• Title/Summary/Keyword: self-occlusion

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The Prevalence of Malocclusion and Related Self-Esteem of Adolescents in Yangsan (양산시 청소년의 부정교합 유병률 및 관련 자존감 조사)

  • Ryu, Hyunjung;Kim, Hyungjun;Jeong, Taesung;Kim, Jiyeon;Kim, Shin
    • Journal of the korean academy of Pediatric Dentistry
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    • v.40 no.4
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    • pp.296-305
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    • 2013
  • For the purpose of evaluating the prevalence of malocclusion and self-esteem in adolescents, 1,380 middle-school students in the Yangsan area were surveyed by oral examination and questionnaires and the obtained results were as follows: The distribution of 1st molar occlusion by Angle's classification was 69.0, 19.4, 10.6% for Class I, II and III respectively. In the horizontal relationship, the prevalence of normal overjet and crossbite was 86.9% and 5.6% respectively whereas larger and extremely larger overjet was found in 6.6% and 0.8%. In the vertical relationship of anterior teeth, normal, deep overbite and openbite was shown in 94.1%, 4.7%, and 1.2%. For the midline discrepancy, the distribution of groups with 0~1 mm, 2~4 mm and over 5 mm was 98.2%, 1.4%, and 0.4%. Crowding only in the maxilla was found in 9.6%, while that only in the mandible and in both arches was 14.1% and 24.1% respectively. Spacing only in the maxilla was seen in 3.0%, while that only in the mandible and in both arches was 2.4% and 1.7% respectively. Significant difference in self-esteem was revealed in female and malocclusion groups of crossbite and openbite(p < 0.05).

Applying the New Technology for Making Pontic Ridge Lap in Posterior Bridge Restoration (대체 신기법을 적용한 구치부 교의치 pontic ridge lap 제작방법)

  • Kim, Wook-Tae
    • Journal of Dental Rehabilitation and Applied Science
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    • v.29 no.3
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    • pp.308-316
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    • 2013
  • The purpose of this study is to investigate the production method of posterior bridges pontic ridge lap type which prevents the infection in bridge pontic base and is able to cleanse itself, in the process of producing final prothesis that maintains healthy mucous membrane of oral cavity and interproximal papilla, minimizing diastema, is aesthetic and has no effect on pronunciation. New technology is applied to make optimal pontic base which prevent inflammation and clean itself and its products were clinically evaluated in 10 places of dental clinics in busan and gyeongnam. The making of posterior 3 unit bridge pontic base, it was presented as the new technology of forming ridge lab type and to carry out clinical validation, existing conventional method and the new technology were compared. Pontic base made with the existing conventional method cause infection and other periodontal disease by 96% but the pontic base made with the new technology cause infection and other periodontal disease by 3%. Remains of food cause infection and other periodontal disease 100% by the existing conventional method and 91% by the new technology, showing a distinct difference. However, after a gargle, the new technology had low 13%. Additionally, the pontic base made with the existing conventional method showed 71% of chance, the new technology method showed 8% of chance in terms of self-cleansing.

Shear bond strength and fracture patterns between Ormocer-based-resin and dentin (Ormocer-Based-Resin의 상아질에 대한 전단결합강도 및 파절 양상에 대한 연구)

  • Ahn, Shi-Hyun;Cho, In-Ho;Lim, Ju-Hwan;Lim, Heon-Song
    • Journal of Dental Rehabilitation and Applied Science
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    • v.18 no.4
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    • pp.289-299
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    • 2002
  • The bond strength is one of the most important factor in establishing long-term success of esthetic restorative dentistry. So, various restorative materials have been introduced to improve the esthetic and physical properties. Ormocer (organically modified ceramic) was developed as a result of such efforts. This study was performed to compare the shear bond strength of ormocer based adhesive with that of existing dentin adhesive. In this study $Admira^{(R)}$ and $Admira^{(R)}$ bond of the ormocer system are grouped together for ADM, Single $Bond^{(R)}$ which is an one-bottle adhesive and Z-250TM which is hybrid composite resin of BIS-GMA system for SIN, and $Definite^{(R)}$ of ormocer and Etch & $Prime^{(R)}$ 3.0 which is a self etching priming/ bonding agent for ETC. The results of this study were as follows. : (1) In the comparison of shear bond strength according to different adhesive system, shear bond strength was increased in the order of ETC group, SIN group, ADM group. There was no significant difference between ADM group and SIN group. However, there was a significant level of difference between ADM and ETC groups as well as SIN and ETC groups( p<0.05). (2) Examination by a scanning electron microscope showed a well established hybrid layer and resin tag in both ADM group and SIN group, while ETC group showed a minimal formation of the hybrid layer when compared with ADM and SIN groups. From the above results, it may be reasonable to start the clinical application of ormocer system, and it is recommended that ormocer system should be used along with an ormocer based adhesive because ormocer system showed the lower shear bond strength when it used with other existing self etching priming/bonding agent. The self etching priming/bonding agent showed relatively low shear bond strength, and it is considered that the further study should be needed.

