1.Shear bond strength of ceramic and resin brackets used with visible light-cured adhesives.
Yu Sun HWANG ; Joon ROW ; Chung Ju HWANG
Korean Journal of Orthodontics 1996;26(2):233-244
The purpose of this study was to compare the shear bond strength obtained from ceramic and plastic brackets bonded with various light-cured adhesives and to evaluate their debonded failure sites. Plastic brackets, Transcend 6000, Signature and Starfire TMB brackets were bonded with Orthobond, Light Bond and Transbond on one hundred forty extracted human premolar teeth as manufacturer's descriptions. After thermocycling the brackets were debonded with an Instron universal testing machine and the debonded bracket base surfaces were inspected under stereoscope to evaluate the failure sites. Also the shear bond strength and failure patterns with different curing time and with two different source of light were compared. The results were as follows. 1. There were no statistically significant differences among the mean shear bond strength of Orthobond, Light Bond and Transbond in a same bracket group except Plastic bracket group(p<0.05). 2. The mean shear bond strength of each adhesive with different bracket groups showed statistically significant differences. Starfire TMB showed the highest shear bond strength among the brackets in this study, but there was no statistically significant difference with Transcend 6000 while there was statistically significant difference with Signature.(p<0.05) 3. The various bonding failure patterns were occurred among different bracket groups but most of failure sites were bracket base-adhesive interfaces. 4. There were no statistically significant differences in shear bond strength between the groups with curing time of 10 second and 20 second, and between the groups with two different sources of light as long as sufficient light intensity(above 400mW/cm2) were provided(p<0.05). According to the result, it should be considered in clinical use of ceramic bracket with light-cured adhesives that the shear strengths of ceramic brackets were influenced by the retention from of bracket base as well as the composition of bracket and there was no difference in the shear bond strength among various light-cured adhesives used in this study.
Adhesives*
;
Bicuspid
;
Ceramics*
;
Humans
;
Plastics
;
Shear Strength
;
Tooth
2.A Case of Type I Glycogen Storage Disease with Decreased Growth Hormone Secretion.
Chi Kwan HWANG ; Sun Hee LEE ; Jeong Won SHIN ; Jae Hong YU ; Dae Young KANG
Journal of Korean Society of Pediatric Endocrinology 2001;6(1):85-91
Glycogen storage diseases(GSD) are inherited disorders affecting glycogen metabolism and type I GSD is due to the absence or deficiency of glucose-6-phosphatase(G6Pase) enzyme in the liver, kidney, and intestinal mucosa. The defect leads to inadequate hepatic conversion of G6P to glucose and thus make affected individuals susceptible to fasting hypoglycemia, and the accumulation of glycogen occurs in the liver and other organs. Type Ia is the most common form of GSD and clinically growth retardation may manifest of GSD itself rather than growth hormone deficiency(GHD), but we experienced a case of type I GSD with GHD in a 14-year-o1d male. The height was 125 cm, compatible with 50 th percentile of height of 8 years of age. He has doll-like face with fat cheek, relatively thin extremities, and metabolic acidosis, hyperuricemia, hypoglycemia, hyperlipidemia. GH stimulation test with clonidine and L-dopa revealed that the patient had decreased GH secretion. After laboratory work up including liver biopsy, he was diagnosed as type I GSD. Hypoglycemia was managed with frequent feeding with high starch diet(uncooked cornstarch). Metabolic acidosis and hyperuricemia were treated with sodium bicarbonate, allopurinol and probenecid. The patient is being followed at out-patient clinic with clinical improvement after of diet therapy and GH administration.
Acidosis
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Allopurinol
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Biopsy
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Cheek
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Clonidine
;
Diet Therapy
;
Extremities
;
Glucose
;
Glycogen Storage Disease*
;
Glycogen*
;
Growth Hormone*
;
Humans
;
Hyperlipidemias
;
Hyperuricemia
;
Hypoglycemia
;
Intestinal Mucosa
;
Kidney
;
Levodopa
;
Liver
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Male
;
Metabolism
;
Outpatients
;
Probenecid
;
Sodium Bicarbonate
;
Starch
3.Influence Of Co-Cultured Fibroblasts On The Differentiation Of Mouse Calvaria-Derived Undifferentiated Mesenchymal Cells In Vitro.
