• Journal of Periodontal and Implant Science
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• v.33 no.3
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• pp.457-474
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• 2003

The ultimate objective of periodontal treatment is to get rid of an on-going periodontal disease and further regenerate the supporting tissue, which is already destroyed, functionally. Currently, the bone grafting operation using various kinds of bone grafting materials and the operation for induced regeneration of periodontal tissue using the blocking membrane are performed for regeneration of the destroyed periodontal tissue. However, there are respective limitations Galenical preparations, which are used for regeneration of periodontal of tissue, has less risk of rejective reaction or toxicity that may be incidental to degradation and their effect is sustainable. Thus, in case they are applicable to a clinic, they can he used economically. Chitosan has such compatibility, biological actions including antibacterial activity, acceleration of wound treatment, etc., and excellent mechanical characteristics, which has recently aroused more interest in it. Also, it has been reported that it promotes osteogenesis directly or indirectly by functioning as a matrix to promote migration and differentiation of a specific precussor cell (for example, osteoblast) and further inhibiting the function of such a cell as fibroblast to prevent osteogenesis. In this study, the pure chitosan solution, which was obtained by purifying chitosan, was used. However, since this chitosan is of a liquiform, it is difficult to sustain it in a defective region. It is, therefore, essential to use a carrier for delivering chitosan to, and sustaining it gradually in the defective region. In the calvarial defect model of the Sprague-Dawley rat, it is relatively easy to maintain a space. Therefore, in this study, the chitosan solution with which ACS was wetted was grafted onto the defective region, For an experimental model, a calvarial defect of rat m s selected, and a critical size of the defective region was a circular defect with a diameter of 8 mm. A group in which no treatment was conducted for the calvarial defect was set as a negative control group. Another group in which treatment was conducted with ACS only was set as a positive control group (ACS group). And another group in which treatment was conducted was conducted with by grafting the pure chitosan solution onto the defective region through ACS which was wetted with the chitosan solution was set an experimental group (Chitosan/ACS group). Chitosan was applied to the Sprague-Dawley rat's calvarial bone by applying ACS which was wetted with the chitosan solution, and each Sprague-Dawley rat was sacrificed respectively 2 weeks and 8 weeks after the operation for such application. Then, the treatment results were compared and observed histologically and his tometrically. Thereby, the following conclusions were obtained. 1. In the experimental group, a pattern was shown that from 2 weeks after the operation, vascular proliferation proceeded and osteogenesis proceeded through osteoblast infiltration, and at 8 week after the operation, ACS was almost absorbed, the amount of osteogensis was increased and many osteoid tissue layers were observed. 2. At 2 weeks after the operation, each amount of osteogenesis appeared to be 8.70.8 %, 13.62.3 % and 4.80.7 % respectively in the experimental group, the positive control group and the negative control group. Accordingly, it appeared to be higher in the Experimental group and the positive control group than in the negative control group, but there was no significant difference statistically (p<0.01). 3. At 8 weeks after the operation, each amount of osteogenesis appeared to be 62.26.1%, 17.42.5 % and 8.21.4 % respectively in the experimental group, the positive control group and the negative control group. Accordingly, it appeared to be substantially higher in the experimental group than in the positive control group and the negative control group, and there was a significant difference statistically (p<0.01). As a result of conducting the experiment, when ACS was used as a carrier for chitosan, chitosan showed effective osteogenesis in the perforated defective region of the Sprague-Dawley rat's calvarial bone.

