• Title/Summary/Keyword: Occlusion areas

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Finite Element Approach to Investigate the Influence of the Jaw Bone Dimension on the Stress Around the Root Analogue Dental Implant (악골폭경이 치근형 임플란트 인접골에서의 응력에 미치는 영향에 대한 유한요소해석적 연구)

  • Jang, Ji-Man;Lee, Kyu-bok;Lee, Cheong-Hee;Jo, Kwang-Hun
    • Journal of Dental Rehabilitation and Applied Science
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    • v.22 no.1
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    • pp.37-53
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    • 2006
  • Purpose: The purpose of this study was to investigate the influences of the jaw dimension on the bone stress. Materials and Methods: Root analogue implant of Frialit-2 Synchro model in the jaw bone of various thickness from 8mm to 13mm were modelled axisymmetrically for a series of finite element analyses. As load conditions, non-axisymmetric lateral load of 20N and an oblique load of 50N, as well as an axisymmetric vertical load of 50N were taken into consideration. Results: The cervical area of implant under the axisymmetric load and the base cortical bone under the non axisymmetric load condition were the areas of main concern where the higher level of stress were likely to be obtained. Conclusion: The results indicated that at the two concerned areas drastically different stress distribution could take place as a function of the load conditions. Under the vertical load, the lower level of stress was observed for the narrow jaw bone at the cervical cortical bone whereas stress at the base cortical bone remained virtually unchanged. Under the non axisymmetric load condition, however, the stress at the base cortical bone increased very rapidly as the jaw bone width increased without inducing any significant change in the stress level at the cervical area.

Muscle Infarction and Calcification of the Semitendinosus Tendon: A Case Report (반건양건내에 발생한 근육 경색 및 석회화: 증례 보고)

  • Cho, Jin-Ho
    • The Journal of the Korean bone and joint tumor society
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    • v.18 no.2
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    • pp.89-93
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    • 2012
  • The most common anatomic location of calcific tendinitis is the suprasupinatus muscle of the shoulder joint. However, it is known to develop in any joint including the hip, knee. Infarction of skeletal muscle in the distal areas of the limbs due to vascular occlusion is a well recognized systemic condition in patients who have diabetes. The author experienced mass-like lesion combined muscle infarction and calcification within pure semitendinosus tendon without diabetes in posterosuperior area of distal thigh in old age.

A CLINICAL STUDY ON THE OCCURRENCE OF FOOD IMPACTION (식편압입의 발현에 관한 임상적 연구)

  • Jung, Jae-Hoon;Oh, Sang-Chun;Dong, Jin-Keun
    • The Journal of Korean Academy of Prosthodontics
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    • v.38 no.1
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    • pp.50-58
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    • 2000
  • The purpose of this study was to investigate the causes of food impaction and to explore solutions as well. For this study, 39 patients with food impaction were selected. 77 contact areas in these patients were investigated mobility, tightness of contact area, gingival index, plaque index, attachment loss, alveolar bone loss, proximal caries, marginal ridge distance and occlusal relationships. The results were as follows ; 1. Teeth without distal support were found to be the most frequent site of food impaction (41.6%). Food impaction was found to be more frequent in the upper teeth (65.2%) than the lower teeth (33.8%). 2. Food impaction was found in tight contact cases (71.4%). Alveolar bone loss was not found in the early stage of food impaction (83.1%) 3. The distance between the marginal ridges of food impaction sites (mean=0.48mm) was short-er than that of the control group. (mean=0.77mm) (p<0.001) 4. In 18.2% of the cases, proximal carries were found at the food impaction site. 5. Food impaction affected patient's occlusion with the following frequencies, cusp to marginal ridge relationship (72.7%), cusp to fossa relationship (3.9%) and stepped relationship (23.4%).

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Person Re-identification using Sparse Representation with a Saliency-weighted Dictionary

  • Kim, Miri;Jang, Jinbeum;Paik, Joonki
    • IEIE Transactions on Smart Processing and Computing
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    • v.6 no.4
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    • pp.262-268
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    • 2017
  • Intelligent video surveillance systems have been developed to monitor global areas and find specific target objects using a large-scale database. However, person re-identification presents some challenges, such as pose change and occlusions. To solve the problems, this paper presents an improved person re-identification method using sparse representation and saliency-based dictionary construction. The proposed method consists of three parts: i) feature description based on salient colors and textures for dictionary elements, ii) orthogonal atom selection using cosine similarity to deal with pose and viewpoint change, and iii) measurement of reconstruction error to rank the gallery corresponding a probe object. The proposed method provides good performance, since robust descriptors used as a dictionary atom are generated by weighting some salient features, and dictionary atoms are selected by reducing excessive redundancy causing low accuracy. Therefore, the proposed method can be applied in a large scale-database surveillance system to search for a specific object.