Journal of the Korean Association of Oral and Maxillofacial Surgeons 2002;28(2):114-125
This study was designed to evaluate the influence of fibroblasts or connective tissue from mouse oral mucosa on differentiation of neonatal mouse calvaria-derived osteoblasts and mineralization of bone nodules. Primary cell cultures from mouse calvarial osteoblasts and 2-4 passaged fibroblasts from oral mucosa were co-cultured in monolayer cultures, devided into 6 experimental group according to cell density or cell confluency. Osteoblasts were also co-cultured with fibroblasts in Transwell(R) culture plate with different co-cultured period according to osteoblast differentiation. The alkaline phosphatase activity were measured in monolayer cultures and cultures using Transwell(R). The mineralized bone nodules were presented by Von Kossa staining and density of mineralized nodules was measured by image analysis. The connective tissues with or without osteoblast seeding were cultured and examined histologically by Von Kossa and Trichrome Goldner staining. The results were as follows; 1. Prolonged maturation of matrix and delayed mineralization of bone nodules were resulted in monolayer cultures. 2. Co-culture of fibroblast with osteoblast using Transwell(R) during osteoblast proliferation stage stimulated proliferation of osteoblasts and increased alkaline phosphatase activity and mineralization of bone nodules. 3. Co-culture of fibroblast with osteoblast using Transwell(R) during matrix mineralization stage decreased and delayed mineralization of bone nodules. 4. In vitro cultured connective tissue with osteoblast seeding resulted in proliferation of osteoblasts and matrix formation with mineralization.
Alkaline Phosphatase
;
Animals
;
Cell Count
;
Coculture Techniques
;
Connective Tissue
;
Fibroblasts*
;
Mice*
;
Mouth Mucosa
;
Osteoblasts
;
Primary Cell Culture
4.Retrospective study on marginal bone loss around maxillary anterior implants with or without bone graft.
Hee Sun HWANG ; Ji Hye JUNG ; Yu Lee KIM
The Journal of Korean Academy of Prosthodontics 2016;54(2):103-109
PURPOSE: This study is to evaluate the clinical significance of implantation with simultaneous bone graft by comparing the marginal bone loss around maxillary anterior implants with or without bone graft MATERIALS AND METHODS: Patients treated with implant-retained restorations on maxillary anterior region at Implant Center, Dental Hospital, Wonkwang University between June 2011 and May 2014 were included in this study. Date of implant placement, implant diameter, implant length, implant-abutment connection type and whether the bone graft was done were investigated. The patient's periapical radiographs taken immediately after implantation and at the most recent visit were compared. Marginal bone loss was measured using Emago advanced v5.6 program (Oral diagnostic systems, Amsterdam, Netherlands). Statistical analysis was done in independent t-test by using SPSS 22.0 program. RESULTS: As a result of observing on 83 implants (without bone graft: 44, with bone graft: 39) of 52 patients for 6 - 45 months (average: 18.4 months), implants without bone graft showed 1.42 ± 0.42 mm, implants with bone graft showed 1.28 ± 0.45 mm of marginal bone loss. CONCLUSION: In limitations of this study, implants with simultaneous bone graft had significantly less marginal bone loss than implants without bone graft.
Dental Implants
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Humans
;
Retrospective Studies*
;
Transplants*
5.The effects of alveolar bone loss and miniscrew position on initial tooth displacement during intrusion of the maxillary anterior teeth: Finite element analysis.
Sun Mi CHO ; Sung Hwan CHOI ; Sang Jin SUNG ; Hyung Seog YU ; Chung Ju HWANG
The Korean Journal of Orthodontics 2016;46(5):310-322
OBJECTIVE: The aim of this study was to determine the optimal loading conditions for pure intrusion of the six maxillary anterior teeth with miniscrews according to alveolar bone loss. METHODS: A three-dimensional finite element model was created for a segment of the six anterior teeth, and the positions of the miniscrews and hooks were varied after setting the alveolar bone loss to 0, 2, or 4 mm. Under 100 g of intrusive force, initial displacement of the individual teeth in three directions and the degree of labial tilting were measured. RESULTS: The degree of labial tilting increased with reduced alveolar bone height under the same load. When a miniscrew was inserted between the two central incisors, the amounts of medial-lateral and anterior-posterior displacement of the central incisor were significantly greater than in the other conditions. When the miniscrews were inserted distally to the canines and an intrusion force was applied distal to the lateral incisors, the degree of labial tilting and the amounts of displacement of the six anterior teeth were the lowest, and the maximum von Mises stress was distributed evenly across all the teeth, regardless of the bone loss. CONCLUSIONS: Initial tooth displacement similar to pure intrusion of the six maxillary anterior teeth was induced when miniscrews were inserted distal to the maxillary canines and an intrusion force was applied distal to the lateral incisors. In this condition, the maximum von Mises stresses were relatively evenly distributed across all the teeth, regardless of the bone loss.
