• Title/Summary/Keyword: crown wall

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Cone-beam computed tomographic evaluation of the temporomandibular joint and dental characteristics of patients with Class II subdivision malocclusion and asymmetry

  • Huang, Mingna;Hu, Yun;Yu, Jinfeng;Sun, Jicheng;Ming, Ye;Zheng, Leilei
    • The korean journal of orthodontics
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    • v.47 no.5
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    • pp.277-288
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    • 2017
  • Objective: Treating Class II subdivision malocclusion with asymmetry has been a challenge for orthodontists because of the complicated characteristics of asymmetry. This study aimed to explore the characteristics of dental and skeletal asymmetry in Class II subdivision malocclusion, and to assess the relationship between the condyle-glenoid fossa and first molar. Methods: Cone-beam computed tomographic images of 32 patients with Class II subdivision malocclusion were three-dimensionally reconstructed using the Mimics software. Forty-five anatomic landmarks on the reconstructed structures were selected and 27 linear and angular measurements were performed. Paired-samples t-tests were used to compare the average differences between the Class I and Class II sides; Pearson correlation coefficient (r) was used for analyzing the linear association. Results: The faciolingual crown angulation of the mandibular first molar (p < 0.05), sagittal position of the maxillary and mandibular first molars (p < 0.01), condylar head height (p < 0.01), condylar process height (p < 0.05), and angle of the posterior wall of the articular tubercle and coronal position of the glenoid fossa (p < 0.01) were significantly different between the two sides. The morphology and position of the condyle-glenoid fossa significantly correlated with the three-dimensional changes in the first molar. Conclusions: Asymmetry in the sagittal position of the maxillary and mandibular first molars between the two sides and significant lingual inclination of the mandibular first molar on the Class II side were the dental characteristics of Class II subdivision malocclusion. Condylar morphology and glenoid fossa position asymmetries were the major components of skeletal asymmetry and were well correlated with the three-dimensional position of the first molar.

Combined Adenomatoid Odontogenic Tumor and Calcifying Epithelial Odontogenic Tumor in the Mandible: Case Report (하악 소구치 부위에 발생한 석회화상피성치성종양이 혼재된 선양치성종양: 증례보고)

  • Noh, Lyang-Seok;Jo, Hyung-Woo;Choi, So-Young;Kim, Chin-Soo
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.33 no.2
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    • pp.176-179
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    • 2011
  • Adenomatoid odontogenic tumors represent 3 to 7 percent of all odontogenic tumors. These tumors are more common in the maxilla than the mandible and usually include the anterior region. Clinically, the most common symptom is painless swelling and the tumor is associated with an unerupted tooth, typically a maxillary or mandibular cuspid. The adenomatoid odontogenic tumor appears radiographically as a unilocular radiolucency around the crown of an impacted tooth, resembling a dentigerous cyst. More often, it contains fine calcifications. Histopathologically, there is a thick wall cystic structure with a prominent intraluminal proliferation of the odontogenic epithelium. The most striking pattern is varying-sized solid nodules of spindle-shaped or cuboidal epithelial cells forming nests or rosette-like structures with minimal stromal connective tissues. Conspicuous within the cellular areas are structures of tubular or duct-like appearance. The duct-like spaces are lined with a single row of cuboidal or low columnar epithelial cells, of which the ovoid nuclei are polarized away from the luminal surface. Small foci of calcification may also be scattered throughout the tumor. These have been interpreted as abortive enamel formations. In some adenomatoid odontogenic tumors, the material has been interpreted as dentoid or cementum.

Maxillary sinus augmentation with biphasic calcium phosphate(Osteon$^{(R)}$); A clinical and radiographic study (Original Article 1 - 합성골 이식재인 Osteon$^{(R)}$을 이용한 상악동 거상술-임상적, 방사선 계측학적 연구)

