212 research outputs found

    Implanto-Prosthetic Rehabilitation of the Mandible by Means of Two Implants

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    Edentulousness is a considerable problem in Croatia. So far prevention has not become the most important part of the dental profession. On the other hand,poor medical knowledge, reduced rights concerning health insurance costs as well as an increasing number of impoverished people in Croatia has resulted in postponed prosthetic rehabilitation. For the above mentioned reasons the Croatian people suffer from premature loss of their teeth. Also lower jaw atrophy occurs, which makes prosthetic rehabilitation even more difficult to achieve. In spite of some disadvantages, the double-implant borne prosthetic suprastructure has proved to be a simple and good solution to the patient\u27s problem, mainly because it is cost-effective. This particularly applies to Croatia patients. Over the last five years we have placed double -implants in 26 patients, in the anterior region of the mandible. The implants were placed in the region of the lower canine or slightly more mesially. Severe atrophy was determined in 13 patients (50%) which impeded their complete denture wearing even before the implant placement started. However, we made up for the loss in two patients by placing the implants again. This time we placed them slightly more mesially. We made one borne implant complete denture for one patient because the examination revealed severe atrophy in one segment of his mandible. In addition since the osseointegration prognosis for this patient was questionable we decided against any additional surgical treatment. Since the belts of the attached gingiva in our patients were wide enough and the diameters of the implants were not very long, no vestibuloplasty was necessary. We installed ITI, IMZ, ASTRA and Ankylos implants. All systems proved to be equally functional

    Implanto-Prosthetic Rehabilitation of the Mandible by Means of Two Implants

    Get PDF
    Edentulousness is a considerable problem in Croatia. So far prevention has not become the most important part of the dental profession. On the other hand,poor medical knowledge, reduced rights concerning health insurance costs as well as an increasing number of impoverished people in Croatia has resulted in postponed prosthetic rehabilitation. For the above mentioned reasons the Croatian people suffer from premature loss of their teeth. Also lower jaw atrophy occurs, which makes prosthetic rehabilitation even more difficult to achieve. In spite of some disadvantages, the double-implant borne prosthetic suprastructure has proved to be a simple and good solution to the patient\u27s problem, mainly because it is cost-effective. This particularly applies to Croatia patients. Over the last five years we have placed double -implants in 26 patients, in the anterior region of the mandible. The implants were placed in the region of the lower canine or slightly more mesially. Severe atrophy was determined in 13 patients (50%) which impeded their complete denture wearing even before the implant placement started. However, we made up for the loss in two patients by placing the implants again. This time we placed them slightly more mesially. We made one borne implant complete denture for one patient because the examination revealed severe atrophy in one segment of his mandible. In addition since the osseointegration prognosis for this patient was questionable we decided against any additional surgical treatment. Since the belts of the attached gingiva in our patients were wide enough and the diameters of the implants were not very long, no vestibuloplasty was necessary. We installed ITI, IMZ, ASTRA and Ankylos implants. All systems proved to be equally functional

    Tooth Morphology in Function of Selfprotective Mechanism

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    The degree of curvature of vestibular and oral tooth surfaces is determined by the shape sequence from the tooth crown to the epithelial attachment and the alveolar bone, and directly influences the health of gingiva and the entire tooth support system. The goal of this research was to determine vestibulo-oral planes of upper and lower permanent premolars and molars and the thickness of the associated alveolar osseous wall, and 2,727 measurings were processed using pertinent statistical procedures. The results have shown the degree of curvature of vestibular and oral tooth surfaces to be higher in upper teeth than in lower ones (p>0.05); vestibular convexities higher than oral ones and especially noticeable at the junction from the meandle to the lower third of the crown. Higher vestibular curvature also entailed thicker osseous wall. All results were higher than the ones found in literature. We consider our results to be relevant for our population. The research on the relationship of teeth and the alveolar bone should be continued by using even more test points and more sophisticated research procedures

    Foramen Mandibulae as an Indicator of Successful Conduction Anesthesia

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    Comparative measurements were made of 144 orthopantomographs in 50 patients with successful and 94 patients with unsuccessful inferior alveolar nerve block anesthesia. The results show that the bony lingula is prominent in 28.5% of all patients, or in 56.0% of those with unsuccessful anesthesia. The variables mandibular notch vs. mandibular foramen (MN-MF) and the anterior ramus ridge vs. mandibular foramen (ARR-MF) show greater distances in the group of patients with successful anesthesia, while the variables of posterior ramus ridge vs. mandibular foramen (PRR-MF) and mandibular angle vs. mandibular foramen (MA-MF) were greater in the group of patients with unsuccessful anesthesia (p > 0.05). It is concluded that the variability in position of the mandibular foramen among others may be responsible for an occasional failure of inferior alveolar nerve block

    Automated Classification of Airborne Laser Scanning Point Clouds

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    Making sense of the physical world has always been at the core of mapping. Up until recently, this has always dependent on using the human eye. Using airborne lasers, it has become possible to quickly "see" more of the world in many more dimensions. The resulting enormous point clouds serve as data sources for applications far beyond the original mapping purposes ranging from flooding protection and forestry to threat mitigation. In order to process these large quantities of data, novel methods are required. In this contribution, we develop models to automatically classify ground cover and soil types. Using the logic of machine learning, we critically review the advantages of supervised and unsupervised methods. Focusing on decision trees, we improve accuracy by including beam vector components and using a genetic algorithm. We find that our approach delivers consistently high quality classifications, surpassing classical methods

