• 제목/요약/키워드: true horizontal plane

검색결과 12건 처리시간 0.024초

두부방사선계측사진(頭部放射線計測寫眞)과 컴퓨터그래프상(像)을 이용(利用)한 성인정상교합자(成人正常咬合者)의 두개안면형태(頭蓋顔面形態)에 관(關)한 연구(硏究) (A CEPHALOMETRIC AND COMPUTERIZED STUDY ON THE CRANIOFACIAL PATTERN IN ADULT WITH NORMAL OCCLUSION)

  • 김광원;이동주
    • 대한치과교정학회지
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    • 제20권1호
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    • pp.87-100
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    • 1990
  • This study was designed to compare the craniofacial structure of orthodontic patients with that of normal adult. For that purpose, 61 male and 64 female adults with normal occlusion were selected and utilizing the cephalogram that had taken under the natural head position and computerized graphic image, the special position of each anatomical structure against true horizontal and vertical reference plane was investigated. The following results were obtained. 1. The absolute special positions of each anatomic structure were calculated. 2. The inclination of Sella-Nasion plane to true horizontal plane was $8.3^{\circ}{\pm}3.9$ in male and $9.3^{\circ}{\pm}3.2^{\circ}$ in female. 3. The inclination of Frankfort horizontal plane to true horizontal plane was $1.3^{\circ}{\pm}3.0^{\circ}$ in male and $1.7^{\circ}{\pm}3.0^{\circ}$ in female. 4. The dimensions of Nasion-sella and Nasion-Anterior nasal spine to be used as the basic units of mesh diagram were $70.7mm{\pm}3.1mm$, $61.8mm{\pm}2.7mm$ in male and $67.8mm{\pm}3.3mm$, $57.0mm{\pm}2.6mm$ in female respectively. 5. The standard templates of craniofacial structure of male and female adult normal group were constructed. 6. The mesh diagrams of craniofacial structure of male and female adult normal group were constructed.

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상악 전치부 견인 시 치아이동에 따른 전방 치조골개조량의 변화에 관한 연구 (THE LIMITATION OF ALVEOLAR BONE REMODELING DURING RETRACTION OF THE UPPER ANTERIOR TEETH)

  • 황충주;문정련
    • 대한치과교정학회지
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    • 제31권1호
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    • pp.97-105
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    • 2001
  • 교정 치료 시 많은 경우 상악 전치부를 상당량 견인하게 되며 이 때 치아의 이동량과 전방 피질골의 개조량이 동일하게 일어나지 않는다면 치주적인 문제가 발생할 수 있게 된다. 이에 본 연구에서는 상악 전치가 후방 견인될 때 치아의 이동량과 피질골의 개조량의 관계를 알아보기 위하여 성장이 완료된 만 18세 이상의 성인 여자환자 56명을 대상으로 치료 전후의 측모두부 방사선 사진을 계측하였다. 연구대상 56명은 전치의 후방견인 시 경사이동이 주로 일어난 환자(26명 )와 치체 이동이 동반된 환자(30명)로 나누었으며 치료 전후의 측모두부방사선 사진을 true horizontal plane 을 기준으로 하여 중첩하였다. Tip-Group(경사이동된 군)에서는 수평적인 bone remodeling/tooth movement ratio가 1:1.63, Torque-Group(치체 이동이 동반된 군)에서는 1:1.66이었다. 두 군 모두에서 치아의 이동량과 골의 개조량이 동일하지 않았기 때문에 경사 이동 시에는 치근첨이 구개측피질골판에서 멀어지고 순측피질골판에 가까워지며, 치체이동이 동반된 군에서는 치근이 순측피질골판에서는 멀어지고 구개측피질골판에 접근하게 된다. 따라서 상악의 전방 피질골의 두께가 매우 얇은 환자에서는 상악 전치의 후방견인량에 제한이 있게 되며 골격적 부조화가 심한 경우에는 악교정수술을 동반한 치료를 고려하고, 교정적 절충치료가 필요한 경우 술자는 그 치료한계를 명확히 인식해야할 것이다.

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백터계산을 이용한 단층의 이동량 산출법 (A Simple Vector Calculation Method for the True Failt Displacement Distance)

  • 황상기
    • 자원환경지질
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    • 제32권4호
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    • pp.365-371
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    • 1999
  • Ture diplacement of a fault monement is calculated from the displacement of the index plane such as bedding on an outcrop surface. The input parameters are the orientations of the index, fault, and outcrop planes. It is also necessary to input the orientation of fault striation and the offset distance of the index plane on the outcrop surface. The distances of the total, strike, horizontal and dip slip components of the fault movement are calculated from the input parameters. Hwang(1998) conducted a simlar calculation using trigonoment method. To apply the previous method, the offset distance of the index plane must be measured on a vertical outcrop surface. The calculation method of this study accepts the offset distence of index plane on an outcrop plane of any orientation. Calculation results from both method are indentical, regardless of the simplicity of the new method.

