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Ricerca traslazionale dell'analisi digitalizzata delle forze occlusali applicata al paziente con disfunzione temporomandibolare
Full text linkTRANSLATIONAL RESEARCH OF DIGITAL ANALYSIS OF OCCLUSAL FORCES APPLIED TO THE PATIENT WITH TEMPOROMANDIBULAR DYSFUNCTION
ABSTRACT
AIM: To date, with the term "Temporomandibular Dysfunction" we indicate a set of pathological pictures involving ATM, masticatory muscles and related structures. In the current state of knowledge, the etiopathogenesis of these dysfunctions is not yet fully clarified. The researchers agree that a series of factors influence the course and constitute the "pattern". Between them, the scientific research has focused its attention on the "occlusal factor", which is still the most controversial and debated today. For his study he focused in particular on the analysis of the occlusal contacts analyzed by number and distribution by using conventional non-digital methods. No study has ever been able to clarify whether certain alterations in the distribution of occlusal contacts detectable on dysfunctional patients were prior or subsequent to the onset of dysfunction and what its role was. The continuous development of technologies in the biomedical field, has made available to researchers a digitized tool, the T-Scan III, able to analyze the occlusal contacts from the point of view of the force that is expressed on them and of their behavior over time.
The purpose of this work is to perform a translational research on the digitized analysis of the occlusal forces applied to the patient with temporomandibular dysfunction to evaluate the possibility of its use to support the clinician both during the diagnostic evaluation and in the control phase.
MATERIALS AND METHODS: The research is divided into four different phases with a progressive deepening in the evaluation of the data detected by means of the tool. In a first phase, data were compared to 28 healthy subjects with those coming from tests carried out on 35 patients with a diagnosis of temporomandibular dysfunction formulated according to the diagnostic criteria DC / TMD. After this phase, the number of patients under examination was expanded to 160. In the second phase the research was carried out to bring out possible relationships between a given pattern of occlusal forces and a given clinical picture. In the third phase, the occlusal force patterns detected before and after treatment with occlusal splints were compared. Finally, the possible correlation between the distribution of occlusal forces and the three main symptoms associated with dysfunction was studied: cervicalgia, headache, joint pain. The analysis of the occlusal forces was carried out by evaluating the following parameters: percentage of the force referred to the single dental element, to the side (right and left), to the sector (posterior and anterior); behavior of the COF (Center of Occlusal Forces); trend of the black line; occlusiontime (OT); the disclusiontime (DT).
RESULTS: The analysis of results highlighted the differences between healthy subjects and dysfunctional patients both from the point of view of the model of distribution of occlusal forces and from the point of view of the behavior of the COF. In the subsequent study phases it was found that there are differences in tendencies that can correlate a given model of force distribution and a given clinical picture. In the research phase on the relationship between occlusal forces and symptoms, it was possible to observe a predictable behavior between occlusal force and symptom intensity evaluated according to the VAS scale. The phase of the research carried out on patients treated with splint, has shown that the evaluation of the forces allows detecting changes in the course of treatment
In vitro assessment of normal and pathological dental structures by nuclear magnetic resonance micro-imaging at high field
Full text linkAims: Aim of this work is to analyze the various field of application of Magnetic Resonance Imaging in endodontics and highlight its current advantages and limitations due to understand its future application in research and clinical practice. The effectiveness in revealing the presence or absence of a pathological condition affecting enamel, dentin, endodontic space and the quality of the apical seal of an endodontic sealing technique was investigated.
Materials and methods: Three extracted monoradicular teeth were analyzed using a Bruker Avance-400 high-resolution spectrometer operating at 9.4 T with a microimaging probe (10 mm internal diameter), equipped with a gradient unit characterized by a maximum gradient strength of 1200 mT/m and a rise time of 100 μs. XWINNMR® and ParaVision® 3.0 software were employed for data acquisition and analysis. Images of teeth were weighted in T2 at different TE to measure T2 relaxation times and in Apparent Diffusion Coefficient (ADC) in different regions of interest (ROI).
Results: T2 and ADC values were obtained at different ROI. Clear images of carious lesions, periodontal tissues, pulpar remnants and endodontic materials such as guttapercha cones were acquired. Presence of microcracks and a calcification of the pulp were also clearly differentiated.
Conclusions: Micro MRI is a non-invasive, non-destructive tool for the assessment of pathological conditions affecting dental hard and soft tissues, and it may help in finding endodontic procedural mistreatments such as incomplete detersion or inadeguate tridimensional filling in vitro
Vaporization techinque by CO2 laser as a treatment of the oral leukoplakia: clinical study
No full textAim: To determine the sufficient safety margins during laser vaporization of oral leukoplakia as a trial to reduce the recurrence. Introduction: Definitive treatment of oral leukoplakia is essential because of its recurrence and potentiality to the malignant transformation. CO2 laser vaporization is characterized by being with minimal damage to the adjacent tissues, limited scarring, little wound contraction, and low post-operative complications. Materials and Methods: This study was conducted on 36 true leukoplakia lesions and diagnosed in 34 patients (20 Females and 14 Males). The range of the patients age was between 39 and 79 years. The lesions were divided into three groups; Group A: 11 lesions in 11 patients, in which the laser vaporization was done for the entire lesion adding a maximum of 1 mm of safety margins; Group B: 9 lesions in 7 patients, in which the laser vaporization was done for the lesion adding at least 3 mm of safety margins; and finally the Control Group: consists of 16 lesions in 16 patients. During six months after the laser vaporization, four follow-up visits were performed in order to evaluate the healing course and to evaluate the recurrence rate and its degree. Results: Among all the completely healed lesions, 75% of which were in groups A and B while 25% were in the Control Group. In this study, it was observed that some of the vaporized lesions which showed partial or complete recurrence after 6 months of follow-up, have shown an initial recurrence after 3 weeks of laser vaporization. The best results were obtained in patients with no history of smoking habits as the complete healing was 87.5% (7 of 8 lesions) and the complete recurrence was 12.5% (1 of 8 lesions). However, in ex-smokers, the complete healing was 41.5% (5 of 12 lesions), the partial recurrence was 41.5% (5 of 12 lesions), and complete recurrence was 17% (2 of 12 lesions). Discussion: The primary treatment of oral leukoplakia focuses on the elimination of associated risk factors (smoking, alcohol, and local irritating factors). In the literature, the recurrence rate varies between 13.6 and 40.7%, while in our study, after 6 months of follow-up, it was 45% in Group A and 33% in Group B. Conclusion: The recommended optimal safety margins should be at least 3 mm in width; in addition, deep surgical margins may be related to the recurrence of oral leukoplakia. Further research can be performed to evaluate the immediate re-vaporization of the lesions which showed an initial recurrence after 3 weeks of vaporization
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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