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1

FEM simulation of a novel medical device for TMJ therapy

Kwieciński K., Żmudzki Jarosław, Chladek G., Popielski P., Kowalczyk M., Duraj E., Sołtysiak-Niedziela M.

Archives of Materials Science and Engineering

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2023

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Vol. 122, nr 1

34--41

EN

Purpose: Temporomandibular disorders (TMD) are one of the leading health problems in dentistry. The work aimed to evaluate, using FEM, the influence of the material elastic properties of the flexible obstacle of the tongue trainer on the range of deflection and strength. Design/methodology/approach: In prototyping the trainer tongue, the starting point was real models with different extents of the tongue obstacle. moulded from dental wax on a dental stone model. Then versions were tested intraorally for the perception of the space occupied by the tongue. The models were scanned on a 3D scanner, and then a parametric CAD model (NX Siemens) was made on their basis. Finally, in order to take into account, the anatomical aspects, the two extreme ranges of the tongue obstacle, named "Long " and " Short ", were developed. Simulation deflection and material strength tests were made using FEM in the linear range (NX Siemens). Calculations were made for materials with Young's modulus equal to 8 MPa, 80 MPa and 800 MPa. The interaction of the tongue with the force of 5N was assumed. The support was provided by the retention surface on the teeth, with the support of the posterior edge of the obstacle on the palate (palatal variant) or lack of support, i.e., the obstacle freely bending in this area (free variant), was additionally tested. In order to assess the drop or retention of the trainer on the teeth, the second type of simulation was performed with the assumption of horizontal (anteriorly directed) tongue pressure with the force of 10N for the condition of rigid support in the area of the teeth and the periodontal zone from the lingual side. In this variant, a simulation was adopted for a material with a modulus of elasticity E=80 MPa. Findings: The stress values of the flexible obstacle of the trainer were obtained, allowing for the selection of potentially valuable materials for the trainer's construction. The results obtained in the simulations indicate the possibility of using ethylene vinyl acetate (EVA) and its blends. The accumulation of saliva inside the sealed obstacle was found, which indicated the need to look for an area to perforate without losing the load capacity of the obstacle. The structural feasibility of solving the problem of saliva accumulation without a significant change in the load capacity and stiffness of the obstacle was confirmed by simulation. Research limitations/implications: Simplifying the model to a linear range does not allow buckling analysis. In addition, the assumption of a linear material further limits the possibility of analysing materials with softening and plateau characteristics, where the compliance of the structure leads to elastic buckling. Practical implications: The range of deflections and stresses for different stiffness of the elastic element of the trainer was determined in order to select the appropriate material for the medical device (MD). Polyurethanes or silicones provide the range of deflection and strength, but in the case of manufacturing prefabricated trainers thermoformed in the patient's mouth (maximum temperature 75°C), the material that can be used is ethylene vinyl acetate (EVA). Originality/value: Simulation tests made it possible to determine the range of deflections and stress for different stiffness of the flexible obstacle of the trainer in order to select the appropriate material for the medical device.

2

Recent advance in appliances and materials enhancing therapy of disorders of the stomatognathic system

Sołtysiak-Niedziela M., Kwieciński K., Żmudzki J.

Archives of Materials Science and Engineering

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2018

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Vol. 90, nr 2

74--84

EN

Purpose: Dysfunctions of the stomatognathic system are treated with a lot of appliances. The aim of the work was to evaluate the current state in the field of diagnostic techniques and technological advance in appliances and materials enhancing therapy of occlusion disorders of the stomatognathic system. Design/methodology/approach: The principles of appliances functioning, manufacturing technology and materials were analysed. The analysis was made on the basis of the literature review and patent databases, conducting searches for a combination of keywords: dental material, occlusion, disorder, bruxism, clenching, grinding, appliance, therapy, tongue, oral, exerciser, trainer, mandible muscle, bite splint, dental plate. In the case of principles of functioning, devices that require insertion into the mouth are included in the tests. In technology and materials, attention has been paid to necessity of involving a dental technician or ability to perform appliance intra-orally ("chairside"), as well as mass production with possibility of custom fit. Findings: The most widespread in the treatment of disorders of the stomatognathic system are thermoformed materials and devices that are introduced between the dental arches to counteract occlusions of all teeth or selected teeth or force the position of the mandible in relation to the maxilla. Devices that function differently are those in which therapeutic effects result from toning of activity of the elevating mandibular muscles by provoking activity of the opposing muscles lowering the mandible or reducing intra-oral space, for example, by sublingual plates or tongue trainers. Appliances are mainly manufactured of: poly (ethylene- vinyl acetate) or polycarbonates, as also mouldable polymers such as: acrylics, polyesters and rubbers. Research limitations/implications: Electronic devices that are not intended to therapy but used only to track mandible mobility or muscle activity during sleep were not taken into account. Practical implications: Solutions activating the action of the opposing muscles to the muscles lifting the mandible are few, and among them one device is retained on teeth without interfering in occlusion. Originality/value: Dental materials for dev/ices for treatment of occlusion disorders are selected with no understanding tines influence of elastic and frictional material properties and structures stiffness on the distribution of occlusion forces between the teeth and reactions in temporo-mandibular joints.

