographs might be clinically useful as a maturity indicator of the pubertal growth period.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.5
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• pp.241-265
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• 1989

The purpose of present study is to describe the taxonomy and early life history of Korean pomfrets, genus Pampus. Egg diameter varied from $0.83\~1.27mm\;and\;1.05\~1.41mm$ in P. argenteus and P. echinogaster respectively. Larvae of P. echinogaster of 16.5 mm in total length has full number of fin rays and enter the juvenile period. The egg is matured at 185.0 mm in total length in P. argenteus and at 95.5 mm in total length in P. echinogaster. P. echinogaster is ossified from jaw bone at $8.5\~10.0mm$ in to1 length and followed by ossification of vertebrae and visceral skeleton. P. argenteus and P. echinogaster are distinguished by the morphology of jaw, fin and isthmus. In P. argenteus, wavy ridges extends over the upper part of pectoral fin and gill membrane is broadly united to isthmus, while in P. echinogaster the ridges are limited to the base of pectoral fin and gill membrane reaching isthmus. These Pampus spp. are easily distinguished based on internal features, such as number of vertebrae, gill raker, pyloric caeca, epipleural bone, esophageal sat and length of intestine.

• The Korean Journal of Nuclear Medicine
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• v.26 no.2
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• pp.318-326
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• 1992

Ga-67 citrate scan has been requested for detection or follow-up of inflammatory or neoplastic disease. Visualization of Ga-67 citrate in the kidneys at 48 and 72 hr post injection is usually interpreted as evidence of renal pathology. But precise mechanisms of abnormal Ga-67 uptake in kidneys were unknown. We undertook a study to determine the clinical value of Ga-67 citrate imaging of the kidneys in 68 patients with primary or secondary nephropathy confirmed by renal biopsy and 66 control patients without renal disease. Renal uptake in 48 to 72 hr images was graded as follows: Grade 0=back-ground activity:1=faint uptake greater than background;2=definite uptake, but less than lumbar vertebrae; 3=same uptake as lumbar vertebrae, but less than liver; 4=same or higher uptake than liver. The results were as follows. 1) 42 of 65 (62%) patients with noninfectious nephritis showed grade 2 or higher Ga-67 renal uptake but only 10 percent of control patients showed similar uptake. 2) In 14 patients with systemic lupus erythematosus, 8 of 9 (89%) patients with lupus nephritis exhibited marked renal uptake 3) 36 of 41 patients (88%) with combined nephrotic syndrome showed Grade 2 or higher renal uptake. 4) Renal Ga-67 uptake was correlated with clinical severity of nephrotic syndrome determined by serum albumin level, 24 hr urine protein excretion and serum lipid levels. 5) After complete remission of nephrotic syndrome, renal uptake in all 8 patients who were initially Grade 3 or 4, decreased to Grade 1 or 0. In conclusion, we think that the mechanism of renal Ga-67 uptake in nephrotic syndrome might be related to the pathogenesis of nephrotic syndrome. In systemic lupus erythematosus, Ga-67 citrate scan is useful in predicting renal involvement.

• Journal of Society of Preventive Korean Medicine
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• v.14 no.3
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• pp.1-12
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• 2010

Objective : Samulatang (herbal description) is much used for women's disease in Korean Traditional Medicine. The aim of this study is to evaluate reproductive toxic effect by Samultang in pregnant rats and fetuses, and ascertain a dose-response relationship Method : Pregnant Sprague-Dawley rats were administered with the Samultang at single, double and quadruple dose for 20 days, orally. Pregnant rats were sacrificed at 20th day of gestation, and observed internal and reproductive organs. Live fetuses of gestation were randomly selected and fixed in 95% ethanol. Fetuses were stained with alcian blue and alizarin red S. We observe maternal body weight,, index associated pregnancy, and skeletal malformations in fetus Result : Maternal body weight of Samultang treated group has increased, side effect was not found in maternal body compared to that of control group. There were no significant difference in internal and reproductive organs. Double concentration administered group had lowest value in number of implantation, live fetuses, implantation rate and delivery rate, Also double concentration administered group showed higher early and late resorption rate than the other group. But, these are not significant. In the sex ratio, number of females, bigger than number of males in all Samultang administered groups. The fetuses of dams treated with Samultang didn't showed external and skeletal malformation. Vertebral and sternal variations were observed in single, double and quadruple concentration administered group but, compared to the control, those variations were insignificant. There were no significant changes in number of ribs, cervical, thoracic, lumber, sacral and caudal vertebrae Conclusion : Samultang is not expected to affect on pregnant rats and fetus about maternal body weight and number of live fetuses. There were no significant changes in organ weight, reproductive organs. Although skeletal variations were showed in vertebrae and sternum, treated groups were shown insignificant changes in skeletal variation