• Journal of Preventive Medicine and Public Health
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• v.11 no.1
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• pp.86-97
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• 1978

The mobile medical service has been operated for many years by a number of medical schools and hospitals as a most convenient means of medical service delivery to the people residing in such area where the geographical and socioeconomic conditions are not good enough to enjoy modern medical care. Despite of official appraisal showing off simply with numbers of outpatients treated and medical persons participated, however, as well recognized, the capability (in respect of budget, equipment and time) of those mobile medical teams is so limitted that it often discourages the recipients as well as medical participants themselves. In the midst of rising need to secure medical service of good quality to all parts of the country, and of developing concept of primary health care system, authors evaluated the effectiveness of and problems associated with mobile medical servies program through the community diagnosis of a village (Opo-myun, Kwangju-gun) to obtain the information which may be halpful for future improvement. 1. Owing to the nationwide Sae-Maul movement powerfully practiced during last several years, living environment of farm villages generally and remarkably improved including houses, water supply and wastes disposal etc. Neverthless, due to limitations in budget time and lack of knowledge (probably the most important), these improvements tend to keep up appearances only and are far from the goal which may being practical benefit in promoting the health of the community. 2. As a result of intensive population policy led by the government since 1962, there has been considerable advances in understanding and the rate of practicing family planning through out the villages and yet, one should see many things, especially education, to be done. Fifty eight per cent of mothers have not received prenatal check and the care for most (72%) delivery was offered by laymen at home. 3. Approximately seven per cent of the population was reported to have chronic illness but since only a few (practically none) of the people has had physical check up by doctors, the actual prevalence of chronic diseases may reach many times of the reported. The same fact was observed also in prevalence of tuberculosis; the patients registered at local health center totaled 31 comprising only 0.51% while the numbers in two neighboring villages (designated as demonstration area of tuberculosis control and mass examination was done recently) were 3.5 and 4.0% respectively. Prevalence rate of all dieseses and injuries expereinced during one month (July, 1977) was 15.8%. Only one tenth of those patients received treatment by physicians and one fifth was not treated at all. The situation was worse as for the chronic patients; 84% of all cases either have never been treated or discontinued therapy, and the main reasons were known to be financial difficulty and ignorance or indifference. 4. Among the patients treated by our mobile clinic, one third was chronic cases and 45% of all patients, by the opinion of doctors attended, were those who may be treated by specially trained nurses or other paramedics (objects of primary care). Besides, 20% of the cases required professional managements of level beyond the mobile team's capability and in this sense one may conclude that the effectiveness (performance) of present mobile medical team is quite limitted. According to above findings, the authors would like to suggest following for mobile medical service and overall medicare program for the people living in remote country side. 1. Establishment of primary health care system secured with effective communication and evacuation (between villages and local medical center) measures. 2. Nationwide enforcement of medical insurance system. 3. Simple outpatient care which now constitutes the main part of the most mobile medical services should largely be yielded up to primary health care unit of the village and the mobile team itself should be assigned on new and more urgent missions such as mass screening health examination of the villagers, health education with modern and effective audiovisual aids, professional training and consultant services for the primary health care organization.

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.4
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• pp.260-268
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• 2017

Purpose: Manufacturing with AM (Additive manufacturing) technique has many advantages; but, due to insufficient study in the area, it is not being widely used in the general clinic. In this study, differences of flexural strength among various materials of 3 unit fixed dental prosthesis were analyzed. Materials and Methods: A metal jig for specimens that had a 3-unit-fixed dental prosthesis figure were fabricated. The jigs were made appropriately to the specifications of the specimens. Three different kinds of materials of specimens which were NC (mathacrylic esther based), DP-1 (Bisphenol A epoxy acrylate type oligomer based), and DT-1 (urethane acrylate based) were printed with DLP machine. Five specimens for each kind of material were printed with an angle of $30^{\circ}$ from the horizontal surface. The specimens were placed on the jig and the flexural strength was measured and recorded using Universal testing machine. The recorded data was analyzed in SPSS using One-way ANOVA and Tukey HSD to determine the significance of the differences of flexural strength among the groups. Results: The flexural strengths of each group were the followings: NC, $1119{\pm}305$ N; DP-1, $619{\pm}150$ N; DT-1, $413{\pm}65N$. Using One-way ANOVA and Tukey Honestly Significant Difference test, significant difference was found between NC and the other groups (P < 0.05), but there was no significant difference between DP-1 and DT-1 (P > 0.05). Conclusion: Higher flexural strength was shown in 3-unit-fixed dental prosthesis that were 3D printed using a DLP machine with NC material.