3

Środowiskowe uwarunkowania zaburzeń w zachowaniu w kontekście zakłóceń układu ekologicznego

Jurczyk M.

Journal of Ecology and Health

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2013

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R. 17, nr 2

91--99

PL

Zdrowie psychiczne każdego człowieka oraz to, kim się stanie w przyszłości w głównej mierze uwarunkowane jest czynnikami środowiskowymi. Podstawowe ekosystemy oddziaływujące na jednostkę oraz mające największy wpływ na rozwój wszelkich nieprawidłowości psychicznych to środowisko szkolne, rodzinne oraz rówieśnicze. Wszelkie negatywne zmiany w tychże ekosystemach w konsekwencji prowadzą do rozwoju zaburzeń w zachowaniu, które warunkują rozwój cech patologicznych jednostki. Tekst przedstawia główne spojrzenie na problematykę zaburzeń w zachowaniu (na czynniki je warunkujące w kontekście zaburzonych ekosystemów, ich rodzaje, cechy osób niedostosowanych społecznie oraz skutki osobowościowe wadliwego przystosowania).

EN

The mental health of every human being, and who they will become in the future, depends mainly on environmental factors. The basic ecological systems influencing an individual and having the greatest impact on the development of all mental abnormalities are school, family and peers. All negative changes in these ecological systems lead in consequence to the development of behavioural disorders which constitute conditions for the development of pathological traits in an individual. The text presents a general overview of issues concerning behavioural disorders (factors behind their development in the context of disrupted ecological systems, their types, characteristics of socially maladjusted persons, and personality-related consequences of maladjustment).

4

Risk assessment and actions to reduction of risk in explosive environment

Paulicek T., Cico P., Zaujec J., Burda M.

Management Systems in Production Engineering

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2012

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nr 3 (7)

18-20

EN

This article deals with assessment and risk reduction measures in explosive atmospheres, respectively of natural gas filling station CNG for cars, lorries and buses. The filling station was monitored for two years and FMEA have been applied to define and evaluate deficiencies, suggest corrective measures to reduce the number of failures in the system. Application of the method FMEA helped by identifying and minimizing the likelihood of failures in the system, which is of great importance from the viewpoint of preventing the occurrence of adverse events.

PL

Artykuł zajmuje się oceną ryzyka i środków redukcji w przestrzeniach zagrożonych wybuchem, dla gazu ziemnego CNG na stacjach przy napełnianiu samochodów osobowych, ciężarówek i autobusów.Stacja paliw była monitorowana przez dwa lata gdzie zastosowano metodę FMEA do zdefiniowania i oceny braków, sugerując środki zaradcze w celu zmniejszenia liczby awarii w systemie. Zastosowanie metody FMEA pomaga poprzez identyfikację i minimalizację prawdopodobieństwa wystąpienia awarii w systemie, co ma ogromne znaczenie z punktu widzenia zapobiegania występowaniu działań niepożądanych.

5

Kondycja architektury naszej współczesności: primum; secundum; czyżby też i tertium datur?

Włodarczyk J. A.

