• The korean journal of orthodontics
• /
• v.35 no.4 s.111
• /
• pp.251-261
• /
• 2005

Enlargement is an inherent property of X-rays which occurs when straight hues diverse from small a focal spot. The purpose of the present study was to evaluate the validity of the correction of gonial angle width enlarged on frontal cephalogram, using frontal and lateral cephalograms taken orthogonally from each other. In 40 adult individuals, frontal and lateral cephalograms were taken at a $90^{\circ}$ angle using the Head Posture Aligner. The angle width was measured on the frontal cephalogram and subsequently. the corrected angle width was calculated using the magnification rate of two cephalograms. Measured and corrected angle widths were compared with the measurement from the 3D CT image. The measurement or the frontal cephalogram showed a 9.10mm of enlargement on average ranging from 7.92 to 11.31mm. Corrected angle width measurement showed a 0.14mm difference with the 3D CT image measurement, which was not statistically significant. The results of the study indicate that actual au91e width can be approached through calculation using frontal and lateral cephalograms taken orthogonally with the help of the Head Posture Aligner The study also showed that the magnitude of correction error did not show a significant correlation with the amount of menton deviation, and it suggests that the present correction method is valid even in individuals with severe facial asymmetry.

• The korean journal of orthodontics
• /
• v.41 no.3
• /
• pp.164-173
• /
• 2011

Objective: The purpose of this study was to perform gender-wise analysis of the related cephalometric factors affecting Korean patients with obstructive sleep apnea (OSA). Methods: We examined 118 adults who had visited the Sleep Disorder Clinic Center in Keimyung university, Daegu, Korea, and evaluated them by using poly-somnography (PSG) and lateral cephalograms. The patients were divided into 4 groups (male simple snorers, male OSA patients, female simple snorers, and female OSA patients) according to AHI (apnea-hypopnea index) and sex. Results: The position of the hyoid bone in the female OSA group was inferior to that in the female simple snorer group. Multiple regression analysis showed that tongue length and soft palate width were significant determinants for the severity of AHI in male OSA patients. However, inferior position of the hyoid was a significant determinant only in women. Conclusions: From a cephalometric point of view, OSA in male and female adult patients may be characterized by different pathogeneses. In particular, in female OSA patients, they might be managed by individualized treatments such as hormone replacement therapy in addition to conventional treatment.

• The korean journal of orthodontics
• /
• v.36 no.3 s.116
• /
• pp.228-236
• /
• 2006

To evaluate the cephalometric and dental characteristics of obstructive sleep apnea (OSA) patients, 23 OSA patients and 15 control, non-OSA, patients who visited the Sleep Disorder Clinic Center, Keimyung University were investigated. Patients who suffered from apnea-hypopnea episodes over 10times per hour were diagnosed as having OSA after polysomnograph testing, Impressions were taken with alginate. Cephalometric radiographs were taken at maximum intercuspation. The dental cast measurements, including transpalatal width, intercanine width, intermolar width and palatal depth did not differ between the control and OAS groups and did not have a positive correlation with the apnea-hypopnea index (AHI). Upper airway width was statistically narrower than the control group. Upper airway width had a low negative correlation with AHI, but, lower airway width had a low positive correlation, and, the higher the AHI score, the longer the mandibular border to hyoid distance.

• The korean journal of orthodontics
• /
• v.31 no.2 s.85
• /
• pp.159-172
• /
• 2001

Three dimensional analysis of malocclusion and craniofacial deformation is essential for the successful orthodontic treatment. But the orthodontists are not familiar with diagnosis and treatment plane based on lateral cephalometric analysis. Since orthodontists do not posses a sufficient knowledge in standard value of posteroanterior cephalometric anaysis and of clinical importance for transverse jaw growth. In this study male(n=130) and female(n=171) aged from 6 to 16 and diagnosed as Class I malocclusion were selected to analysis width of cranium, maxilla and mandible on the posteroanterior cephalogram. The changes as a function of chronologic age and cervical vertebrae maturity index(CVXI) were examined. The Proper regression model was selected by sex with polynominal regression models and method of variable selection. Mean of each measurements and 70% confidence interval of individual measurement according to age was assesed and a graphs were made. Results are as follows :1. All the measurements for the width are gradually incresed as increase in chronologic age and CVMI. From the total amount of change between age 6 and 16, there is a tendency that mandibular width is broader than maxillary width and the width of male is broader than female. 2. There is no statistically significant sexual difference in Mx-Mn difference, Mx-Mn width differential, Mx/Mn ratio according to age and CVMI. 3. Mean of each measurement and 70% confidence interval of individual measurement according to age and sex were assessed and graphs were made for maxillary width, mandibular width, Mx-Mn difference, Mx/Mn ratio. 4. The width of maxilla and mandible in Korean children are broader than Western children during growth period.

