Sample records for partial molar volume

  1. Partial molar volumes of amino acid derivatives in water

    Microsoft Academic Search

    Fereidoon Shahidi

    1983-01-01

    The partial molar volumes at infinite dilution for a number of hydrochlorides and sodium salts of N-methyl derivatives of a, ?-aminocarboxylic acids in water at 25°C are measured and related to their van der Waals volumes. Results indicate that 4.96±0.48 water molecules hydrate a betaine hydrochloride. Volumes of proton ionization and interaction terms are evaluated. Group contributions to the partial

  2. Partial molar volumes of uni-univalent electrolytes in methanol + water; 1: Lithium chloride, sodium chloride, and potassium chloride

    SciTech Connect

    Takenaka, Nobuo; Takemura, Takeshi; Sakurai, Masao (Hokkaido Univ., Sapporo (Japan). Research Inst. for Electronic Science)

    1994-04-01

    Densities of methanol + water + lithium chloride, + sodium chloride, and + potassium chloride were measured at 15, 25, 35, and 45 C. The apparent molar volumes of the electrolytes in these mixtures were calculated, and the apparent molar volumes at infinite dilution, the partial molar volumes, and partial molar thermal expansivities were evaluated.

  3. Apparent molar and partial molar volumes of aqueous ceric ammonium nitrate solutions at 20, 25, 30, and 35°C

    NASA Astrophysics Data System (ADS)

    Deosarkar, S. D.; Wanale, S. G.; Shelke, M. P.

    2014-07-01

    Present paper reports the measured densities (?) and refractive indices ( n D) of aqueous solutions of ceric ammonium nitrate (CAN) at 20, 25, 30, and 35°C in different concentrations of solution. Apparent molar volumes (?v) have been calculated from the density data at different temperatures and fitted to Massons relation to get limiting partial molar volumes (?{v/0}) of CAN. Refractive index data were fitted to linear dependence over concentration of solutions and values of constant K and n {D/0} for different temperatures were evaluated. Specific refractions ( R D) of solutions were calculated from the refractive index and density data. Concentration and temperature effects on experimental and derived properties have been discussed in terms of structural interactions.

  4. Fluctuation-based computer calculation of partial molar properties. I. Molecular dynamics simulation of constant volume fluctuations

    Microsoft Academic Search

    Pablo G. Debenedetti

    1987-01-01

    Partial molar volumes, energies, and enthalpies are calculated via the (N,U,V) molecular dynamics implementation of their corresponding operational definitions in terms of constant volume fluctuations. The method is exact for the former property but only approximate for the latter two. The partial molar volume operational definition satisfies Euler’s homogeneous function theorem identically. The corresponding energy definition is based upon a

  5. How big is the hydrated electron? Thermodynamics of electron solvation and its partial molar volume

    NASA Astrophysics Data System (ADS)

    Bartels, David

    2015-03-01

    Several models for the hydrated electron solvation structure have been proposed, which all can do a reasonable job of reproducing the room temperature optical spectrum. As Larsen, Glover and Schwartz demonstrated, tweaking the electron-water pseudopotential can completely change the structure from a cavity to a non-cavity geometry. Deciding between the competing models then requires comparison with other observables. The resonance Raman spectrum and the temperature dependence of the optical spectrum can be cited as evidence in favor of a non-cavity structure. In the present work we will re-examine the thermodynamics of hydration. In particular, we will present new experimental and simulation results for the partial molar volume, which can bear directly on the cavity vs. non-cavity controversy. DMB is supported by the U.S. Department of Energy Office of Science, Office of Basic Energy Sciences under Award Number DE- FC02-04ER1553.

  6. Studies of Partial Molar Volumes of Some Narcotic-Analgesic Drugs in Aqueous-Alcoholic Mixtures at 25°C

    NASA Astrophysics Data System (ADS)

    Sharma, Poonam; Chauhan, S.; Syal, V. K.; Chauhan, M. S.

    2008-04-01

    Partial molar volumes of the drugs Parvon Spas, Parvon Forte, Tramacip, and Parvodex in aqueous mixtures of methanol (MeOH), ethanol (EtOH), and propan-1-ol (1-PrOH) have been determined. The data have been evaluated using the Masson equation. The parameters, apparent molar volumes {(?_v)}, partial molar volumes {(?_v0)}, and S v values (experimental slopes) have been interpreted in terms of solute solvent interactions. In addition, these studies have also been extended to determine the effect of these drugs on the solvation behavior of an electrolyte (sodium chloride), a surfactant (sodium dodecyl sulfate), and a non-electrolyte (sucrose). It can be inferred from these studies that all drug cations can be regarded as structure makers/promoters due to hydrophobic hydration. Furthermore, the results are correlated to understand the solution behavior of drugs in aqueous-alcoholic systems, as a function of the nature of the alcohol and solutes.

  7. Limiting Partial Molar Volumes of Electrolytes in 2Methyl2Butanol + Water Mixtures at 298.15 K

    Microsoft Academic Search

    Eugenio Garcia-Pañeda; Pilar Guardado; Alfredo Maestre

    2004-01-01

    Partial molar volumes at infinite dilution, V02, of alkali–metal halides (LiCl, NaCl KCl RbCl CsCl, NaBr, KBr, KI), tetra-n-alkylammonium bromides, R4NBr (R=Me, Et, n-Pr, n-Bu, n-Pen), NaBPh4, and Ph4PCl have been determined in binary solvent mixtures of water with 2-methyl-2-butanol covering the water-rich region and the alcohol-rich region at 298.15 K. V02 for alkali–metal halides show relatively little dependence on

  8. Partial Molar Volumes of Some of ?-Amino Acids in Binary Aqueous Solutions of MgSO 4 ·7H 2 O at 298.15 K

    Microsoft Academic Search

    Bairagi C. Mallick; Nand Kishore

    2006-01-01

    The apparent molar volume, V\\u000a o\\u000a ?, 2, of glycine, alanine, ?-amino-n-butyric acid, valine and leucine have been determined in aqueous solutions of 0.25, 0.5 and 1.0 mol?dm?3 magnesium sulfate, and the partial specific volume from density measurements at 298.15 K. These data have been used to calculate the infinite dilution apparent molar volume, V\\u000a o\\u000a 2,m\\u000a , group contribution

  9. Octanol-Water Partition Coefficient from 3D-RISM-KH Molecular Theory of Solvation with Partial Molar Volume Correction.

    PubMed

    Huang, WenJuan; Blinov, Nikolay; Kovalenko, Andriy

    2015-04-30

    The octanol-water partition coefficient is an important physical-chemical characteristic widely used to describe hydrophobic/hydrophilic properties of chemical compounds. The partition coefficient is related to the transfer free energy of a compound from water to octanol. Here, we introduce a new protocol for prediction of the partition coefficient based on the statistical-mechanical, 3D-RISM-KH molecular theory of solvation. It was shown recently that with the compound-solvent correlation functions obtained from the 3D-RISM-KH molecular theory of solvation, the free energy functional supplemented with the correction linearly related to the partial molar volume obtained from the Kirkwood-Buff/3D-RISM theory, also called the "universal correction" (UC), provides accurate prediction of the hydration free energy of small compounds, compared to explicit solvent molecular dynamics [ Palmer , D. S. ; J. Phys.: Condens. Matter 2010 , 22 , 492101 ]. Here we report that with the UC reparametrized accordingly this theory also provides an excellent agreement with the experimental data for the solvation free energy in nonpolar solvent (1-octanol) and so accurately predicts the octanol-water partition coefficient. The performance of the Kovalenko-Hirata (KH) and Gaussian fluctuation (GF) functionals of the solvation free energy, with and without UC, is tested on a large library of small compounds with diverse functional groups. The best agreement with the experimental data for octanol-water partition coefficients is obtained with the KH-UC solvation free energy functional. PMID:25844645

  10. Density of some titanium-bearing silicate liquids and the compositional dependence of the partial molar volume of TiO 2

    NASA Astrophysics Data System (ADS)

    Dingwell, Donald B.

