• Title/Summary/Keyword: Angulation angles

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Comparison Study of Dose Rate and Physical Parameters in Low and High Dose Rate Intracavitary Radiation Systems for Carcinoma of the Uterne Cervix. (자궁경부암 강내 방사선조사에 있어서 고 및 저 선량율방법에 의한 선량율 비교 고찰)

  • Yang, Chil-Yong
    • The Journal of Korean Society for Radiation Therapy
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    • v.1 no.1
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    • pp.70-78
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    • 1985
  • The intrauterine irradiation is essential to achieve adequate tumor dose to centeral tumor mass in radio therapy for uterine malignancy. The complications of pelvic organ are known to be directly related to radiation dose and physical parameters. The comparison study of currently using 2 systems was undertaken. The simulation films and medical records of 135 patients who was treated with intrauterine irradiation at one of general hospitals in Busan and Seoul between Jan. 1983 and June 1983, were critically analized and physical parameters of low dose rate system and remote controlled high dose rate system were measured. The physical parameters include distances between lateral walls of vaginal fornices, longitudinal and lateral angles of tandem to the body axis, the distance from the external os of uterine cervix to the central axis of ovoids, the radiation dose ratio to rectum and bladder to reference point A. Followings were summary of study results: 1. In distances between lateral walls of vaginal fornices the low dose rate system showed wide distribution and relatively larger distances. In low dose rate system 5.0-5.9 cm was $55.89\%$ 6.0-6.9 cm: $23.53\%$, 4.0-4.9cm: $10.29\%$, 3.0-3.9cm: $10.29\%$, and in high dose rate system 5.0-5.9cm was $80.59\%$, 4.0-4.9cm: $17.91\%$, $6.0\~6.9\;cm:\;1.5\%$. 2. In lateral angulation of tandem to body axis, the low does system revealed mid position (the position along body axis) $64.7\%$, Lt. deviation $19.13\%$ and Rt. deviation $16.17\%$. However the high dose rate system revealed mid position $49.26\%$ Lt. deviation $40.29\%$ and Rt. deviation $10.45\%$. 3. In longitudinal angulation of tandem to body axis the mid position was $11.77\%$ and anterior angulation $88.23\%$ in low dose rate system but in high dose rate system the mid position was $1.56\%$ and anterior angulation $98.44\%$. 4. Down ward displacement of ovoids below external os was only $2.94\%$ in low dose rate system and $67.69\%$ in high dose rate system. 5. The radiation dose ration to rectum to reference point A was $102.70\%$ in high dose rate system and $70.09\%$ in low dose rate system. The dose ratio to bladder to reference point A was $78.14\%$ in high dose rate system and $75.32\%$ in low dose rate system.

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Dose Distribution of Rectum and Bladder in Intracavitary Irradiation (자궁경부암 강내 방사선 조사장치에 의한 직장 및 방광의 피폭선량 평가)

  • Chu S. S.;Oh W. Y.;Suh C. O.;Kim G. E.
    • Radiation Oncology Journal
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    • v.2 no.2
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    • pp.261-270
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    • 1984
  • The intrauterine irradiation is essential to achieve adequate tumor dose to central tumor mass of uterine malignancy in radiotherapy. The complications of pelvic organ are known to be directly related to radiation dose and physical parameters. The simulation radiation and medical records of 203 patients who were treated with intrauterine irradiation from Feb. 1983 to Oct. 1983, were critically analized. The physical parameters to include distances between lateral walls of vaginal fornices, longitudinal and lateral angles of tandem applicator to the body axis, the distance from the external os of uterine cervix to the central axis of ovoids were measured for low dose rate irradiation system and high dose rate remote control afterloading system. The radiation doses and dose distributions within cervical area including interesting points and bladder, rectum, according to sources arrangement and location of applicator, were estimated with personal computer. Followings were summary of study results ; 1. In distances between lateral walls of vaginal fornices, the low dose rate system showed as $4\~7cm$ width and high dose rate system showed as $5\~6cm$. 2. In horizontal angulation of tandem to body axis, the low dose rate system revealed mid position$64.6\%$, left deviation $19.2\%$and right deviation $16.2\%$. 3. In longitudinal angulation of tandem to body axis, the mid position was $11.8\%$ and anterior angulation $88.2\%$ in low dose rate system but in high dose rate system, anterior angulation was $98.5\%$. 4. Down ward displacement of ovoids below external os was only $3\%$ in low dose rate system and $66.7\%$ in high dose rate system. 5. In radiation source arrangement, the most activities of tandem and ovoid were 35 by 30 in low dose rate system but 50 by 40 in high dose rate system. 6. In low and high dose rate system, the total doses an4 TDF were 50, 70 Gy and 141, 123, including 40 Gy external irradiation. 7. The doses and TDF in interesting points Co, B, were 93, 47 Gy and 230, 73 in high dose rate system but in low doss rate system, 123, 52 Gy and 262, 75 respectively. 8. Doses and TDF in bladder and rectum were 70, 68 Gy and 124, 120 in low dose rate system, but in high dose rate system, 58, 64 Gy 98, 110 respectively, and then grades of injuries in bladder and rectum were 25, $30\%$ and 18, $23\%$ respectively.

