• Journal of Periodontal and Implant Science
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• v.54 no.2
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• pp.96-107
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• 2024

Purpose: Deproteinized bovine bone or synthetic hydroxyapatite are 2 prevalent bone grafting materials used in the clinical treatment of peri-implant bone defects. However, the differences in bone formation among these materials remain unclear. This study evaluated osteogenesis kinetics in peri-implant defects using 2 types of deproteinized bovine bone (Bio-Oss^® and Bio-Oss/Collagen^®) and 2 types of synthetic hydroxyapatite (Apaceram-AX^® and Refit^®). We considered factors including newly generated bone volume; bone, osteoid, and material occupancy; and bone-to-implant contact. Methods: A beagle model with a mandibular defect was created by extracting the bilateral mandibular third and fourth premolars. Simultaneously, an implant was inserted into the defect, and the space between the implant and the surrounding bone walls was filled with Bio-Oss, Bio-Oss/Collagen, Apaceram-AX, Refit, or autologous bone. Micro-computed tomography and histological analyses were conducted at 3 and 6 months postoperatively (Refit and autologous bone were not included at the 6-month time point due to their rapid absorption). Results: All materials demonstrated excellent biocompatibility and osteoconductivity. At 3 months, Bio-Oss and Apaceram-AX exhibited significantly greater volumes of formation than the other materials, with Bio-Oss having a marginally higher amount. However, this outcome was reversed at 6 months, with no significant difference between the 2 materials at either time point. Apaceram-AX displayed notably slower bioresorption and the largest quantity of residual material at both time points. In contrast, Refit had significantly greater bioresorption, with complete resorption and rapid maturation involving cortical bone formation at the crest at 3 months, Refit demonstrated the highest mineralized tissue and osteoid occupancy after 3 months, albeit without statistical significance. Conclusions: Overall, the materials demonstrated varying post-implantation behaviors in vivo. Thus, in a clinical setting, both the properties of these materials and the specific conditions of the defects needing reinforcement should be considered to identify the most suitable material.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.2
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• pp.128-137
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• 2011

Purpose: Resonance frequency analysis, Periotest, and removal torque (RT) test were known as the methods to assess implant stability. The results of these methods are affected by the bone condition, implant diameter and shape. The purpose of this study is to access the meaning and the correlationship of the resonance frequency analysis, Periotest and RT test in osseointegration simulated acrylic resin when the engaged bone thickness and peri-implant bone defect are changed. Materials and methods: To simulate osseointegration, the fixture was fixed to an aluminum mold with a screw. Acrylic resin powder and liquid were poured into the mold for polymerization. The engaged resin thickness with implant was controlled. Simulated cortical bone thicknesses were 1, 3, 5 and 10 mm. Additional 1, 3 and 5 mm peri-implant bone defects were simulated. Three types of implants were used; 4 mm diameter implants of straight shape, 4 mm diameter implants of tapered shape and 5 mm diameter implants of tapered shape. Five fixtures per each type were tested in respective bone condition. Resonance frequency analysis and Periotest were evaluated in all bone conditions. Peak removal torque was measured at simulated cortical bone thicknesses of 1 and 3 mm. The statistical analysis was performed with the Kruskal-Wallis test, Mann-Whitney U test, and Spearman test using a 95% level of confidence. Results: With increasing engaged bone depth, the Implant Stability Quotient (ISQ) values increased and the Periotest values (PTVs) decreased (P<.001, P<.001). With increasing peri-implant bone defect, ISQ values decreased and PTVs increased (P<.001). When the diameter of implant increased, ISQ values increased and Periotest values (PTV) decreased (P<.001). There was a strong correlation between ISQ values and PTVs (r = -0.99, P<.001). Furthermore, the peak removal torque values had weak correlations with both ISQ values and PTVs (r = 0.52, P<.001 ; r = -0.52, P<.001). Conclusion: This study confirmed favorable implant stability with increasing engaged bone depth and implant diameter and decreasing peri-implant bone defect. ISQ values and PTVs showed strong correlation with each other and not with the peak removal torque values.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.3
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• pp.241-248
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• 2008

Tibial bone grafts provide an adequate volume of cancellous bone with cortical bone, high biologic value of bone, minimal gait disturbance and complications, and no special contraindications, and offer a superior clinical results than any other donor sites. Lateral appoach in tibial bone graft was used to gain large bone volume traditionally, but medial approach provides low morbidity associated with the tibial anatomic structure, simple and safety surgical procedure, and better comfortable to patients recently. We have undertaken clinical and retrospective studies on patients in Dept. of Oral and Maxillofacial Surgery, Inha University Hospital from April 2004 to January 2008. 50 patients have maxillofacial bony defect as resection of bening tumor, cyst enucleation, alveolar bone resorption, sinus pneumatization were received the tibial proximal autogenous particulated cancellous bone grafts. They were analyzed sex, age, diagnosis of recipient site, lesion size, dornor site, cortical bone repositioning, complications and we concluded favorable following results. 1. Medial approach for proximal tibia is safer and technically easier than lateral approach, associated with the proximal tibial anatomic structures, and short operative times. 2. Proximal tibia provides an adequate bone volume with predictability for oral and maxillofacial reconstruction. 3. Patients rarely complain of pain, swelling, discomfort and dysfunction such as gait disturbance. In conclusion, medial approach for proximal tibial graft seems to be a valuable tool for oral and maxillofacial reconstruction.

