• Journal of dental hygiene science
• /
• v.7 no.3
• /
• pp.179-185
• /
• 2007

The purpose of this study targeted on high school student in the department of liberal arts, industry in Daegu metropolitan city, is to get basic data necessary for the development of dental educational program, to discern prevention and treatment of temporomandibular joint disorder by observing the situation temporomandibular joint disorder and contribution element, of relationship of school life stress The results are as follows.: 1. The percentage of occurring temporomandibular joint disorder in the high school resulted in a joint noise at 61.8% and joint dislocation 6.9%, sharp pain 47.5% at time of chewing. 29.8% at the time of the non-chewing, lockjaw 11.3%, a headache appeared at 40.4%.2. In the contribution factor of occurring temporomandibular joint disorder, the cause of joint noise was the clench one's teeth, lip and cheek clench, For the pain at the time of chewing clench one's teeth, one side chewing, over-chewing, lip clench, sideways sleeping showed the difference. (P < 0.01) For the pain at the time of non-chewing, clench one's teeth, bruxism, one side chewing, lip and cheek clench were similar, and for the lockjaw, clench one's teeth, bruxism, sideways sleeping showed the difference. The plum evil thing period at time of the fault writing that statistically showed the difference. For the headache, the contribution factors were the all bad habits mentioned above excluding one side sleeping.(P < 0.01, P < 0.05). 3. The rate of experiencing temporomandibular joint disorder by oral and maxillofacia was 13.4% in industrial department, and 19.6% in liberal arts. And for the factor of wound was that exercise 26.8%, others 24.4%, fall-down 19.5%. And for the industrial, exercise 44.4%, fall-down 22.2%, others 14.9%. The treatment experience appeared at 5.0% in industrial department, 2.9% in liberal arts. And for the medical institutions, liberal arts were dental clinic 50%, orthopedics 50%, and the industrial department orthopedics 40%, oriental medicine clinic 30%, dental clinic 30%. 4. In case of temporomandibular joint disorder, there were no difference by grades or educational background. And at the time of chewing or non-chewing showed similar difference.(P < 0.01). 5. Compared to stress in the high school, it generally showed higher in liberal arts than in industrial department due to school record. Its scope was $3.75{\pm}1.14$ in liberal arts, $3.01{\pm}1.23$ in industrial department. 6. The school record, school life, stress problems by teachers, chewing/non-chewing pain of temporomandibular joint disorder, joint noise had a similar correlation.(P < 0.01, < 0.05).

• Journal of dental hygiene science
• /
• v.13 no.3
• /
• pp.271-280
• /
• 2013

This study aims to analyze the effects of tooth-brushing facilities (TBF) at middle schools that installed TBF in 2012 as part of the oral health project in Seongdong-gu, Seoul. The subjects were the first graders at A middle school that installed TBF previously and B middle school that installed TBF in 2012. The results are as follows: DMFT, DMFS and CPI didn't show significant difference by schools (p>0.05), but code (0) was higher and code (2) was lower in female students than male students (p<0.05). As to PHP index, the students at A school with TBF indicated better oral hygiene (p<0.01). In the research on before and after installing TBF, the oral hygiene was improved significantly more after the installation than before (p <0.01). In the comparison on the oral health-related behavior, the percentage of not brushing after lunch was higher B school than A school and the frequency of toothbrushing after lunch was higher A school than B school (p<0.01). About the reasons why not to brush after lunch, there was difference in 'lack of the place' as A school showed 2.6% while B school without TBF indicated 14.2% (p<0.01). About the changes of the oral health-related behavior before and after TBF installation, the percentage of not brushing after lunch increased from 78.7% to 83.8% after the installation. The average frequency of tooth-brushing after lunch for one week also decreased from 0.50 to 0.34 (p>0.05). Among the reasons why not to brush after lunch, 'lack of the place' significantly reduced, but 'because other friends don't do it' increased greatly after the installation (p <0.05). Only with the improvement of oral health knowledge, we cannot expect either clinical or behavioral significance. Not only schools but policies of governmental agencies and financial support, cooperation of community-related groups for program development and evaluation will contribute altogether to helping teenagers to habitualize proper oral health management.

