• The Journal of the Korean bone and joint tumor society
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• v.13 no.2
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• pp.81-87
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• 2007

Purpose: Chondroblastoma of bone is rare with the potential for local recurrence and metastasis. A retrospective review of 30 patients with chondroblastoma of bone treated at a single institution during a 24-year period was conducted to determine the clinical outcome and relevant prognostic factors. Materials and Methods: Thirty patients with biopsy-proven chondroblastoma of bone, treated between September of 1981 and September of 2005, were retrospectively reviewed. There were 16 men and 14 women with an average follow-up period of 7.2 years (range, 1.6~21.2). The most common sites were the distal femur (n=7), proximal humerus (n=6), proximal tibia (n=6) and proximal femur (n=4). The average age of the patients was 20 years (range, 12~47) with closed physes in 20 patients(67%.) Twenty-seven patients(90%) were treated by curettage of the tumor with or without bone grafting or cementing. Three patients(10%) were treated with en bloc resection. Clinical and pathological factors reported to be associated with poor outcome were analyzed. Results: Four local recurrences(13%) developed in postoperative 4, 6, 7 and 16 months. These patients underwent further curettage (once in 2 patients and twice 2) and had no further recurrence. All patients showed no evidence of disease at the final follow-up. Local recurrence developed in the two cases which removal of the tumor was incomplete. Curettage and bone-grafting (1) and cementing (1) were performed in the two other cases with local recurrences. In contrast, no local recurrences were observed in the 3 cases treated with en-bloc resection. The status of physes or the histologic presence of aneurysmal bone cyst, the anatomic location of the tumor did not affect local recurrence. Conclusion: Adequate removal of the tumor with aggressive curettage or en bloc resection seems to be necessary to prevent local recurrence in chondroblastoma. The status of physes, the histologic presence of aneurysmal bone cyst or the anatomic location of the tumor was not related with local recurrence.

• Research in Community and Public Health Nursing
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• v.7 no.1
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• pp.80-99
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• 1996

Young black men(YBM) have the most severs levels of high blood pressure(HBP) and, in all reports but one, the lowest of HBP control of any age /sex /race group. To increase entry into care, remaining in care, and BP control for young(18-49 years) Black men, It is needed to review socio-demographic, medical characteristics, and behaviors(importance of and difficulty with HBP control behaviors, or worry about mdication) for experimental intervention study(educational- behavior strategies) of hypertensive urban young black men. The 204 participants had an average age of 38.8+7.0 years and an average educational level of $11.0{\pm}2.4$ years; only 23.1% were employed full- or part-time while 26% were on disability ; and 6% were married. Only 35.3% had an MD for HBP care and 37.3% had some form of health insurance. The average BP of those men currently being in care on medication(35.3%) was $148.2/95.1{\pm}19.5/11.3$ compared to those men not taking HBP care $153.7/99.1{\pm}14.0/9.8(p<.05)$. The average creatinine level was 1.3(excluding 3 marked elevations of 15.9, 9.6, and 7.7) for the 163 men consenting to have their blood drawn. Self-reported co-morbidity induded heart disease 7.8%, diabetes 8.9%, high cholesterol 18.2%, CVA 3.4%, alcohol and drug related problems 27.9% and 22.5% respectively. The kidney disease of those men currently being in care & on medication was 9.7 compared to those men not taking HBP care 0.8(p<.05). The problems of with sex life, physicl activity and dearly thinking of those men currently being in care & on medication was higher compared to those men not taking HBP care(p<.05). Questions of 'during the past month, on how many days did you have 5 or more drinks (bottles) of any alcoholic beverag?' and smoking of those men currently being in care & on medication was 18.1% and 72.2% compared to those men not taking HBP care 27.3 and 82.6%, respectively. HBP control behaviors was assessed with 1-5 point Likert subscales(5=extreme, 1-none at all), In general, th men reportd low levels of perceived psychological barrier to HBP care and control behaviors; importance of and difficulty with HBP control behaviors, or worry about mdication. For example, on a five point scale(1=none at all, 5=extreme), average ratings for perceived important and difficulty with BP care and behaviors were 2.8(SD=1.2) and 2.5(SD=1.1). Average ratings for perceived benefit with BP care and behaviors worry about medication of those men currently being in care on medication was 4.0(SD=0.9) and 2.2(SD=1.1) compared to those men not taking HBP care 3.6(SD=0.8), 2.8 (SD=1.6) respectively(p<.05). These data support the need for educational-behavioral strategies of community health nurse to improve high blood pressure control in this high risk group through perceived barriers to treatment, health care skills and use of resources, and social support.

