• 제목/요약/키워드: Root Length

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여성 하악 제2대구치 치근발육에 관한 방사선학적 연구 (A Radiographic Study on the Development of Roots of Mandibular Second Molars in Female)

  • Joong-Ho Choi;Myung-Yun Go
    • Journal of Oral Medicine and Pain
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    • 제17권2호
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    • pp.119-128
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    • 1992
  • In order to evaluate the relationship of age with the developmental stage on mandibular second molars in female, the author examined the radiographs in standard films taken by intraoral paralleling technic and analysed the development of 620 roots of 310 females ranged from 10 to 18 years. The development was divided into 7 stages : Crown complete (Cr.C.), Root lengthed 1/4(R.1/4), Root length 1/2 (R.1/2), Rooth length 3/4 (R.3/4), Rooth length complete (R.C), Apex 1.2 closed (A. 1/2), Apical closure complete (A.C) The obtained results were as follows : 1. The formation of roots in fulllength of mandibular second molars was completed at 14.21-year-age in mesial root and at 14.96-year-age in distal root. 2. The formation of apical foramen of mandibular second molars was completed at 17.11-year-age in mesial root and at 17.53-year-age in distal root. 3. The mesial root of mandibular second molar was generally developed earlier than distal root (p<0.01) 4. Coefficients of correlation and regression equations between for age(Y) and the developmental stage of mandibular second molar(X) were "Y=1.53X+6.54, r=0.91 (p<0.01)" in mesial root and "Y=1.52X+7.11, r=0.92(p<0.01)" in distal root respectively.l root respectively.

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치아장경 측정을 위한 방사선학적 방법 (A RADIOGRAPHIC METHOD FOR DETERMINING THE ACTUAL TOOTH LENGTH)

  • 나경수;조봉혜
    • 치과방사선
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    • 제25권2호
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    • pp.281-286
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    • 1995
  • Tooth length determination is a crucial step in endodontic treatment. Traditionally, radiographs are used to confirm working length of the root length. This study was performed to evaluate the radiographic distortion(magnification) and calculate correction coefficients for the object-film distance. Ninty-six radiographs were made of eight extracted teeth(two upper first premolars, two lower first premolars, two upper first molars, and two lower first molars) by using the 16 inch long cone paralelling techniques with 1mm interval from 5 to 16mm tooth-film distance. The results were as follows. 1. The least mean radiographic distortion from 5 to 16mm tooth-film distance was 2.42±0.68%(the length of mesiobuccal cusp-mesial root of lower first molars), the greatest distortion was 4.74±1.36%(the length of mesiobuccal cusp-mesiobuccal root of upper first molars). 2. The greatest correction coefficient was 0.986(the mesiobuccal cusp-mesial root of lower first molars, the lowest one was 0.937(the mesiobuccal cusp-mesiobuccal root of upper first molars).

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인삼의 각종 주요형질간의 상관관계 (Correlations among Agronomic Characters of Ginseng Plants)

  • 최광태;안상득;신희석
    • 한국작물학회지
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    • 제25권3호
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    • pp.63-67
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    • 1980
  • 인삼의 재래종에 대해서 유용형질과 관계가 있는 가시 Marker gene을 탐색하고, 선발을 용역하게 할수 있는 육종의 기초자료를 얻고저 년생별 각종 농경형질간의 상관관계를 조사하였던 바 그 결과를 요약하면 다음과 같다. 1. 형질상호간의 상관관계는 년생에 따라 다소 차이가 있었으나 경직경, 엽중, 경중은 각년생 공히 거의 모든 형질과 고도의 유의성이 있는 정(+) 상관을 보였다. 2. 각년생차에 관계없이 수량형질인 근중과 상관이 높았던 지상부형질은 경직경, 엽중, 엽폭, 장엽수, 소엽수, 엽중, 경중이었으며, 이들은 모두 정(+)상관을 보였다. 3. 따라서 경직경이 굵고, 엽면적이 넓고, 엽수가 많은 것이 다수성일 것으로 사료됨으로 경직경과 엽면적 및 엽수를 표식형질로 활용, 선발하는 것이 효과적일 것으로 생각된다.

