• Title/Summary/Keyword: 절대교정

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Patient Specific Quality Assurance of IMRT: Quantitative Approach Using Film Dosimetry and Optimization (강도변조방사선치료의 환자별 정도관리: 필름 선량계 및 최적화법을 이용한 정량적 접근)

  • Shin Kyung Hwan;Park Sung-Yong;Park Dong Hyun;Shin Dongho;Park Dahl;Kim Tae Hyun;Pyo Hongryull;Kim Joo-Young;Kim Dae Yong;Cho Kwan Ho;Huh Sun Nyung;Kim Il Han;Park Charn Il
    • Radiation Oncology Journal
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    • v.23 no.3
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    • pp.176-185
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    • 2005
  • Purpose: Film dosimetry as a part of patient specific intensity modulated radiation therapy quality assurance (IMRT QA) was peformed to develop a new optimization method of film isocenter offset and to then suggest new quantitative criteria for film dosimetry. Materials and Methods: Film dosimetry was peformed on 14 IMRT patients with head and neck cancers. An optimization method for obtaining the local minimum was developed to adjust for the error in the film isocenter offset, which is the largest part of the systemic errors. Results: The adjust value of the film isocenter offset under optimization was 1 mm in 12 patients, while only two patients showed 2 mm translation. The means of absolute average dose difference before and after optimization were 2.36 and $1.56\%$, respectively, and the mean ratios over a $5\%$ tolerance were 9.67 and $2.88\%$. After optimization, the differences in the dose decreased dramatically. A low dose range cutoff (L-Cutoff) has been suggested for clinical application. New quantitative criteria of a ratio of over a $5\%$, but less than $10\%$ tolerance, and for an absolute average dose difference less than $3\%$ have been suggested for the verification of film dosimetry. Conclusion: The new optimization method was effective in adjusting for the film dosimetry error, and the newly quantitative criteria suggested in this research are believed to be sufficiently accurate and clinically useful.

The Effect of Dental Protrusion on the Width of Attached Gingiva (치아돌출이 부착치은 폭경에 미치는 영향)

  • Hwang, Hyeon-Shik;Kim, Jong-Chul;Kim, Jeong-Moon
    • The korean journal of orthodontics
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    • v.28 no.1 s.66
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    • pp.135-142
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    • 1998
  • The purpose of the present study was to evaluate the effect of incisor protrusion on the mucogingival parameters including the width of attached gingiva. Thirty-seven young adults with lower anterior crowding were selected for this study. From the study model, the degrees of relative and absolute protrusions were measured for each lower incisor. Clinical non height, the width of keratinized gingiva, probing depth and the width of attached gingiva were measured with digital vernier calipers and Florida Probe System. Through comparing the difference of the above measurements between protruded and non-protruded incisors, and correlation analysis between each measurement, following results were obtained: 1. The protruded incisor showed narrow width of keratinized and attached gingiva comparing to non-protruded incisor. 2. The protruded incisor showed greater clinical crown height comparing to non-protruded side while there was no difference in the probing depth between protruded and non-protruded side. 3. The difference in the width of attached gingiva between protruded and non-protruded incisors showed higher significance in the lateral incisor than in the central incisor. 4. The degree of relative protrusion showed higher correlation with the width of attached gingiva than the degree of absolute protrusion. 5. Clinical crown height showed higher correlation with the width of attached gingiva than the degree of protrusion.

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The determinants of vertical overbite and overbite depth indicator(ODI) (수직피개의 결정요인과 수직피개 심도지수(ODI)의 상호관계)

  • Yang, Sang-Duk
    • The korean journal of orthodontics
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    • v.29 no.3 s.74
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    • pp.349-360
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    • 1999
  • The concept of denture frame, both the vertical and horizontal relationship of the dentitions are ultimately related to a skeletal configuration, leads to postulate that the vertical overbite will be determined by the jaw rotations and anteroposterior jaw relationship. Also, ODI is analyzed to be composed of the determinant factors of overbite such as FMA PPA and FABA. From the geometric analyses of an interrelationship between the ODT and the overbite determinants, the following formula can be induced. ODI norm=$85^{\circ} - 0.5 PMA-(1.08 - 0.01 FMA)(FABA - 81^{\circ})$. This formula indicates that the norm of ODI is not constant value but variable one according to the individual skeletal frames. Through the application of the formula to the various clinical cases, it is proved that the new concept, relativity of the ODI norm, is very diagnostically useful.

