1.Effects of maxillary protraction on the displacement of the maxilla.
Korean Journal of Orthodontics 1995;25(5):543-555
In the orthopedic therapy, the biomechanical analysis of the appliance is necessary to get a desirable orthopedic effect. The purpose of this study was to investigate the desirable direction and application position of the protraction force. The protraction force of 500g was applied to the first premolar or to the first molar. The direction of force application was paralell or 20degrees downward to the occlusal plane respectively. The stress distribution and the displacement within the maxilla was analyzed by a 3-dimensional finite element method. The findings obtained were as follows : 1. Protraction forces caused a counterclockwise rotation of the maxilla. 2. The degree of maxillary rotation was less when the force was applied 20degrees downward direction to the occlusal plane than when applied to the parallel direction. 3. The degree of rotation of maxilla was greater when the parallel force was applied to the 1st premolar than when applied to the first molar, whereas it was greater when force is applied 20degrees downward than at the first premolar. In conclusion, the 20degrees downward protraction from the first premolar induced the least counterclockwise rotation of the maxilla and was thought as the desirable direction and application position of the protraction force.
Bicuspid
;
Dental Occlusion
;
Maxilla*
;
Molar
;
Orthopedics
2.Frictional forces between orthodontic wire and bracket under artificial saliva.
Korean Journal of Orthodontics 1988;18(1):55-64
It has been suggested that the frictional force between bracket and arch wire may impede the tooth movement. The present study was aimed to compare and analyze the effect of wire size, type of ligation, and duration of ligation on the magnitude of frictional force between cobalt chromium wire and stainless steel bracket under the artificial saliva. The results were as follows: 1. Type of ligation and size of wire were the main influencing factor on the level of friction. 2. Stainless steel ligature generated higher frictional forces thanelastomeric module. 3. The rectangular wire consistently exhibited more frictional force values than round wires, while there was no significant difference between frictional forces of round wires. 4. In elastic ligature, frictional force decreased with time. 5. Artificial saliva had no significant influence on the frictional force between cobalt chromium wire and bracket.
Chromium
;
Cobalt
;
Friction*
;
Ligation
;
Orthodontic Wires*
;
Saliva, Artificial*
;
Stainless Steel
;
Tooth Movement
3.Prognostic utility of N-terminal pro-B-type natriuretic peptide in adult and elderly patients with community acquired pneumonia
Jeong Min CHOI ; Ki Young JEONG ; Han Sung CHOI ; Hoon Pyo HONG ; Jong Seok LEE ; Seok Hun KO
Journal of the Korean Society of Emergency Medicine 2020;31(4):380-390
Objective:
N-terminal pro-B-type natriuretic peptide (NT-proBNP) is suggested as a prognostic biomarker for communityacquired pneumonia (CAP). However, its predictive value for an individual adult and elderly CAP patients has not been fully investigated.
Methods:
Patients with CAP aged 18 years and older, who visited the emergency department (ED) from March 1, 2016 to March 31, 2019, were included in this study. Patients were divided into the adult group and the elderly group (age ≥70 years). Data was collected from the ED-based registry, and medical charts were retrospectively reviewed. The registry data included sociodemographic and past medical characteristics, as well as laboratory findings including NT-proBNP and C-reactive protein (CRP), Pneumonia Severity Index (PSI), and CURB65 (confusion, urea, respiratory rate, blood pressure, and aged 65 or more). The independent potential of NT-proBNP to predict mortality was assessed in both groups using multivariable logistic regression, and its predictive ability was evaluated in terms of performance (using areas under the curve [AUCs]) and goodness-of-fit (using the Bayesian information criterion [BIC]).
Results:
Totally, 325 CAP patients were evaluated, of which 208 (64%) belonged to the elderly group. NT-proBNP was identified as an independent predictor of CAP mortality in elderly patients, but not in adult patients. Moreover, AUC of the NT-proBNP for mortality was comparable to AUC of the PSI, but was higher than that of the CURB65, in elderly CAP patients. Similarly, the NT-proBNP had a better overall fit (lower BIC value) compared to the CURB65, for mortality. Additionally, both AUC and overall fit of the NT-proBNP for mortality were significantly superior to values obtained for CRP.
Conclusion
For elderly CAP patients in the ED, the NT-proBNP is an independent and useful predictor of mortality.
4.A Forensic Autopsy Case of Lissencephaly for Evaluating the Possibility of Child Abuse.