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CEPHALOMETRIC EVALUATION ON THE MAXILLOFACIAL TYPE IN KOREAN ADULTS (악안면의 형태에 관한 X선학적 연구)

  • Ahn Hyoung Kyu;You Dong Soo;Park Tae Won
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.3 no.1
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    • pp.29-34
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    • 1973
  • The study was made on the facial profile of the normal Korean adults using the roentgenographic cephalograms. The subjects ccnsisted of 50 males and 50 females with the normal occlusion. The measurements were made of the facial angles in skeletal pattern and depth, height and the length in the soft tissue profile. The mean and standard deviations from the subjects were calculated and compared with the samples of male and female. The authors have drawn the conclusions as follows: 1. Compared with the angulation in skeletal patterns, there were no differences between both sexes. 2. Individual variations of the lower face were larger than the upper face in most measuring points. 3. Generally, facial heights were lesser than facial depth in sexual differences. 4. Most dimensions of the facial depth, height and length of the male were larger than those of female.

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Modified Chevron Osteotomy for the Treatment of Hallux Valgus (Modified chevron 절골술을 이용한 무지외반증의 치험)

  • Lee, Bum-Gu;Park, Hong-Gi;We, Sung
    • Journal of Korean Foot and Ankle Society
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    • v.1 no.2
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    • pp.95-101
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    • 1997
  • Hallux valgus has been characterized by a valgus deformity of the great toe at the metatarsophalangeal joint, along with medial deviation of the first metatarsal, and by three components. First, there is a valgus angle more than $20^{\circ}$ at the first, metatarsophalangeal joint. Second, there is a greater angle than $9^{\circ}$ between the first. and second metatarsals. Third, there is bursal hypertrophy at the medial eminence of the first metatarsals head. The etiology is multifactorial and many procedures have been reported in the treatment of hallux valgus. Most of the procedures are directed towards pain relief, correction of deformity, and preservation of dorsiflexion in the first metatarsophalangeal joint. One such treatment is the Modified chevron osteotomy. It is technically simple, and provides greater stability than a standard osteotomy, and allows early ambulation after surgery. We a reviewed 19 cases with 13 patients of hallux valgus deformity. They were all treated with the Modified chevron osteotomy at the Department of Orthopedic Surgery, Choong ang Gil Hospital, between June 1988 and May 1994. The results of the study were as follows; 1. The mean age was 36 years. Three patients(5 case) were male and ten patients(14 cases) were female. 2. The mean value of the hallux valgus angle was $34.1^{\circ}$, and the first to second intermetatarsal angle was $12.1^{\circ}$, preoperatively. These angles were corrected to $15.8^{\circ}$ and $8.5^{\circ}$, respectively. 3. The metatarsalgia subsided in 17 cases (89.5%). avascular necrosis, non union, and dorsal angulation complicatious were nonexistant. Early bone healing occurred in all cases. 4. The Modified chevron osteotomy is technically simple. It provides excellent pain relief, early ambulation, increased mechanical stability, and many avoids many complications such as AVN, non-union, and dorsal angulation.

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Effects of Osteotomy Angle on Tibial Angulation and Torsion During CORA-Based Leveling Osteotomy in Toy Breed Dogs: A Computer Modeling-Based Study