• Childhood Kidney Diseases
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• v.18 no.2
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• pp.85-91
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• 2014

Purpose: We aimed to investigate the correlation between serum cystatin C and clinical manifestations in pediatric patients with urinary tract infections (UTIs). Methods: We studied 137 patients admitted with UTIs from June 2012 to May 2014. Depending on the presence of renal cortical defects on 99m Tc-dimercaptosuccinic acid scintigraphy, we classified patients into non-renal and renal defect groups. Laboratory and clinical parameters were analyzed, including the levels of serum cystatin C. The correlation between cystatin C and other variables was assessed. Results: Serum cystatin C levels did not differ between the non-renal and renal defect groups. In both groups, serum cystatin C levels increased after 4-5 days of treatment, compared with the level at admission (P<0.001). However, mean levels were within normal ranges. The concentration of serum cystatin C positively correlated with serum creatinine and negatively correlated with age (P <0.05). In contrast, there was no correlation between serum cystatin C and other variables. Conclusion: Serum cystatin C does not appear to be a useful biomarker for renal defects in pediatric patients with UTIs. Further studies are necessary to conclude whether serum cystatin C is helpful in predicting deterioration in renal function in pediatric patients with UTIs.

• Childhood Kidney Diseases
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• v.14 no.2
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• pp.195-202
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• 2010

Purpose : The purpose of this study is to determine if there are prognostic factors leading to permanent parenchymal damages to kidney in children after acute pyelonephritis. Methods : This study was conducted in 160 pediatric patients with acute pyelonephritis admitted to Ajou University Hospital from 2000 to 2005, whose renal cortical defects were confirmed by $^{99m}Tc$-dimercaptosuccinic acid scintigraphy (DMSA scan). Along with the follow-up DMSA scan after 6 months, they were classified into two groups; recovered group (106) and scarred group (54). The clinical characteristics of each group were compared. Results : Among the total of 160 patients, 106 (66.3%) showed recovery of the initial defect (the recovered group), while 54 (33.8%) showed permanent defects on the followup DMSA scan (scarred group). Recovery rate was poor for patients of 1 year and older, or patients with the duration of fever and pyuria longer than 7 days. The recovery rate was poor in the patients with history of frequent febrile episodes and abnormal results of imaging studies, such as voiding cystourethrography (VCUG), ultrasonography. Conclusion : The recovery rate of children with renal defects on DMSA scan with acute pyelonephritis was lower when the patient is older than 1 year, when the duration of fever and pyuria exceeded 7 days, and when the patients had the histories of frequent febrile episodes and had urinary tract abnormalities on imaging studies. These findings suggest that there may be under- or mis-diagnosis of acute pyelonephritis by pediatrician.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.12 no.3
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• pp.68-73
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• 1990

Fibrous dysplasia is an idiopathic skeletal disorder in which medullary bone is replaced and disturbed by poorly organized, structually unsound fibroosseous tissue, which may produce cortical expansion. When facial bones are involed, considerable esthetic deformity may result. The term monostotic fibrous dysplasia has been applied when one bone is involved : when more than one bone is affected, the term polyostotic used. The polyostotic form may be accomplished by pigmented skin lesion (Jaffe type), or by pigmented skin lesions with endocrine disturbance (Albright syndrome). No general agreement exists on the cause of fibrous dysplasia. A few authors have suggested that fibrous dysplasia arises as a resujlt of trauma. It occurs predominantly in infant, adolescent females and runs a variable clinical course. When several bones are involed, it tends to be unilateral. Involements of alveolar bone may produce displacement of teeth with malocclusion, or loss of teeth, or both. Radiographycally, it shows an indistinctly delimited osteolytic defect with a bubble - like pattern, but without a sclerotic rim. The preferred treatment is almost always surgery. If the lesion is extensive, surgical intervention with use of recontouring procedures aimed at the correction of esthetic or funtional disturbances is preferred treatment. Now, we present a case of fibrous dysplasia on the left maxilla and the zygoma treated by bony contourign via hemicoronal flap and intraoral approach with good results.

• Childhood Kidney Diseases
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• v.8 no.2
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• pp.239-243
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• 2004

Acute poststreptococcal glomerulonephritis(APSGN) is the most common form of postinfectious glomerulonephritis, and acute pyelonephritis(APN) is the most severe form of urinary tract infection in childhood. However, the concurrence of two diseases is uncommon in the literature. We describe a case of APSGN accompanied with APN in a 5-year-old female who presented with fever, left flank pain, headache and facial edema. Urinalysis showed pyuria, microscopic hematuria, and mild proteinulra. Serial urine cultures grew Escherichia coli. ${^99m}$Tc-DMSA renal scan revealed a cortical defect in the upper pole of left kidney. She had a history of preceding pharyngitis, in addition, showed high blood pressure, high anti-streptolysin 0 titer, and low serum complement levels. The patient improved completely with supportive treatment, Including antibiotic and antihypertensive therapy. These findings suggested that APSGN and APN could be manifested simultaneously or be .superimposed on each other.