A Study on Assembly Part Recognition Using Part-Based Superquadric Model (부품 기반한 수퍼쿼드릭 모델을 이용한 기계부품 인식에 관한 연구)

  • 이선호;홍현기;최종수
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.4B
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    • pp.734-742
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    • 2000
  • This paper presents a new volumetric approach to 3D object recognition by using PBSM (part-based superquadric model). The assembly part object can be constructed with the set of volumetric primitives and the relationships between them. We describe volumetric characteristics of the model object with superquadric parameters. In addition, our model base has the relationships between volumetric primitives as well as the surface information : the surface type, the junction type between neighboring surfaces. These surface properties and relationships between parts are effectively used in recognition process. Our integrated method is robust to recognition of the identity, position, and orientation of randomly oriented assembly parts. Furthermore, we can reduce the effects of self-occlusion and non-linear shape changes according to viewpoint. In this paper, we show that our integrated method is robust to recognition of the identity, position, and orientation of randomly oriented assembly parts through experimental results.

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Evaluation of Microleakage with Retrograde Filling Materials in Blood Contamination (혈액 오염된 역충전 재료의 미세누출 평가)

  • Cho, Hye-Jin;Moon, Jhong-Hyun;Chon, Seong-Min;Yu, Mi-Kyung
    • Journal of Dental Rehabilitation and Applied Science
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    • v.23 no.1
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    • pp.85-93
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    • 2007
  • The purpose of this study was to evaluate the microleakage of root-end filling material filled in blood contaminated root-end cavity and self-etching adhesive placed over blood contaminated resected root apices without root-end preparation. Extracted, human maxillary incisors, canines and mandibular premolar were randomly divided into four groups of 15 teeth each. After canal preparation, resection of the apex and root-end preparation, MTA and IRM were filled in the root-end cavity (A and B group). After canal preparation and resection of the apex, Clearfil SE Bond and Prompt L-Pop were applied over the contaminated root-end surfaces (C and D group). The roots were then subjected to 15cm of water pressure to simulate periapical microleakage stress. Data were analyzed using one-way ANOVA. The results were as follows : 1. All groups showed a tendency of decreasing microleakage in process of time after 2weeks later except IRM group. 2. After 2 weeks and 1 month, MTA group showed less microleakage significantly than other groups(p<0.05). After 2 months, Prompt L-Pop group showed less microleakage significantly than other groups(p<0.05). 3. After 9 months, there were no significant differences among four groups(p>0.05). Thus it is considered that apical sealing using adhesives system without root-end preparation is good method in endodontic surgery.

View Morphing for Generation of In-between Scenes from Un-calibrated Images (비보정 (un-calibrated) 영상으로부터 중간영상 생성을 위한 뷰 몰핑)

  • Song Jin-Young;Hwang Yong-Ho;Hong Hyun-Ki
    • Journal of KIISE:Computer Systems and Theory
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    • v.32 no.1
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    • pp.1-8
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    • 2005
  • Image morphing to generate 2D transitions between images may be difficult even to express simple 3D transformations. In addition, previous view morphing method requires control points for postwarping, and is much affected by self- occlusion. This paper presents a new morphing algorithm that can generate automatically in-between scenes from un-calibrated images. Our algorithm rectifies input images based on the fundamental matrix, which is followed by linear interpolation with bilinear disparity map. In final, we generate in-between views by inverse mapping of homography between the rectified images. The proposed method nay be applied to photographs and drawings, because neither knowledge of 3D shape nor camera calibration, which is complex process generally, is required. The generated in-between views can be used in various application areas such as simulation system of virtual environment and image communication.