• Korean Journal of Agricultural Science
• /
• v.20 no.1
• /
• pp.68-87
• /
• 1993

Data acquisition system and computer program developed in this study could be well used in engine vibration analysis. The system and program developed were also operated to be able to control measuring interval, number of channels, number of data. The flywheel was specially studied to provide the proper weight with rubber damper for the engine design at low level of vibration. This study was conducted to obtain basic data which affect the engine vibration. The experiment of this study was performed on original weight flywheel, weight-reduced flywheel, weight-reduced and rubber-coated flywheel, weight-reduced and damper-attached flywheel. Avarage of peak value, maximum vibration, power spectrum density based on FFT analysis are major factors of this experiment. Results were obtained as follows : 1. When rubber was inserted in the flywheel rim of which weight was reduced from 32.2kgf to 24.4kgf, maximum vibration of the engine was decreased 48.3% at X axis, 35.5% at Y axis and 34.6% at Z axis in comparison with the flywheel of original weight. 2. When the flywheel of rubber damper was compared with the original flywheel, the average of absolute vibration for rubber damped flywheel was decreased at X, Y, Z axis and especially its decreasing rate was so high at X-axis comparing with the other flywheel, which implied that rubber damper was very useful to reducing the vibration of the engine at X axis. 3. Hysteresis losses of X, Y, Z axis were greatly decreased in the flywheel with rubber damper on rim. 4. Damped oscillation effect on X and Y axis vibration above average peak vibration by the flywheel of rubber damper on rim was larger than those by the other flywheels. 5. Power spectrums of vibration at real and imaginery part were bi-mode type. The vibration frequency of rubber dampered flywheel which weight is decreased was slightly increased as compared with original flywheel.

• The Journal of Korean Society for Radiation Therapy
• /
• v.26 no.1
• /
• pp.59-67
• /
• 2014

Purpose : This study aims to evaluate 3D dosimetric impact for MIP image and each phase image in stereotactic body radiotherapy (SBRT) for lung cancer using volumetric modulated arc therapy (VMAT). Materials and Methods : For each of 5 patients with non-small-cell pulmonary tumors, a respiration-correlated four-dimensional computed tomography (4DCT) study was performed. We obtain ten 3D CT images corresponding to phases of a breathing cycle. Treatment plans were generated using MIP CT image and each phases 3D CT. We performed the dose verification of the TPS with use of the Ion chamber and COMPASS. The dose distribution that were 3D reconstructed using MIP CT image compared with dose distribution on the corresponding phase of the 4D CT data. Results : Gamma evaluation was performed to evaluate the accuracy of dose delivery for MIP CT data and 4D CT data of 5 patients. The average percentage of points passing the gamma criteria of 2 mm/2% about 99%. The average Homogeneity Index difference between MIP and each 3D data of patient dose was 0.03~0.04. The average difference between PTV maximum dose was 3.30 cGy, The average different Spinal Coad dose was 3.30 cGy, The average of difference with $V_{20}$, $V_{10}$, $V_5$ of Lung was -0.04%~2.32%. The average Homogeneity Index difference between MIP and each phase 3d data of all patient was -0.03~0.03. The average PTV maximum dose difference was minimum for 10% phase and maximum for 70% phase. The average Spain cord maximum dose difference was minimum for 0% phase and maximum for 50% phase. The average difference of $V_{20}$, $V_{10}$, $V_5$ of Lung show bo certain trend. Conclusion : There is no tendency of dose difference between MIP with 3D CT data of each phase. But there are appreciable difference for specific phase. It is need to study about patient group which has similar tumor location and breathing motion. Then we compare with dose distribution for each phase 3D image data or MIP image data. we will determine appropriate image data for treatment plan.

• Restorative Dentistry and Endodontics
• /
• v.30 no.2
• /
• pp.79-85
• /
• 2005

The purpose of this study was to evaluate the obturation efficiency of a non-standardized gutta-percha cone in curved root canals prepared with 0.06 taper nickel-titanium instruments. Sixty simulated curved root canals in clear resin blocks were prepared with crown-down technique using 0.06 taper rotary $ProTaper^{TM}$and ProFile (Dentsply-Maillefer) until apical canal was size 30. Root canals were randomly divided into 4 groups of 15 blocks and obturated with cold-laterally compacted gutta-percha technique by using either a non-standardized size medium gutta-percha cone or an ISO-standardized size 30 one as a master cone. Gutta-percha area ratio were calculated at apical levels of 1, 3 and 5 mm using AutoCAD 2000 after cross-sectioning, and the data were analyzed with one-way and two-way ANOVAs and Duncan's multiple range test. Non-standardized size medium cone groups showed significantly higher gutta-percha area ratio than standardized cone groups at all apical levels (p < 0.01). Non-standardized cone groups used significantly less accessory cones than standardized cone groups (p < 0.01).