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전자근관장 측정기의 정확도에 관한 연구 (IN VIVO EVALUATION OF ACCURACY OF TWO ELECTRONIC APEX LOCATORS)

  • 김회정;홍찬의
    • Restorative Dentistry and Endodontics
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    • 제21권1호
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    • pp.289-299
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    • 1996
  • It is necessary to measure the length of a root canal in order to attain a satisfactory prognosis after root canal therapy. There are several methods for determining root canal length, such as tactile sensation by the dental practitioner, the utilization of x-ray film, and electronic root canal measurement. Among these, the electrical measurement methods, in which the impedence between the oral mucous membrane and periodontal membrane is determined, have advantages of simplicity and accuracy. During root canal treatment, the root canal contains a solution of high electrical conductivity such as pus, blood, sodium hypochlorite and so on. Recently a new electronic root canal measurement device of frequency-dependent type has been developed, which is capable of measuring the length of root canal under moist conditions. Endex and Root ZX, which are frequency-dependent type, were evaluated for accuracy of measuring root canal length in vivo by stereomicroscope. The result were as follows ; 1. 82.5% of Endex and 87.5% of Root ZX measured in the range of ${\pm}0.5$ mm from the apical foramen and both showed 57.5 % in the range of 0.1 mm to 0.5 mm. 2. Endex showed significantly higher accuracy in vital teeth than nonvital teeth(p<0.05). But in case of Root ZX, there was no significant difference between vital and nonvital teeth. 3. As a result of this study, there was no significant difference in accuracy between Endex and Root ZX, and both devices showed file passes the apical foramen in more than half of the cases, and it is thought that this must be considered clinically.

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대두의 근계에 관한 연구 제 1 보 지상부와 근계와의 관계 (Studies on the Root System of Soybeans I. Relations between the top and the root)

  • 장권열
    • 한국작물학회지
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    • 제13권
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    • pp.77-81
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    • 1973
  • 대두의 근계에 관한 연구의 제1보로 3개품종을 상토와 모래의 2개토양에서 각시기별로 재료를 채취하여 몇 개형질에 대한 조사측정을 하고 통계처리를 한 바 그 결과를 요약하면 다음과 같다. 1. 경직경의 비대는 발육초기 1개월까지는 완만하며 8월하순이후부터 급격하여지고 모래보다 상토에서 그 비대정도가 높았다. 2. Top의 길이의 신장도 발육 1개월이후부터 급격하여지고 모래보다 상토에서 더욱 신장이 잘된다. 3. Top길이보다 Root길이가 발육초기 1개월까지는 길고 Root의 길이는 반대로 상토보다 모래에서 신장이 잘된다. 4. Top무게도 발육초기 1개월까지는 완만히 증가하고 모래보다 상토에서 무겁게 나타나나 Top길이보다 Top무게의 경우에 그 증가의 정도가 완만하다. 5. Top무게보다 Root무게는 발육초기 1개월까지는 무거우며 상토에서 모래보다 무겁게 나타난다. 6. 5개형질 상호간에는 모래, 상토, 전체에 있어서 어느것이나 높은 상관관계를 보이고 Root길이와의 관계를 보면 Top무게, Top길이, Root무게, 경직경의 순서로 높은 상관계수를 나타내었다. 7. Root무게와의 관계를 보면 경직경, Top무게, Top길이, Root길이의 순서로 상관계수가 높았다.