• Research in Community and Public Health Nursing
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• v.15 no.4
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• pp.587-599
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• 2004

Purpose: The purpose of this study is to compare abdomen-fat rate, life style and social-support between normal weight women and obese women. Method: 304 women objectives from their 30 to 59 years of age were selected living in Je-chon city, Chung-Buck province and their height and weight were measured from April 1st to June 30th, 2003. Data were classified into low-weight group ($18.5kg/m^2$), normal-weight group ($18.5{\sim}22.9kg/m^2$), over weight group ($23{\sim}24.9kg/m^2$), and obese group ($25kg/m^2$) following the Korean Conference of Obesity, 2001. in which 119 people in the normal weight group and 91 people in the obese group, i.e. total 210 people were analyzed in sequence. Using SPSS Win 10.1 Program, frequency and percentile, and by ANOVA, $X^2-test$ and t-test were treated. Results: The average age of obese women was 46.68 distributing 40.7% of forties and 39.6% of fifties while normal-weight women were average 41.73-year old distributing 53.8% of forties and 34.5% of thirties, which revealed aged in obese women. The body fat rate of obese women averaged $37.52{\pm}4.17%$, in which 98.9% of obese women and 21.0% of normal weight women with a more than 30% of body-fat rate resulted in a higher body-fat rate in obese women. The waists of obese women averaged $88.37{\pm}8.22cm$, in which more than 85cm showed in obese women of 68.2% and normal weight women of 7.6% indicating a higher waist-fat rate in obese women. The abdomen-fat rate of more than 0.85 of waist vs hip-fat showed 74.7% in obese women and 58.4% in normal weight women, indicating a higher abdomen-fat rate in obese women. Obese women and normal weight women showed significant differences in education level, number of children, religion, menstrual status, and mother's weight. Especially, obese women ate hotter or saltier food than normal weight women preferring meat. However, no significant differences appeared in marital status, social economic status. occupation. eating habits. smoking. drinking and physical exercise. Social support levels showed a lower rate in obese women than in normal weight women, indicating a statistically significant difference (p<.05). Observing areas of social support, obese women showed lower rates in attachment/intimacy, social integrity, opportunity of foster and confidence in value except help and instruction, which indicated a statistically significant difference (p<.05). Social support for obese women showed significant differences in age, education level, social hierarchy, religion and menstrual status. Obese women were more negative than normal weight women in health recognition, indicating a statistically significant difference (p<.01). Normal weight women showed higher health recognition when provided high social support and significantly low (p<.01) health recognition when provided low social support. However, there was no significant difference in health recognition in obese women whether high or low social support was given. The health recognition of obese women showed significant differences in age, education level, social hierarchy, number of children, menstrual status, physical exercise, eating habits, eating taste and preference of food. Conclusion: Obese women showed elder than normal-weight women, higher body-fat rate and abdomen-fat rate, lower social support, and a tendency to more negative health recognition. Therefore, providing weight-control programs for the treatment of obesity and prevention of recurrence for obese women to prevent progressing to adult disease and promote a healthy life, we suggest that better eating habits and the encouragement of regular physical exercise should be included, as well as total approachment on change of health recognition and social support would be needed.