  • Cha, Jae-Kook;Jung, Ui-Won;Kim, Min-Soo;Um, Yoo-Jung;Kim, Chang-Sung;Cho, Kyoo-Sung;Choi, Seong-Ho;Chung, Sung-Min
    • The Journal of the Korean dental association
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    • v.48 no.1
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    • pp.45-55
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    • 2010
  • Purpose: The aim of this study was to evaluate 1 year cumulative survival rate of implants placed on augmented sinus using Osteon$^{(R)}$, bone graft material and to assess height of the grafted material radiographically. Material and Methods: 10 maxillary sinuses were augmented in 10 patients and 25 implant fixtures were installed simultaneously or after 6 months healing period. The height of the sinus graft material was measured using panoramic images immediately after augmentation and up to 19 months subsequently. Changes in the height of the sinus graft material were calculated with respect to implant length and original sinus wall height. Results: The cumulative survival rate was 100% in all 25 implants. Additionally, normal healing process without any complication was observed in all patients. The mean crown/Implant ratio was 1.25. The mean marginal bone loss was 0.95mm and the mean resorption rate of Osteon$^{(R)}$ was 0.05mm/month. The fastest resorption site of Osteon$^{(R)}$ is the first molar area. The grafted material was well maintained in sinus and decreased slightly over 1 year. Conclusion: In conclusion, It can be suggested that Osteon$^{(R)}$ may have predictable result when it was used as a grafting material for sinus floor augmentation.

A Study on the Koguryo ancient mural paintings in the An-Ak 3rd ancient tomb, focusing on the hair styles (안악3호분을 통해서 본 머리모양 연구)

  • Kim Min-Sun;Maeng You-Jin;Lee Sang-Eun
    • Journal of the Korea Fashion and Costume Design Association
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    • v.7 no.3
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    • pp.95-112
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    • 2005
  • Hair styles, dresses and their ornaments are basic measures that show the trend of the times, the people and their life in both Eastern and Western societies. The history of a country could start or be extinguished at any time, but life goes on. Koguryo was founded around Anno Domini and fell at 668 A. D. What was Koguryo people like? How was their hair style and costume? This study aims to respond those questions. The Koguryo ancient mural paintings can be broadly divided into the Jip-An region and the Pyon-Yang region. Among the paintings found, that in the An-Ak 3rd ancient tomb at the Pyon-Yang region is the biggest and the most splendid. It is a figure genre painting, which contains a kitchen, a rice mill, a stable, a barn, a garage, etc. Those places illustrate the way of life at the time. The painting also comprises a man with a crown, who is seen as the king and owner of this tomb. The woman with a vertically designed hair style is perceived as the queen. A highly guarded and decorated royal parade is also presented in detail. The hair styles and costume evidence in the An-Ak 3rd ancient tomb are not seen in the paintings of the Jip-An region. This study inquires into the differences between the Pyon-Yang and lip-An regions through the history and the culture of those areas. Nevertheless, it could prove tentative to confirm the owner of the An-Ak 3rd ancient tomb with the only evidence of the words found in the wall of the tomb. It is the author's intention to study and analyse further.

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A Study on the Numerical Modeling Criteria for Underground Openings (지하공동굴착의 수치해석방법 적용기준 설정연구)

  • 이경진
    • The Journal of Engineering Geology
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    • v.5 no.1
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    • pp.31-44
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    • 1995
  • The puppose of this study is to propose the numerical modelling criteria for underground opening, rock mass continuum is regarded as homogeneous rock behaved linear elastic. The results of this study are summarized as follows: - Boundaries of the finite element mesh should be located at least 6 radii away from the center of the opening. - For circular openings, tension only developed when $K_0$ was less than one-fourAs the ratio of initial horiwntal to vertical stress increased, the inward springline movement increased and the inward crown movement decreased. - The displacement patterns developing for opening I shaped horse-shoe and opening II shaped powerstation are similar to those for circular openings. For both type opening I and opening II, stress concentrations develop at the intersection of the wall and floor. Greater stress concentrations are found for the type opening II.