Seong Hwan PARK ; Juck Joon HWANG ; Kwang Soo KO ; Sun Hee KIM ; Tae Sung KO ; Min Hee JEONG ; Eun Hye LEE ; Hong Il HA ; Joong Seok SEO
Korean Journal of Legal Medicine 2013;37(2):84-89
A 9-year-old Korean boy with lissencephaly was found dead at home. He had previously been diagnosed with lissencephaly that presented with infantile spasm on the basis of magnetic resonance imaging and electroencephalogram results. Antemortem chromosomal banding revealed a normal karyotype. A legal autopsy was requested to eliminate the possibility of neglect or abuse by his parents. The autopsy findings revealed type I lissencephaly with the associated microcephaly. No external wounds or decubitus ulcers were noted. Postmortem fluorescence in situ hybridization for the LIS1 locus and nucleotide sequence analysis of the whole coding regions of the LIS1 gene did not reveal any deletions. The antemortem and postmortem findings revealed that lissencephaly syndrome was associated with isolated lissencephaly sequence. External causes of death were excluded by the full autopsy and toxicology test results. Because patients with mental retardation are frequently victimized and suffer neglect or abuse, thorough external and internal examinations should be conducted at the time of autopsy.
Autopsy
;
Base Sequence
;
Cause of Death
;
Child
;
Child Abuse
;
Classical Lissencephalies and Subcortical Band Heterotopias
;
Clinical Coding
;
Electroencephalography
;
Fluorescence
;
Forensic Pathology
;
Humans
;
In Situ Hybridization
;
Infant
;
Infant, Newborn
;
Intellectual Disability
;
Karyotype
;
Lissencephaly
;
Magnetic Resonance Imaging
;
Microcephaly
;
Parents
;
Pressure Ulcer
;
Spasms, Infantile
;
Toxicology
5.Predictive Factors for Prostate Cancer in Biopsy of Patients with Prostate-Specific Antigen Levels Equal to or Less Than 4 ng/ml.
Hyoung Woo KIM ; Young Hwii KO ; Seok Ho KANG ; Jeong Gu LEE
Korean Journal of Urology 2011;52(3):166-171
PURPOSE: This study was conducted to identify the predictive factors for prostate cancer in patients with prostate-specific antigen (PSA) levels equal to or less than 4 ng/ml. MATERIALS AND METHODS: A retrospective study of medical records was conducted on 292 patients with initial serum PSA < or =4 ng/ml among 2,305 patients who underwent prostate biopsy from January 2003 to December 2008. Prostate biopsy was performed on patients with PSA < or =4 ng/ml in the case of abnormal findings in the digital rectal examination (DRE) or transrectal ultrasonography (TRUS) or in those with a PSA level higher than the age-adjusted PSA levels. The patients were divided into the group diagnosed with prostate cancer and the non-prostate-cancer group. Subsequently, the variables of the two groups were compared. RESULTS: The patients' mean age was significantly higher in the prostate cancer group (n=28) than in the non-prostate-cancer group (n=264; p=0.033). In addition, for the patients with a PSA range of 2.0-2.9 ng/ml, their age (p=0.049) and PSA density (PSAD; p=0.042) were significantly higher and the prostate volume (p=0.028) was significantly smaller in the prostate cancer group than in the non-prostate-cancer group. CONCLUSIONS: Of the patients with PSA < or =4 ng/ml, the age of the patients who showed abnormal findings in the DRE or TRUS or who had a PSA level higher than the age-adjusted PSA level was a significant predictive factor for prostate cancer. In particular, for the PSA range of 2.0-2.9 ng/ml, a thorough screening test for prostate cancer was required if the patients had conditions such as higher age, smaller prostate, and higher PSAD.
Biopsy
;
Digital Rectal Examination
;
Humans
;
Mass Screening
;
Medical Records
;
Prostate
;
Prostate-Specific Antigen
;
Prostatic Neoplasms
;
Retrospective Studies
6.Usefulness of the Carotid Ultrasonography to Predict the Severity of Coronary Artery Stenosis.
