95 research outputs found
Frequency of Temporomandibular Disorders in Asymptomatic Removable Partial and Complete Denture Wearers
A dogmatic view on occlusion as the main aetiological factor for temporomandibular disorder (TMD) has been present in the literature for a long time, but a direct scientific correlation between occlusal disorders and TMD has never been proven. The purpose of this study was to determine the frequency of TMD signs and tissue-specific diagnoses in a population of 164 asymptomatic participants, 70 removable partial denture wearers and 94 complete denture wearers of an average age of 61.3 years, by means of clinical manual functional analysis. TMD was found in 42.1% of the participants. No statistically significant difference in the occurrence of TMD was found between removable partial and complete denture wearers and between genders (P > 0.05). The most frequent tissue-specific diagnoses were osteoarthrosis (11%), total anterior disc displacement (9.1%) and partial anterolateral disc displacement (8.5%). The frequency of tissue-specific diagnoses was also not influenced by the type of prosthetic replacements
Registration and Measurement of Right and Left Mediotrusion by using the Method of Electronic Axiography
PURPOSE. The aim of this study was to register and measure lower jaw movements and to analyse the measured length of maximal right and left mediotrusion movement in asymptomatic and symptomatic subjects.
MATERIALS AND METHODS. A symptomatic group consisted of 51 subjects with temporomandibular disorders. A control group consisted of 43 subjects without signs and symptoms of temporomandibular joint disorders. In the symptomatic group of subjects signs and symptoms of temporomandibular disorders were crepitation, bruxism, sensitivity, pain in the temporomandibular
joint and muscles, as well as pain and sensitivity in the region surround and anterior to the ear, together with difficulties while opening the mouth. Each subject was registered by the GAMMA CADIAX system for registration of positions and movement of the lower jaw, which consist of a convetional SAM axiograph, electronic device for drawing of curves with a computer.
RESULTS. No significant differences were found between the groups of subject for the measured variables.
CONCLUSION. The results of the length of the mandibular and condyle movements are important, alhough unreliable indicators of temporomandibular join function. Description analysis of a graphic recording of mandibular and TMJ movement remains a precise evaluation method for determination of TMJ dysfunction
Control and Correction of Occlusal Relations of Complete Dentures
Control and correction of occlusal relations are a constituent part of clinical and laboratory procedures of complete denture fabrication. Denture materials and fabrication procedures cannot ensure dimensionally correct complete dentures, and therefore it is necessary to check the occlusion. A remount procedure is carried out in order to establish correct occlusal contacts of denture teeth by
mounting the finished dentures back on the articulator. There are several reasons for remounting: changed volume of the acrylic resin during polymerisation, dimensional changes in the early days of wearing due to water absorption in the acrylic base and placement of denture bases to the denture foundation area. Remounting starts
with fabrication of transfer casts, determination and transfer of interarch relations to the articulator. When the dynamic concept of occlusion is chosen, priority is given to incisor or canine teeth guided occlusion. Remounting should be a constituent part of complete denture fabrication. Supported by Ministry of Science and Technology.
Republic of Croatia, Project No. 065010
Control and Correction of Occlusal Relations of Complete Dentures
Control and correction of occlusal relations are a constituent part of clinical and laboratory procedures of complete denture fabrication. Denture materials and fabrication procedures cannot ensure dimensionally correct complete dentures, and therefore it is necessary to check the occlusion. A remount procedure is carried out in order to establish correct occlusal contacts of denture teeth by
mounting the finished dentures back on the articulator. There are several reasons for remounting: changed volume of the acrylic resin during polymerisation, dimensional changes in the early days of wearing due to water absorption in the acrylic base and placement of denture bases to the denture foundation area. Remounting starts
with fabrication of transfer casts, determination and transfer of interarch relations to the articulator. When the dynamic concept of occlusion is chosen, priority is given to incisor or canine teeth guided occlusion. Remounting should be a constituent part of complete denture fabrication. Supported by Ministry of Science and Technology.