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Intercomparison of the KAERI Reference Photon and Beta Radiation Measurements (한국원자력연구소 기준 광자 및 베타선장 측정의 국제상호비교)

  • Chang, Si-Yeong;Kim, Bong-Hwan;Kim, Jang-Lyul;McDonald, J.C.;Murphy, M.K.
    • Journal of Radiation Protection and Research
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    • v.21 no.4
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    • pp.255-262
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    • 1996
  • This paper describes the results of intercomparison measurements of KAERI reference photon and beta radiation fields between the KAERI and the PNNL(Pacific Northwest National Laboratory), recently performed at KAERI radiation calibration and dosimetry laboratory on the basis of the ANSI N13.11 criteria for personal dosimeter performance test. Each laboratory used her own radiation detectors or measurement devices traceable to her national primary standard in measuring the exposure rates for photon fields, the absorbed dose rates for beta radiation fields. The agreements in reference radiation measurements between two laboratories were found to be less than ${\pm}2.0%$ for photon fields, ${\pm}1.0%$ for beta radiation fields. Therefore, it could be concluded that KAERI reference radiation fields comply well with the international standard and thus can further serve as a national basis for the researches and developments in radiation protection dosimetry in Korea.

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Nonextraction treatment of Class II division 2 in an adult patient using microimplant anchorage (MIA) (Microimplant Anchorage(MIA)를 이용한 II급 2류 성인 환자의 비발치 치험례)

  • Chae, Jong-Moon
    • The korean journal of orthodontics
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    • v.35 no.6 s.113
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    • pp.485-494
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    • 2005
  • Maxillary anterior teeth were intruded and lingually root torqued with two maxillary anterior microimplants between the lateral incisors and canines. Overerupted maxillary canines were intruded with two other microimplants between the maxillary canines and first premolars. Maxillary posterior teeth and canines were distalized, then the maxillary incisors were retracted with two maxillary posterior microimplants between the first and second molars. The mandibular anterior teeth were intruded and the mandibular posterior teeth were extruded with conventional method such as anterior bite plane, intrusion arch and Class II elastics. The mandible moved slightly forward after the correction of deep bite and retroclination of the upper incisors. Consequently, microimplant anchorage (MIA) provided absolute anchorage for simultaneous correction of Class II canine and molar relationships and deep overbite.

Comparative Evaluation of Cardiac Output using Echocardiography in Beagle Dogs (비글견에서 심초음파를 이용한 심박출량 측정에 관한 비교 연구)

  • Park, Kitae;Yeon, Seongchan;Lee, Heechun
    • Journal of Veterinary Clinics
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    • v.29 no.5
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    • pp.384-390
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    • 2012
  • Echocardiographic measurements of cardiac output, including the modified Simpson's method, Automated Contour Tracking(ACT) method, and left ventricular outflow method are well described methods of evaluating cardiac function due to its reliability and the benefits of its non-invasive technique in human medicine. The purpose of this study was to evaluate the accuracy of an echocardiography estimate of cardiac output in isoflurane-anesthetized beagle dogs and was to compare the ACT method to the other methods used in measurement of cardiac output. In healthy beagle dogs, cardiac output results by echocardiography estimate methods showed an excellent correlations with those by the thermodilution method (The modified Simpson's method : r = 0.815, $r^2=0.665$, y = 0.434x + 0.311 ; ACT method : r = 0.86, $r^2=0.748$, y = 0.391x + 0.242 ; ventricular outflow method : r = 0.691, $r^2=0.478$, y = 0.593x + 0.242). Among the results obtained, the ACT method showed the highest correlation coefficient. In conclusion, our study demonstrated that echocardiography estimate methods did not prove to be suitable in accurately measuring absolute cardiac output values but showed an excellent correlation with thermodilution method. Therefore, by using the measurement of cardiac output as supplemental data, echocardiography estimate methods can be used for detection and correction of hemodynamic disturbances during emergency and anesthesia in veterinary practice.

Improvement of Spatial Radiance Uniformity of Small Integrating Spheres (소형 적분구의 공간 복사 휘도 균일도 향상 연구)

  • Yong Shim Yoo;Dong Joo Shin;Bong Hak Kim
    • Korean Journal of Optics and Photonics
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    • v.34 no.5
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    • pp.202-209
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    • 2023
  • A KRISS-type small integrating sphere with a high spatial radiance uniformity was made using pressed polytetrafluoroethylene (PTFE) and a reflective rod to calibrate the spectral radiance responsivity of absolute radiant thermometers. The spatial radiance uniformity of the KRISS-type small integrating sphere was ±0.009%, five times higher than the best value reported by foreign national metrology institutions thus far. In addition, we improved the spatial radiance uniformity of a commercial sintered PTFE integrating sphere by a factor of 10.