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전산화단층사진을 이용한 하악지구조분석 (A COMPUTERIZED TOMOGRAPHIC STUDY ON THE STRUCTURE OF THE MANDIBULAR RAMUS)

  • 김평수;안융;진우정;고광준
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제21권4호
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    • pp.345-352
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    • 1999
  • This study was conducted for the purpose of suggestion of the new technique of sagittal split ramus osteotomy pararell to the true sagittal plane. This pararellism is the important concept of the sagittal split ramus osteotomy to reduce the condylar sagging including mandibular hypomobility, temporomandibular disorder, occlusal relapse and other complications. We used 26 adult dry manibles(52 rami), and obtained the computed tomographs through the sagittal, horizontal and coronal sections. The results were obtained as follows. 1. On sagittal section, mean area of S1 was $8.63{\pm}2.10cm^2$, S2 was $8.93{\pm}1.94cm^2$, S3 was $9.49{\pm}2.15cm^2$, S6 was $10.72{\pm}2.22cm^2$. The wider area of sagittal section, the more lateral section, But, no significant differency between the areas of the sagittal sections(P>0.05). 2. On horizontal section, The distance between the inferior alveolar canal and the lateral cortical plate of the mandibular ramus were $6.73{\pm}1.24mm$ minum, $7.70{\pm}1.44mm$ maximum. 3. On coronal section, Outer mandibular angle were $4.84{\pm}2.37^{\circ}$ right side, $4.93{\pm}2.12^{\circ}$ left side. 4. The design of the ideal true sagittal split ramus osteotomy is that posterior border of osteotomy must be limited vertically, at the right posterior point of lingula mandibularis and anterior of osteotomy must be extended to mandibular body, anteroinferiorly.

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황금 분할 마스크를 이용한 대학생 안면의 수평적 분석 (Horizontal Ratio of the Korean University Student's Face and Facial Golden Mask)

  • 이준호;박건욱;김용하
    • Archives of Plastic Surgery
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    • 제35권5호
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    • pp.514-520
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    • 2008
  • Purpose: Many attempts have been made to describe ideal facial proportions for over two thousands year and constantly lasted till now. Dr. Marquardt has derived supposedly ideal facial proportions from the facial golden mask using golden ratio of 1 : 1.618. On the other hand, facial reducing surgeries such as mandible angle reduction are popularized in Asia because the width of mid and lower face of Korean is recognized to be wider. The purpose is to analyze characters of Korean university students' faces in horizontal plane and establish the objective data for facial width distributions and clinical applications. Methods: We applied the facial golden mask to the photographs in 1000 cases, compared the width of mid and lower face between the facial golden mask and Korean university students' faces. And we first calculated the horizontal ratio(HR) of middle and lower face each for using comparative scale of width, facial golden mask. We divided 1,000 cases into 3 groups by degrees of HR and analyzed data of HR on each groups. Using calculated horizontal ratio, we newly invented the cumulative frequency of distribution graphs in Korean university students' faces. Results: Mean data of HR were over 1.0 in all groups, which means that Korean university students' faces are typically wider than facial golden mask in horizontal planes. And this study was statistically significant(p- value < 0.05). Clinically using the cumulative frequency distributions of Korean university students' face width, we can easily explain changes of facial width to patient after facial reducing surgery and describe the changes into objective data. Conclusion: This study concludes thatKorean university students' faces are wider than facial golden mask is significantly true and the cumulative frequency of distribution graphs are expected to be widely used for comparison of results in facial reducing surgery.

Comparison of three midsagittal planes for three-dimensional cone beam computed tomography head reorientation