• The Korean Journal of Nuclear Medicine
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• v.24 no.2
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• pp.325-331
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• 1990

Radionuclide renal scintigraphies were performed in a 24-year-old man with right renal artery branch stenosis. Captopril enhanced $^{99m}Tc-DTPA$ renal scintigraphy revealed no abnormal finding in the right kidney. But, $^{99m}Tc-DMSA$ renal scintigraphy showed regional cortical photon deficient area corresponding to the area supplied by the stenotic branch artery. The defect size increased in captopril enhanced $^{99m}Tc-DMSA$ renal scintigrphy and nearly disappeared after successful transluminal renal angioplasty. This case suggests that the captopril enhanced $^{99m}Tc-DMSA$ renal scintigraphy may be a useful method in the evaluation of renovascular hypertension, especially due to branch renal srtery stenosis.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.3
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• pp.161-171
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• 2010

Introduction: This study was to assess the effectiveness of new bone formation and regeneration by using a rhBMP-2 and $\beta-TCP$ as a carrier in rabbits’mandible. Materials and Methods: The mandibles of 36 rabbits were exposed and cortical bone was penetrated for this study. The experimental subjects were divided into 3 groups each 12 rabbits ; control group, experimental group 1, and experimental group 2. Control group had the defect itself without any treatment, in the experimental group 1, $\beta-TCP$P only was grafted, and in the experimental group 2, rhBMP-2 soaked in $\beta-TCP$ was grafted. The rabbits were sacrificed after 1, 2, 3, 4, 6, and 8weeks, and new bone formation area was examined and measured for bone quantitative and qualitative analysis with light, fluorescent and polarized microscopy. Results: In the experimental group 1, new bone formation from the adjacent host bone was made by osteoconduction, and in the experimental group 2, direct new bone formation by osteoinduction of rhBMP-2 as well as new bone formation by osteoconduction of $\beta-TCP$ were observed. Conclusion: rhBMP-2 of experimental group 2 is very effective in the bone formation in early 2weeks and bone remodelling from 3weeks.

• Journal of Korean Neurosurgical Society
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• v.29 no.10
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• pp.1309-1315
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• 2000

Objectives : We performed an in vivo experiment to investigate the effect of $^{166}Holmium$ and $^{166}Holmium$-chitosan complex($^{166}Ho$-CHICO) on the normal brain of rats and to determine the sublethal dose of $^{166}Ho$-CHICO. Materials and Methods : $^{166}Ho$ is a beta and gamma ray emitter. $^{166}Ho$-CHICO is a novel radio-pharmaceutical complex with chitosan to facilitate the transport of $^{166}Ho$ obtained from Korea Atomic Energy Research Center(Taejon, Korea). It is in acidic form and becomes gel state at alkaline pH. One hundred and seventy consecutive rats were divided into four groups : $^{166}Ho$ treated(n＝50), $^{166}Ho$-CHICO treated(n＝57), saline treated(n＝5) and chitosan treated(n＝5) groups. $^{166}Ho$ and $^{166}Ho$-CHICO were injected into the rat brain stereotactically with various doses of 0.1mCi/$20{\mu}l$, 0.2mCi/$20{\mu}l$, 0.3mCi/$20{\mu}l$, and 0.4mCi/$20{\mu}l$ using an automated microinjector. Nuclear imaging, histopathological and hematological studies were performed in 10 rats in each group at 1 day, 3days, 7 days, 1 month and 3 months after the injections. Results : An infiltration of inflammatory cells and necrotic changes were noted in $^{166}Ho$ treated group at 1 week after the injection. A wedge-shaped tissue defect due to necrosis, lined with infiltrated glial cells in $^{166}Ho$ treated group and a cystic defect lined with reactive astroglial cells in $^{166}Holmium$-CHICO treated group at 3 months after the injection were observed. $^{166}Ho$ alone without chitosan leaked out and caused necrotic lesion on the cerebral surface but $^{166}Holmium$-CHICO treated group did not show this feature. As the dose of $^{166}Ho$ increased, the mortality rates were also increased. The mortality rate of the $^{166}Holmium$-CHICO group was higher than the $^{166}Ho$ treated group at a dose of 0.4mCi/$20{\mu}l$/300g. There was no detectable radioactivity due to the leakage or extravasation from the injected site of the brain on the scintigraphy performed at 1 hour, 24 hours and 48 hours after the injection. There was also no detectable activity of $^{166}Holmium$-CHICO in other organs including spleen, liver and kidney. Conclusions : $^{166}Ho$-CHICO did not leak out to the critical cortical surface of the brain from the injection site and induced radiation changes of the parenchyma around the injection site without cortical damage. The sublethal dose of $^{166}Ho$-CHICO for the normal brain in rats was determined to be 0.2mCi/$20{\mu}l$/300g.