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A hybrid technique for sinus floor elevation in the severely resorbed posterior maxilla

  • Jung, Ui-Won;Hong, Ji-Youn;Lee, Jung-Seok;Kim, Chang-Sung;Cho, Kyoo-Sung;Choi, Seong-Ho
    • Journal of Periodontal and Implant Science
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    • v.40 no.2
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    • pp.76-85
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    • 2010
  • Purpose: This study aimed to evaluate the effectiveness of the modified sinus floor elevation technique described hereafter as a "hybrid technique," in 11 patients with severely resorbed posterior maxillae. Methods: Eleven patients who received 22 implants in the maxillary premolar and molar areas by the hybrid technique were enrolled in this study. A slot-shaped osteotomy for access was prepared on the lateral wall along the lower border of the sinus floor. The Schneiderian membrane was fully reflected through the lateral slot. Following drilling with the membrane protected by a periosteal elevator, the bone was grafted. All implants were placed simultaneously with sinus augmentation. The cumulative success rate was calculated and clinical parameters were recorded. Radiographic measurements were performed. Results: All implants were well maintained at last follow up (cumulative success rate=100%). The mean residual bone height, augmented bone height, crown-to-implant ratio, and marginal bone loss were $4.1{\pm}1.64mm$, $8.76{\pm}1.77mm$, $1.21{\pm}0.34mm$, and $0.34{\pm}0.72mm$, respectively. Conclusions: Simultaneous implant placement with sinus augmentation by hybrid technique showed successful clinical results over a 2-year observation period and may be a reliable modality for reconstruction of a severely resorbed posterior maxilla.

A Tunnel Mock-up Test and Numerical Analysis on Steel Fiber Reinforced Shotcrete (강섬유 보강 숏크리트의 터널모형실험 및 수치해석적 검증)

  • You, Kwang-Ho;Jung, Ji-Sung;Park, Yeon-Jun
    • Tunnel and Underground Space
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    • v.18 no.2
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    • pp.107-117
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    • 2008
  • In this study, the failure and deformation characteristics of steel fiber reinforced shotcrete (SFRS) which is a primary tunnel support was investigated to find out ground-support mutual behavior. To this end, a mock-up of a tunnel was made and experimented with the conditions of lateral earth pressure coefficient 0.5 and 1.0. During the tests, 11 hydraulic cylinders were used for loading. for better simulation of the lateral earth pressure effect, these cylinders were controlled separately by two groups; crown and side wall. Meanwhile, the deformation of shotcrete was measured by 11 LVDTs. Backfill material was also used fur better load transfer from hydraulic cylinders to shotcrete. For the validation of the mock-up test results, 3D numerical analysis is carried out. To do numerical analysis under the same condition as a mock-up test, the load history curve which was obtained during the test was tried to be simulated using an individual FISH routine in the numerical analysis.

Dynamic response of a lined tunnel with transmitting boundaries

  • Fattah, Mohammed Y.;Hamoo, Mohammed J.;Dawood, Shatha H.
    • Earthquakes and Structures
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    • v.8 no.1
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    • pp.275-304
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    • 2015
  • The objective of this paper is to investigate the validity of transmitting boundaries in dynamic analysis of soil-structure interaction problems. As a case study, the proposed Baghdad metro line is considered. The information about the dimensions and the material properties of the concrete tunnel and surrounding soil were obtained from a previous study. A parametric study is carried out to investigate the effect of several parameters including the peak value of the horizontal component of earthquake displacement records and the frequency of the dynamic load. The computer program (Mod-MIXDYN) is used for the analysis. The numerical results are analyzed for three conditions; finite boundaries (traditional boundaries), infinite boundaries modelled by infinite elements (5-node mapped infinite element) presented by Selvadurai and Karpurapu, 1988), and infinite boundaries modelled by dashpot elements (viscous boundaries). It was found that the transmitting boundary absorbs most of the incident energy. The distinct reflections observed for the "fixed boundaries" disappear by using "transmitted boundaries". This is true for both cases of using viscous boundaries or mapped infinite elements. The type and location of the dynamic load represent two controlling factors in deciding the importance of using infinite boundaries. It was found that the results present significant differences when earthquake is applied as a base motion or a pressure load is applied at the surface ground. The peak value of the vertical displacement at nodes A, B, E and F (located at the tunnel's crown and side walls, and at the surface above the tunnel and at the surface 6.5 m away from tunnel's centre respectively) increases with the frequency of the surface pressure load for both cases 1 and 2 (traditional boundaries and mapped infinite elements respectively) while it decreases for case 3 (viscous boundaries). The modular ratio Ec/Es (modulus of elasticity of the concrete lining to that of the surrounding soil) has a considerable effect on the peak value of the horizontal displacement at node B (on the side wall of the tunnel lining) increase about (17.5) times, for the three cases (1, 2, and 3).