Alveolar Bone Loss*
;
Finite Element Analysis*
;
Incisor
;
Tooth*
6.Clinical feasibility and nutritional effects of early oral feeding after pancreaticoduodenectomy.
Si Eun HWANG ; Mi Jin JUNG ; Baik Hwan CHO ; Hee Chul YU
Korean Journal of Hepato-Biliary-Pancreatic Surgery 2014;18(3):84-89
BACKGROUNDS/AIMS: Pancreaticoduodenctomy (PD) is associated with high rates of postoperative morbidity and mortality. Although many studies have shown that early postoperative enteral nutrition improves postoperative outcomes, limited clinical information is available on postoperative early oral feeding (EOF) after PD. The aim of this study was to evaluate the clinical feasibility, safety, and nutritional effects of EOF after PD. METHODS: Clinical outcomes were investigated in 131 patients who underwent PD between 2003 and 2013, including 81 whose oral feeding was commenced within 48 hours (EOF group) and 50 whose oral feeding was commenced after resumption of bowel movements (traditional oral feeding [TOF] group). Postoperative complications, energy intake, and length of stay (LOS) were reviewed. RESULTS: Demographic factors were similar in the two groups. The EOF group had a significantly shorter LOS (25.9+/-8.5 days vs. 32.3+/-16.3 days; p=0.01) than the TOF group. The rates of anastomotic leak (1.2% vs. 16%, p=0.00) and reoperation (3.7% vs. 20%, p=0.01) were significantly lower in the EOF group. In the clinically acute phase from postoperative day 1 to day 5, the mean daily calorie intake (847.0 kcal vs. 745.6 kcal; p=0.04) and mean daily protein intake (42.2 g vs. 31.9 g; p=0.00) in the EOF group were significantly higher than that in the TOF group. CONCLUSIONS: Postoperative EOF is a clinically safe, feasible, and effective method of nutritional support after PD.
Anastomotic Leak
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Demography
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Energy Intake
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Enteral Nutrition
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Humans
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Length of Stay
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Mortality
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Nutritional Support
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Pancreaticoduodenectomy*
;
Postoperative Complications
;
Reoperation
7.Analysis of Dental Plaque Removal Effect by Floss Type Using QLF-D
Myoung-Hee KIM ; Yu Jin PARK ; Young Sun HWANG
Journal of Dental Hygiene Science 2022;22(4):199-205
Background:
The use of dental floss is associated with a reduction in dental caries and periodontal disease. According to personal preference, not only thread type but also C type and Y type floss are used. Although the effectiveness of dental floss for removing dental plaque has been proven, plaque removal effect of C type and Y type floss has not been well reported. In this study, the plaque removal effect of C type and Y type floss compared to thread type floss was experimentally verified.
Methods:
Thread type, C type and Y type floss were used to remove dental plaque. Ten people in each flossing group participated, and by applying dental floss to the 6 incisors of the maxilla and mandible, the degree of dental plaque was analyzed by QLF-D. To evaluate the removal degree of dental plaque before and after flossing, Simple Plaque Score (SPS), Area R30, Area R70, and Area R120 score were measured.
Results:
In the analysis using the Area R30 fluorescence score of the QLF-D system, the degree of plaque removal according to the application of dental floss was effective in all the thread type (p=0.018), C-type (p=0.012), and Y-type (p=0.012) floss groups compared to before the application of the floss. Among them, C type floss was more effective in removing plaque than thread type and Y type floss. However, the plaque removal effect between the three floss types was not significantly different in ∆SPS (p=0.674), ∆Area R30 (p=0.726), ∆Area R70 (p=0.504), and ∆Area R120 scores (p=0.423).
Conclusion
Thread type, C type, and Y type floss were all effective in removing dental plaque, but there was no significant difference in dental plaque removal effect according to the type of floss.
8.Incidence and Predictors of Cataract among People with Type 2 Diabetes Mellitus: Using Secondary Data Analysis from the Ansan Cohort of the Korean Genome and Epidemiology Study
Ihn Sook JEONG ; Eun Joo LEE ; Myo Sung KIM ; Jung Ok YU ; Hae Sun YUN ; Jeong Hee JEONG ; Youn Sun 6 HWANG
Journal of Korean Academy of Nursing 2022;52(1):24-35
Purpose:
This study investigated the incidence and risk factors of cataract in people with diabetes mellitus (DM) using data from Ansan cohort of the Korean Genome and Epidemiology Study (KoGES).