    1992-09-01

    The densities of thirteen silicate liquids along the Na 2SiO 3-TiO 2 and CaSiO 3-TiO 2 joins and six other titanium-bearing silicate liquids of the general formula X 2/nn+TiSiO 5 (where X = Li, Na, K, Rb, Cs, Ca, Sr, Ba) have been measured in equilibrium with air using the double Pt bob Archimedean method. The Na 2SiO 3-TiO 2 join was investigated from 10-50 mole% TiO 2 in the temperature range 1000-1150°C whereas the CaSiO 3-TiO 2 join was investigated from 10-80 mole% TiO 2 in the temperature range of 1400-1625°C. Density increases with TiO 2 content along both joins. Partial molar volumes of the binary endmembers, Na 2SiO 3 and CaSiO 3, and of TiO 2 have been computed. The partial molar volume of Na 2SiO 3 agrees well with that determined by BOCKRIS et al. (1955). The partial molar volume of CaSiO 3 is in disagreement with that of TOMLINSON et al. (1958). The partial molar volume of TiO 2 derived from a linear fit to the Na 2SiO 3-TiO 2 join is 27.6(3) cm 3/mole at 1150°C. The partial molar volume of TiO 2 derived from linear extrapolation of the CaSiO 3-TiO 2 data to TiO 2 at 1600°C is 24.3(4) cm 3/mole. Comparison of the partial molar volume data from these binary joins with TiO 2 liquid density data ( DINGWELL, 1991) requires the existence of a large positive excess volume in the Na 2SiO 3-TiO 2 system at 1150°C.

  11. Partial molar volumes of NiO and CoO liquids: implications for the pressure dependence of metal-silicate partitioning

    NASA Astrophysics Data System (ADS)

    Courtial, Philippe; Gottsmann, Joachim; Holzheid, Astrid; Dingwell, Donald B.

    1999-08-01

    Volumetric measurements have been conducted on 7 Ni- and Co-containing sodium disilicate liquids within a compositional range varying from 0 to 9 mol% of NiO and from 0 to 23 mol% of CoO and over a large temperature interval (i.e., above their respective glass transition temperature and up to at least 1473 K). Their molar volumes and thermal expansivities have been determined by combining high-temperature measurements using the Pt-based double-bob Archimedean method and low-temperature measurements using the method described by Webb et al. [S.L. Webb, R. Knoche, D.B. Dingwell, Determination of silicate liquid thermal expansivity using dilatometry and calorimetry, Eur. J. Mineral. 4 (1992) 95-104] based on an assumed equivalence of the relaxation of volume and enthalpy at the glass transition. The molar volume of the present liquids decreases with increasing NiO and CoO contents and the Co-containing liquids exhibit a greater molar volume than the Ni-containing liquids at equivalent molar concentrations. The present results were analysed using a regression equation from which the partial molar volume of NiO and CoO liquids was obtained by the least squares method. This procedure yields partial molar volumes valid over the entire temperature range of 11.506 ± 0.687 and 14.884 ± 0.149 cm 3/mol and temperature derivatives of 2.684 ± 1.6 × 10 -3 and 1.441 ± 0.4 × 10 -3 cm 3/mol K, respectively for NiO and CoO at 800 K. The behavior of M-Fe metal-silicate exchange partition coefficient (M = Ni, Co), based on present molar volume determinations, has been estimated as a function of pressure over a wide temperature range. The metal-silicate exchange partition coefficients of both Ni and Co decrease with increasing pressure within the entire temperature range considered in this study (i.e., 800-3000 K).

  12. Cul3-mediated Nrf2 ubiquitination and antioxidant response element (ARE) activation are dependent on the partial molar volume at position 151 of Keap1.

    PubMed

    Eggler, Aimee L; Small, Evan; Hannink, Mark; Mesecar, Andrew D

    2009-08-15

    Nrf2 (nuclear factor erythroid 2-related factor 2) is a transcription factor that activates transcription of a battery of cytoprotective genes by binding to the ARE (antioxidant response element). Nrf2 is repressed by the cysteine-rich Keap1 (kelch-like ECH-associated protein 1) protein, which targets Nrf2 for ubiquitination and subsequent degradation by a Cul3 (cullin 3)-mediated ubiquitination complex. We find that modification of Cys(151) of human Keap1, by mutation to a tryptophan, relieves the repression by Keap1 and allows activation of the ARE by Nrf2. The Keap1 C151W substitution has a decreased affinity for Cul3, and can no longer serve to target Nrf2 for ubiquitination, though it retains its affinity for Nrf2. A series of 12 mutant Keap1 proteins, each containing a different residue at position 151, was constructed to explore the chemistry required for this effect. The series reveals that the extent to which Keap1 loses the ability to target Nrf2 for degradation, and hence the ability to repress ARE activation, correlates well with the partial molar volume of the residue. Other physico-chemical properties do not appear to contribute significantly to the effect. Based on this finding, a structural model is proposed whereby large residues at position 151 cause steric clashes that lead to alteration of the Keap1-Cul3 interaction. This model has significant implications for how electrophiles which modify Cys(151), disrupt the repressive function of Keap1. PMID:19489739

  13. Density and sound speed measurements on model basalt (An-Di-Hd) liquids at one bar: New constraints on the partial molar volume and compressibility of the FeO component

    NASA Astrophysics Data System (ADS)

    Guo, Xuan; Lange, Rebecca A.; Ai, Yuhui

    2014-02-01

    Density and sound speed measurements were obtained over a wide range of temperature for three model basalt liquids in the An-Di-Hd (CaAl2Si2O8-CaMgSi2O6-CaFeSi2O6) system. High-temperature (1585-1838 K) double-bob density measurements were combined with low-temperature (943-930 K) measurements at the limiting fictive temperature for each sample to provide liquid volume data over a temperature interval of ?900 K. In addition, relaxed sound speeds were obtained with a frequency sweep acoustic interferometer from 1665-1876 K. An ideal mixing model for molar volume, thermal expansivity, and isothermal compressibility recovers the new data from this study and leads to the following fitted values (±2?) at 1723 K for VbarFeO (12.86±0.32 cm/mol), ?VbarFeO/?T((3.69±1.16)×10-3 cm/mol-K) and ?barT,FeO((4.72±0.46)×10-2 GPa). These volumetric properties for the FeO component are estimated to reflect Fe2+ in an average coordination of 5.7 (±0.2), based on the relationship between VbarFeO and Fe2+ coordination derived by a comparison to mineral molar volumes (Guo et al., 2013). Application of these volumetric data to a calculation of the pressure dependence of the Fe-Mg exchange reaction between orthopyroxene and basaltic liquid results in a small decrease in Fe-MgKD with pressure. In contrast, partial melting experiments of peridotite show a small increase in Fe-MgKD(opx-liq) with pressure (e.g., Walter, 1998). This difference in the pressure dependence is proposed to reflect the role of alkalis in reducing the average coordination number of Fe2+ toward five compared to the alkali-free model basalt compositions in this study, thus changing the volume and compressibility of the FeO liquid component. The results from this study may be most appropriately applied to lunar basalts, which are impoverished in alkalis.

  14. Molar volumes of molten indium at high pressures measured in a diamond Guoyin Shen,a)

    E-print Network

    Shen, Guoyin

    Molar volumes of molten indium at high pressures measured in a diamond anvil cell Guoyin Shen for publication 18 June 2002 Molar volumes of molten indium have been measured in an isothermal compression up the molar volume of amorphous materials in a DAC and report the results on molten indium in an isothermal

  15. Temperature dependence of partial molar heat capacities of binary critical mixtures: Study of the system isobutyric acid\\/water

    Microsoft Academic Search

    M. Pelger; H. Klein; D. Woermann

    1981-01-01

    Data of the temperature dependence of partial molar heat capacities of isobutyric acid and water near the critical point are reported. It is found that the singular part of the partial molar heat capacity of isobutyric acid in a critical mixture has a positive sign whereas that of water has a negative sign. A relationship between the critical amplitudes of

  16. Density, partial, and excess volumes of solutions of methacrylic acid in organic solvents at 293 K

    NASA Astrophysics Data System (ADS)

    Sergeev, V. V.; Van-Chin-Syan, Yu. Ya.