• Health Policy and Management
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• v.2 no.1
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• pp.42-65
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• 1992

To survey the specialties or sujects of practice displayed by the private practitioners the authors visited 691 clinics in Taegu from April 1 to May 18, 1991, At the same time, a mail questionnaire was administered to ask the number of displayed subjects of practice, and the reasons for displaying the subjects, reasons for not displaying in case of no specialty was displayed, composition of patients, and role as a specialist. The questionnaire was returned by 308(44.6%) practitioners. The distributions of private practitioners by specialty were 13.9% for internal medicine (IM), 11.7% for pediatrics(Ped), 13.0% for obstetrics '||'&'||' gynecology(OBGY), 11.1% for general surgery(GS), 10.0% for family practice(FP), and 5.3% for general practitioner(GP). Ninety percent of the specialists have displayed their specialty in their offices. Among all the private practitioners, 61.9% of them have displayed their subjects of practice and 23.7% have shown telephone number. Among private practitioners who displayed the subjects of practice, 80.6% have signs of 'subjects of practice'. Mean number of the displayed subjects of practice for the all private practitioners is 1.20, and 1.93 for the private practitioners who displayed subjects of practice. FP and GS have displayed their subjects of practice in 91.2% and 87.0% respectively and OBGY have displayed in 32.2%, the lowest percentage among all the soecuaktues. IM specialists displays pediatrics as a major subject of practice in 72.1% the pediatricians display IM in 88.9% the OBGYs display pediatrics in 77.8%, and the GSs display IM in 51.9%. Most commonly displayed subjects of practice are Ped and IM. Sixty-five percent of the private practitioners answered that they don't display their specialties because their clinics are "primary health care facility". The reasons for displaying the subjects of practice and its relevance with their own specialty(45.6%), and the difficulty in clinic management only with the patients for their own specialty(36.9%). The proportion of clinics whose patients of other specialty are than their own specialty accounted less than 10% was 52.8% and that accounted more than 51% was 16.0%. Specially, 51.4% of GS specialists cared more than 51% of patients of other specialty area than their own specialty. Most of the patients of IM, Ped, and OBGY specialists are the patients of their own specialty. However, 56.8% of GS care more of IM patients and only 24.3% of them care mostly GS patients, The respondents to the mail questionnaire who stated that they can not play the role of specialist well are 30.5% and especially 72.9% of the GS specialists state so. The proportion of respondents who do not suffort the private practice of specialists is 71.1%. Among the surgical specialists, 82.7% of them rarely perform operation. The reasons for not performing operation are insufficient insurance fee (76.9%), and risk of operation(58.0%), so as the OBGY specialists. Above finidngs suggest that most of the specialists, especially surgeons, in the private practice can not play their role as a specialist. It is necessary to develop a policy that facilitates the production of practice and the retention of the specialists in the hospitals.s.

• Journal of radiological science and technology
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• v.40 no.2
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• pp.261-267
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• 2017