Kwang Il KO ; Byoung Hyun PARK ; Seok Kyu OH ; Nam Ho KIM ; Chung Gu CHO ; Jin Won JEONG
Journal of the Korean Geriatrics Society 2001;5(4):302-310
BACKGROUND: High-resolution carotid ultrasonography is considered a fundamental technique for the investigation of the vascular system. However, it is still very unclear whether ultrasonographic studies of carotid arteries are useful for the prediction of cardiovascular events in patients with coronary heart disease. We have tried to assess the usefulness of carotid ultrasonography to predict the severity of coronary artery stenosis in the patients with ischemic heart disease. METHODS: We studied in 80 patients(53 men, 27 women) with acute chest pain, mean ages 63.1 10.8 yr(35 to 84 yrs), who underwent both coronary angiography and carotid ultrasonography with 10 MHz transducer. The patients who had received revascularization procedure were excluded. We classified the patients into two groups, the control group without significant coronary stenosis(23 patients) and the coronary artery disease(CAD) group(57 patients) with significant stenosis(>50%). The intima-media thickness (IMT) was measured in the far wall of CCA at 10 mm proximal to carotid bulb and the abnormal IMT was defined when the measurement was greater than mean IMT+2 SD of control group(>0.99 mm). Serum total cholesterolQlC), low density lipoprotein(LDL), high density lipoprotein(HDL), triglyceride(TG) and lipoprotein (a) (LP(a)) were measured and history of hypertension, diabetes mellitus, and smoking were investigated. RESULTS: A significant difference in IMT of the CCA was found between control and CAD group(0.75+/-0.12mm vs. 1.02+/-0.34 mm; p<0.001). Also a significant difference in the existence of plaque(control; 26.1% vs. CAD; 73.7%, p<0.00l) and the number of plaque(control; 0.39+/-0.94 vs. CAD; 2.20+/-1.87 p<0.001) was found. The existence and number of carotid plaque were more conelated with coronary artery stenosis severity than carotid IMT. The sensitivity of IMT for prediction of significant CAD was 42.1%, the specificity 95.7%, the positive predictive value 96%, and the negative predictive value 40%. The sensitivity of plaque presence on the carotid artery for prediction of CAD was 73.7%, the specificity 73.9%, the positive predictive value 87.5% and the negative predictive value 53.1%. Among the risk factors, age and LP(a) were correlated with IMT of CCA, and diabetes, hypertension, age were correlated with the presence of plaque. Smoking and hypertension were correlated with coronary artery disease. CONCLUSION: Carotid atherosclerosis was significantly correlated with severity of coronary atherosclerosis. We therefore suggest that carotid ultrasonography is useful to predict the severity of coronary artery stenosis and that the best index of coronary artery stenosis severity may be carotid plaque rather than carotid intima-media thickness.
Carotid Arteries
;
Carotid Artery Diseases
;
Carotid Intima-Media Thickness
;
Chest Pain
;
Coronary Angiography
;
Coronary Artery Disease
;
Coronary Disease
;
Coronary Stenosis*
;
Coronary Vessels*
;
Diabetes Mellitus
;
Humans
;
Hypertension
;
Lipoprotein(a)
;
Male
;
Myocardial Ischemia
;
Risk Factors
;
Sensitivity and Specificity
;
Smoke
;
Smoking
;
Transducers
;
Ultrasonography*
7.Comparison of micro CT and cross-section technique for evaluation of marginal and internal fit of lithium disilicate crowns.
In Seok KO ; Jeong Mi KIM ; Hye Won CHO
The Journal of Korean Academy of Prosthodontics 2016;54(3):226-233
PURPOSE: The purpose of this study was to evaluate the adaptation of lithium disilicate crowns fabricated by CAD-CAM (computer aided design-computer aided manufacturing) and heat-press technique to compare two different measurement methods in assessing fit of the ceramic crowns: micro CT and cross-section technique. MATERIALS AND METHODS: A prepared typodont mandibular molar for ceramic crown was duplicated and ten dies were produced by milling the PMMA (polymethylmethacrylate) resin. Ten vinyl polysiloxane impressions were made and stone casts were produced. Five dies were used for IPS e.max Press crowns with heat-press technique. The other five dies were used for IPS e.max CAD crowns with CAD-CAM technique. Ten lithium disilicate crowns were cemented on the resin dies using zinc phosphate cement with finger pressure. The marginal and internal fits in central buccolingual plane were evaluated using a micro CT. Then the specimens were embedded and cross-sectioned and the marginal and internal fits were measured using scanning electronic microscope. The two measurement methods and two manufacturing methods were compared using Mann-Whitney U test (SPSS 22.0). RESULTS: The marginal and internal fit values using micro CT and cross-section technique were similar, showing no significant differences. There were no significant differences in adaptation between lithium disilicate crowns fabricated with CAD-CAM and heat-press technique. CONCLUSION: Both micro CT and cross-section technique were acceptable methods in the evaluation of marginal and internal fit of lithium disilicate crown. There was no difference in adaptation between lithium disilicate crowns fabricated with CAD-CAM and heat-press technique except occlusal fit.