• Nuclear industry
• /
• v.4 no.6 s.22
• /
• pp.72-79
• /
• 1984

방사선관리의 엄격화에 따른 관리의 복잡화와 노력의 증가에 의해서 관리의 합리화, 성력화가 요구되고 있다. 이에 대응하여 마이컴을 이용한 장치, 컴퓨터와 접속시켜서 관리할 수 있는 시스템, 신기술인 광전송을 받아들인 시스템 등이 출현하고 있다. 또한 종래에는 저레벨측정을 주로 하여 기술개발이 진행되어 왔으나 TMI사고를 계기로 고레벨측정도 재검토되고 있다. 다음은 주로 일본에서 사고시의 계측을 위해 개발된 모니터, 합리화와 성력화를 목적으로한 모니터, 신기술을 이용한 모니터의 개요이다.

• 대한방사선방어학회:학술대회논문집
• /
• 2010.04a
• /
• pp.168-169
• /
• 2010

• Journal of Radiation Protection and Research
• /
• v.32 no.1
• /
• pp.27-34
• /
• 2007

In this paper, We are evaluated about bio-signal between general workers and nuclear medicine workers which is more radiation exposure relatively. In order to reciprocal evaluated two group, we experimented nuclear medicine workers in Chung-Buk National University Hospital at department of nuclear medicine and worker in Chon-Nam National University Hospital at CT room, general radiographic room, medical recording room, receipt room, general office room. Used of experimental Equipments as follows, for a level of radiation measurement by pocket dosimeter which made by Arrow-Tech company, for heart rate and blood pressure measurement by TONOPORT V which made by GE medical systems company, for heat flux and skin temperature and energy expenditure measurement by Armband senseware 2000 which made by Bodymedia company. Result of experiment obtains as follows: 1) Individual radiation exposure is recorded 3.05 uSv at department of nuclear medicine and order as follows CT room, general radiograpic room, medical recording room, receipt room, general office room. Department of nuclear medicine more 1.5 times than other places. 2) Radiation accumulated dose is not related to Heat flux, Skin temperature, Energy expenditure. 3) Blood pressure is recorded equal to nuclear medical workers, general officer, general people about systolic blood pressure and diastolic blood pressure. Compared to blood pressure between nuclear medical works which is more radiation exposure and other workers was not changed. Consequently, more radiation exposed workers at nuclear medicine field doesn't have hazard.

• The korean journal of orthodontics
• /
• v.27 no.5 s.64
• /
• pp.761-770
• /
• 1997

71 Class I malocclusion samples were selected and they were divided into premolar-extraction and non-extraction groups. Vertical and horizontal cephalometric evaluations on dental and soft tissue measurements were done before and after treatment. Also, treatment results in adolescent patients and adult patients were compared. The following conclusions were obtained: 1. In comparison of extraction and non-extraction groups, all the dental and soft tissue measurements, with exception of SN-MP angle, upper lip to E-line, vertical movement of upper first molar, md horizontal movement of lower first molar, showed statistically significant differences. 2. In comparison of extraction and non-extraction groups of adolescent samples, there were statistically significant differences in upper and lower incisor inclinations, horizontal dental movements from vertical reference line, positional changes in upper and lower lips, and mesial movements of upper first molar. 3. In comparison of extraction and non-extraction groups of adult samples, there were statistically significant differences in upper and lower incisor inclinations, horizontal dental movements from vertical reference line, positional changes in upper and lower lips from I-line and vertical reference line, vertical height of upper first molar, and mesial movement of lower first molar. 4. There was no statistically significant difference in SN-MP angle between extraction and non-extraction groups of both adolescent and adult samples.

• Journal of Radiation Protection and Research
• /
• v.26 no.4
• /
• pp.393-398
• /
• 2001

The non-combustible RI wastes disposed of in hospital every year emit ${\gamma}$-ray or ${\beta}$-ray but their activities are very low to the extent of background. Development of more simple methods is needed because the conventional detection methods are so ineffective and complex. In this study, to solve this problem, detection method using efficiency curve for ${\gamma}$-ray emitting radioactive wastes measurement is proposed and experimental detection efficiency equation is also determined through HPGe's standard specimen measurement. For ${\beta}$-emitting radioisotopes detection, new measurement method using detection efficiency estimated by Monte Carlo simulation and SBD measurements is also proposed. According to the results of this paper, the unknown activity of low-level radioactive wastes without LSC requiring the preparation of standard sample and measurement for standard source detection efficiency could be determined efficiently and simply about ${\pm}17%$ in errors by using the theoretical detection efficiency and the SBD measurement result.

• Journal of Biomedical Engineering Research
• /
• v.18 no.3
• /
• pp.307-313
• /
• 1997

he photoconductive gain mechanism in amorphus silicon devices was investigated in connection with applications to radiation detection. Various device types such as p-i-n, n-i-n and i-i-p-i-n structures were fabricated and tested. Photoconductive gain was measured in two time scales : one for short pulses of visible light(<$1{\mu}sec$) which simulate the transit of energetic charged particles or ${\gamma}$-rays, and the other for rather long pulses of light(1msec) which simulate x-ray exposure in medical imaging, We used two definitions of phtoconductive gain : current gain and charge gain which is an integration of the current gain. We obtained typical charge gains of 3~9 for short pulses and a few hundreds for long pulses at a dark current density level of 10mA/$cm^2$. Various gain results are discussed in terms of the device structure, applied bias and dark current density.