  • Jeong, Youngeun;Jeong, Jaemin;Cho, Cheongwoon;Jeong, SeongMok;Lee, Hae Beom
    • Journal of Veterinary Clinics
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    • v.37 no.4
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    • pp.175-179
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    • 2020
  • The objective of this study was to determine the effect of osteotomy angle and tibial proximal segment rotation angle on angular and torsional tibial deformities and to assess the trends of these deformities during the rotation of the tibial proximal segment in a center of rotation of angulation (CORA)-based leveling osteotomy (CBLO) by performing computer modeling of the tibia. Four tibias of toy breed dogs with no history of lameness were used in this study. Osteotomies were performed in the proximal tibias at angles of 0°, 10°, 20°, -10°, and -20°, perpendicular to either the proximodistal or craniocaudal tibial axes. The mechanical medial proximal tibial angle (mMPTA) and transcondylar (TC) and distal cranial tibial (CnT) axes were used to measure angular and torsional deformities, respectively. All tibias showed an increase in angular and rotational deformities with an increase in the tibial plateau rotation angle. The tibia with osteotomies performed in the proximodistal and craniocaudal directions showed the highest magnitude of torsional and angular deformities, respectively. The results of this study revealed a tendency of occurrence of angular and torsional deformities with osteotomy performed along the proximodistal and craniocaudal directions in the CBLO.

Effects of the Angulation of Orthodontic Mini-Implant as an Indirect Anchorage : A Three-Dimensional Finite Element Analysis (교정용 미니임플란트의 식립각도에 따른 간접골성 고정원의 효과에 대한 유한요소 해석)

  • Kim, Min-Ji;Park, Yong-Jin;Park, Sun-Hyung;Chun, Youn-Sic
    • Journal of Dental Rehabilitation and Applied Science
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    • v.27 no.3
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    • pp.293-304
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    • 2011
  • The purpose of this study was to investigate the displacement and pattern of stress distribution on periodontal ligaments of maxillary first and second molar, and on orthodontic mini-implant (OMI) surface, according to three different insertion angles to the bone surface of OMI using Dragon helix appliance, which is a newly introduced scissors-bite correcting appliance. OMI were placed between second premolar and first molar with three different insertion angles (45, 60, 90 degrees). Displacement and maximum stress distribution area (MSDA) were analyzed by finite element analysis. When the insertion angle to the alveolar bone surface was 90 degrees, maxillary first and second molar both exhibited MSDA at the palatal root apex. Maxillary first molar did not show any significant displacement, while the second molar exhibited intrusive and palatal displacement. On the OMI, as the insertion angle decreased, the MSDA shifted towards the tip, and the amount of displacement had increased. When the OMI was inserted at a 90 degree angle, anchor loss was minimized and scissors-bite correcting effect was maximized.

A ROENTGENOCEPHALOMETRIC STUDY OF SOFT TISSUE PROFILE FOR THE CHILDREN IN THE DECIDUOUS DENTITION (유치열기(乳齒列期) 아동(兒童)의 악안면연조직(顎顔面軟組織)의 두부방사선(頭部放射線) 계측학적(計測學的) 연구(硏究))

  • Kim, Dong-Phil;Kim, Nam-Hong
    • Journal of the korean academy of Pediatric Dentistry
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    • v.11 no.1
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    • pp.191-213
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    • 1984
  • This study was made on the facial profile of the normal Korean children using the roentgenographic cephalograms. The subjects consisted 51 males and 47 females children of primary dentition with the normal occlusion and acceptable profile. For this study 13 soft tissue profile landmarks were plotted and 14 liner length, 9 soft tissue thickness, 8 vertical height length, 12 angles of soft tissue profile, and 2 vertical proportion were measured. The mean and standard deviations in the subjects were calculated and compared between male and female. The following results were obtained : 1. By the significant test, total facial convexity angle and soft tissue thickness were no significant difference between both sexes. 2. Lower facial height was greater than upper facial height in both sexes. 3. The vertical length of the upper and lower lips were 21.95 mm, 40.74 mm in male and 21.62 mm, 39.63 mm in female. 4. In the relationship of the upper lip and lower lip to the Ricketts' esthetic line, the male was 1.3 mm, 1.18 mm and the female was 1.16 mm, 1.27 mm front of the esthetic line. 5. Compared with the angulation of flush terminal plane group and mesial step group, the mesial step group was greater than the flush terminal plane group except the chin angle.