• Journal of the Korea Concrete Institute
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• v.17 no.6 s.90
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• pp.947-953
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• 2005

Previous test results showed that the current ASTM(American Standard for Testing and Materials) grip adapter for GFRP(Glass Fiber Reinforced Polymer) rebar was not fully successful in developing the design tensile strength of GFRP rebars with reasonable accuracy. It is because the current ASTM grip adapter which is composed of a pair of rectangular metal blocks of which inner faces are grooved along the longitudinal direction does not take into account the various geometric characteristics of GFRP rebar such as surface treatment, shape of bar cross section as well as physical characteristics such as poisson effect, elastic modulus in the transverse direction and so on. The objective of this paper is to provide how to proportion the optimum diameter of inner groove in ASTM grip adapter to develop design tensile strength of GFRP rebar. The proportioning of inner groove in ASTM grip adapter is based on the force equilibrium of GFRP rebar between tensile capacity and minimum frictional resistance required along the grip adapter. The frictional resistance of grip adapter is calculated based on the compressive strain compatibility in radial direction induced by the difference between diameter of GFRP rebar and inner groove In ASTM grip. All testing procedures were made according to the CSA S806-02 recommendations. From the preliminary test results on round-type GFRP rebars, it was found that maximum tensile loads acquired under the same testing conditions is highly affected by the diameter of inner groove in ASTM grip adapter. The grip adapter with specific dimension proportioned by proposed method recorded the highest tensile strength among them.

• Journal of Technologic Dentistry
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• v.19 no.1
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• pp.21-35
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• 1997

The Ag-Pd-Cu alloys containing a small amount of Au is commonly used for dental purposes, because this alloy is cheaper than Au-base alloys for clinical use. However, the most important characteristic of this alloy is age-hardenability, which is not exhibited by other Ag-base dental alloys. The specimens used were Ag-20Pd-20Cu ternary alloy and Au addition alloy. These alloys were melted and casted by induction electic furace and centrifugal casting machine in Ar atmoshpere. These specimens were solution treated for 2hr at $800^{\circ}C$ and were then quenched into iced water, and aged at $350{\sim}550^{\circ}C$ Age-hardening characteristics of the small Au-containing Ag-pPd-Cu dental alloys were investigated by means of hardness testing, X-ray diffraction and electron microscope observations, electrical resistance, differential scanning calorimetric, emergy dispersed spectra and electron probe microanalysis. Principal results are as follows : Hardening occured in two stages, I. e., stage I in low temperature and stage II in high temperature regions, during continuous aging. The case of hardening in stage I was due to the formation of the Llo type face centered tetragonal PdCu-ordered phase in the grain interior and hardening in stage I was affedted by the Cu concentration. In stage II, decomposition of the $\alpha$ solid solution to a PdCu ordered phase(L1o type) and an Agrich ${\alpha}2$ phase occurred and a discontiunous precipitation occurred at the grain boundary. Form the electron microscope study, it was concluded that the cause of age-hardening in this alloy is the precipitation of the PdCu ordered phase, which has AuCu I type face-centered tetragonal structure. Precipitation procedure was ${\alpha}\to{\alpha}+{\alpha}2+PdCu\to{\alpha}1+{\alpha}2+PdCu$ at Pd/Cu = 1 Ag-Pd-Cu alloy is more effective dental alloy as ageing treatment and is suitable to isothermal ageing at $450^{\circ}C$.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.6
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• pp.421-425
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• 2012

Purpose: The aim of this study is to compare the soft tissue changes of the midfacial area at the repose position and the natural smiling position for the improvement of evaluation and planning in the orthognathic surgery. Methods: The total of 30 subjects, 15 male and 15 female, were included in this study. The metal point landmarks were placed at the cheek, orbital rim, subpupil, and nasal base. The movements of the landmarks were evaluated at the repose position and smiling position in the lateral and posteroanterior cephalograms. Paired t test and correlation analysis were used for the evaluation of the soft tissue changes statistically. Results: In the lateral cephalograms, the cheek point (4.49 mm in female, 4.87 mm in male) showed the most distant movement. All points presented significant movements, except the orbital rim and nasal base point in male. Cheek point presented significant positive correlation between the horizontal and vertical change in male. Subpupil point presented significant positive correlation between horizontal and vertical change in both male and female. In the posteroanterior cephalograms, the nasal base point (5.41 mm in female, 6.30 mm in male) showed the most distant movement. Subpupil point and nasal base point presented significant movements in both female and male. Nasal base point presented significant negative correlation between the horizontal and vertical change in both male and female. In the lateral and posteroanterior cephalograms, the positional changes of all points presented significant positive correlation with each other in both female and male. Conclusion: The cheek point in the sagittal view and the nasal base point in the frontal view showed the most distant movement on smile. In the sagittal view, the subpupil point and cheek point moved anteriorsuperiorly on smile. In the frontal view, the nasal base points moved laterosuperiorly on smile. In both the sagittal and frontal view, the positional changes of all point were highly correlated to each other. These results may be used in the soft tissue references for the treatment planning of the dentofacial deformity patients.