Ceramics
;
Computer-Aided Design
;
Crowns*
;
Fingers
;
Lithium*
;
Molar
;
Polymethyl Methacrylate
;
Siloxanes
;
Zinc Phosphate Cement
8.Interference of Union after the Use of Beta-Tricalcium Phosphate Block in High Tibial Osteotomy.
Man Seok KO ; Ju Seon JEONG ; Dong Wook JUNG
The Journal of the Korean Orthopaedic Association 2015;50(5):424-428
High tibial osteotomy (HTO) is a commonly used treatment for genu varum and medial compartment osteoarthritis. Recently open wedge HTO has been the preferred method due to its facilitated technique, fewer neurovascular and joint injuries, etc. In open wedge HTO materials such as autogenous, allogenous bone graft and tricalcium phosphate (TCP) are used to help with bone union and have a role in filling in the empty space. However the authors of this study report on two cases of nonunion 1 year after HTO using TCP block.
Genu Varum
;
Joints
;
Osteoarthritis
;
Osteotomy*
;
Transplants
9.National Petition Analysis Related to Nursing: Text Network Analysis and Topic Modeling
HyunJung KO ; Seok Hee JEONG ; Eun Jee LEE ; Hee Sun KIM
Journal of Korean Academy of Nursing 2023;53(6):635-651
Purpose:
This study aimed to identify the main keyword, network structure, and main topics of the national petition related to “nursing” in South Korea.
Methods:
Data were gathered from petitions related to the national petition in Korea Blue House related to the topic “nursing” or “nurse” from August 17, 2017, to May 9, 2022. A total of 5,154 petitions were searched, and 995 were selected for the final analysis. Text network analysis and topic modeling were analyzed using the Netminer 4.5.0 program.
Results:
Regarding network characteristics, a density of 0.03, an average degree of 144.483, and an average distance of 1.943 were found. Compared to results of degree centrality and betweenness centrality, keywords such as “work environment,” “nursing university,” “license,” and “education” appeared typically in the eigenvector centrality analysis. Topic modeling derived four topics: (1) “Improving the working environment and dealing with nursing professionals,” (2) “requesting investigation and punishment related to medical accidents,” (3) “requiring clear role regulation and legislation of medical and nonmedical professions,” and (4) “demanding improvement of healthcare-related systems and services.”
Conclusion
This is the first study to analyze Korea's national petitions in the field of nursing. This study's results confirmed both the internal needs and external demands for nurses in South Korea. Policies and laws that reflect these results should be developed.
10.The Clinical Results of Autologous Osteochondral Grafts in Osteochondral Lesion of the Talus.
Hong Joon CHOI ; Jeong Seok MOON ; Woo Chun LEE ; Han Seok KO
Journal of Korean Foot and Ankle Society 2007;11(2):209-215
PURPOSE: To evaluate clinical results of autologous osteochondral graft in osteochondral lesions of the talus. MATERIALS AND METHODS: Twenty feet in twenty patients underwent osteochondral autologous transfer in the osteochondral lesions of the talus. Sixteen were men and four were women. The mean age was 40.8 years old. The mean follow up was 2 years 9 months. Eighteen cases were medial, one case was lateral and one case was both, respectively. The average duration of symptom was 4 years 3 months. AOFAS ankle/hindfoot score (AOFAS score), visual analogue scale (VAS), Lysholm knee score were evaluated preoperatively and at the final follow up. RESULTS: Postoperative AOFAS score was 87.3 (range, 69-100), which was significantly improved from preoperative AOFAS score of 62.0 (p=0.000). Postoperative VAS was 2.9 (range, 0-7), which was significantly improved from preoperative VAS of 7.5 (p=0.000). Postoperative Lysholm knee score was 92.4 (range, 80-100). All osteotomy of medial malleolus was united by the 4th month after surgery. Postoperative VAS was conversely correlated with the follow up period (p=0.024). There was no complications associated with surgery. CONCLUSION: Autologous osteochondral grafts in osteochondral lesion of the talus demonstrated excellent results with a short-term follow up.
Female
;
Follow-Up Studies
;
Foot
;
Humans
;
Knee
;
Male
;
Osteotomy
;
Talus*
;
Transplants*