    2015-03-01

    The densities of solutions of methacrylic acid in acetonitrile, benzene, hexane, 1,2-dichloroethane, and acetic acid at a temperature of 293 K and atmospheric pressure are determined by means of pycnometry. The values of the excess molar volume for the studied systems and those of the partial molar volumes of the components are calculated. It is found that the excess molar volume of binary systems of methacrylic acid with benzene, hexane, 1,2-dichloroethane, and acetic acid is positive over the range of concentrations and is negative in the methacrylic acid-acetonitrile system.

  17. Sealing versus partial caries removal in primary molars: a randomized clinical trial

    PubMed Central

    2014-01-01

    Background The resin-based pit and fissure sealant is considered a successful tool in caries prevention, however there is a growing evidence of its use in controlling already established caries in posterior teeth. The aim of this clinical trial is to verify the efficacy of pit and fissure sealants in arresting dentinal caries lesions compared to partial excavation and restorative treatment in primary molar teeth. Methods Thirty six patients with occlusal cavitated primary molar reaching outer half of dentin were selected. The patients were randomly allocated into two groups: sealant application (experimental group – n?=?17) and restoration with composite resin (control group – n?=?19). Clinical and radiograph evaluation were performed after 6, 12 and 18 months. The chi-square test was used to verify the distribution of characteristics variables of the sample among the groups. The survival rate of treatments was evaluated using Kaplan–Meier survival and log-rank test. Fisher’s Exact and logistic regression tests were calculated in each evaluation period (??=?5%). Results The control group showed significantly better clinical survival after 18 months (p?=?0.0025). In both groups, no caries progression was registered on the radiographic evaluations. Conclusions Sealing had similar efficacy in the arrestment of caries progression of cavitated occlusal lesions compared to partial excavation of the lesions, even though the frequency of re-treatments was significantly higher in sealed lesions. Trial registration Registro Brasileiro de Ensaios Clínicos (ReBEC): RBR-9kkv53 PMID:24884684

  18. The Component Slope Linear Model for Calculating Intensive Partial Molar Properties: Application to Waste Glasses and Aluminate Solutions - 13099

    SciTech Connect

    Reynolds, Jacob G. [Washington River Protection Solutions, LLC, P.O. Box 850, Richland, WA 99352 (United States)] [Washington River Protection Solutions, LLC, P.O. Box 850, Richland, WA 99352 (United States)

    2013-07-01

    Partial molar properties are the changes occurring when the fraction of one component is varied while the fractions of all other component mole fractions change proportionally. They have many practical and theoretical applications in chemical thermodynamics. Partial molar properties of chemical mixtures are difficult to measure because the component mole fractions must sum to one, so a change in fraction of one component must be offset with a change in one or more other components. Given that more than one component fraction is changing at a time, it is difficult to assign a change in measured response to a change in a single component. In this study, the Component Slope Linear Model (CSLM), a model previously published in the statistics literature, is shown to have coefficients that correspond to the intensive partial molar properties. If a measured property is plotted against the mole fraction of a component while keeping the proportions of all other components constant, the slope at any given point on a graph of this curve is the partial molar property for that constituent. Actually plotting this graph has been used to determine partial molar properties for many years. The CSLM directly includes this slope in a model that predicts properties as a function of the component mole fractions. This model is demonstrated by applying it to the constant pressure heat capacity data from the NaOHNaAl(OH){sub 4}-H{sub 2}O system, a system that simplifies Hanford nuclear waste. The partial molar properties of H{sub 2}O, NaOH, and NaAl(OH){sub 4} are determined. The equivalence of the CSLM and the graphical method is verified by comparing results determined by the two methods. The CSLM model has been previously used to predict the liquidus temperature of spinel crystals precipitated from Hanford waste glass. Those model coefficients are re-interpreted here as the partial molar spinel liquidus temperature of the glass components. (authors)

  19. Entropy Estimates for Some Silicates at 298{degrees}K from Molar Volumes.

    PubMed

    Saxena, S K

    1976-09-24

    Third law entropies for silicates of Be, Mg, Ca, Zn, Na, and K containing the same anion group, for example, SiO(4) or SiO(3) or AlSi(3)O(8), are found to be linearly related to their molar volumes. The relationship between the molar volume and the entropy of silicates of Fe and Mn, atoms with unfilled d electron subshells, is different from that of other silicates. The linear correlations yield a useful method of estimating the entropies of ortho-, meta-, and framework silicates (feldspars and feld-spathoids). The estimated entropies of pyrope and almandine at 298 degrees K are 47.47 and 68.13 gibbs per mole, respectively. PMID:17837020

  20. Partial specific volume of xanthan

    NASA Astrophysics Data System (ADS)

    Wohlfarth, Ch.

    This document is part of Subvolume D2 'Polymer Solutions - Physical Properties and their Relations I (Thermodynamic Properties: PVT -Data and miscellaneous Properties of polymer Solutions) of Volume 6 `Polymers' of Landolt-Börnstein - Group VIII `Advanced Materials and Technologies'.

  1. Excess molar volumes of mixtures of hexane + natural oils from 298.15 to 313.15 K

    SciTech Connect

    Gonzalez, C.; Resa, J.M.; Ruiz, A.; Gutierrez, J.I. [Univ. del Pais Vasco, Vitoria (Spain). Dept. of Chemical Engineering] [Univ. del Pais Vasco, Vitoria (Spain). Dept. of Chemical Engineering

    1997-03-01

    Excess molar volume data for mixtures containing hexane with three edible oils: olive, corn, and pip of grape have been determined from density measurements at various temperatures between 298.15 and 313.15 K using a vibrating tube densimeter. Results have been correlated by the Redlich-Kister equation. Systems showed negative deviations from ideality in the whole composition range.

  2. Volume analysis of heat-induced cracks in human molars: A preliminary study

    PubMed Central

    Sandholzer, Michael A.; Baron, Katharina; Heimel, Patrick; Metscher, Brian D.

    2014-01-01

    Context: Only a few methods have been published dealing with the visualization of heat-induced cracks inside bones and teeth. Aims: As a novel approach this study used nondestructive X-ray microtomography (micro-CT) for volume analysis of heat-induced cracks to observe the reaction of human molars to various levels of thermal stress. Materials and Methods: Eighteen clinically extracted third molars were rehydrated and burned under controlled temperatures (400, 650, and 800°C) using an electric furnace adjusted with a 25°C increase/min. The subsequent high-resolution scans (voxel-size 17.7 ?m) were made with a compact micro-CT scanner (SkyScan 1174). In total, 14 scans were automatically segmented with Definiens XD Developer 1.2 and three-dimensional (3D) models were computed with Visage Imaging Amira 5.2.2. The results of the automated segmentation were analyzed with an analysis of variance (ANOVA) and uncorrected post hoc least significant difference (LSD) tests using Statistical Package for Social Sciences (SPSS) 17. A probability level of P < 0.05 was used as an index of statistical significance. Results: A temperature-dependent increase of heat-induced cracks was observed between the three temperature groups (P < 0.05, ANOVA post hoc LSD). In addition, the distributions and shape of the heat-induced changes could be classified using the computed 3D models. Conclusion: The macroscopic heat-induced changes observed in this preliminary study correspond with previous observations of unrestored human teeth, yet the current observations also take into account the entire microscopic 3D expansions of heat-induced cracks within the dental hard tissues. Using the same experimental conditions proposed in the literature, this study confirms previous results, adds new observations, and offers new perspectives in the investigation of forensic evidence. PMID:25125923

  3. Clinical features of multiple conception with partial or complete molar pregnancy and coexisting fetuses.

    PubMed

    Steller, M A; Genest, D R; Bernstein, M R; Lage, J M; Goldstein, D P; Berkowitz, R S