Changes of bite force and occlusal contacts after stabilization splint therapy (교합안정장치 사용후 교합력 및 교합접촉의 변화양상에 관한 연구)

  • Park, Hyung-Soo;Kim, Kwang-Won;Yoon, Young-Jooh
    • The korean journal of orthodontics
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    • v.30 no.1 s.78
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    • pp.91-99
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    • 2000
  • This study was done to identify the changes of bite force and occlusal contact between before and after stabilization splint therapy. 16 female patients, accepted for orthodontic treatment at the Department of Orthodontics, College of Dentistry, Chosun University, were selected as the sample of this investigation. For comparisons, the samples of 16 were divided into just before stabilization splint, 1 month after stabilization splint, 2 months after stabilization splint, and 3 months after stabilization splint and used the T-scan system to identify the bite force and occlusal contact changes for each group. Statistical analysis of the data was carried out ANOVA tests, and Turkey tests using $SPSS/PC^+$. The results were as follows : 1. Bite force change from just before treatment to 1 month after stabilization splint therapy was statistical significantly decreased (P<0.05). 2. Bite force changes from 1 to 3 months after stabilization splint therapy showed no statistical significance (p>0.05). 3. The changes of anterior occlusal contacts showed no statistical significance regardless of the wearing periods of stabilization splint (P>0.05). 4. The changes of posterior occlusal contacts from just before treatment to 1 month after stabilization splint therapy was statistical significantly decreased (P<0.05). 5. The changes of posterior occlusal contacts Outing 1 to 3 months after stabilization splint therapy showed no statistical significance (P>0.05). 6. Posterior teeth rather than anterior teeth were more influenced by the changes of the number of occlusal contacts. To sum up above results, we may respect to capturing and stabilizing centric relation Position just 1 month after stabilization splint therapy.

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SEMI-LONGITUDINAL STUDY OF GROWTH AND DEVELOPMENT OF CRANIO-FACIAL SOFT TISSUE OF CHILDREN AGED FROM 3 TO 11 (3-11세 아동의 두개 및 연조직의 성장변화에 관한 준종단적 연구)

  • Park, Young-chel;Choy, Kwang-chul;Han, Hee-kyung
    • The korean journal of orthodontics
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    • v.27 no.6 s.65
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    • pp.891-904
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    • 1997
  • Today's orthodontic treatment goals lie in functional esthetics, and the importance of the latter is increasing gradually in trend. Considering such, study on growth and development of soft as well as hard tissues becomes inevitable. Early studies emphasize mainly on skeletal analysis using cephalometric data. However, more recent studies report that maxillofacial soft tissue, which plays a critical role in determining facial esthetics, is influenced by underlying hard tissue, and yet close relationship between them was not noticed. Cephalometric x-rays were taken of 137 Korean boys and 106 girls with no systemic disease, fair developmental status and normal occlusion for two consecutive years; afterwards, soft tissue analysis, which was divided into four parts, facial form lip position & posture, nose, and thickness, was done to correlate them with general growth.

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THE RETROSPECTIVE STUDY ON THE PROGNOSIS OF CLASS III MALOCCLUSION TREATMENTS (III급 부정교합의 치료후 예후에 관한 후향적 고찰)

  • Sung, Jae-Hyun;Kwon, Oh-Won;Kim, Sang-Doo
    • The korean journal of orthodontics
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    • v.28 no.2 s.67
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    • pp.175-187
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    • 1998
  • The purpose of this study was to predict the prognosis of class III malocclusion treatments. 25 patients selected for this study were devided into two groups by the stability of dentitional, skeletal and soft tissue profile improvement. One was stable group which consisted of 12 children and the other was relapse group with 13 children. Various measurements in initial lateral cephalogram were calculated and analyzed by t-test, correlation coefficient and discriminant analysis. The results of this study were summarized as follows 1. In both stable and relapse groups, there was not distinct difference in the antero-posterior skeletal relationship (P<0.05). 2. As the result of wits, hn to occlusal plane angle and occlusal plane to mandubular plane angle, the occlusal plane of relapse group was stepper than that of the stable group. 3. In correlation coefficient analysis, the overjet and the occlusal plane to mandibular plane angle showed significant correlations (p<0.001, p<0.01). 4. The discriminant function was obtained from three major influential measurements; overjet, AB to occlusal plane angle and articular angle, and this function could discriminate correctly in 88% of these samples.

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