The study has attempted to evaluate and compare the image evaluation and exposure dose by respectively applying filter back projection (FBP), the existing test method, and adaptive statistical iterative reconstruction (ASIR) with different values of tube voltage during the low dose computed tomography (LDCT). With the image reconstruction method as basis, chest phantom was utilized with the FBP and ASIR set at 10%, 20% respectively, and the change of tube voltage (100 kVp, 120 kVp). For image evaluation, back ground noise, signal-noise ratio (SNR) and contrast-noise ratio (CNR) were measured, and, for dose assessment, CTDIvol and DLP were measured respectively. In terms of image evaluation, there was significant difference in ascending aorta (AA) SNR and inpraspinatus muscle (IM) SNR with the different amount of tube voltage (p < 0.05). In terms of CTDIvol, the measured values with the same tube voltage of 120 kVp were 2.6 mGy with no-ASIR and 2.17 mGy with 20%-ASIR respectively, decreased by 0.43 mGy, and the values with 100 kVp were 1.61 mGy with no-ASIR and 1.34 mGy with 20%-ASIR, decreased by 0.27 mGy. In terms of DLP, the measured values with 120 kVp were $103.21mGy{\cdot}cm$ with no-ASIR and $85.94mGy{\cdot}cm$ with 20%-ASIR, decreased by $17.27mGy{\cdot}cm$ (about 16.7%), and the values with 100 kVp were $63.84mGy{\cdot}cm$ with no-ASIR and $53.25mGy{\cdot}cm$ with 20%-ASIR, a decrease by $10.62mGy{\cdot}cm$ (about 16.7%). At lower tube voltage, the rate of dose significantly decreased, but the negative effects on image evaluation was shown due to the increase of noise.

• Radiation Oncology Journal
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• v.20 no.1
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• pp.1-16
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• 2002

Purpose : Three dimensional conformal radiotherapy planning is being used widely for the treatment of patients with brain tumor. However, it takes much time to develop an optimal treatment plan, therefore, it is difficult to apply this technique to all patients. To increase the efficiency of this technique, we need to develop standard radiotherapy plant for each site of the brain. Therefore we developed several 3 dimensional conformal radiotherapy plans (3D plans) for tumors at each site of brain, compared them with each other, and with 2 dimensional radiotherapy plans. Finally model plans for each site of the brain were decide. Materials and Methods : Imaginary tumors, with sizes commonly observed in the clinic, were designed for each site of the brain and drawn on CT images. The planning target volumes (PTVs) were as follows; temporal $tumor-5.7\times8.2\times7.6\;cm$, suprasellar $tumor-3\times4\times4.1\;cm$, thalamic $tumor-3.1\times5.9\times3.7\;cm$, frontoparietal $tumor-5.5\times7\times5.5\;cm$, and occipitoparietal $tumor-5\times5.5\times5\;cm$. Plans using paralled opposed 2 portals and/or 3 portals including fronto-vertex and 2 lateral fields were developed manually as the conventional 2D plans, and 3D noncoplanar conformal plans were developed using beam's eye view and the automatic block drawing tool. Total tumor dose was 54 Gy for a suprasellar tumor, 59.4 Gy and 72 Gy for the other tumors. All dose plans (including 2D plans) were calculated using 3D plan software. Developed plans were compared with each other using dose-volume histograms (DVH), normal tissue complication probabilities (NTCP) and variable dose statistic values (minimum, maximum and mean dose, D5, V83, V85 and V95). Finally a best radiotherapy plan for each site of brain was selected. Results : 1) Temporal tumor; NTCPs and DVHs of the normal tissue of all 3D plans were superior to 2D plans and this trend was more definite when total dose was escalated to 72 Gy (NTCPs of normal brain 2D $plans:27\%,\;8\%\rightarrow\;3D\;plans:1\%,\;1\%$). Various dose statistic values did not show any consistent trend. A 3D plan using 3 noncoplanar portals was selected as a model radiotherapy plan. 2) Suprasellar tumor; NTCPs of all 3D plans and 2D plans did not show significant difference because the total dose of this tumor was only 54 Gy. DVHs of normal brain and brainstem were significantly different for different plans. D5, V85, V95 and mean values showed some consistent trend that was compatible with DVH. All 3D plans were superior to 2D plans even when 3 portals (fronto-vertex and 2 lateral fields) were used for 2D plans. A 3D plan using 7 portals was worse than plans using fewer portals. A 3D plan using 5 noncoplanar portals was selected as a model plan. 3) Thalamic tumor; NTCPs of all 3D plans were lower than the 2D plans when the total dose was elevated to 72 Gy. DVHs of normal tissues showed similar results. V83, V85, V95 showed some consistent differences between plans but not between 3D plans. 3D plans using 5 noncoplanar portals were selected as a model plan. 4) Parietal (fronto- and occipito-) tumors; all NTCPs of the normal brain in 3D plans were lower than in 2D plans. DVH also showed the same results. V83, V85, V95 showed consistent trends with NTCP and DVH. 3D plans using 5 portals for frontoparietal tumor and 6 portals for occipitoparietal tumor were selected as model plans. Conclusion : NTCP and DVH showed reasonable differences between plans and were through to be useful for comparing plans. All 3D plans were superior to 2D plans. Best 3D plans were selected for tumors in each site of brain using NTCP, DVH and finally by the planner's decision.

