• Title/Summary/Keyword: ridge part

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Novel design of implant prosthesis considering esthetics and periodontal maintenance: case report (심미성 및 치주 조직의 유지 관리를 고려한 임플란트 보철 증례)

  • Paek, Janghyun
    • Journal of the Korean Academy of Esthetic Dentistry
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    • v.23 no.2
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    • pp.70-76
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    • 2014
  • After extraction of tooth, alveolar ridge resorption is inevitable in most cases. Clinicians confront with horizontal and vertical resorption of alveolar bone. Without massive amount of bone and soft tissue graft, dental implant will be placed apically to gain stability. In those cases, not only white esthetic part, but also pink esthetic part should be restored with pink porcelain. The margin of prosthesis should be located apically to reproduce natural look with adjacent teeth. However, when the margin is located apically, it is always hard to remove remaining cement, thus complications may arise. In this report, a novel design of implant prosthesis is introduced to solve those issues. The novel design is consisted of zirconia framework with pink porcelain and separate crowns on top of the framework. It eliminates the possibility of cement remnants by bringing the crown margin coronally. Pink esthetic part is incorporated in abutment part instead of crown part and the screw hole is covered with separate crowns.

Thinning Compensation and Pseudo Minutiae Removal Using Ridge Trace (융선 추적을 이용한 세선화 보정 및 의사 특징점 제거)

  • Lee, Keon-Ik;Kim, Sung-Nak
    • The KIPS Transactions:PartB
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    • v.11B no.1
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    • pp.7-12
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    • 2004
  • This thesis studies about thinning compensation and the removal of pseudo minutiae using ridge trace. As for the process of thinning compensation, first, it removes unnecessary pixel when 8-neighbor connection sum among the pixels with the crossing count number 6 is not 3. Second, it deals with repeatedly until there is no pixel to remove while tracing the ridge, beginning with the pixel equivalent to the ridge and the pixel with the crossing count number 2 among the 8 pixels around the pixels with the crossing count number 6. When the thinning compensation is finished, it extracts substitute minutiae to use the crossing count number and the 8-neighbor connection sum. Among the extracted substitute minutiaes, it extracts the real minutiae to utilize the pseudo minutiae removal algorithm again. It compares with the existing method for the performance evaluation of proposal method. By the experimental results, The proposal method indicated that a degree of thinning is excellent and a lot of minutiaes were removed.

Stress Analysis of Abutment and Supporting Tissues by Changing Angles and Heights of Konus Telescope Inner Crown (Konus Telescopic Denture의 내관 각도 및 높이에 따른 지대치 및 지지조직의 응력 분석)

  • Vang, Mong-Sook;Gettleman, Lawrence
    • Journal of Dental Rehabilitation and Applied Science
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    • v.19 no.3
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    • pp.139-151
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    • 2003
  • This study was to evaluate and to compare the compressive strength and the displacement effecting the abutment or the residual ridge which are transformed by the angle and the heights of the konus denture inner crown when restorating the unilateral konus denture by using the mandibular canine and the 1st premolar as an abutment. The author made 9 different models for different inner crown heights and konus angles. The inner crown height were divided to 5mm, 6mm, and 7mm and konus angles was divided to $4^{\circ}$, $6^{\circ}$, and $8^{\circ}$. And then in each model, 5kg of $15^{\circ}$ mesial load was stressed on the central fossa of the 1st premolar and the 1st molar. The stresses and displacement were measured using the finite element analysis. The results were as follows 1. The maximum compressive strength was shown on the connective area of the abutment and the denture base. 2. As the angle of the inner crown becomes increased, the compressive strength was shown smaller. 3. As the height of the inner crown becomes increased, the maximum compressive strength was shown smaller while the compressive strength of the root apex and the residual ridge showed larger. 4. When the stress was loaded only on the 1st premolar, the more compressive strength was concentrated on the root apex area of the 1st premolar. 5. When the stress was loaded only on the 1st premolar, the compressive strength was concentrated uniformly on the abutment and the residual ridge. 6. When the stress was loaded only on the 1st molar, the maximum displacement was shown on the distal part of the residual ridge.