    1994-03-01

    The estimated incidence of twin pregnancy consisting of hydatidiform mole and a coexisting fetus is 1 per 22,000-100,000 pregnancies. Since 1965, nine patients with this entity have been treated at the New England Trophoblastic Disease Center (NETDC), Boston. One patient had a partial hydatidiform mole coexisting with a normal placenta and fetus. The other eight patients had twin pregnancies with a complete hydatidiform mole (CHM) and coexisting fetus. We compared the clinical outcomes in these 8 patients and 14 additional published case reports of multiple gestations composed of CHM and coexisting fetuses with a group of 71 patients with singleton CHM treated at NETDC. Twelve of the 22 patients (55%) with CHM and coexisting fetuses developed persistent gestational trophoblastic tumor, requiring chemotherapy. Five of these patients developed metastases requiring multiple cycles of chemotherapy to achieve remission. The presenting symptoms of multiple conception with CHM and coexisting fetuses were similar to those in patients with a singleton conception and complete mole. However, as compared to singleton CHM, patients having a multiple conception with CHM and coexisting fetuses were diagnosed at a later gestational age, had higher preevacuation beta-human chorionic gonadotropin levels and had a greater propensity to develop persistent tumor. These data indicate that patients with multiple conceptions consisting of CHM and coexisting fetuses are at high risk of developing persistent gestational trophoblastic tumor. PMID:8035369

  4. Apparent molar volumes of La(CF{sub 3}SO{sub 3}){sub 3}(aq) and Gd(CF{sub 3}SO{sub 3}){sub 3}(aq) at 278 K, 298 K, and 318 K at pressures to 30.0 MPa

    SciTech Connect

    Xiao, C.; Tremaine, P.R. [Memorial Univ. of Newfoundland, St. John`s, Newfoundland (Canada). Dept. of Chemistry] [Memorial Univ. of Newfoundland, St. John`s, Newfoundland (Canada). Dept. of Chemistry; Simonson, J.M. [Oak Ridge National Lab., TN (United States). Chemical and Analytical Sciences Div.] [Oak Ridge National Lab., TN (United States). Chemical and Analytical Sciences Div.

    1996-09-01

    Densities of La(CF{sub 3}SO{sub 3}){sub 3}(aq) and Gd(CF{sub 3}SO{sub 3}){sub 3}(aq) have been measured at 278 K, 298 K, and 318 K at pressures of 0.1 MPa, 7.0 MPa, and 30.0 MPa using vibrating-tube densimeters. Apparent molar volumes obtained from the density data have been fitted to the Pitzer equation. The standard partial molar volumes V{sub {phi}}{sup {infinity}} and the ion-interaction parameters {beta}{sup (0)V} and {beta}{sup (1)V} have been determined through least-squares fitting to the experimental results. The standard partial molar volume of the trifluoromethanesulfonate anion V{sub {phi}}{sup {infinity}}(CF{sub 3}SO{sub 3}{sup {minus}},aq) was calculated at 298 K and 0.1 MPa from the partial molar volumes of the gadolinium and lanthanum salts and the available values for the standard partial molar volumes of the cations. Excellent agreement is obtained for V{sub {phi}}{sup {infinity}}(CF{sub 3}SO{sub 3}{sup {minus}},aq) calculated from the data for the two salts.

  5. The threshold strength of laminar ceramics utilizing molar volume changes and porosity

    NASA Astrophysics Data System (ADS)

    Pontin, Michael Gene

    It has been shown that uniformly spaced thin compressive layers within a ceramic body can arrest the propagation of an otherwise catastrophic crack, producing a threshold strength: a strength below which the probability of failure is zero. Previous work has shown that the threshold strength increases with both the magnitude of the compressive stress and the fracture toughness of the thin layer material, and finite element analysis predicts that the threshold strength can be further increased when the elastic modulus of the compressive layer is much smaller than the thicker layer. The current work describes several new approaches to increase the threshold strength of a laminar ceramic system. The initial method utilized a molar volume expansion within the thin layers, produced by the tetragonal-to-monoclinic phase transformation of unstabilized zirconia during cooling, in order to produce large compressive stresses within the thin layers. High threshold strengths were measured for this system, but they remained relatively constant as the zirconia content was increased. It was determined that microcracking produced during the transformation reduced the magnitude of the compressive stresses, but may also have served to reduce the modulus of the thin compressive layer, providing an additional strengthening mechanism. The second approach studied the addition of porosity to reduce the elastic modulus of the thin compressive layers. A new processing method was created and analyzed, in which thick layers of the laminate were fabricated by tape-casting, and then dip-coated into a slurry, containing rice starch, to create thin porous compressive layers upon densification. The effects of porosity on the residual compressive stress, elastic modulus, and fracture toughness of the thin layers were measured and calculated, and it was found that the elastic modulus mismatch between the thin and thick layers produced a large strengthening effect for volume fractions of porosity below a critical level. Specimens with greater volume fractions of porosity exhibited complete crack arrest, typically followed by non-catastrophic failure, as cracks initiating in adjacent thick layers coalesced by cracking or delamination along the thin porous layers.

  6. Simple program calculates partial liquid volumes in vessels

    Microsoft Academic Search

    Koch

    1992-01-01

    This paper reports on a simple calculator program which solves problems of partial liquid volumes for a variety of storage and process vessels, including inclined cylindrical vessels and those with conical heads. Engineers in the oil refining and chemical industries are often confronted with the problem of estimating partial liquid volumes in storage tanks or process vessels. Cistern, the calculator

  7. The Determination of Partial Specific Volume: A Physical Chemistry Experiment

    ERIC Educational Resources Information Center

    Sun, S. F.; Serpentino, Peter M.

    1974-01-01

    Describes a method for the accurate determination of partial specific volume of a protein. Method is simple enough to include in the undergraduate physical chemistry laboratory but requires patience and careful handling which provide good training in laboratory techniques. (SLH)

  8. Excess molar volumes of the systems m-xylene?+?1-propanol, +2-propanol, +1-butanol,?+2-methyl-2-propanol

    Microsoft Academic Search

    M. A. Saleh; M. Habibullah; M. Shamsuddin Ahmed; M. Ashraf Uddin; S. M. H. Uddin; M. Afsar Uddin; F. M. Khan

    2005-01-01

    Densities, ?, of the systems m-xylene?+?1-propanol,?+?2-propanol,?+?1-butanol and?+?2-methyl-2-propanol have been determined from 303.15 to 323.15?K with an interval of 5?K. Excess molar volumes, , have been calculated from density data.???and have been fitted to appropriate polynomial equations and plotted against mole fraction of alkanols. For the systems, m-xylene?+?1-propanol and m-xylene?+?1-butanol, sigmoid type of curves have been observed, but for the systems,

  9. Densities and excess molar volumes of binary mixtures containing propylene carbonate + chlorohydrocarbons at 298.15 K and atmospheric pressure

    SciTech Connect

    Comelli, F. [Centro di Studio per la Fisica delle Macromolecule del CNR, Bologna (Italy); Francesconi, R. [Univ. degli Studi, Bologna (Italy). Dipt. di Chemica

    1995-11-01

    Densities and excess molar volumes, V{sub m}{sup E}, for binary mixtures containing propylene carbonate + 10 chlorohydrocarbons (dichloromethane, 1,2-dichloroethane, 1,3-dichloropropane, 1,4-dichlorobuthane, 1,6-dichlorohexane, 1,10-dichlorodecane, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane, trans-1,2-dichloroethene, and trichloroethene) have been measured at 298.15 K and at atmospheric pressure using an Anton Paar digital vibrating tube density meter. The results are fitted to the Redlich-Kister equation. The values of V{sub m}{sup E} for the mixtures containing dichloroalkanes show an increasing trend with the increase of the chain length and vary from a minimum of {minus}0.24 cm{sup 3}/mol for dichloromethane up to a maximum of +0.31 cm{sup 3}/mol for 1,10-dichlorodecane. The excess molar volumes for the other mixtures are negative over the entire range of composition. Results are qualitatively discussed in terms of molecular interactions.