Facial-feature Detection in Color Images using Chrominance Components and Mean-Gray Morphology Operation (색도정보와 Mean-Gray 모폴로지 연산을 이용한 컬러영상에서의 얼굴특징점 검출)

  • 강영도;양창우;김장형
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.3
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    • pp.714-720
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    • 2004
  • In detecting human faces in color images, additional geometric computation is often necessary for validating the face-candidate regions having various forms. In this paper, we propose a method that detects the facial features using chrominance components of color which do not affected by face occlusion and orientation. The proposed algorithm uses the property that the Cb and Cr components have consistent differences around the facial features, especially eye-area. We designed the Mean-Gray Morphology operator to emphasize the feature areas in the eye-map image which generated by basic chrominance differences. Experimental results show that this method can detect the facial features under various face candidate regions effectively.

Radiation prosthetic stents applied to oral cancer patients during the radiation therapy: case reports (효율적 방사선요법을 위한 구강 방사선스텐트의 적용: 증례보고)

  • Nam, Ki Young
    • Journal of Dental Rehabilitation and Applied Science
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    • v.36 no.4
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    • pp.282-288
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    • 2020
  • Radiation prosthetic stent is defined as the customized oral devices which serve for an efficient administration of radiation dose to the affected areas or a minimizing the unnecessary irradiation to surrounding normal tissues during maxillofacial cancer radiotherapy. Since the use of stents is individualized, a close collaboration among radiotherapist, surgeon and prosthodontist is essential thereby which helps in limiting the post-therapy morbidity as well as the stable oral rehabilitation. In this report, two customized stents (bolus carrier and tongue depressing) were fabricated and applied to patient undergone irradiation for soft palate and tongue carcinoma selectively. Multidisciplinary approach can be a proper strategy and recommended for control the sequel of post-irradiation.

The Influence of Home Position(H.P.) and Random Position(R.P.) on the Shape of Prepared Tooth Surfaces -Upper Left 1st Molar for Full Cast Crown- (시술자세가 치관 삭제면 형태에 미치는 영향 -상악 좌측 제 1 대구치의 전부 주조관-)

  • Lee, Seung-Jeong;Choi, Dae-Gyun
    • Journal of Dental Rehabilitation and Applied Science
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    • v.17 no.4
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    • pp.257-274
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    • 2001
  • To properly prepare teeth, dentists require a direct view of the working area and are often placed in a difficult position, moreover, a high proportion of dentists suffer from headache and back pain. Dentists who make use of the dental mirror and position their patients carefully to gain a proper view report less headache, pain and discomfort in the shoulders. It is recommended that dentists learn the "Home Position(H.P.)" which among the various "Random Position(R.P.)" methods, enables dentists to approach their patients in a stable posture. The purpose of this study was to compare tooth preparation in the H.P. and the R.P., and evaluate the clinical efficacy of the H.P.. Tooth preparation for a full cast crown was performed on the maxillary left 1st molar using the H.P. and the R.P., and the shapes of the prepared tooth surfaces at the two different operating positions were compared. The amount of occlusal reduction, marginal width, height, and axial taper were measured and analyzed. A T-test was performed separately to compare the results of the H.P. and the R.P. with respect to the accuracy of the corresponding tooth reduction. The results were as follows. ; 1. The amount of occlusal reduction was excessive on the mesiobuccal cusp(P<0.05), and deficient on the lingual cusp in the H.P.(P<0.01). In the R.P., this was excessive on the buccal cusp and deficient on the fossa and distolingual cusp(P<0.01). 2. The amounts of marginal width were excessive in all areas except on the lingual and mesial surfaces in the H.P. and lingual surface in the R.P.(P<0.01). 3. The marginal heights were achieved more accurately in the R.P. than the H.P.(P<0.01). 4. Axial surface taper was excessive in all areas in the H.P.(P<0.01). But the axial taper of measured areas was even, and tooth is more like to retain its original axis after reduction. In the R.P., axial surface taper was excessive on the mesial and buccal area, and deficient on the distolingual area(P<0.01), and therefore, the axis of the prepared teeth was tipped in the distolingual direction. 5. The times needed for preparation were 12 minutes and 49 seconds in the H.P., and 11 minutes and 35 seconds in the R.P., and the R.P. was statistically faster(P<0.01). The tooth preparation in the H.P. achieved its goal, in that it enabled the operator to make even tooth reduction. In conclusion, the H.P. system offers an improved method that can be used in clinic after specific training.