A Study on the Roof Components of the Traditional Single-Room Square Type Pavilion (한칸형 전통 사각정자의 지붕부 연구)

  • Jeong, Da-In;Kim, Choong-Sik
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.39 no.3
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    • pp.56-64
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    • 2021
  • Pavilion is an important landscape installation in the traditional landscaping and a representative facility that organizes space. To interpret and succeed the traditional landscape space, researches on the shape and structure of the traditional pavilion are also needed. However, researches on the style and structure of the traditional pavilion are difficult to be found. Accordingly this study aimed to identify the structural characteristics of roof part that occupied the largest portion in determining the shape of pavilion. Our research findings are as follows. As a result of analyzing 15 traditional Single-room square pavilions whose structure could be identified, it was found that the main building elements that distinguished the type of roof part in the Single-room square were crossbeam, ridge pole, and baluster. Depending on the presence of roofing members, pavilion was classified into five types: crossbeam, crossbeam+ridge pole, crossbeam+baluster, ridge pole, and baluster. In addition, as a result of analyzing the load and joint that worked on crossbeam based on the shape classification of roof part, it was found that in the traditional Single-room square pavilion, crossbeam was designed to play a balancing role between pillar and load. This study is significant in that it attempted to make a close interpretation of the shape of roof part in the pavilion and the role and function of building elements in terms of size, ratio, and load.

Novel Connective tissue graft technique for Ridge Augmentation in case of Conventional fixed partial denture : Case reports (치조제 결손부 증대를 위한 새로운 결합조직 이식술)

  • Ahn, Myung-Hwan
    • Journal of the Korean Academy of Esthetic Dentistry
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    • v.22 no.1
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    • pp.47-55
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    • 2013
  • There have been a great number of developments in clinical techniques and dental materials in dentistry to date. Looking at these developments, while it could be seen that functional elements such as mastication were prioritized rather than aesthetic aspect in the past, aesthetic needs of patients have steadily increased over time and accordingly the aesthetic has become considered a priority in the development of dentistry. Although the first to be considered in discussing the aesthetic in clinical dentistry will be the white aesthetic that is the tooth part of prosthesis, the pink aesthetic that refers to the harmony of such prosthesis with gingiva can be an important consideration not to be ignored aesthetically. However, the harmony with the gingiva often cannot be obtained only by the beautiful prosthesis, and in particular, the pontic and implant areas have poor conditions to achieve the gingival (pink) aesthetic due to the absorption of alveolar ridge compared to natural teeth. Among the most important elements of the gingival aesthetic are the gingival level and the interproximal papilla height. It is very difficult to make the gingival aesthetic in the case of insufficient alveolar ridge, and the recovery of ridge volume and contour is necessary in order to overcome this condition. To this end, the most widely used method is the "connective tissue graft". Many techniques of the connective tissue graft have already been introduced for the ridge augmentation, and each technique has different purposes, and advantages and disadvantages. Rather, due to the excessive amount of techniques, there is confusion about selecting the right technique at a certain time. However, the goal is clear. Ways to increase the success rates must be found, and at the same time, a more favorable way to the gingival aesthetic is to be chosen. Thus, in this study, considerations for the gingival aesthetic that makes harmony and the techniques to achieve it are discussed.