  10. Partial specific volume and solvent interactions of amphipol A8-35.

    PubMed

    Gohon, Yann; Pavlov, Georgy; Timmins, Peter; Tribet, Christophe; Popot, Jean-Luc; Ebel, Christine

    2004-11-15

    Amphipols are small amphiphilic polymers that can stabilize and keep soluble membrane proteins in aqueous solutions in the absence of detergent. A prerequisite to solution studies of membrane protein/amphipol complexes is the determination of the partial specific volume v2 and effective charge z of the polymer. The ratio (R) of the buoyant molar masses of particles in D2O and H2O solutions, obtained from sedimentation velocity (sH/sD method) and sedimentation equilibrium experiments, and their contrast match point (CMP), determined in small-angle neutron scattering experiments, depend on v2 and z. When z is known, v2 can be estimated from R with a good accuracy as long as v2 is close to 1. The effects of labile H/D exchange and of polyelectrolyte counter-ion dissociation in general cannot be neglected. The accuracy, advantages, and limits of the sH/sD method have been studied in details using model macromolecules (DNA, protein, and polysaccharide). The sH/sD method appears particularly advantageous for the study of heterogeneous samples. Measurements of density, sD/sH buoyant molar masses in H2O, D2O, and D2(18)O, and CMP of hydrogenated and partially deuterated A8-35, a polyacrylate-based amphipol containing 35 underivatized carboxylates per 100 monomers, led to a consistent description of its buoyancy and charge properties. PMID:15494140

  11. Positron Emission Tomography Partial Volume Correction: Estimation and Algorithms

    Microsoft Academic Search

    John A. D. Aston; Vincent J. Cunningham; Marie-Claude Asselin; Alexander Hammers; Alan C. Evans; Roger N. Gunn

    2002-01-01

    Partial volume effects in positron emission tomography (PET) lead to quantitative under- and over-estimations of the regional concentrations of radioactivity in reconstructed images and corresponding errors in derived functional or parametric images. The limited resolution of PET leads to “tissue-fraction” effects, reflecting underlying tissue heterogeneity, and “spillover” effects between regions. Addressing the former problem in general requires supplementary data, for

  12. Improved prediction of octanol-water partition coefficients from liquid-solute water solubilities and molar volumes

    USGS Publications Warehouse

    Chiou, C.T.; Schmedding, D.W.; Manes, M.

    2005-01-01

    A volume-fraction-based solvent-water partition model for dilute solutes, in which the partition coefficient shows a dependence on solute molar volume (V??), is adapted to predict the octanol-water partition coefficient (K ow) from the liquid or supercooled-liquid solute water solubility (Sw), or vice versa. The established correlation is tested for a wide range of industrial compounds and pesticides (e.g., halogenated aliphatic hydrocarbons, alkylbenzenes, halogenated benzenes, ethers, esters, PAHs, PCBs, organochlorines, organophosphates, carbamates, and amidesureas-triazines), which comprise a total of 215 test compounds spanning about 10 orders of magnitude in Sw and 8.5 orders of magnitude in Kow. Except for phenols and alcohols, which require special considerations of the Kow data, the correlation predicts the Kow within 0.1 log units for most compounds, much independent of the compound type or the magnitude in K ow. With reliable Sw and V data for compounds of interest, the correlation provides an effective means for either predicting the unavailable log Kow values or verifying the reliability of the reported log Kow data. ?? 2005 American Chemical Society.

  13. PROPERTIES OF THE SYSTEM URANYL NITRATE-ALUMINUM NITRATE-NITRIC ACID (OR SODIUM HYDROXIDE)SODIUM NITRATE-WATER-HEXONE. PART 2. DENSITY, APPARENT MOLAR VOLUME AND VISCOSITY

    Microsoft Academic Search

    L. L. Burger; I. M. Rehn; H. R. Schmidt; C. M. Slansky

    1949-01-01

    The viscosity and density of various Redox Process solutions were ; determined at 15, 25. and 40 ction prod- C. Apparent molar volumes for UO\\/sub ; 2\\/(NOâ)â and HNOâ in hexone and in aqueou s solutions were ; calculated from the density data as a function of concentration. The molar ; volumes of Al(NOâ)â in water and of hexone in

  14. An MRI-guided PET Partial Volume Correction Method

    PubMed Central

    Wang, Hesheng; Fei, Baowei

    2013-01-01

    Accurate quantification of positron emission tomography (PET) is important for diagnosis and assessment of cancer treatment. The low spatial resolution of PET imaging induces partial volume effect to PET images that biases quantification. A PET partial volume correction method is proposed using high-resolution, anatomical information from magnetic resonance images (MRI). The corrected PET is pursued by removing the convolution of PET point spread function (PSF) and by preserving edges present in PET and the aligned MR images. The correction is implemented in a Bayesian's deconvolution framework that is minimized by a conjugate gradient method. The method is evaluated on simulated phantom and brain PET images. The results show that the method effectively restores 102 ± 7% of the true PET activity with a size of greater than the full-width at half maximum of the point spread function. We also applied the method to synthesized brain PET data. The method does not require prior information about tracer activity within tissue regions. It can offer a partial volume correction method for various PET applications and can be particularly useful for combined PET/MRI studies. PMID:24386530

  15. The Molar Volume of FeO-MgO-Fe2O3-Cr2O3-Al2O3-TiO2 Spinels

    NASA Astrophysics Data System (ADS)

    Hamecher, E. A.; Antoshechkina, P. M.; Ghiorso, M. S.; Asimow, P. D.

    2011-12-01

    A new model of molar volume has been calibrated in the spinel supersystem (Mg,Fe2+)(Al,Cr,Fe3+)2O4 - (Mg,Fe2+)2TiO4. A total of 832 X-ray and neutron diffraction experiments performed on spinels at ambient and in situ high-P, T conditions (from the American Mineralogist Crystal Structure Database (Downs and Hall-Wallace, 2003) and other sources) were used to calibrate end-member equations of state and an excess volume model for this system. The effect on molar volume of cation ordering over the octahedral and tetrahedral sites is captured with linear dependence on Mg2+, Al3+, and Fe3+ site occupancy terms. We allowed standard state volumes and coefficients of thermal expansion of the end members to vary within their uncertainties during extraction of the mixing properties, in order to achieve the best fit. Published equations of states of the various spinel end members were analyzed to obtain optimal values of the bulk modulus and its pressure derivative, for each explicit end member. For any spinel composition in the supersystem, the model molar volume is obtained by adding excess volume and cation order-dependent terms to a linear combination of the five end member volumes, estimated at pressure and temperature using the high-T Vinet equation of state. The model has a total of 31 parameters and fits nearly all experiments to within 0.02 J/bar/mol, or better than 0.5% in volume. The model is compared to the current MELTS (Ghiorso and Sack, 1995; Ghiorso et al., 2002) spinel model with a demonstration of the impact of the model difference on the estimated spinel-garnet lherzolite transition pressure. Our primary motivation in this work is the development of a comprehensive spinel molar volume model for use in calibration of activity-composition models of garnet and pyroxene solid solutions. The thermodynamic models, along with a new silicate liquid equation of state, will be incorporated into the next generation MELTS model, xMELTS. The new solid solution models will include some minor components, including Ti4+ and Cr3+. Because most constraints on the activity of garnet and pyroxene at high-P are derived from experiments with coexisting spinel, we must be confident in the ability of our spinel model to realistically reproduce thermodynamic behavior over all applicable compositions. Additionally, producing a spinel molar volume model calibrated with recent in situ high-P, T diffraction data is crucial to our ability to accurately model the spinel-garnet transition in Earth's upper mantle. For example, we recently calibrated Cr-Al exchange equilibria for garnet and spinel. When this new calibration is used with the current MELTS model, a region of garnet-spinel coexistence in lherzolites is predicted with width in pressure comparable to experimental constraints. The transition occurs, however, at the unexpectedly low pressure of ~1.7 GPa. The improved model of spinel molar volume presented here, along with a new garnet molar volume model in the system FeO-MgO-CaO-Fe2O3-Cr2O3-Al2O3-TiO2-Na2O-SiO2 currently being calibrated, will enable coupled recalibration of the garnet and pyroxene models to match both the absolute pressure and width of this key transition in mantle lithology.