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A ROENTGENOCEPHALOMETRIC STUDY ON THE RELATIONSHIP BETWEEN HEAD POSTURE AND CRANIOFACIAL MORPHOLOGY (두부자세와 두개안면형태의 상관관계에 대한 두부방사선 계측학적 연구)

  • Han, Sung-Hee;Nahm, Dong-Soek
    • The korean journal of orthodontics
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    • v.18 no.1 s.25
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    • pp.253-265
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    • 1988
  • This study was designed to compare the normal head posture group with the extended head posture group in order to investigate the relatinship between head posture and craniofacial morphology. The subjects were devided into two groups; one included 80 children with normal head posture and occlusion, and the other 60 malocclusion patients with extended head posture. Their lateral cephalograms were traced and analysed based on 38 selected items. The following conclusion were reached. 1. The craniocervical angulations in normal group; OPT to SN, CVT to SN, OPT to FH and CVT to FH angles were $101.7^{\circ},\;104.8^{\circ},\;91.7^{\circ}\;and\;100.7^{\circ}$, respectively. 2. Compared with normal group, experimental group showed increase in mandibular plane angle, decrease in facial plane angle, airway space and posterior facial height but, there were insignificant differences in anterior facial height and tongue level between two groups. 3. Of the craniocervical angulations, OPT to FH angle was most highly correlated to the variables of the craniofacial morphology. 4. The effect of craniocervical angulation on craniofacial morphology in experimental group was different from that in comparison of normal group and experimental group.

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Is All Anterior Oblique Fracture Orientation Really a Contraindication to Anterior Screw Fixation of Type II and Rostral Shallow Type III Odontoid Fractures?

  • Cho, Dae-Chul;Sung, Joo-Kyung
    • Journal of Korean Neurosurgical Society
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    • v.49 no.6
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    • pp.345-350
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    • 2011
  • Objective : It is debatable whether an anterior oblique fracture orientation is really a contraindication to anterior odontoid screw fixation. The purpose of this study was to investigate the feasibility of anterior odontoid screw fixation of type II and rostral shallow type III fracture with an anterior oblique fracture orientation. Methods : The authors evaluated 16 patients with type II and rostral shallow type III odontoid fracture with an anterior oblique fracture orientation. Of these 16 patients, 8 (group 1) were treated by anterior odontoid screw fixation, and 8 (group 2) by a posterior C1-2 arthrodesis. Results : Of the 8 patients in group 1, seven patients achieved solid bone fusion (87.5%), and one experienced screw back-out of the C-2 body two months after anterior screw fixation. All patients treated by posterior C1-C2 fusion in group 2 achieved successful bone fusion. Mean fracture displacements and fracture gaps were not significantly different in two groups. (p=0.075 and 0.782). However, mean fracture orientation angles were $15.3{\pm}3.2$ degrees in group 1, and $28.6{\pm}8.1$ degrees in group 2 (p=0.002), and mean fragment angulations were $3.2{\pm}2.1$ degrees in group 1, and $14.8{\pm}3.7$ degrees in group 2 (p=0.001). Conclusion : Even when the fracture lines of type II and rostral shallow type III fractures are oriented in an anterior oblique direction, anterior odontoid screw fixation can be feasible in carefully selected patients with a relatively small fracture orientation angle and relatively small fragment angulation.

Kinematic Comparative Analysis of Long Turns between Experienced and Inexperienced Ski Instructors

  • Jo, Hyun Dai
    • Korean Journal of Applied Biomechanics
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    • v.30 no.1
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    • pp.17-25
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    • 2020
  • Objective: The purpose of this study is to provide a better understanding of long turn mechanism by describing long turns after kinematic analysis and provide skiers and winter sports instructors with data through which they are able to analyze right postures for turns in skiing in a systematic, rational and scientific manner. Method: For this, a mean difference of kinematic variables (the center of gravity (CG) displacement of distance, trajectory, velocity, angle) was verified against a total of 12 skiers (skilled and unskilled, 6 persons each), regarding motions from the up-start to down-end points for long turns. Results: First, concerning the horizontal displacement of CG during a turn in skiing, skilled skiers were positioned on the right side at the upstart and edge-change points at a long turn. There was no difference in anteroposterior and vertical displacements. Second, in terms of CG-trajectory differences, skilled skiers revealed a significant difference during a long turn. Third, regarding skiing velocity, skilled skiers were fast at the edge-change and maximum inclination points in long turns. Fourth, there was no difference in a hip joint in terms of a lower limb joint angle. In a knee joint, a large angle was found at the up-start point among skilled skiers when they made a long turn. Conclusion: In overall, when skilled and unskilled skiers were compared, to make a good turn, it is required to turn according to the radius of turn by reducing weight, concerning the CG displacement. Regarding the CG-trajectory differences, the edge angle should be adjusted via proper inclination angulation. In addition, a skier should be more leaned toward the inside of a turn when they make a long turn. In terms of skiing velocity, it is needed to reduce friction on snow through the edging and pivoting of the radius or turn according to curvature and controlling ski pressure. Regarding a lower limb joint angle, it is important to make an up move by increasing ankle and knee angles instead of keeping the upper body straight during an up motion.