Morphological Characteristics of Ocean Core Complexes (OCC) in Central Indian Ridge Using High-Resolution Bathymetry and Backscatter Intensity Data from a Deep-Towed Vehicle (심해예인 고해상도 수심 자료와 후방산란 강도 자료를 이용한 인도양 중앙해령 내 Ocean Core Complex 구조의 지형적 특성 분석)

  • Hwang, Gyuha;Kim, Seung-Sep;Son, Seung Kyu;Kim, Jonguk;Ko, Youngtak
    • Ocean and Polar Research
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    • v.42 no.1
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    • pp.49-61
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    • 2020
  • We analyzed the morphological characteristics of OCC (Ocean Core Complexes) in the middle part of the Central Indian Ridge (MCIR) using high-resolution geophysical data recorded on the Deep-Tow SideScan Sonar IMI-30 system. In terms of slope-gradient variations calculated from the high-resolution bathymetry data, the normal faults formed by seafloor spreading were associated generally with slopes > 30° and resulted in high backscatter intensities, which reflect more topographic effects than acoustic medium variation. However, the areas associated with gentle slopes < 10° tend to show the backscatter intensities reflecting the acoustic characteristic of the medium. We show that the detachment faults exposing the OCCs were initiated with high-angle normal faults (58°) exhibiting outward and inward dips of a breakaway zone. In order to examine the spatial distribution of OCC structures, we characterized the transition from magmatic-dominant seafloor with abyssal hills to tectonic-dominant seafloor with OCC using the down-slope direction variation. The slope direction of the seafloor generally tends to be perpendicular to the ridge azimuth in the magmatic-dominant zone, whereas it becomes parallel to the given ridge azimuth near the OCC structures. Therefore, this spatial change of seafloor slope directions indicates that the formation of OCC structures is causally associated with the tectonic-dominant spreading rather than magmatic extension. These results also suggest that the topographical characteristics of seafloor spreading and OCC structures can be distinguished using high-resolution geophysical data. Thus, we propose that the high-resolution bathymetry and backscatter intensity data can help select potential areas of exploitation of hydrothermal deposits in MCIR effectively.

Seismic Stratigraphy and Sedimentary Environment of the Dukjuk-Do Sand Ridge in Western Gyeonggi Bay, Korea (경기만 서부 덕적도 사퇴의 탄성파층서 및 퇴적환경 연구)

  • Lee, Yoon-Oh;Choi, Sang-Il;Jeong, Gyo-Cheol
    • The Journal of Engineering Geology
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    • v.24 no.1
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    • pp.9-21
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    • 2014
  • We examined high-resolution seismic data, side scan sonar data, surface sediments, and vibrocore samples from a sand ridge off the western part of Dukjuk-Do in Gyeonggi Bay, with the aim of interpretation of seismic stratigraphy and sedimentary environment. Based on the seismic data, the deposited sands are divided into three sedimentary units. 14C age data indicate that the top sequence (sequence I) formed at 5000-6000 yr BP, when a transgression resulted in strong shifting tides. Analyses of the vibrocore samples indicate that sequence II is a paleo-mudflat layer of intertidal sediments dominated by mud. Sequence III consists of terrestrial sediments that are presumed to have been deposited at the end of the Pleistocene, unconformably overlying the acoustic bedrock and Mesozoic granite. The side scan sonar data indicate that sand waves were formed on the seabed on top of the sand ridge. Generally, this is the direction of $N20^{\circ}E$, which coincides with the direction of tidal flow. Sand ripples occur away from the top of the sand ridge and are distributed homogeneously across a sandy slope. Vibrocore analyses indicate that the surface sediments and core sediments (samples VC-1, -2, and -3) are homogeneous, without any internal structures, and are characterized by a mixture of medium and fine sand (1-$2{\phi}$), respectively.

