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$_2$ 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 LaFeAsO0.9_{0.9}F0.1_{0.1} studied by microwave surface impedance

Temperature and magnetic field dependent measurements of the microwave surface impedance of superconducting LaFeAsO$_{0.9}$F$_{0.1}$ (\Tc $\approx$ 26K) reveal a very large upper critical field ($B_{\rm c2} \approx 56$T) and a large value of the depinning frequency ($f_{0}\approx 6$GHz); together with an upper limit for the effective London penetration depth, $\lambda_{\rm eff} \le 200 \rm nm$, our results indicate a strong similarity between this system and the high-$T_{\rm c}$ 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.