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.35 no.8
• /
• pp.1016-1024
• /
• 2006

The purpose of this study was to investigate students' and parents' perceptions of nutrition education. In this survey, 7,577 elementary school students and 6,003 of their parents across the country were surveyed about the necessity of implementing nutrition education, its present status and problems and future methods for nutrition education implementation. The results showed that 96.6% of the parents and 62.8% of the students responded that nutrition education was urgently needed, at least once per week in the lower grades of elementary school, and that it should be related to and coordinated with special activities class. In addition, the survey showed that students and their parents wanted nutrition teachers to establish a nutrition counseling room, a practical cooking class, a special activity class, and/or dietary camp during school breaks. With regard to the status of nutrition education at home, there was statistical evidence that suggests significant differences between urban and rural schools. Approximately 63% of the parents indicated that they had difficulty teaching nutrition education in their own homes, because it was difficult to determine the dietary habits and nutritional status of their children. When asked about attending a dietary class for parents, 74% expressed their intent to attend. Parents were most interested in learning about cooking practices, diet therapy, and food information in that order. The results showed that the most effective method of dietary education was to teach appropriate nutritional practices in school and at home simultaneously. Hence, necessary information and education should be provided through special lectures, special cooking classes, and dietary classes for parents. The conclusions of this study suggest that a variety of education programs should be developed to achieve effective nutrition education for students and their parents.

• The korean journal of orthodontics
• /
• v.36 no.6
• /
• pp.412-421
• /
• 2006

Objective: The result of finite element analysis depends on material properties, structural expression, density of element, and boundar or loading conditions. To represent proper elastic behavior, a finite element model was made using Hounsfield unit (HU) values in CT images. Methods: A 13 year 6 month old male was used as the subject. A 3 dimensional visualizing program, Mimics, was used to build a 3D object from the DICOM file which was acquired from the CT images. Model 1 was established by giving 24 material properties according to HU. Model 2 was constructed by the conventional method which provides 2 material properties. Protraction force of 500g was applied at a 45 degree downward angle from Frankfort horizontal (FH) plane. Results: Model 1 showed a more flexible response on the first premolar region which had more forward and downward movement of the maxillary anterior segment. Maxilla was bent on the sagittal plane and frontal plane. Model 2 revealed less movement in all directions. It moved downward on the anterior part and upward on the posterior part, which is clockwise rotation of the maxilla. Conclusion: These results signify that different outcomes of finite element analysis can occur according to the given material properties and it is recommended to use HU values for more accurate results.

• Journal of Radiation Protection and Research
• /
• v.40 no.2
• /
• pp.118-123
• /
• 2015

The frequency of diagnostic radiation examinations in medical institutions has recently increased to 220 million cases in 2011, and the annual exposure dose per capita was 1.4 mSv, 51% and 35% respectively, compared to those in 2007. The number of chest radiography was found to be 27.59% of them, the highest frequency of normal radiography. In this study, we developed a shielding device to minimize radiation exposure by shielding areas of the body which are unnecessary for image interpretation, during the chest radiography. And in order to verify its usefulness, we also measured the difference in entrance surface dose (ESD) and the absorbed dose, before and after using the device, by using an international standard pediatric (10 years) phantom and a glass dosimeter. In addition, we calculated the effective dose by using a Monte Carlo simulation-based program (PCXMC 2.0.1) and evaluated the reduction ratio indirectly by comparing lifetime attributable risk of cancer incidence (LAR). When using the protective device, the ESD decreased by 86.36% on average, nasal cavity $0.55{\mu}Sv$ (74.06%), thyroid $1.43{\mu}Sv$ (95.15%), oesophagus $6.35{\mu}Sv$ (78.42%) respectively, and the depth dose decreased by 72.30% on average, the cervical spine(upper spine) $1.23{\mu}Sv$ (89.73%), salivary gland $0.5{\mu}Sv$ (92.31%), oesophagus $3.85{\mu}Sv$ (59.39%), thyroid $2.02{\mu}Sv$ (73.53%), thoracic vertebrae(middle spine) $5.68{\mu}Sv$ (54.01%) respectively, so that we could verify the usefulness of the shielding mechanism. In addition, the effective dose decreased by 11.76% from $8.33{\mu}Sv$ to $7.35{\mu}Sv$ before and after wearing the device, and in LAR assessment, we found that thyroid cancer decreased to male 0.14 people (95.12%) and female 0.77 people (95.16%) per one million 10-year old children, and general cancers decreased to male 0.14 people (11.70%) and female 0.25 people (11.70%). Although diagnostic radiation examinations are necessary for healthcare such as the treatment of diseases, based on the ALARA concept, we should strive to optimize medical radiation by using this shielding device actively in the areas of the body unnecessary for the diagnosis.