  • Lee, Eon-Hwa;Yu, Hyung-Seog;Lee, Kee-Joon;Han, Sang-Sun;Jung, Hwi-Dong;Hwang, Chung-Ju
    • 대한치과교정학회지
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    • 제50권1호
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    • pp.3-12
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    • 2020
  • Objective: This study compared three prominent midsagittal planes (MSPs) to identify the MSP that best approximates the true symmetrical MSP. Methods: Forty-three patients (mean age, 23.0 ± 8.20 years) were grouped as follows: group 1 consisted of 10 patients with skeletal Class I and a menton (Me) deviation of < 2 mm; group 2, 11 patients with skeletal Class III and a Me deviation < 2 mm; group 3, nine patients with skeletal Class III and a Me deviation of 2 to less than 4 mm; and group 4, 13 patients with skeletal Class III and an Me deviation ≥ 4 mm. The candidate MSPs were established by three-dimensional (3D) cone beam computed tomography (CBCT) reorientation methods (RMs): (1) the MSP perpendicular to the Frankfort horizontal (FH) plane while passing through the crista galli and basion; (2) the MSP including the nasion, incisive foramen, and basion; (3) the MSP including the nasion, anterior nasal spine, and posterior nasal spine. The mean absolute distances (MADs) to the MSPs were calculated from the coordinates of 1,548 points on 129 CBCT images. The differences in the values of the 3D coordinates among RMs were compared. Results: The MADs of the three RMs showed significant differences (p < 0.05). Most of the differences in values of the coordinates were not significant among RMs. Conclusions: Although the differences in distance among the three MSPs were minor, the MSP perpendicular to the FH plane while passing through the crista galli and basion best approximated the true symmetrical MSP.

Does the maxillary anterior ratio in Korean adults follow the Golden Proportion?

  • Jin, Ming-Xu;Hong, Min-Ho;Lee, Kee-Joon;Lee, Kyu-Bok
    • The Journal of Advanced Prosthodontics
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    • 제8권2호
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    • pp.125-130
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    • 2016
  • PURPOSE. The purpose of this study was to determine the effect of changes in the horizontal plane angle on the mesiodistal width ratios of the maxillary anterior teeth during the acquisition of frontal view photographs, derive these ratios for Korean adults on the basis of the data obtained, and analyze them using the Golden Proportion as a reference. MATERIALS AND METHODS. In experiment I, 30 plaster casts were mounted on an articulator and positioned on the angle-measuring device with a center setting of $0^{\circ}$. The device was rotated to $10^{\circ}$ in $1^{\circ}$ increments in a counterclockwise direction. At each angle, photographs were obtained and analyzed. Experiment II was based on 60 patients who visited the Department of Prosthodontics at Kyungpook National University Dental Hospital from February 2012 to February 2015. The patients were divided into three groups [Male (M), Female (F), Total (M + F)]. Frontal views were obtained for all groups and analyzed. RESULTS. From $1^{\circ}$ to $10^{\circ}$, the relative mesiodistal width ratios for the maxillary anterior teeth showed no significant differences from those at $0^{\circ}$. In all three groups, the relative width ratio of the maxillary central incisor was smaller than that specified in the Golden Proportion; the opposite was true for the canine. CONCLUSION. Our results suggest that the mesiodistal width ratios of the maxillary anterior teeth do not follow the Golden Proportion in Korean adults, and that a change in the horizontal plane angle from $1^{\circ}$ to $10^{\circ}$ during frontal photography does not affect these ratios.

자연 두부 위치 및 안정위에서 한국 성인 환자 골격의 전.후 관계 결정 (Assessment of antero-posterior skeletal relationships in adult Korean patients in the natural head position and centric relation)

  • 안장훈;배광학;박영주;홍윤기;남정훈;김미자
    • 대한치과교정학회지
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    • 제40권6호
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    • pp.421-431
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    • 2010
  • SN 기준선과 FH 기준선이 안모의 심미에 종종 맞지 않아서 모든 치열 교정 및 악교정 수술 증례를 이 기준선을 이용하여 반복적으로 정확히 진단하기가 매우 어렵다. 따라서, 이 연구의 목적은 한국 성인 환자를 대상으로 안정위에서 자연 두부 위치의 개인내 재현성을 확인하고 진성 수평선에 대해 SN 기준선과 FH 기준선의 개인간 다양성을 증명하는 것이다. 그러고, 상기 두 연구를 바탕으로 Na 기준 진수선에서 A점 및 B점까지의 거리가 SNA 및 SNB 각도와 상관 관계가 있는지 여부를 조사하는 것이다. 부정교합 및 악골의 부조화를 치료받기 위해 강남성심병원과 한강성심병원 교정과에 내원한 116 명의 환자(남자 23명, 여자 93명)를 조사하였다. 중심위 왁스 바이트는 모든 대상들로부터 채득하였고 1주일 간격으로 자연 두부 위치와 중심위 상태에서 모든 대상자들의 측모두부방사선사진을 2번 촬영하였다. 3개의 변수에서 위치 선정의 방법 오류는 다른 연구에 비해 낮은 수치를 보였다. 그리고 6개의 변수에서 군내 상관계수를 이용하여 자연두부 위치의 개인간 재현성을 증명하였다 (p < 0.001). 각 환자에서 진성 수평선에 대한 FH 기준선간의 각도는 통계적으로 기준치 0도와 다르지 않았다 (p > 0.05). 하지만 임상적으로 다양한 수치를 보였다 (SD: $3.89^{\circ}$). 반면 각 에서 진성 수평선에 대한 SN 기준선간의 각도는 기준치 7도와 매우 다르게 나타났다 (p < 0.05). Na 기준 진수선에서 A점 및 B점까지의 거리와 SNA 및 SNB 각도와의 피어슨 상관 계수에서 유의하지만 매우 낮은 수치를 보였다 (p < 0.01). 이에 자연 두부 위치는 치열 교정 환자 및 악교정 수술 환자의 진단을 위해 재현적이고 믿을 만한 위치이며 자연두부 위치 및 중심위 상태에서 Na 기준 진수선은 SN과 FH기준선을 대신하여 한국인 성인 환자에서 상악쿨과 하악골의 전후 관계를 결정하는데 매우 유용한 기준선으로 이용될 수 있을 것으로 생각한다.

