Can Fixed Space Maintainers Have Adverse Effect on the Teeth and Periodontium?

BACKGROUND Space maintenance after premature loss of primary teeth is of importance in preventing space loss and potential crowding in future. Fixed space maintainers are used to prevent space loss but the presence of such fixed appliances near the tooth and its supporting structures may have some adverse effects. The purpose of this study was to evaluate the potential adverse effects of fixed space maintainers on the teeth and periodontium. METHODS Twenty young children in mixed dentition period (between 8 – 11y 7m years old) who were considered for space maintainer treatment were selected. Each patient had bilateral first molars that went under the band for fixed space maintainer. The patients were examined for decayed, missed and filled teeth (DMFT), bleeding on probing, clinical attachment level, gingival index and periodontal pocket depth at the beginning (T0), one month (T1), three months (T2) and six months (T3) later. Repeated measures ANOVA then Post - hoc LSD (Friedman test for gingival index) tests were used to interpret the data. RESULTS As compared to the beginning of the study, at the end of the 6 months follow-up period DMFT of the involved first molars did not change significantly (P = 0.163). But bleeding on probing, clinical attachment level, gingival index and periodontal pocket depths changed significantly at the same time frame (P < 0.001). CONCLUSIONS The fixed space maintainers might have some adverse effects on the periodontal structures of the banded teeth, so the clinicians should insist more on oral hygiene instructions and the patients must be under intense oral hygiene control. KEY WORDS Space Maintainers, DMFT, Bleeding on Probing, Clinical Attachment Level, Periodontal Pocket Depth

Stress Evaluation of Various Breeding Environments in Mouse

Laboratory animals are raised in a fixed space during the study period and are environmentally bound. Laboratory animal may be under stress on the constrained environment, which changes physiological indicators, affecting the reproducibility and accuracy of animal study. Therefore, reducing animal stress by providing proper breeding environment and environmental enrichment can be the basis for animal study. In this study, the stress level was assessed according to the mouse breeding environment. According to the results of the experiment, it was determined that the individual ventilation cage had less cortisol concentration in serum and body weight increased in the individual ventilation cage than individual isolated cage, when providing environmental enrichment rather than group breeding or not providing environmental enrichment. The results will provide appropriate guidelines for laboratory animal welfare.

NORMAL REFLECTION SUBGROUPS OF COMPLEX REFLECTION GROUPS

We study normal reflection subgroups of complex reflection groups. Our approach leads to a refinement of a theorem of Orlik and Solomon to the effect that the generating function for fixed-space dimension over a reflection group is a product of linear factors involving generalised exponents. Our refinement gives a uniform proof and generalisation of a recent theorem of the second author.

COGNITIVE-PRAGMATIC APPROACH TO CATEGORIZATION: THEORY OF ROBERT MACLAURY

The purpose of the article is to determine the principles of Robert MacLaury’s Vantage Theory and to review its application in various linguistic studies.Methods, used in the paper, include analysis and description, the application of which was conditioned by the task to distinguish the main tenets of the Vantage Theory and to present experience of its application in various linguistic studies. Results. A groundbreaking theory of R. MacLaury has overcome the lack of explanatory power of cognitive grammar and the prototype theory. The starting point of the Vantage Theory is the recognition that categorization takes place on analogy of human’s orientation on terrain with regard to movement. Adapted by primitive people for information processing, the cognitive mechanism of orientation in space and time is deeply rooted in human consciousness. Any category appears in comparison with images or other types of discrete ideas that correspond to fixed space-time coordinates to which observer’s attention is drawn while detecting similarities and differences in the object of perception. The categorization model consists of three levels, which correspond to a pair of fixed and variable coordinates. A person can focus on only one pair of coordinates at a time, others are stored in memory as proven facts, which become a prerequisite for inference and an integral part of the categorization model. Apart from numerous works on colour semantics, the theory is applied to address a wide range of issues in sociolinguistic studies, discourse analysis, cognitive grammar, etc. The theory is also applicable in the study of verbalized sociocultural stereotypes. The author of the article uses the Vantage Theory in the cognitive-linguistics study of sociocultural stereotypes in American media discourse. As verbalized, conventionally evaluative patterns of social groups, sociocultural stereotypes are formed in comparison with the ethical, behavioural, and aesthetic standards of American culture that act as fixed coordinates of mental space.Conclusions. The Vantage Theory of Robert MacLaury is a further step in the development of cognitive linguistics. The universality of this theory lies in its ability to explain many linguistic facts and therefore it can be applied in the study of a wide range of issues related to the linguistic representation of knowledge, such as concepts and stereotypes, which are categories of a verbalized picture of the world.Key words: vantage theory, categorization, space-time orientation, perspectivization, sociocultural stereotype. Мета статті полягає у визначенні основних положень теорії побудови перспектив Роберта Маклорі та огляді її застосування у лінгвістичних студіях різної спрямованості.Методи дослідження включають аналіз та опис, застосування яких зумовлене завданням виділити окремі положення, представити складну для розуміння теорію, виявити можливості її пристосування для різних дослідницьких цілей у лінгвістичних дослідженнях.Результати. Вихідним положенням цієї теорії є визнання того, що категоризація проходить за глибоко вкоріненою в людську свідомість аналогією орієнтації людини на місцевості з урахуванням руху. Категорії виникають у процесі пізнавальної взаємодії з фіксованими та змінними координатами, які створюють різні перспективи, аналогічні тим, що люди використо-вують для орієнтації у фізичному просторі. Будь-яка категорія формується у зрівнянні з визначеними образами чи іншими видами дискретних ідей, при цьому увага людини фіксується на подібності та різниці до встановлених образів. Модель категоризації складається з трьох рівнів, що співвідносяться з парою фіксованої і змінної координати. Людина може концентрувати увагу тільки на одній парі координат, інші зберігаються в пам’яті як доведені факти, які стають передумовою умовиводів та невід’ємною частиною категоризаційної моделі. Теорія успішно використовується у дослідженнях дискурсу, лексичній семантиці, у соціолінгвістиці та когнітивній граматиці. Автор статті використає теорію Маклорі у лінгвокогнітивному дослідженні соціокультурних стереотипів американського медіадискурсу. Як вербалізовані конвенційно-оцінні зразки соціальних груп, соціокультурні стереотипи формуються у зрівнянні з етичними, поведінковими та естетичними стандартами американської культури, що діють як фіксовані координати ментального простору.Висновки. Теорія Маклорі є подальшим кроком у розвитку когнітивної лінгвістики. Універсальність цієї теорії полягає в тому, що вона може бути застосована у дослідженнях широкого кола питань, що стосуються мовної репрезентації знання у вербалізованих концептах та стереотипах як категоріях мовленнєвої картини світу.Ключові слова: теорія побудови перспектив, просторово-часова орієнтація, фіксовані і змінні координати, перспективізація, вербалізований соціокультурний стереотип.