  16. Partial Volume Reduction by Interpolation with Reverse Diffusion

    PubMed Central

    Hillenbrand, Claudia M.; Wilson, David L.

    2006-01-01

    Many medical images suffer from the partial volume effect where a boundary between two structures of interest falls in the midst of a voxel giving a signal value that is a mixture of the two. We propose a method to restore the ideal boundary by splitting a voxel into subvoxels and reapportioning the signal into the subvoxels. Each voxel is divided by nearest neighbor interpolation. The gray level of each subvoxel is considered as “material” able to move between subvoxels but not between voxels. A partial differential equation is written to allow the material to flow towards the highest gradient direction, creating a “reverse” diffusion process. Flow is subject to constraints that tend to create step edges. Material is conserved in the process thereby conserving signal. The method proceeds until the flow decreases to a low value. To test the method, synthetic images were downsampled to simulate the partial volume artifact and restored. Corrected images were remarkably closer both visually and quantitatively to the original images than those obtained from common interpolation methods: on simulated data standard deviation of the errors were 3.8%, 6.6%, and 7.1% of the dynamic range for the proposed method, bicubic, and bilinear interpolation, respectively. The method was relatively insensitive to noise. On gray level, scanned text, MRI physical phantom, and brain images, restored images processed with the new method were visually much closer to high-resolution counterparts than those obtained with common interpolation methods. PMID:23165058

  17. A Theoretical Solution to MAP-EM Partial Volume Segmentation of Medical Images

    E-print Network

    A Theoretical Solution to MAP-EM Partial Volume Segmentation of Medical Images Su Wang, Hongyu Lu, Zhengrong Liang Department of Radiology, State University of New York, Stony Brook, NY 11794 Received 4

  18. Partial volume effect modeling for segmentation and tissue classification of brain magnetic resonance images: A review

    PubMed Central

    Tohka, Jussi

    2014-01-01

    Quantitative analysis of magnetic resonance (MR) brain images are facilitated by the development of automated segmentation algorithms. A single image voxel may contain of several types of tissues due to the finite spatial resolution of the imaging device. This phenomenon, termed partial volume effect (PVE), complicates the segmentation process, and, due to the complexity of human brain anatomy, the PVE is an important factor for accurate brain structure quantification. Partial volume estimation refers to a generalized segmentation task where the amount of each tissue type within each voxel is solved. This review aims to provide a systematic, tutorial-like overview and categorization of methods for partial volume estimation in brain MRI. The review concentrates on the statistically based approaches for partial volume estimation and also explains differences to other, similar image segmentation approaches. PMID:25431640

  19. Binary diffusion coefficients, partition ratios and partial molar volumes at infinite dilution for ?-carotene and ?-tocopherol in supercritical carbon dioxide

    Microsoft Academic Search

    Toshitaka Funazukuri; Chang Yi Kong; Seiichiro Kagei

    2003-01-01

    Binary diffusion coefficients D12 and partition ratios k at infinite dilution for ?-carotene and ?-tocopherol in supercritical carbon dioxide were measured at temperatures from 308.15 to 333.15 K and pressures from 9 to 30 MPa by a tracer response technique with a poly(ethylene glycol) coated capillary column. Both parameters, simultaneously determined by fitting the calculated response curve to that measured

  20. FMDP Reactor Alternative Summary Report: Volume 3 - partially complete LWR alternative

    SciTech Connect

    Greene, S.R.; Fisher, S.E.; Bevard, B.B. [and others

    1996-09-01

    The Department of Energy Office of Fissile Materials Disposition (DOE/MD) initiated a detailed analysis activity to evaluate each of ten plutonium disposition alternatives that survived an initial screening process. This document, Volume 3 of a four volume report summarizes the results of these analyses for the partially complete LWR (PCLWR) reactor based plutonium disposition alternative.

  1. The impact of oxygen nonstoichiometry upon partial molar thermodynamic quantities in PrBaCo{sub 2}O{sub 5+?}

    SciTech Connect

    Suntsov, A.Yu., E-mail: suntsov@ihim.uran.ru [Institute of Solid State Chemistry, Pervomaiskaya str.91, Yekaterinburg 620990 (Russian Federation); Leonidov, I.A. [Institute of Solid State Chemistry, Pervomaiskaya str.91, Yekaterinburg 620990 (Russian Federation); Ural Federal University, Mira str.19, Ekaterinburg 620002 (Russian Federation); Patrakeev, M.V.; Kozhevnikov, V.L. [Institute of Solid State Chemistry, Pervomaiskaya str.91, Yekaterinburg 620990 (Russian Federation)

    2014-05-01

    The coulometric titration data are utilized in order to calculate changes of oxygen partial entropy and enthalpy in PrBaCo{sub 2}O{sub 5+?} with variations of oxygen content and temperature. The thermodynamic equilibrium of the cobaltite with the ambient gas phase is analyzed based on the interface of oxygen exchange and oxidation, and the intrinsic reaction of thermal excitation of Co{sup 3+} cations. The partial thermodynamic functions of the movable oxygen in PrBaCo{sub 2}O{sub 5+?} are shown to be interrelated with the thermodynamic parameters of the defect formation reactions. The existence of a band gap of about 0.4 eV in the electronic spectrum of the cobaltite follows from a favorable comparison of the calculated and experimental dependencies of the partial thermodynamic functions of the movable oxygen. - Graphical abstract: Partial thermodynamic functions of movable oxygen in PrBaCo{sub 2}O{sub 5+?}. - Highlights: • Thermodynamic functions of oxygen in PrBaCo{sub 2}O{sub 5+?} are obtained from pO{sub 2}–T–? diagram. • The defect model is developed to describe changes in thermodynamic functions. • Thermodynamic analysis gives evidence to a band gap in PrBaCo{sub 2}O{sub 5+?}.

  2. Mutual Information Based CT-MR Brain Image Registration Using Generalized Partial Volume Joint Histogram Estimation

    Microsoft Academic Search

    Hua-mei Chen; Pramod K. Varshney

    2003-01-01

    Mutual information (MI)-based image registration has been found to be quite effective in many medical imaging applications. To determine the MI between two images, the joint histogram of the two images is required. In the literature, linear interpolation and partial volume interpolation (PVI) are often used while estimating the joint histogram for registration purposes. It has been shown that joint

  3. Concealed Air Leak Associated with Large Tidal Volumes in Partial Liquid Ventilation

    Microsoft Academic Search

    PETER N. COX; HELENA FRNDOVA; PATRICK S. K. TAN; TOMOHIKO NAKAMURA; KEIKO MIYASAKA; YOSHIO SAKURAI; WILLIAM MIDDLETON; DAVID MAZER; A. CHARLES BRYAN

    1997-01-01

    Current ventilator strategies aim at maintaining an open lung and limiting both peak inspiratory pressures and tidal volumes to avoid alveolar distension. Perfluorocarbons, as well as being excellent solvents for oxygen and carbon dioxide, have the unique properties of being able to recruit depen- dent lung regions and improve pulmonary mechanics. Optimal ventilator strategies for partial liquid ventilation (PLV) have

  4. Impact of partial volume effects correction on the predictive and prognostic value of baseline 18

    E-print Network

    Boyer, Edmond

    in the primary tumor or lymph nodes (4). On the other hand, non responders may be unnecessarily affected F-FDG PET images in esophageal cancer Mathieu Hatt1 , Adrien Le Pogam1,2 , Dimitris Visvikis1, France Running title: Partial volume correction on FDG PET Corresponding author: Mathieu HATT, La

  5. Unsupervised Partial Volume Estimation in Single-Channel Image Data Dzung L. Pham

    E-print Network

    Prince, Jerry L.

    in the resulting segmentation. Figure 1c shows a gray matter membership function com- puted using the fuzzy c-means vol- umes and the means of the different tissue classes in the image. To compensate for the ill partial volume effects. 1 Introduction Segmentation of three-dimensional volumetric images is an important