    On Coloring Resilient Graphs

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    We introduce a new notion of resilience for constraint satisfaction problems, with the goal of more precisely determining the boundary between NP-hardness and the existence of efficient algorithms for resilient instances. In particular, we study rr-resiliently kk-colorable graphs, which are those kk-colorable graphs that remain kk-colorable even after the addition of any rr new edges. We prove lower bounds on the NP-hardness of coloring resiliently colorable graphs, and provide an algorithm that colors sufficiently resilient graphs. We also analyze the corresponding notion of resilience for kk-SAT. This notion of resilience suggests an array of open questions for graph coloring and other combinatorial problems.Comment: Appearing in MFCS 201

    An Automatic Digital Terrain Generation Technique for Terrestrial Sensing and Virtual Reality Applications

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    The identification and modeling of the terrain from point cloud data is an important component of Terrestrial Remote Sensing (TRS) applications. The main focus in terrain modeling is capturing details of complex geological features of landforms. Traditional terrain modeling approaches rely on the user to exert control over terrain features. However, relying on the user input to manually develop the digital terrain becomes intractable when considering the amount of data generated by new remote sensing systems capable of producing massive aerial and ground-based point clouds from scanned environments. This article provides a novel terrain modeling technique capable of automatically generating accurate and physically realistic Digital Terrain Models (DTM) from a variety of point cloud data. The proposed method runs efficiently on large-scale point cloud data with real-time performance over large segments of terrestrial landforms. Moreover, generated digital models are designed to effectively render within a Virtual Reality (VR) environment in real time. The paper concludes with an in-depth discussion of possible research directions and outstanding technical and scientific challenges to improve the proposed approach

    Maximizing Happiness in Graphs of Bounded Clique-Width

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    Clique-width is one of the most important parameters that describes structural complexity of a graph. Probably, only treewidth is more studied graph width parameter. In this paper we study how clique-width influences the complexity of the Maximum Happy Vertices (MHV) and Maximum Happy Edges (MHE) problems. We answer a question of Choudhari and Reddy '18 about parameterization by the distance to threshold graphs by showing that MHE is NP-complete on threshold graphs. Hence, it is not even in XP when parameterized by clique-width, since threshold graphs have clique-width at most two. As a complement for this result we provide a nO(ā„“ā‹…cwā”)n^{\mathcal{O}(\ell \cdot \operatorname{cw})} algorithm for MHE, where ā„“\ell is the number of colors and cwā”\operatorname{cw} is the clique-width of the input graph. We also construct an FPT algorithm for MHV with running time Oāˆ—((ā„“+1)O(cwā”))\mathcal{O}^*((\ell+1)^{\mathcal{O}(\operatorname{cw})}), where ā„“\ell is the number of colors in the input. Additionally, we show O(ā„“n2)\mathcal{O}(\ell n^2) algorithm for MHV on interval graphs.Comment: Accepted to LATIN 202

    The rationale and design of the perindopril genetic association study (PERGENE): A pharmacogenetic analysis of angiotensin-converting enzyme inhibitor therapy in patients with stable coronary artery disease

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    Background: Angiotensin-converting enzyme (ACE) inhibitors reduce clinical symptoms and improve outcome in patients with hypertension, heart failure, and stable coronary artery disease (CAD) and are among the most frequently used drugs in these patient groups. For hypertension, treatment is guided by the level of blood pressure. In the secondary prevention setting, there are no means of guiding therapy. Prior attempts to target ACE-inhibitors to those patients that are most likely to benefit have not been successful, mainly due to the consistency in the treatment effect in clinical subgroups. Still, for prolonged prophylactic treatment with ACE-inhibitors it would be best to target treatment to only those patients most likely to benefit, which would considerably lower the number needed to treat and increase cost-effectiveness. A new approach for such "tailored-therapy" may be to integrate information on the genetic variation between patients. Until now, pharmacogenetic research of the efficacy of ACE-inhibitor therapy in CAD patients is still in a preliminary stage. Methods: The PERindopril GENEtic association study (PERGENE) is a substudy of the EUROPA trial, a randomized double-blind placebo-controlled multicentre clinical trial which demonstrated a beneficial effect of the ACE-inhibitor perindopril in reducing cardiovascular morbidity and mortality in 12.218 patients with stable coronary artery disease (mean follow-up 4.2 years). Blood tubes were received from patients at the beginning of the EUROPA trial and buffy coats were stored at -40Ā°C at the central core laboratory. Candidate genes were selected in the renin-angiotensin-system and bradykinin pathways. Polymorphisms were selected based on haplotype tagging principles using the HapMap genome project, Seattle and other up-to-date genetic database platforms to comprehensively cover all common genetic variation within the genes. Selection also took into consideration the functionality of SNP's, location within the gene (promoter) and existing relevant literature. The main outcome measure of PERGENE is the effect of genetic factors on the treatment benefit with ACE-inhibitors. The size of this pharmacogenetic substudy allows detection with a statistical power of 98% to detect a difference in hazard ratios (treatment effect) of 20% between genotypes with minor allele frequency of 0.20 (two-sided alpha 0.05). Conclusion: The PERGENE study is a large cardiovascular pharmacogenetic study aimed to assess the feasibility of pharmacogenetic profiling of the treatment effect of ACE-inhibitor use with the perspective to individualize treatment in patients with stable coronary artery disease
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