• The korean journal of orthodontics
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• v.31 no.1 s.84
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• pp.51-61
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• 2001

Cleft lip and/or palate (CLP) is one of the most common congenital craniofacial anomalies and occurs more frequently in Asian people. Dental abnormalities in number, size, shape, and eruption of teeth are frequently associated with CLP. The purposes of this study were to investigate the effects of CLP on number, size, shape and eruption of teeth and to provide basic clinical data for diagnosis and treatment of the CLP patients. With the orthodontic and cleft charts, diagnostic models, orthopantomograms and intraoral x-ray films from 241 CLP patients who visited Dept. of Orthodontics, Seoul National University Dental Hospital, we evaluated the frequency of congenital missing teeth, supernumerary teeth, Impacted teeth, and microdontia. The results were as fellows ; 1. Frequency of congenital missing was relatively high up to $56.8\%$. Congenital missing occurred frequently in the maxillary lateral incisor and the maxillary second premolar. Among the CLP types, frequencies of congenital missing in cleft lip and Palate group and cleft lip and alveolus group were higher than those of cleft lip group and cleft palate group. And bilateral cleft showed higher frequencies than unilateral ones. 2. Supernumerary tooth was shown in $11.2\%$ of CLP patients. It occurred frequently in the area between the maxillary lateral Incisors and the maxillary canine. Among the CLP types, cleft lip group showed relatively most highest frequency. 3. Impaction was shown in $18.3\%$ of CLP patients. It occurred most frequently In the maxillary lateral incisor and the maxillary canine than other teeth. Among the CLP types, cleft lip group and cleft lip and palate group showed most highest frequencies. 4. Microdontia was shown in $15.8\%$ of CLP patients. It occurred the most frequently In the maxillary lateral incisors and maxillary canines. Among the CLP types, cleft lip and alveolus group and cleft lip and palate group showed relatively higher frequencies. There was no microdontia in cleft palate group.

• The korean journal of orthodontics
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• v.26 no.2 s.55
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• pp.153-162
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• 1996

Rapid maxillary expansion is widely used for the correction of anteroposterior discrepancies, constriction of the maxillary arch, etc. This experiment was undertaken to examine the serial changes in the osteogenesis as well as the collagen fiber bundles in the intermaxillary suture during the rapid maxillary expansion treatment. Four young female dogs aged 6 to 8 months old and not showing menarche yet were used for the experiment. The maxillary impression of dogs were taken, expansion device cast and Hyrax screw soldered at the midline in the 1st premolar area. RME device was delivered to the dogs and the activation of 0.25 mm per quarter-turn was done 2 times per day for 10 days until 5 mm separation was made. Separation of the maxilla was confirmed by X-ray. The animals were sacrificed on 0, 15, 30, 60 days from the finish of maxillary separation and preparations for light microscopy and surface electron microscopy were made. The sutures were cut into frontal serial sections for examination of the histological reactions. The following results were obtained and the conclusions made. 1. The edges of the two palatal plates bordering the midpalatal suture which at the beginning of the retention period were mainly composed of compact bone, underwent extensive resorption followed by new bone formation and gradually became spongy bone rich in bone marrow which in the 60 day retention animal became the compact bone with short intermaxillary suture space. During this transformation, newly formed trabecular bone tissues were added to the original margin. 2. Throughout the expansion period, the collagen fibers underwent successive changes such as stretching, loss of polarity, and finally fibrillogenesis. Towards the end of the expansion procedure, sharpey's fiber formation in newly formed bones were observed. 3. Bony spicules were found in the initial stage of retention on occlusal topographic X-rays, which later were confirmed to have ossified. 4. Judging from the histological changes occuring during the experimental expansion, excessive expansion will cause an excessive bleeding, and retard the remodeling of intermaxillary suture. According to the above results, the bone remodeling after rapid maxillary expansion was preceded by the migration of migratory cells into the intermaxillary suture area. The bone remodeling phenomena were on-going during the 2 months retention sample.