  6. Partial volume segmentation of brain magnetic resonance images based on maximum a posteriori probability

    E-print Network

    resonance imaging, fuzzy C-mean algorithm, Markov random field, PV segmentation, intensity inhomogeneityPartial volume segmentation of brain magnetic resonance images based on maximum a posteriori, and image-intensity inhomogeneity render a challenging task for segmentation of brain magnetic resonance MR

  7. Target volume definition for external beam partial breast radiotherapy: Clinical, pathological and technical studies informing current approaches

    Microsoft Academic Search

    Anna M. Kirby; Charlotte E. Coles; John R. Yarnold

    2010-01-01

    Partial breast irradiation (PBI) is currently under investigation in several phase III trials and, following a recent consensus statement, its use off-study may increase despite ongoing uncertainty regarding optimal target volume definition. We review the clinical, pathological and technical evidence for target volume definition in external beam partial breast irradiation (EB-PBI). The optimal method of tumour bed (TB) delineation requires

  8. Reduction of thioredoxin significantly decreases its partial specific volume and adiabatic compressibility.

    PubMed Central

    Kaminsky, S. M.; Richards, F. M.

    1992-01-01

    The partial specific volume and adiabatic compressibility were determined at several temperatures for oxidized and reduced Escherichia coli thioredoxin. Oxidized thioredoxin had a partial specific volume of 0.785-0.809 mL/g at the observed upper limit for all proteins whereas the partial specific volume of reduced thioredoxin was 0.745-0.755 mL/g, a value in the range found for a majority of proteins. The adiabatic compressibility of oxidized thioredoxin was also much larger (9.8-18 x 10(-12) cm2 dyne-1) than that of the reduced protein (3.8-7.3 x 10(-12)). Apart from the region immediately around the small disulfide loop, the structures of the oxidized (X-ray, crystal) and reduced protein (nuclear magnetic resonance, solution) are reported to be very similar. It would appear that alterations in the solvent layer in contact with the protein surface must play a major role in producing these large changes in the apparent specific volumes and compressibilities in this system. Some activities of thioredoxin require the reduced structure but are not electron transfer reactions. The large changes in physical parameters reported here suggest the possibility of a reversible metabolic control function for the SS bond. PMID:1304879

  9. Comparison of EM-based and level set partial volume segmentations of MR brain images

    NASA Astrophysics Data System (ADS)

    Tagare, Hemant D.; Chen, Yunmei; Fulbright, Robert K.

    2008-03-01

    EM and level set algorithms are competing methods for segmenting MRI brain images. This paper presents a fair comparison of the two techniques using the Montreal Neurological Institute's software phantom. There are many flavors of level set algorithms for segmentation into multiple regions (multi-phase algorithms, multi-layer algorithms). The specific algorithm evaluated by us is a variant of the multi-layer level set algorithm. It uses a single level set function for segmenting the image into multiple classes and can be run to completion without restarting. The EM-based algorithm is standard. Both algorithms have the capacity to model a variable number of partial volume classes as well as image inhomogeneity (bias field). Our evaluation consists of systematically changing the number of partial volume classes, additive image noise, and regularization parameters. The results suggest that the performances of both algorithms are comparable across noise, number of partial volume classes, and regularization. The segmentation errors of both algorithms are around 5 - 10% for cerebrospinal fluid, gray and white matter. The level set algorithm appears to have a slight advantage for gray matter segmentation. This may be beneficial in studying certain brain diseases (Multiple Sclerosis or Alzheimer's disease) where small changes in gray matter volume are significant.

  10. Density Contrast Sedimentation Velocity for the Determination of Protein Partial-Specific Volumes

    PubMed Central

    Brown, Patrick H.; Balbo, Andrea; Zhao, Huaying; Ebel, Christine; Schuck, Peter

    2011-01-01

    The partial-specific volume of proteins is an important thermodynamic parameter required for the interpretation of data in several biophysical disciplines. Building on recent advances in the use of density variation sedimentation velocity analytical ultracentrifugation for the determination of macromolecular partial-specific volumes, we have explored a direct global modeling approach describing the sedimentation boundaries in different solvents with a joint differential sedimentation coefficient distribution. This takes full advantage of the influence of different macromolecular buoyancy on both the spread and the velocity of the sedimentation boundary. It should lend itself well to the study of interacting macromolecules and/or heterogeneous samples in microgram quantities. Model applications to three protein samples studied in either H2O, or isotopically enriched H218O mixtures, indicate that partial-specific volumes can be determined with a statistical precision of better than 0.5%, provided signal/noise ratios of 50–100 can be achieved in the measurement of the macromolecular sedimentation velocity profiles. The approach is implemented in the global modeling software SEDPHAT. PMID:22028836

  11. Excess molar volumes of (benzene + isopropylbenzene, or 1,3,5-trimethylbenzene, or 1,2,4-trimethylbenzene) at temperatures between 298.15 K and 328.15 K

    Microsoft Academic Search

    L. Morávková; J. Linek

    2003-01-01

    The densities of (benzene+isopropylbenzene, or 1,2,4-trimethylbenzene, or 1,3,5-trimethylbenzene) were measured at temperatures (298.15, 308.15, 318.15, and 328.15) K by means of a vibrating-tube densimeter. The excess molar volumes VmE calculated from the density data provide the temperature dependence of VmE in the temperature range of (298 to 328) K. The VmE results were correlated using the fourth-order Redlich–Kister equation, with

  12. Prevalence of missing and impacted third molars in adults aged 25 years and above

    PubMed Central

    Jung, Yun-Hoa

    2013-01-01

    Purpose The purpose of this study was to determine the prevalence of missing and impacted third molars in people aged 25 years and above. Materials and Methods The study sample of 3,799 patients was chosen randomly from patients who visited Pusan National University Dental Hospital and had panoramic radiographs taken. The data collected included presence and impaction state, angulation, and depth of impaction of third molars, and radiographically detected lesions of third molars and adjacent second molars. Results A greater percentage of men than women retained at least one third molar. The incidence of third molars decreased with increasing age. The incidence of partially impacted third molars greatly declined after the age of 30. Vertically impacted maxillary third molars and horizontally impacted mandibular third molars were most frequent in all age groups. Among the maxillary third molars, those impacted below the cervical line of the second molar were most frequent in all age groups, and among the mandibular third molars, deeply impacted third molars were most frequent in those aged over 40. Dental caries was the most common radiographic lesion of the third molars. Mesioangularly impacted third molars showed radiographic lesions in 13 (9.5%) adjacent maxillary second molars and 117 (27.4%) mandibular second molars. Conclusion The number of remaining third molars decreased and the percentage of Class C depth increased with age. Caries was the most frequent lesion in third molars. Partially impacted mesioangular third molars showed a high incidence of caries or periodontal bone loss of the adjacent second molar. Regular oral examination will be essential to keep asymptomatic third molars in good health. PMID:24380060

  13. Finite-volume and partial quenching effects in the magnetic polarizability of the neutron

    E-print Network

    J. M. M. Hall; D. B. Leinweber; R. D. Young

    2015-02-19

    There has been much progress in the experimental measurement of the electric and magnetic polarizabilities of the nucleon. Similarly, lattice QCD simulations have recently produced dynamical QCD results for the magnetic polarizability of the neutron approaching the chiral regime. In order to compare the lattice simulations with experiment, calculation of partial quenching and finite-volume effects is required prior to an extrapolation in quark mass to the physical point. These dependencies are described using chiral effective field theory. Corrections to the partial quenching effects associated with the sea-quark-loop electric charges are estimated by modelling corrections to the pion cloud. These are compared to the uncorrected lattice results. In addition, the behaviour of the finite-volume corrections as a function of pion mass is explored. Box sizes of approximately 7 fm are required to achieve a result within 5% of the infinite-volume result at the physical pion mass. A variety of extrapolations are shown at different box sizes, providing a benchmark to guide future lattice QCD calculations of the magnetic polarizabilities. A relatively precise value for the physical magnetic polarizability of the neutron is presented, beta_n = 1.93(11)stat(8)sys x 10^-4 fm^3, which is in agreement with current experimental results.