• Radiation Oncology Journal
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• v.25 no.1
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• pp.54-61
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• 2007

[ $\underline{Purpose}$ ]: The purpose of this study is to develop a practical method for determining accurate marker positions for prostate cancer radiotherapy using CT images and kV x-ray images obtained from the use of the on- board imager (OBI). $\underline{Materials\;and\;Methods}$: Three gold seed markers were implanted into the reference position inside a prostate gland by a urologist. Multiple digital image processing techniques were used to determine seed marker position and the center-of-mass (COM) technique was employed to determine a representative reference seed marker position. A setup discrepancy can be estimated by comparing a computed $COM_{OBI}$ with the reference $COM_{CT}$. A proposed algorithm was applied to a seed phantom and to four prostate cancer patients with seed implants treated in our clinic. $\underline{Results}$: In the phantom study, the calculated $COM_{CT}$ and $COM_{OBI}$ agreed with $COM_{actual}$ within a millimeter. The algorithm also could localize each seed marker correctly and calculated $COM_{CT}$ and $COM_{OBI}$ for all CT and kV x-ray image sets, respectively. Discrepancies of setup errors between 2D-2D matching results using the OBI application and results using the proposed algorithm were less than one millimeter for each axis. The setup error of each patient was in the range of $0.1{\pm}2.7{\sim}1.8{\pm}6.6\;mm$ in the AP direction, $0.8{\pm}1.6{\sim}2.0{\pm}2.7\;mm$ in the SI direction and $-0.9{\pm}1.5{\sim}2.8{\pm}3.0\;mm$ in the lateral direction, even though the setup error was quite patient dependent. $\underline{Conclusion}$: As it took less than 10 seconds to evaluate a setup discrepancy, it can be helpful to reduce the setup correction time while minimizing subjective factors that may be user dependent. However, the on-line correction process should be integrated into the treatment machine control system for a more reliable procedure.

• Clinical and Experimental Pediatrics
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• v.48 no.1
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• pp.75-80
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• 2005

Purpose : Internal tibial torsion is prevalent in East Asian countries such as Korea and Japan, where sitting on the floor is common behavior. Internal tibial torsion or excessive lateral tibial torsion may cause esthetical, functional, or psychological problems and also may induce degenerative arthritis in older age. The purpose of this study is to measure the tibial torsion in children of the Jeju area. Methods : Tibial torsion was measured in 1,042 lower extremities of 521 children from one to 12 years of age. The values of transmalleolar angles were analyzed for each age group divided by 6 months. Quadratic and linear regression models were used to fit patterns of changes in mean values of transmalleolar angles. The age at seven, which provides the highest coefficient of determination for quadratic regression analysis, was used as a cut-off point to fit different statistical models. Results : The mean transmalleolar angle was $0.10{\pm}5.79^{\circ}$ in all children,$ 0.90{\pm}5.49^{\circ}$ in males, and $-0.80{\pm}5.97^{\circ}$ in females. The value was $4.25{\pm}4.04$ in 1 year of age, gradually decreased to the lowest level of $-1.98^{\circ}$ in four years and seven months of age, increased again with age until it reached $0.67{\pm}1.10^{\circ}$ at seven years of age, and stayed at that level thereafter. Conclusion : Internal tibial torsion in infancy is known to correct spontaneously in the normal developing process. But in this study, the mean transmalleolar angle in children of Jeju area annually decreased after one year of age; to the lowest angle at four years and seven months of age; increased again gradually to the age of seven; and persisted in that level, about $10^{\circ}$ less than western children, not correcting further thereafter. These findings suggest tibial torsion might be caused by lifestyle, especially sitting on feet. To prevent abnormalities of joints and gaits, early diagnosis of tibial torsion in childhood and posture correction or early treatment when needed, seems to be necessary.