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정화 처리토가 렌틸(콩과식물)의 지상부 및 뿌리 성장에 주는 영향에 대한 정량평가 (Quantifying Inhibitory Effects of Reclaimed Soils on the Shoot and Root Growth of Legume plant Lentil(Lens culinaris))

  • 박혜선;강수아;배범한
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제26권5호
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    • pp.1-8
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    • 2021
  • A series of pot experiments were conducted to quantitatively estimate inhibitory effects of reclaimed soil on the growth of Lentil (Lens culinaris) with two soils remediated by land farming (DDC) and low temperature thermal desorption(YJ), respectively. After cultivation in a growth chamber for 8 days, plants were harvested for the analysis of 8 indices including chlorophyll-a and carotenoid in leaves, shoot fresh weight, root dry weight, root length, number of later roots, specific root length (SRL) as well as germination rate in comparison to control experiment conducted on nursery soil. Root length was estimated by SmartRoot program from the digital images of the roots. The results showed germination rate on YJ and DDC soil decreased 29 and 71%, respectively. In comparison to the control, the averaged value of the 8 indices for YJ and DDC soil showed overall growth inhibition was 48 and 68%, respectively. When the same experiment was conducted with 25% (W/W) vermiculate amended soil, plant growth on each soil was comparable to that of the control. The results implies reclaimed soils requires additional processes and/or amendments to reuse for plant growth.

식물종자의 액상오존처리에 의한 종자 발아 및 초기 성장 증진 (Enhanced Germination & Initial Seedling Development by Liquid Phase Ozonation of Plant Seeds)

  • 양희경;정윤아;최원철;배범한
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제24권5호
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    • pp.1-10
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    • 2019
  • The effects of liquid phase ozonation on seed dormant alleviation and subsequent seedling growth were studied using two plant seeds of Indian jointvetch (Aeschynomene indica L.) and Indian mallow (Abutilon avicennae Gaertn.). At a constant ozone concentration ($80g/m^3$), contact time varied from 10 to 60 min with 10 min interval. Germination rate, root length, and specific root length were compared after 3-day incubation on gel-medium. The germination rate increased significantly (p<0.05) in the 50 min treatment of Indian mallow by 30% compared to the control. Enhanced root elongation was observed in the seeds of 30 min treatment of Indian jointvetch and 30~50 min treatment of Indian mallow. Specific root length, an indicator of environmental change, did not show significant changes, suggesting the level of ozone treatment has no adverse effect on seedling development. The results indicate that liquid phase seed ozonation can be an effective on-site germination alleviation method in the application of phytoremediation.

Does apical root resection in endodontic microsurgery jeopardize the prosthodontic prognosis?

  • Cho, Sin-Yeon;Kim, Euiseong
    • Restorative Dentistry and Endodontics
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    • 제38권2호
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    • pp.59-64
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    • 2013
  • Apical surgery cuts off the apical root and the crown-to-root ratio becomes unfavorable. Crown-to-root ratio has been applied to periodontally compromised teeth. Apical root resection is a different matter from periodontal bone loss. The purpose of this paper is to review the validity of crown-to-root ratio in the apically resected teeth. Most roots have conical shape and the root surface area of coronal part is wider than apical part of the same length. Therefore loss of alveolar bone support from apical resection is much less than its linear length.The maximum stress from mastication concentrates on the cervical area and the minimum stress was found on the apical 1/3 area. Therefore apical root resection is not so harmful as periodontal bone loss. Osteotomy for apical resection reduces longitudinal width of the buccal bone and increases the risk of endo-perio communication which leads to failure. Endodontic microsurgery is able to realize 0 degree or shallow bevel and precise length of root resection, and minimize the longitudinal width of osteotomy. The crown-to-root ratio is not valid in evaluating the prosthodontic prognosis of the apically resected teeth. Accurate execution of endodontic microsurgery to preserve the buccal bone is essential to avoid endo-perio communication.