Performance Improvement of Human Detection in Thermal Images using Principal Component Analysis and Blob Clustering (주성분 분석과 Blob 군집화를 이용한 열화상 사람 검출 시스템의 성능 향상)

  • Jo, Ahra;Park, Jeong-Sik;Seo, Yong-Ho;Jang, Gil-Jin
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.13 no.2
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    • pp.157-163
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    • 2013
  • In this paper, we propose a human detection technique using thermal imaging camera. The proposed method is useful at night or rainy weather where a visible light imaging cameras is not able to detect human activities. Under the observation that a human is usually brighter than the background in the thermal images, we estimate the preliminary human regions using the statistical confidence measures in the gray-level, brightness histogram. Afterwards, we applied Gaussian filtering and blob labeling techniques to remove the unwanted noise, and gather the scattered of the pixel distributions and the center of gravities of the blobs. In the final step, we exploit the aspect ratio and the area on the unified object region as well as a number of the principal components extracted from the object region images to determine if the detected object is a human. The experimental results show that the proposed method is effective in environments where visible light cameras are not applicable.

Successful Treatment Using Wire-reinforced Interdental Splint for a Puppy with Rostral Mandibular Fractures

  • Kim, Se Eun;Shim, Kyung Mi;Kim, Seung Hyun;Bae, Chun-Sik;Kang, Seong Soo
    • Journal of Veterinary Clinics
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    • v.35 no.4
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    • pp.137-140
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    • 2018
  • A five-month-old toy poodle was referred for treatment of bilateral mandibular fractures. Preoperative skull and dental radiographs showed rostral mandibular fractures and permanent teeth that had not yet erupted. In addition to providing stability for the healing of fractures, it is very important to focus on restoring normal occlusion. The mandibular fractures were repaired using interdental wiring in a dentate area where the deciduous canines and fourth premolars were stable and could be used to anchor the interdental fixation. In the absence of an erupted permanent mandibular first molar, the modified Risdon wiring was performed using the deciduous mandibular fourth premolars as anchor teeth. An intraoral splint was placed on the mandibular teeth using self-curing composite resin. Five months after surgery, the patient had experienced no complications, and the permanent teeth had erupted normally. In this case, which involves a small-breed puppy with deciduous dentition, treatment with a wire-reinforced interdental splint using intact deciduous fourth premolar teeth as anchor teeth can be considered as a suitable method for rostral mandibular fracture restoration.

A simple technique for impression taking of teeth and functionally generated paths

  • Yamamoto, Takatsugu;Sato, Yohei;Watanabe, Hidehiko;Punj, Amit;Abe, Minoru;Momoi, Yasuko;Ohkubo, Chikahiro
    • Restorative Dentistry and Endodontics
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    • v.43 no.1
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    • pp.9.1-9.6
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    • 2018
  • The objective of this case report is to introduce a simple technique for simultaneously taking a closed-mouth impression and functionally generated path (FGP) for a full coverage crown restoration. A monolithic zirconia crown was the restoration of choice. An alginate impression of the abutment tooth was taken to fabricate a custom-made closed-mouth impression tray covering the abutment tooth and the adjacent teeth. The tray had an FGP table and an abutment tray in cameo and intaglio surfaces, respectively. The impression was taken with silicone impression material after adjusting the abutment tray and inscribing the FGP using self-curing acrylic resins. Plaster casts were made from the impression, and a zirconia crown was fabricated. The crown was cemented to the abutment tooth with minimal adjustments. This simple technique resulted in a well-fitting crown that accounted for mandibular movements. Using the custom closed-mouth impression tray incorporating an FGP table simultaneously aids in fabricating an accurately fitting restoration that incorporates harmonious mandibular movements using a single impression capture.

Queue Detection using Fuzzy-Based Neural Network Model (퍼지기반 신경망모형을 이용한 대기행렬 검지)

  • KIM, Daehyon
    • Journal of Korean Society of Transportation
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    • v.21 no.2
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    • pp.63-70
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    • 2003
  • Real-time information on vehicle queue at intersections is essential for optimal traffic signal control, which is substantial part of Intelligent Transport Systems (ITS). Computer vision is also potentially an important element in the foundation of integrated traffic surveillance and control systems. The objective of this research is to propose a method for detecting an exact queue lengths at signalized intersections using image processing techniques and a neural network model Fuzzy ARTMAP, which is a supervised and self-organizing system and claimed to be more powerful than many expert systems, genetic algorithms. and other neural network models like Backpropagation, is used for recognizing different patterns that come from complicated real scenes of a car park. The experiments have been done with the traffic scene images at intersections and the results show that the method proposed in the paper could be efficient for the noise, shadow, partial occlusion and perspective problems which are inevitable in the real world images.