Architecturae et Artibus

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2012

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Vol. 4, no. 1

58-64

PL

W odwołaniu się do przykładów architektury międzywojnia (wczesny modernizm), jako też PRL-u (modernizm dojrzały), autor próbuje scharakteryzować i uporządkować obraz polskiej architektury, czy lepiej: przestrzeni ostatniego ćwierćwiecza, zaistniałej po roku 1989 w Polsce, w nowych warunkach politycznych, społecznych i gospodarczych. Obraz ten jawi się jako bardzo zróżnicowany: od liczących się osiągnięć w zakresie formy i funkcji, logiki czasu i miejsca, po totalną dezorganizację, chaos przestrzenny i brzydotę

EN

With reference to architecture of the early modernity of the between-two-world-wars time and the after-the-second-worldwar (polish people’s republic), the author tries to characterize and to tidy the picture of architecture and urban space realized after the year 1989, times of the new order of the policy, the social conditions and economy. This picture seems to be extremely differentiated: from the big achievements in form and function to completely disorganisation and ugliness of the architectural space.

6

Fałszywe alarmy pożarowe

Kośnik J.

Bezpieczeństwo i Technika Pożarnicza

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2007

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Nr 2

179--188

PL

Nowe systemy radiokomunikacyjne i teleinformatyczne wprowadzają zagrożenia w prawidłowej pracy Systemów Automatyki Pożarniczej. Działające na czujkę pożarową pole elektromagnetyczne telefonu komórkowego GSM lub bezprzewodowej lokalnej sieci komputerowej WLAN, może wywołać fałszywy alarm pożarowy. W analizie przyczyn alarmów posłużono się danymi statystycznymi otrzymanymi z Komendy Głównej PSP.

EN

New generation teleinformatic and radio systems bring distortions into Automatic Fire Systems. A fire picket which receive the electromagnetic field from a GSM mobile phone or from wireless local network (WLAN) can initiate a false fire alarm. Analyze of alarms reasons was realized based on

7

Conductivity and transmission coefficients of ultra-thin disordered metallic films

Spisak B.J., Paja A.

Materials Science Poland

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2006

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Vol. 24, No. 3

605--609

EN

The diffusive motion of quasi-two-dimensional electron gas through an ultra-thin system of disordered potentials is considered. In such system the Fermi sphere splits into a set of independent sheets due to the small thickness of the system. Each sheet can be seen as an electron sub-band. The electron transport goes through these sub-bands independently. The sum of electrical conductivities over these sub-bands determines the total current which is calculated for ultra-thin films of cesium. We also present the relation between our approach and Landauer formalism based on the notation of the transmission coefficient.

8

On the localization of electrons in disordered molecular wires

Wołoszyn M., Spisak B. J.

Materials Science Poland

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2004

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Vol. 22, No. 4

545--551

EN

The aim of this report is to investigate electronic properties of a chain of atoms when its translational symmetry is broken by a topological disorder. The study uses the inverse participant ratio to obtain information on the localization of electrons in phase space.

9

The crystal structure of bis(ethylammonium) pentachloroantimonate(III)-ethylammonium chloride (C2H5NH3)2SbCl5 (C2H5NH3)Cl at 295 and 90 K : On the deformation of the octahedral coordination of SbIII

Bujak M., Zaleski J.

Polish Journal of Chemistry

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1999

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vol. 73 nr 5

773-782

EN

Bis(ethylammonium) pentachloroantimonate(III)-ethylamonium chloride belongs to alkylammonium chloroantimonates(III). The anionic sublattice of (C2H5NH3)2SbCl5 × (C2H5NH3)cl is built of isolated Sb2Cl10 4- units composed of two SbCl-36 octahedra, connected by edge and two single chlorine Cl- ions. There are three crystallographically non-equivalent ethylammonium cations, two of them are disordered at room temperature and all of them are ordered at 90 K. The disorder is realized by two positions for carbon atoms. Ethylammonium cations are connected to the anionic sublattice by N-H…Cl hydrogen bonds. The influence of temperature and hydrogen bonds together with electrostatic interactions on the deformation of the octahedral coordination of SbIII is discussed.

10

Synthesis and crystal Structure of Bis(2-iminopent-2-en-4-onato)nickel(II)

Nowak E., Gdaniec M., Gierczyk B., Urbaniak W.

Polish Journal of Chemistry

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1999

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Vol. 73, nr 11

1757-1762

EN

Synthesis and crystal and molecular structure of the title compound have been performed. It crystallizes in the space group Cccca with 12 molecules in the unit cell. There are two crystallographically indendent molecules located on special positions with symmetry 2 or 222. Each molecule is disordered over two sites.