IRF-k kriging of electrical resistivity data for estimating the extent of saltwater intrusion in a coastal aquifer system

  • Shim B. O.;Chung S. Y.;Kim H. J.;Sung I. H.
    • 한국지구물리탐사학회:학술대회논문집
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    • 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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    • pp.352-361
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    • 2003
  • We have evaluated the extent of saltwater intrusion from electrical resistivity distribution in a coastal aquifer system in the southeastern part of Busan, Korea. This aquifer system is divided into four layers according to the hydrogeologic characteristics and the horizontal extent of intruded saltwater is determined at each layer through the geostatistical interpretation of electrical resistivity data. In order to define the statistical structure of electrical resistivity data, variogram analysis is carried out to obtain best generalized covariance models. IRF-k (intrinsic random function of order k) kriging is performed with covariance models to produce the plane of spatial mean resistivities. The kriged estimates are evaluated by cross validation to show a good agreement with the true values and the statistics of cross validation represented low errors for the estimates. In the resistivity contour maps more than 5 m below the surface, we can see a dominant direction of saltwater intrusion beginning from the east side. The area of saltwater intrusion increases with depth. The northeast side has low resistivities less than 5 ohm-m due to the presence of saline water in the depth range of 20 m through 70 m. These results show that the application of geostatistical technique to electrical resistivity data is useful for assessing saltwater intrusion in a coastal aquifer system.

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슬관절의 측면 방사선 촬영에서 보조기구를 이용한 검사방법의 정확성과 편의성에 대한 연구 (A Study on the Accuracy and Convenience of Imaging Method Using Support Device in Knee Joint Lateral Radiography)

  • 엄소영;조용근;강성진
    • 한국방사선학회논문지
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    • 제11권4호
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    • pp.253-262
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    • 2017
  • 슬관절의 측면 촬영 검사방법에서 기존에 권고되고 있는 정 측면 자세에서 중심 X선의 입사 각도를 머리 쪽 $5{\sim}7^{\circ}$로 조정하는 방법을 검사방법 A, 중심 X선이 슬관절 강을 향해 검사대의 수평면과 수직으로 입사하는 방법을 검사방법 B, 경골 원위부(distal tibia)의 바깥 면(lateral side)을 방사선 투과성 물질(radiolucent materials)로 보상한(compensated) 상태에서 중심 X선을 관절 강에 수직 입사하는 방법을 검사방법 C로 분류하였다. 연구 대상자들을 분류하여 3가지 검사방법을 각각 시행한 후, 검사영상에서 관절 강 거리(joint space distance)와 양측과의 거리(both condyle distance)를 정량적 지표로 설정하여 이를 측정하고 비교하였다. 또한 각 검사방법의 편의성을 검사자(Practician)들을 대상으로 설문조사를 통해 확인하였다. 정량적 지표의 측정 결과 검사방법 A와 C는 통계적 분석 결과 특징적인 차이가 없었지만(p>0.05), 검사 방법 B는 A와 C 모두에서 차이를 보였다(p<0.05). 검사방법의 편의성을 평가한 결과, 검사방법 A가 모든 항목에서 검사방법 B, C 보다 상대적으로 점수가 낮게 평가되었고, 검사방법 B와 C는 근소한 차이로 B가 높은 평가를 받았다. 본 연구를 통해 제안한 간단한 보조기구(support device)를 이용한 슬관절 측면 촬영 검사방법은 다소 복잡한 준비과정 없이도 기존의 권고 방법과 큰 차이가 없는 관절 강의 묘사가 가능하고, 검사의 진행과정에서 검사자의 편의성을 증가시킬 수 있었다.