Effect of Seed Leachates of 'Vernal' Alfalfa on Inhibition of Alfalfa Germination and Root Growth

  • Chon, Sang-Uk
    • 한국작물학회지
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    • 제45권2호
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    • pp.134-138
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    • 2000
  • Most parts of alfalfa plant have been reported to contain autotoxic substances that inhibit seed germination and early seedling growth, however, the chemical(s) is not still studied much. Effect of seed leachates of 'Vernal' alfalfa (Medicago sativa L.) was evaluated for inhibition of alfalfa germination and root growth through bioassay. Alfalfa seeds were extracted in 1 L deionized water for 1 h after soaking and the leachates caused to reduce root length of alfalfa significantly as the soaking time increased. Crude seeds at 4 g L$L^{-1}$ exudated autotoxins that reduce significantly root length by 34 % compared to the control, when the seeds soaked in deionized water for 24 h. However, the extracts did not affect final germination as well as speed of germination. Extracts from ground seeds significantly reduced speed of germination (GT 50) and root length. The results indicate that release of autotoxic substances from seeds during seed imbibition was increased with increase of soaking time and seed amount, and that autotoxicity was more occurred in ground seeds than in crude seeds.

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근관장 측정에 있어서 디지털 영상 처리기와 주파수 의존형 측정기의 정확도 (The Accuracy of the Digital Imaging System and the Frequency Dependent Type Apex Locator in Root Canal Length Measurement)

  • 이병립;박창서
    • 치과방사선
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    • 제28권2호
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    • pp.435-459
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    • 1998
  • In order to achieve a successful endodontic treatment, root canals must be obturated three-dimensionally without causing any damage to apical tissues. Accurate length determination of the root canal is critical in this case. For this reason, I've used the conventional periapical radiography, Digora/sup (R)/(digital imaging system) and Root ZX/sup (R)/(the frequency dependent type apex locator) to measure the length of the canal and compare it with the true length obtained by cutting the tooth in half and measuring the length between the occlusal surface and the apical foramen. From the information obtained by these measurements, I was able to evaluate the accuracy and clinical usefulness of each systems. whether the thickness of files used in endodontic therapy has any effect on the measuring systems was also evaluated in an effort to simplify the treatment planning phase of endodontic treatment. 29 canals of 29 sound premolars were measured with #15, #20, #25 files by 3 different dentists each using the periapical radiography. Digora/sup (R)/ and Root ZX/sup (R)/. The measurements were then compared with the true length. The results were as follows: 1. In comparing mean discrepancies between measurements obtained by using periapical radiography(mean error: -0.449±0.444 mm), Digora/sup (R)/(mean error: -0.417±0.415 mm) and Root ZX/sup (R)/(mean error: 0.123±0.458 mm) with true length. periapical radiography and Digora/sup (R)/ system had statistically significant differences(p<0.05) in most cases while Root ZX/sup (R)/ showed none(p>0.05). 2. By subtracting values obtained by using periapical radiography, Digora/sup (R)/ and Root ZX/sup (R)/ from the true length and making a distribution table of their absolute values. the following analysis was possible. In the case of periapical film. 140 out of 261<53.6%) were clinically acceptable satisfying the margin of error of less than 0.5 mm. 151 out of 261 (53,6%) were acceptable in the Digora/sup (R)/ system while Root ZX/sup (R)/ had 197 out of 261(75.5%) within the limits of 0.5mm margin of error. 3. In determining whether the thickness of files has any effect on measuring methoths, no statistically significant differences were found(p>0.05). 4. In comparing data obtained from these methods in order to evaluate the difference among measuring methods, there was no statistically significant difference between periapical radiography and Digora/sup (R)/ system(p>0.05), but there was statistically significant difference between Root ZX/sup (R)/ and periapical radiography(p<0.05). Also there was statistically significant difference between Root ZX/sup (R)/ and Digora/sup (R)/ system(p<0.05). In conclusion, Root ZX/sup (R)/ was more accurate when compared with the Digora/sup (R)/ system and periapical radiography and seems to be more effective clinically in determining root canal length. But Root ZX/sup (R)/ has its limits in determining root morphology and number of roots and its accuracy becomes questionable when apical foramen is open due to unknown reasons. Therefore the combined use of Root ZX/sup (R)/ and the periapical radiography are mandatory. Digora/sup (R)/ system seems to be more effective when periapical radiographs are needed in a short period of time because of its short processing time and less exposure.

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