Methods:
Data from a total of 329 patients with type 2 DM without cataract who participated in Ansan cohort of the KoGES from baseline survey (2001–2002) to fifth follow-up visit (2011–2012) were examined.The characteristics of the subjects were analyzed with frequency and percentage, and mean and standard deviation. Cataract incidence was measured as incidence proportion (%). For risk factors of cataract, hazard ratio (HR) and 95% confidence interval (CI) were obtained using the Cox proportional hazard model.
Results:
The cataract incidence over a 10-year follow-up period was 19.1% (15.1 in males and 25.8 in females), and mean age at the incidence of cataract was 63.48 years (61.58 years in males and 65.31 years in females). Age (HR=1.09, 95% CI=1.05–1.13) and HbA1c (HR=1.21, 95% CI=1.07–1.37) or the duration of DM (HR=1.05, 95% CI=1.00–1.09) were found to be independently associated with cataract development.
Conclusion
Cataract development in people with DM is common, and its likelihood increases with age, HbA1c, and the duration of DM. Considering negative effect of cataract on their quality of life and economic burden, nurses should identify people with DM at a higher risk of cataract development, and plan individual eye examination programs to detect cataract development as early as possible.
9.A Comparative Coagulopathic Study for Treatment of Vasospasm by Using Low- and High-molecular Weight Hydroxyethyl Starches.
Sung Ho HWANG ; Yu Sam WON ; Jang Sun YU ; Jae Young YANG ; Chun Sik CHOI
Journal of Korean Neurosurgical Society 2007;42(5):377-381
OBJECTIVE: High-molecular-weight hydroxyethyl starch (HES) compromises blood coagulation more than does low-molecular-weight HES. We compared the effects of low- and high-molecular-weight HES for the treatment of vasospasm and investigated the dose relationship with each other. METHODS: Retrospectively, in a series of consecutive 102 patients with subarachnoid hemorrhage (SAH), 35 patients developed clinical symptoms of vasospasm of these fourteen patients were treated with low-molecularweight HES for volume expansion while the other 21 received high-molecular-weight HES as continuous intravenous infusion. Prothrombin time (PT), partial thromboplastin time (PTT), fibrinogen level, and platelet count were all measured prior to initiation, during treatment and after termination of therapy for symptomatic vasospasm. The total dose of HES ranged from 5 L to 14 L and median infusion duration was 10 days. RESULTS: A more pronounced PTT prolongation was observed in high-molecular-weight HES group compared with low-molecular-weight HES group. No other coagulation parameters were altered. Dosage (=duration) shows a positive correlation with PTT. Clinically, significant bleeding episodes were noted in four patients who received high-molecular-weight HES. CONCLUSION: Coagulopathy was developed in direct proportion to molecular weight of starch and dosages. We propose the extreme caution in the administration of HES solution for the vasospasm treatment.
Blood Coagulation
;
Fibrinogen
;
Hemorrhage
;
Humans
;
Infusions, Intravenous
;
Molecular Weight
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Partial Thromboplastin Time
;
Platelet Count
;
Prothrombin Time
;
Retrospective Studies
;
Starch*
;
Subarachnoid Hemorrhage
10.Reverse Controlled Antegrade and Retrograde Subintimal Tracking in Chronic Total Occlusion of Right Coronary Artery.
Yeon Hwa KIM ; Seung Hwan HWANG ; Chur Hoan LIM ; Hye Mi AN ; Hee Jong KIM ; Se Gwon MOON ; Won Yu KANG ; Sun Ho HWANG ; Weon KIM ; Wan KIM
Korean Circulation Journal 2012;42(9):625-628
Passage failure of guidewire is still remained most common reason for percutaneous coronary intervention (PCI) failure in chronic total occlusion (CTO). Intravascular ultrasound study (IVUS) and cardiac CT angiography can help identify features that most influence current success rates of PCI. We report our experience using the reverse controlled antegrade and retrograde subintimal tracking technique under the aid of IVUS, cardiac CT angiography for an ambiguous CTO of proximal right coronary artery.
Angiography
;
Angioplasty
;
Chronic Disease
;
Coronary Occlusion
;
Coronary Vessels
;
Percutaneous Coronary Intervention
;
Track and Field