A Study of a Heavy Rainfall Event in the Middle Korean Peninsula in a Situation of a Synoptic-Scale Ridge Over the Korean Peninsula (종관규모 기압능이 한반도를 덮고 있는 기간에 중부지방에서 나타난 호우의 발생 원인)

  • Kim, Ah-Hyun;Lee, Tae-Young
    • Atmosphere
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    • v.26 no.4
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    • pp.577-598
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    • 2016
  • Observational and numerical studies have been carried out to understand the cause and development processes of the heavy rainfall over the middle Korean Peninsula during 0300 LST-1500 LST 29 June 2011 (LST = UTC + 0900). The heavy rainfall event occurred as the synoptic-scale ridge extended from Western Pacific Subtropical High (WPSH) was maintained over East Asia. Observational analysis indicates that the heavy rainfall is mainly due to scattered convective systems, formed over the Yellow Sea, traveling northeastward across the middle peninsula without further organization into larger systems during 0300 LST-0800 LST, and mesoscale convective systems (MCSs) over the Yellow Sea, transformed into a squall line, traveling eastward during 0800 LST-1500 LST. Organization of convective systems into MCSs can be found over the area of mesoscale trough and convergence zone in the northern end of the low-level jet (LLJ) after 0600 LST. Both observational and numerical investigations indicate that a strong LLJ extended from the East China Sea to the Yellow Sea plays an essential role for the occurrence of heavy rainfall. The strong LLJ develops in between the WPSH and a pressure trough over eastern China. Numerical experiments indicate that the land-sea contrast of solar heating of surface and latent heating due to convective developments are the major factors for the development of the pressure trough in eastern China. Numerical study has also revealed that the mountainous terrain including the mountain complex in the northern Korean Peninsula contributes to the increase of rainfall amount in the middle part of the peninsula.

The heavy Minerals of the Recent Sediments of North Carolina Sounds and Estuaries In U.S.A

  • Park, Byong-Kwon
    • 한국해양학회지
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    • v.7 no.2
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    • pp.59-73
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    • 1972
  • The heavy minerals of a barred estuarine and lagoonal sediments along the North Carolina coast have been studied with more than one hundred samples. Currents, salinity, and pH exhibit well-developed gradients from the upstream parts of the estuaries on the west toward the open ocean on the east. Twenty- four heavy minerals were identified in sediments of the study area. However, less than half of these occur frequently and the remainder exist only in minor quantities or trace amounts. Heavy minerals usually comprise less than 1% of the sample but vary from sample to sample. The maximum amount of heavy minerals in sediments of sounds and estuaries is 2.4% and in sediments of Outer Banks is 16.7%. Opaque minerals range from 10 to 85% of the total heavy mineral assemblage. Garnet and sillimanite are relatively more abundant in the eastern part than the western part in the area. Garnet more abundant in the northern part than the southern part, whereas sillimanite is more abundant in the southern part than the northern part, because the garnet source is in the northern part and one of the sillimanite source is in the southern part in the study area. The results of heavy mineral study indicate that the source of sediments is the Blue Ridge and Piedmont crystalline complex, and Coastal Plain formations. Some portions of sediments are transported from the Atlantic Ocean by the landward currents. They further indicate that the sediments of the Atlantic coast in the study area are transported mainly from the northern part to southern part by longshore littoral currents, and some portions of sediments are transported from the southern part to the northern part by the Gulf Stream.

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Taxonomic position of Cymopterus melanotiligia (H. Boissieu) C.Y. Yoon based on morphological and anatomical characters (외부형태 및 해부학적 형질에 의한 큰참나물의 분류학적 위치)

  • Yoon, Chang-Young
    • Korean Journal of Plant Taxonomy
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    • v.31 no.3
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    • pp.253-265
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    • 2001
  • Cymopterus melanotilingia (Apiaceae) was reviewed by external morphology and cross-section of leaf-margin and mericarp, and the taxonomic position of species and genus was reexamined. Based on these results, the description and adistribution map of C. melanotiligia were obtained. The leaf-margin forms a collenchymatous ridge by projecting toward the lower part. One mericarp has 2-lateral ribs and 2-intermediate ribs and the other mericarp has 2-lateral ribs and 1-dorsal rib, suggesting each of them is asymmetric. These characters show that this species does not belong to the genus Ostericum s.s., but should be treated as the genus Cymopterus.

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