• Clinical and Experimental Pediatrics
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• v.51 no.6
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• pp.584-596
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• 2008

Purpose : This study was conducted to investigate treatment compliance and related factors in pediatric patients. Methods : Three hundred and fifty-five patients diagnosed with various acute diseases at a teaching hospital or clinic in October 2003 were enrolled. Data were analyzed using the Health Belief Model, which includes items on self-efficacy and family assistance. Results : The study found that 62.9% of pediatric patients adhered faithfully to agreed-upon hospital revisits, 41.6% complied with dose timings instructions, 65.8% precisely took medication, and 27.2% complied with all of these requirements. According to ${\chi}^2$ test analysis, the factors found to be related to therapeutic compliance (the taking of medicines requested) were; susceptibility, severity, benefit, barriers, mother's self-efficacy, and family assistance (P<.05). Multiple logistic analysis and path analysis showed that susceptibility, severity, barriers, and mother's self-efficacy were related to therapeutic compliance (P<.05). Moreover, mother's self-efficacy was identified as the most important factor. Conclusion : To improve therapeutic compliance among pediatric patients, parental education is necessary, and a health care professional must take a thorough history of how the medication was taken before it is assumed that treatment failure is attributable to the medication prescribed. Furthermore, the type of device recommended for dosing should be determined by clinicians. In addition, it is important that pediatric medications be discussed in relation to their palatability and internal acceptability.

• Journal of radiological science and technology
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• v.31 no.2
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• pp.149-159
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• 2008

The purposes of this study are to analyze abnormal dilatation of the extrahepatic bile ducts by using transabdominal ultrasound, to confirm the existence of bile ducts diseases and their interrelationship, and for it to give a new theoretical basis for the technical access to extrahepatic bile ducts, upon which to analyze the ripple effects of the scan training. After teaching technical access process based on the new theory about extrahepatic bile duct to the thirty students who are studying ultrasonography, we allocated three hours per one student (30 mins ${\times}$ 6 times) to focus on the training of scanning skill. Training has been performed by one-to-one method. For evaluation, all the students have to perform the scans on (1) confluence of the right and left hepatic ducts (extrahepatic bile ducts and cystic duct), (2) the suprapancreatic bile duct, (3) the intrapancreatic bile duct, (4) intrapapilla Duct, based on the clearly divided concept. The existing training and methods have had low confidency about transabdominal ultrasonography of the extrahepatic bile duct and had limitation with which they could image only the suprapancreatic bile duct. The evaluation after finishing the train based on the new theory, however, all the students (30students) can access to (1) confluence of the right and left hepatic ducts(extrahepatic bile ducts and cystic duct), (2) the suprapancreatic bile duct objectively. 24 students can access to (3) the intrapancreatic bile duct and only one student can even make an image for (4) the intrapapilla Duct Though the evaluation on extrahepatic bile duct has to be performed with multi-sided method considering intrahepatic cause, bile duct cause and pathophysiological cause, only if we can image the extrahepatic bile duct to ampular of Vater objectively and confidently, we can greatly reduce invasive procedure such as ERCP, which is for the purpose of simple differential diagnosis and painful to the patients. Therefore if we concentrate on the scanning train based on the new theory to raise the confidency about ultrasonography, the effect will be doubled.