• The Journal of the Korea Contents Association
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• v.9 no.6
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• pp.207-215
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• 2009

There has been a diversity of therapeutic interventions for patients with chronic low back pain. However most of them have been focused on only pain. But the patients usually have a kind of structurally abnormal have fixed in lumbar vertebrae, which can decrease range of joint movement and, what is worse, reduce immediate dynamic balancing ability(IDBA). The reduced IDBA can increase the risk of injury and decrease coping ability in dangerous situation. So we introduced Maitland's manual therapy in this study in order to recover the IDBA in patients with chronic low back pain. Sixty-four patients diagnosed with chronic low back pain were included for the study. Among them, thirty-two patients(experimental group) were managed by Maitland's manual therapy, another thirty-tow patients(control group) were treated by physical science methods(H/P, TENS, U/S). Each group made use of highly reliable(0.81$\sim$0.96) star excursion balance test(SEBT) to compare the possible changes of IDBAs in two groups after treatment. In experimental group, IDBA has increased in forward, rightward, leftward, and backward, but in control group, not changed. According to the results, we concluded that Maitland's manual therapy is effective for increasing IDBA by making joints more flexible in lumbar vertebrae.

• Journal of Korean Neurosurgical Society
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• v.64 no.3
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• pp.437-446
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• 2021

Objective : To investigate the radiographic characteristics of the uppermost instrumented vertebrae (UIV) and UIV+1 compression fractures that are predictive of revision surgery following long-segment spinal fixation. Methods : A total 27 patients who presented newly developed compression fracture at UIV, UIV+1 after long segment spinal fixation (minimum 5 vertebral bodies, lowest instrumented vertebra of L5 or distal) were reviewed retrospectively. Patients were divided into two groups according to following management : revisional surgery (group A, n=13) and conservative care (group B, n=14). Pre- and postoperative images, and images taken shortly before and after the occurrence of fracture were evaluated for radiologic characteristics Results : Despite similar degrees of surgical correction of deformity, the fate of the two groups with proximal junctional compression fractures differed. Immediately after the fracture, the decrement of adjacent disc height in group A (32.3±7.6 mm to 23.7±8.4 mm, Δ=8.5±6.9 mm) was greater than group B (31.0±13.9 mm to 30.1±15.5 mm, Δ=0.9±2.9 mm, p=0.003). Pre-operative magnetic resonance imaging indicated that group A patients have a higher grade of disc degeneration adjacent to fractured vertebrae compared to group B (modified Pfirrmann grade, group A : 6.10±0.99, group B : 4.08±0.90, p=0.004). Binary logistic regression analysis indicated that decrement of disc height was the only associated risk factor for future revision surgery (odds ratio, 1.891; 95% confidence interval, 1.121-3.190; p=0.017). Conclusion : Proximal junctional vertebral compression fractures with greater early-stage decrement of adjacent disc height were associated with increased risk of future neurological deterioration and necessity of revision. The condition of adjacent disc degeneration should be considered regarding severity and revision rate of proximal junctional kyphosis/proximal junction failures.

• Journal of the Korean Society of Radiology
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• v.12 no.7
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• pp.833-844
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• 2018

Dual energy X-ray absorptiometry is mainly used as an X-ray test method. For equipment manufactured GE and Hologic, cross-calibration analyses (CCA) of machines from the same manufacturer and between units from different manufacturers have been conducted, but the CCA of equipment manufactured in Korea are inadequate. Through CCA, we present a formula of the intersections between the Korean medical equipment company (KEC) with GE and Hologic manufactured DXA, and among the KEC DXA. The CCA was conducted for the European Spine Phantom on DXA from four KEC and three global medical equipment company (GEC) manufacturers. We compared bone mineral density (BMD) values and calculated the CCA equation by linear regression analysis. The standard-deviations (SD) of the BMD values were highest for the Dexxum T for the low, medium, and high spine, which were 0.030, 0.029, and 0.037, respectively. The smallest SD in the low and medium vertebrae were 0.005 and 0.004 for the Horizon Ci, respectively, and 0.005 for the Osteo Pro Max in the high vertebrae. Based on the intersection equations of the KEC DXA established in this study, CCA of various KEC DXA should be established for more accurate follow-up of BMD tests in clinical environments.