Republic of Croatia, Project No. 065010
Transport, magnetic and superconducting properties of RuSr2RCu2O8 (R= Eu, Gd) doped with Sn
Ru{1-x}Sn{x}Sr2EuCu2O8 and Ru{1-x}Sn{x}Sr2GdCu2O8 have been comprehensively
studied by microwave and dc resistivity and magnetoresistivity and by the dc
Hall measurements. The magnetic ordering temperature T_m is considerably
reduced with increasing Sn content. However, doping with Sn leads to only
slight reduction of the superconducting critical temperature T_c accompanied
with the increase of the upper critical field B_c2, indicating an increased
disorder in the system and a reduced scattering length of the conducting holes
in CuO2 layers. In spite of the increased scattering rate, the normal state
resistivity and the Hall resistivity are reduced with respect to the pure
compound, due to the increased number of itinerant holes in CuO2 layers, which
represent the main conductivity channel. Most of the electrons in RuO2 layers
are presumably localized, but the observed negative magnetoresistance and the
extraordinary Hall effect lead to the conclusion that there exists a small
number of itinerant electrons in RuO layers that exhibit colossal
magnetoresistance.Comment: 10 pages, 9 figure
Coherence lengths and anisotropy in MgB2 superconductor
Field and temperature microwave measurements have been carried out on MgB2
thin film grown on Al2O3 substrate. The analysis reveals the mean field
coherence length xi_{MF} in the mixed state and a temperature independent
anisotropy ratio gamma_{MF} = xi_{MF}^{ab} / xi_{MF}^c approximately 2. At the
superconducting transition, the scaling of the fluctuation conductivity yields
the Ginzburg-Landau coherence length with a different anisotropy ratio
gamma_{GL} = 2.8, also temperature independent.Comment: submitted to PR
Upper critical field, penetration depth, and depinning frequency of the novel high-temperature superconductor LaFeAsOF studied by microwave surface impedance
Temperature and magnetic field dependent measurements of the microwave
surface impedance of superconducting LaFeAsOF (\Tc
26K) reveal a very large upper critical field (T) and a
large value of the depinning frequency (GHz); together with an
upper limit for the effective London penetration depth, , our results indicate a strong similarity between this system and
the high- superconducting cuprates.Comment: 4 pages, 6 figures, minor corrections and rephrasin
Influence of Occlusal Interference on the Prevalence of Temporomandibular Disorders
The significance of occlusal interference in the etiology of temporomandibular disorders has been questioned in numerous recent articles. The aim of this study was to determine the prevalence of the clinical signs and symptoms of temporomandibular disorders in a young male nonpatient population and to investigate a possible association between the signs and symptoms of temporomandibular disorders and occlusal interference. A questionnaire including data from history and clinical functional
examination was used in the study. All subjects (a total of 230) were male (army recruits), of 19 to 28 years of age (mean 21.3). Temporomandibular joint clicking was reported in 91 subjects, temporomandibular joint pain on palpation and functional loading in 78 subjects, masticatory muscle pain on palpation and functional loading in 58 subjects, tension type headache in 30 subjects, and
mandibular deviation on opening and closing movements greater than 2 mm in 43 subjects. The prevalence of occlusal interference in percentage in 230 young adults, 65% had no occlusal interference during examination of the functional state of occlusion, while 14%subjects had centric slide between centric relation and maximum intercuspation, 5% subjects had working side interference and
16% subjects had non-working side interference during lateral and protrusive mandibular movements. Clinical signs and symptoms were correlated with occlusal interference, although their correlation cannot be considered unique or dominant in definition of a temporomandibular disorder population
Decoupled CuO_2 and RuO_2 layers in superconducting and magnetically ordered RuSr_2GdCu_2O_8
Comprehensive measurements of dc and ac susceptibility, dc resistance,
magnetoresistance, Hall resistivity, and microwave absorption and dispersion in
fields up to 8 T have been carried out on RuSr_2GdCu_2O_8 with the aim to
establish the properties of RuO_2 and CuO_2 planes. At ~130 K, where the
magnetic order develops in the RuO_2 planes, one observes a change in the slope
of dc resistance, change in the sign of magnetoresistance, and the appearance
of an extraordinary Hall effect. These features indicate that the RuO_2 planes
are conducting. A detailed analysis of the ac susceptibility and microwave data
on both, ceramic and powder samples show that the penetration depth remains
frequency dependent and larger than the London penetration depth even at low
temperatures. We conclude that the conductivity in the RuO_2 planes remains
normal even when superconducting order is developed in the CuO_2 planes below
\~45 K. Thus, experimental evidence is provided in support of theoretical
models which base the coexistence of superconductivity and magnetic order on
decoupled CuO_2 and RuO_2 planes.Comment: 11 pages, 11 figures, submitted to PR
A Transport and Microwave Study of Superconducting and Magnetic RuSr2EuCu2O8
We have performed susceptibility, thermopower, dc resistance and microwave
measurements on RuSr2EuCu2O8. This compound has recently been shown to display
the coexistence of both superconducting and magnetic order. We find clear
evidence of changes in the dc and microwave resistance near the magnetic
ordering temperature (132 K). The intergranular effects were separated from the
intragranular effects by performing microwave measurements on a sintered
ceramic sample as well as on a powder sample dispersed in an epoxy resin. We
show that the data can be interpreted in terms of the normal-state resistivity
being dominated by the CuO2 layers with exchange coupling to the Ru moments in
the RuO2 layers. Furthermore, most of the normal-state semiconductor-like
upturn in the microwave resistance is found to arise from intergranular
transport. The data in the superconducting state can be consistently
interpreted in terms of intergranular weak-links and an intragranular
spontaneous vortex phase due to the ferromagnetic component of the
magnetization arising from the RuO2 planes.Comment: 20 pages including 6 figures in pdf format. To be published in Phys.
Rev.
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