Effect of method of synthesis on antifungal ability of ZnO nanoparticles: Chemical route vs green route

  • Patino-Portela, Melissa C.;Arciniegas-Grijalba, Paola A.;Mosquera-Sanchez, Lyda P.;Sierra, Beatriz E. Guerra;Munoz-Florez, Jaime E.;Erazo-Castillo, Luis A.;Rodriguez-Paez, Jorge E.
    • Advances in nano research
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    • v.10 no.2
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    • pp.191-210
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    • 2021
  • To compare the antifungal effect of two nanomaterials (NMs), nanoparticles of zinc oxide were synthesized by a chemical route and zinc oxide-based nanobiohybrids were obtained using green synthesis in an extract of garlic (Allium sativum). The techniques of X-Ray Diffraction (XRD), Infrared (IR) and Ultraviolet Visible (UV-Vis) absorption spectroscopies and Scanning (SEM) and Transmission Electron Microscopies (TEM) were used to determine the characteristics of the nanomaterials synthesized. The results showed that the samples obtained were of nanometric size (< 100 nm). To compare their antifungal capacity, their effect on Cercospora sp. was evaluated. Test results showed that both nanomaterials had an antifungal capacity. The nanobiohybrids (green route) gave an inhibition of fungal growth of ~72.4% while with the ZnO-NPs (chemical route), inhibition was ~87.1%. Microstructural studies using High Resolution Optical Microscopy (HROM) and ultra-structural analysis using TEM carried out on the treated strains demonstrated the effect of the nanofungicides on the vegetative and reproductive structures, as well as on their cell wall. To account for the antifungal effect presented by ZnO-NPs and ZnO nanobiohybrids on the fungi tested, effects reported in the literature related to the action of nanomaterials on biological entities were considered. Specifically, we discuss the electrical interaction of the ZnO-NPs with the cell membrane and the biomolecules (proteins) present in the fungi, taking into account the n-type nature of the ZnO semiconductor and the electrical behavior of the fungal cell membrane and that of the proteins that make up the protein crown.

Regenerative potential of biphasic calcium phosphate and enamel matrix derivatives in the treatment of isolated interproximal intrabony defects: a randomized controlled trial

  • Pal, Pritish Chandra;Bali, Ashish;Boyapati, Ramanarayana;Show, Sangita;Tejaswi, Kanikanti Siva;Khandelwal, Sourabh
    • Journal of Yeungnam Medical Science
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    • v.39 no.4
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    • pp.322-331
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    • 2022
  • Background: The combined use of biomaterials for regeneration may have great biological relevance. This study aimed to compare the regenerative potential of biphasic calcium phosphate (BCP) alone and with growth factor enamel matrix derivatives (EMDs) for the regeneration of intrabony defects at 1 year. Methods: This randomized controlled trial included 40 sites in 29 patients with stage II/III periodontitis and 2/3 wall intrabony defects that were treated with BCP alone (control group) or a combination of BCP and EMD (test group). BCP alloplastic bone grafts provide better bio-absorbability and accelerate bone formation. EMDs are commercially available amelogenins. Mean values and standard deviations were calculated for the following parameters: plaque index (PI), papillary bleeding index (PBI), vertical probing pocket depth (V-PPD), vertical clinical attachment level (V-CAL), and radiographic defect depth (RDD). Student paired and unpaired t-tests were used to compare the data from baseline to 12 months for each group and between the groups, respectively. The results were considered statistically significant at p<0.05. Results: At 12 months, the PI and PBI scores of the control and test groups were not significantly different (p>0.05). The mean V-PPD difference, V-CAL gain, and RDD difference were statistically significant in both groups at 12 months (p<0.001 for all parameters). Intergroup comparisons showed that the mean V-PPD reduction (2.13±1.35 mm), V-CAL gain (2.53±1.2 mm), and RDD fill (1.33±1.0 mm) were statistically significant between the groups at 12 months (p<0.001 for all parameters). Conclusion: BCP and EMDs combination is a promising modality for the regeneration of intrabony defects.