• The korean journal of orthodontics
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• v.36 no.6
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• pp.422-433
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• 2006

Objective: Several ions and components are released from self-etching primers in the oral cavity. This may cause injury to the periodontal tissues throughout orthodontic treatment. The purpose of this study was to assess the cytotoxicity of self-etching primers to HGF-1, HaCaT, and RHEK cells. Method: Transbond XT Primer (3M Unitek, Monrovia, CA, USA), and self-etching primers, Clearfil SE Bond (Kuraray, Osaka, Japan), Transbond Plus SEP (3M Unitek, Monrovia, CA, USA), and Adper Prompt L-Pop (3M Unitek, Monrovia, CA, USA), were evaluated by MTT assay, and cellular changes were also observed. Results: In all cells after 72 hours with all primers, severe morphological changes such as atrophy and necrosis were observed. In the MTT assay using HGF-1, Clearfil SE Bond, Transbond XT Primer, Transbond Plus SEP, and Adper Prompt L-Pop were lined up in order of ascending cytotoxicity When using HaCaT, Clearfil SE Bond, Adper Prompt L-Pop, Transbond Plus SEP, and Transbond XT Primer were lined up in order of ascending cytotoxicity. When using RHEK, Clearfil SE Bond, Transbond XT Primer, Adper Prompt L-Pop, and Transbond Plus SEP were lined up in order of ascending cytotoxicity. Conclusion: The result of this study shows that care is needed because self-etching primers show cytotoxic properties similar to conventional primers.

• The korean journal of orthodontics
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• v.24 no.2
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• pp.303-317
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• 1994

This study was designed to measure the changes in the titer of tooth root antibodies accompanying root resorption associated with orthodontic tooth movement in dogs to explore a role of the specific immune response in root resorption during orthodontic tooth movement. Five adult mongrel dogs, 2 years of age, were used in the study. Six lower incisors were extracted as sources of homologous antigen in the dogs. Tooth root antigen preparations were made from a 6M Guanidine-HCl-10% EDTA(pH5.0) extract of these root dentins. Root resorption was elicited by intrusion of six maxillary incisors with 200-250gm intrusive force. In 9th week, resorbing six maxillary anterior teeth were extracted. Serum samples were taken from each dog prior to intrusion and weekly for 11 consecutive weeks. Serum autoantibody titers were determined with an enzyme-linked immunosorbent assay. As controls for antibody specificity, sera which were previously incubated with tooth root antigen as well as sera to an unrelated bacterial antigen (Porphyromonas gingivalis 33277) for 3 hours at 25 were measured in all runs. Root resorption was monitored monthly using occlusal radiographs. And then root resorption patterns were observed with a zoom stereo microscope (Model SZH-121, Olympus optical Co. Ltd.). Incisors did not show clear radiographic evidence of significant and progressive root resorption, but periodontal ligament space had widened. But root resorption was observed on the apical regions of the maxillary incisors with a zoom stereo microscope. Teeth showed the shallow depression generally accompanying deep resorption. These demonstrate a slight tendency for an immediate decrease followed by rebound to levels above the pre-treatment baseline. A peak titer of autoantibody to dentin antigen occurred on day 28, then steadily decreased during the 9th week period as the roots resorbed and then rapidly spiked in animals when the resorbing teeth were extracted. When sera is incubated with tooth root antigen, serum activity in the ELISA was almost absent. This is because serum activity in the ELISA could be removed by absorption of the serum with dog dentin antigen. Serum ELISA activity to the unrelated bacterial antigen remained essentially unchanged in all animals throughout the experimental period. When the time course of changes in autoantibody to homologous tooth root antigen prepatration and unrelated bacterial antigen was compared, no significant differences were found(${\alpha}=0.05$). In general, the overall pattern of changes in autoantibody was similar to the two antigens. These findings suggest the possibility that these immunologic changes precede a significant development of root resorption lesions rather than merely reflecting their presence. Therefore, this suggests that the changes of antibody levels may have some predictive value for root resorption.