• Sleep Medicine and Psychophysiology
• /
• v.6 no.1
• /
• pp.38-45
• /
• 1999

Objectives: We explored the characteristics of physiological variables such as electrodermal response(EDR) and electromyography(EMG) in patients with insomnia, panic disorder, and other anxiety disorders. we aimed to decide the minimum sessions in biofeedback treatment to make the treatment effective and examine the effects of long-term biofeedback treatment by measuring the physiological variables. Methods: Thirty seven outpatients who received biofeedback treatment were divided into 3 groups according to the number of biofeedback sessions(patients who received 4-5 sessions, who received 6-9 sessions, and who received more than 10 sessions). We measured mean and delta values of EDR and EMG levels, and the Hamilton Anxiety Rating Scale(HARS), and Slef-Relaxation Inventory(SRI) in all patients. Data were analyzed by t-test and repeated measures analysis of variance. Results: The mean and delta values of EDR and EMG levels were not different among the 3 groups during the first 4 biofeedback sessions. However, patients who received more than 10 biofeedback sessions had higher baseline mean EDR value(F=2.233, p=0.036) in the first session, compared with other patients. In patients who received more than 10 biofeedback sessions, mean EDR was significantly reduced after $5^{th}$ session(F=10.41, p<0.01). They showed significant improvement in SRI scores at 12th biofeedback session(t=2.726, p<0.05) and in HARS scores at $6^{th}$(t=3.10, p<0.05) and $12^{th}$ biofeedback session(t=10.93, p<0.001). Conclusions: Wesuggest that patients should receive more than 5 biofeedback sessions to experience internal cues and get a good clinical response to biofeedback treatment.

• Tuberculosis and Respiratory Diseases
• /
• v.47 no.4
• /
• pp.507-516
• /
• 1999

Background : Patients with lung cancer and their relatives often ask the advice of relative or friends who are doctors on the treatment and prognosis of the disease. Therefore a doctor's opinion may play a role in determining the treatment modality and affect therapeutic compliance of patients. The purpose of this study was to find the opinion of general practitioners on lung cancer treatment. Method : A mail survey for general practitioners in Taegu City and Northern Kyungsang Province was performed. Each individual was sent a written questionnaire in which he or she was asked for ten questions about management and prognosis of lung cancer. Results : Two hundred and twenty eight doctors filled in the questionnaire. Of the respondents, 68% had the experience of being asked about lung cancer by their friends or relatives. About 52% replied that it was better to tell the patient of his or her disease. And about 22% considered it better to follow the relatives' opinion. On the question about choosing the treatment modality, following the doctors' plan was most appropriate in 86.9%, showing that most respondents favored actively recommending doctors. Nonsurgical treatment was preferable in patients over 80 years old with resectable lung cancer and with an increase in age, significant increase was observed in respondents recommending nonsurgical treatment. Most respondents said that they would actively recommend or advise following the doctors' plan about radiotherapy and chemotherapy. But a large percent of the respondents had a negative view on the effect of radiotherapy and chemotherapy. Conclusion : The opinions of general practitioners on the treatment and prognosis of lung cancer was variable. And they did not prefer active treatment for patients with old age or advanced lung cancer.