PREDICTING THE STATE OF THE ICE BARRIER OF A VERTICAL MINE SHAFT UNDER ARTIFICIAL THAWING

At the end of the shaft penetration under the protection of the ice barrier and the termination of the process of freezing the rocks, the transition period from freezing to thawing begins. First of all, the tubing support of the trunk and the layer of rocks adjacent to the concrete support are subjected to thawing. At this time, water is pumped through the grouting holes in the tubing to check the tightness of the tubing column, after which the grouting is performed with cement mortar of the fixed space. Thus, grouting is an integral part of the work on waterproofing the support. For successful work on grouting, it is necessary to ensure the thawing of the ice barrier by a value of 1 m from the contour of the trunk in the sinking. The necessary defrosting can be provided in various ways, including the circulation of warm air in the barrel, the supply of warm coolant to the freezing columns, etc. A program for calculating the defrosting parameters has been developed, depending on the combination of methods for supplying warm air and heated brine. It is determined that in order to create reliable conditions for the production of plugging of the fixing space and water-proofing of the tubing support, the most favorable option is thawing by feeding warm air into the barrel and circulating the coolant at a temperature of +15°C.

Effects of Fixed and Removable Space Maintainers on Dental Plaque and DMFT/dft Values

Purpose: Space maintainers are important for the health and placement of children’s primary and permanent teeth. However, plaque and caries levels can be negatively affected when a dental appliance is in the mouth. This study aims to evaluate the oral health of pediatric patients that have space maintainers applied as a result of early tooth loss. Methods: This study included 100 systemically healthy patients between the ages of 4-15 years that were treated with space maintainers due to early loss of teeth. Decayed, missing, filled tooth index values and dental plaque status of the participants were recorded. Controls were performed in the 6th and 12th month. The index results were compared and evaluated statistically using ANOVA and paired-t-tests. Results: A total of 116 space maintainers, including 36 band and loops, 16 lingual arches, 21 palatal arches, 43 removable appliances, were evaluated in the study. Statistically significant differences were found between the pre-treatment and post-treatment index values (p<0.001). In the group of band and loops and removable space maintainers; the increases in DMFT/dft values of 6th month and 12th month according to initial DMFT/dft values were statistically significant (p<0.05). For plaque index, the increase in 12th month of all types of appliances were found statistically significant (p<0.001). The greatest increase in plaque index level was seen in the teeth of patients that had been treated with a lingual arch. Conclusions: Incompatible space maintainers can lead to caries, increased plaque accumulation, demineralized areas, and periodontal problems. The accumulation of plaque and difficulty of cleaning the teeth, especially in the fixed space maintainers, negatively affects the health of teeth. For this reason, good oral hygiene should be provided to patients and controls should be regularly performed.

Semi-Fixed Space Maintainer Treatment In Premature Loss Deciduous Tooth

Introduction: The period of deciduous teeth is an important period in child development. Damage to deciduous teeth that occur and cannot be treated conservatively will cause premature decay of teeth which is often called premature loss. A space maintainer is a passive tool used to maintain dental arches due to premature loss of deciduous teeth. Method: An 11-year-old girl accompanied by her mother came to RSGMP Unjani in 2018 with complaints of lower right back teeth missing because they have removed. The patient's mother is worried that her replacement teeth will not grow properly. Intraoral examination revealed tooth loss 85. The study model was analyzed using the Moyers method. Results: Analysis of the lower jaw model showed excess space. Patients were treated with a semi-fixed band and loop space maintainer on teeth 85. Conclusion: Premature loss results in excess space in the arch, so as to prevent further occlusion abnormalities in the child's growth and development process, we need a special tool used to maintain space due to premature loss of deciduous teeth.