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Clinical characteristics of sleep bruxism patients with idiopathic facial pain (특발성 안면 통증 환자에서 수면 이갈이의 임상적 특징)

  • Myung, Yangho;Seo, Jeong-Il;Kim, Bok Eum;Kim, Young Gun;Kim, Seong Taek
    • Journal of Dental Rehabilitation and Applied Science
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    • v.37 no.2
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    • pp.81-87
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    • 2021
  • Purpose: To profile various clinical characteristics of sleep bruxism (SB) patients with idiopathic facial pain (IFP) in the orofacial region. Materials and Methods: We analyzed 28 SB patients among 210 patients with IFP complaints. The profiles were evaluated using patient charts including gender, age, pain duration, pain location, pain intensity and affected areas by pain. Results: SB with IFP occurred more often in females (85.7%) than males (14.3%). The mean age at presentation was 48.9 years. The most common IFP sites of SB patients were the right maxilla (28.6%) and the right mandible (25.0%). The pain complaints occurred mostly in 2 teeth or areas (50.0%), followed by 1 area (28.6%) and then in ≥ 3 teeth or areas (21.4%). The mean pain intensity was 5.9 on a visual analogue scale from 0 to 10. The pain was spontaneous in 20 patients (71.4%), and the mean pain duration was 24.4 months. Conclusion: Identification of clinical characteristics of SB patients with IFP could be useful in the diagnosis of various IFP patients and beneficial in decreasing unnecessary care to reduce IFP. Further studies with larger number of subjects and extended duration are required for more systemized diagnostic methods and development of future treatment guidelines.

Effect of Pressurization Training with Walking on Body Composition, Respiratory Function, and Cardiovascular Response in Middle-Aged Obese Women (중년 비만여성들의 가압 트레이닝이 체성분, 호흡·순환계 기능 및 심혈관 반응에 미치는 효과)

  • Choi, Hyun-Min;Lee, Dong-Jun
    • Journal of Life Science
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    • v.22 no.4
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    • pp.545-551
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    • 2012
  • Pressurization walk training (PWT) with blood flow occlusion has been investigated with regard to muscle hypertrophy and physical fitness function in athletes and healthy people. However, the cardiorespiratory and cardiovascular responses of obese people to PWT are unknown. Thus, we investigated the effects of PWT on body composition (Weight, FM, LBM, %fat, BMI), cardiovascular responses (HR, SV, CO, TVC), and cardiorespiratory responses ($VO_2max$, VEmax, HRmax) in middle-aged obese women. They participated in walk training with (n=15) blood flow occlusion and cross-sectional areas of the quadriceps on both legs. Five sets of 3-min walking (5.5 km/h at 5% grade) and 1-min resting were performed twice a day, 5 days/week for 3 weeks. The results showed that the LBM was significantly increased, and decreased body weight of reducing FM, %bodyfat in PWT ($p$<0.05). For the cardiovascular response, SBP and TPR were significantly decreased ($p$<0.05), and CO increased ($p$<0.05). In addition, the $VO_2max$ and VEmax were improved through PWT. Therefore, this study suggests that the presence of obesity in middle-aged women may result in body composition, cardiorespiratory, and cardiovascular responses caused by PWT.

Mandibular Clinical Arch Forms in Koreans with Normal Occlusions (한국인 정상교합자의 하악 치열궁 형태)

  • Yun, Young-Kuk;Kook, Yoon-Ah;Kim, Seong-Hoon;Mo, Sung-Seo;Cha, Kyung-Suk;Kim, Jong-Ghee;Tae, Ki-Chul
    • The korean journal of orthodontics
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    • v.34 no.6 s.107
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    • pp.481-487
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    • 2004
  • The purpose of this study was to clarify morphologic characteristics between mandibular clinical arch forms in Koreans with normal occlusions. The study included data from 102 Koreans. The most facial portion of 13 proximal contact areas was digitized from photocopied images of the mandibular dental arches. Clinical bracket points were calculated for each tooth based on mandibular tooth thickness data. Four linear and two proportional measurements were taken. The dental arches were classified into ovoid, square and tapered forms. The frequency distributions of the three mandibular arch form classifications were determined and compared between male and female subjects. No significant differences in arch form size were found between the sexes. However, there were a few differences in molar width. It was useful to classify mandibular clinical arch forms present in normal occlusion samples into ovoid, square and tapered categories. The frequency of the ovoid form was the highest, and that of the square form was the second highest. The tapered arch form was found in less than 10 percent of subjects. No significant differences in their frequency distributions and dimensions were shown between males and females.