  14. A Partial Volume Effect Correction Tailored for 18F-FDG-PET Oncological Studies

    PubMed Central

    Gallivanone, F.; Canevari, C.; Gianolli, L.; Salvatore, C.; Della Rosa, P. A.; Gilardi, M. C.; Castiglioni, I.

    2013-01-01

    We have developed, optimized, and validated a method for partial volume effect (PVE) correction of oncological lesions in positron emission tomography (PET) clinical studies, based on recovery coefficients (RC) and on PET measurements of lesion-to-background ratio (L/Bm) and of lesion metabolic volume. An operator-independent technique, based on an optimised threshold of the maximum lesion uptake, allows to define an isocontour around the lesion on PET images in order to measure both lesion radioactivity uptake and lesion metabolic volume. RC are experimentally derived from PET measurements of hot spheres in hot background, miming oncological lesions. RC were obtained as a function of PET measured sphere-to-background ratio and PET measured sphere metabolic volume, both resulting from the threshold-isocontour technique. PVE correction of lesions of a diameter ranging from 10?mm to 40?mm and for measured L/Bm from 2 to 30 was performed using measured RC curves tailored at answering the need to quantify a large variety of real oncological lesions by means of PET. Validation of the PVE correction method resulted to be accurate (>89%) in clinical realistic conditions for lesion diameter > 1?cm, recovering >76% of radioactivity for lesion diameter < 1?cm. Results from patient studies showed that the proposed PVE correction method is suitable and feasible and has an impact on a clinical environment. PMID:24163819

  15. Generalized method for partial volume estimation and tissue segmentation in cerebral magnetic resonance images

    PubMed Central

    Khademi, April; Venetsanopoulos, Anastasios; Moody, Alan R.

    2014-01-01

    Abstract. An artifact found in magnetic resonance images (MRI) called partial volume averaging (PVA) has received much attention since accurate segmentation of cerebral anatomy and pathology is impeded by this artifact. Traditional neurological segmentation techniques rely on Gaussian mixture models to handle noise and PVA, or high-dimensional feature sets that exploit redundancy in multispectral datasets. Unfortunately, model-based techniques may not be optimal for images with non-Gaussian noise distributions and/or pathology, and multispectral techniques model probabilities instead of the partial volume (PV) fraction. For robust segmentation, a PV fraction estimation approach is developed for cerebral MRI that does not depend on predetermined intensity distribution models or multispectral scans. Instead, the PV fraction is estimated directly from each image using an adaptively defined global edge map constructed by exploiting a relationship between edge content and PVA. The final PVA map is used to segment anatomy and pathology with subvoxel accuracy. Validation on simulated and real, pathology-free T1 MRI (Gaussian noise), as well as pathological fluid attenuation inversion recovery MRI (non-Gaussian noise), demonstrate that the PV fraction is accurately estimated and the resultant segmentation is robust. Comparison to model-based methods further highlight the benefits of the current approach.

  16. Comparison of Partial Volume Effects in Arterial and Venous Contrast Curves in CT Brain Perfusion Imaging

    PubMed Central

    Riordan, Alan J.; Bennink, Edwin; Dankbaar, Jan Willem; Viergever, Max A.; Velthuis, Birgitta K.; Smit, Ewoud J.; de Jong, Hugo W. A. M.

    2014-01-01

    Purpose In brain CT perfusion (CTP), the arterial contrast bolus is scaled to have the same area under the curve (AUC) as the venous outflow to correct for partial volume effects (PVE). This scaling is based on the assumption that large veins are unaffected by PVE. Measurement of the internal carotid artery (ICA), usually unaffected by PVE due to its large diameter, may avoid the need for partial volume correction. The aims of this work are to examine i) the assumptions behind PVE correction and ii) the potential of selecting the ICA obviating correction for PVE. Methods The AUC of the ICA and sagittal sinus were measured in CTP datasets from 52 patients. The AUCs were determined by i) using commercial CTP software based on a Gaussian curve-fitting to the time attenuation curve, and ii) by simple integration of the time attenuation curve over a time interval. In addition, frames acquired up to 3 minutes after first bolus passage were used to examine the ratio of arterial and venous enhancement. The impact of selecting the ICA without PVE correction was illustrated by reporting cerebral blood volume (CBV) measurements. Results In 49 of 52 patients, the AUC of the ICA was significantly larger than that of the sagittal sinus (p?=?0.017). Measured after the first pass bolus, contrast enhancement remained 50% higher in the ICA just after the first pass bolus, and 30% higher 3 minutes later. CBV measurements were significantly lowered when the ICA was used without PVE correction. Conclusions Contradicting the assumptions underlying PVE correction, contrast in the ICA was significantly higher than in the sagittal sinus, even 3 minutes after the first pass of the contrast bolus. PVE correction might lead to overestimation of CBV if the CBV is calculated using the AUC of the time attenuation curves. PMID:24858308

  17. Taurodontism in deciduous molars

    PubMed Central

    Bafna, Yash; Kambalimath, H V; Khandelwal, Vishal; Nayak, Prathibha

    2013-01-01

    Taurodont teeth are characterised by large pulp chambers at the expense of roots. An enlarged pulp chamber, apical displacement of the pulpal floor and no constriction at the level of the cement-enamel junction are the characteristic features of taurodont tooth. It appears more frequently as an isolated anomaly but its association with syndromes and other abnormalities have also been reported. Permanent dentition is more commonly affected than deciduous dentition. This paper presents a case report of taurodontism in relation to mandibular deciduous second molars. PMID:23737594

  18. A three-dimensional model-based partial volume correction strategy for gated cardiac mouse PET imaging

    Microsoft Academic Search

    Tyler Dumouchel; Stephanie Thorn; Myra Kordos; Jean DaSilva; Rob S B Beanlands; Robert A deKemp

    2012-01-01

    Quantification in cardiac mouse positron emission tomography (PET) imaging is limited by the imaging spatial resolution. Spillover of left ventricle (LV) myocardial activity into adjacent organs results in partial volume (PV) losses leading to underestimation of myocardial activity. A PV correction method was developed to restore accuracy of the activity distribution for FDG mouse imaging. The PV correction model was

  19. A nonlinear spatially variant object-dependent system model for prediction of partial volume effects and scatter in PET

    Microsoft Academic Search

    Chi-Hsien Chen; Raymond F. Muzic Jr.; A. Dennis Nelson; Lee P. Adler

    1998-01-01

    Accurate quantitation of small lesions with positron emission tomography (PET) requires correction for the partial volume effect. Traditional methods that use Gaussian models of the PET system were found to be insufficient. A new approach that models the non-Gaussian object-dependent scatter was developed. The model consists of eight simple functions with a total of 24 parameters. Images of line and

  20. Comparative assessment of statistical brain MR image segmentation algorithms and their impact on partial volume correction in PET

    Microsoft Academic Search

    Habib Zaidi; Torsten Ruest; Frederic Schoenahl; Marie-Louise Montandon

    2006-01-01

    Magnetic resonance imaging (MRI)-guided partial volume effect correction (PVC) in brain positron emission tomography (PET) is now a well-established approach to compensate the large bias in the estimate of regional radioactivity concentration, especially for small structures. The accuracy of the algorithms developed so far is, however, largely dependent on the performance of segmentation methods partitioning MRI brain data into its

  1. Binary diffusion coefficient, partition ratio, and partial molar volume for docosahexaenoic acid, eicosapentaenoic acid and ?-linolenic acid at infinite dilution in supercritical carbon dioxide

    Microsoft Academic Search

    Toshitaka Funazukuri; Chang Yi Kong; Seiichiro Kagei

    2003-01-01

    A tracer response technique with a poly(ethylene glycol) coated capillary column was employed to measure binary diffusion coefficient and partition ratio for the ?3 group of long chain unsaturated fatty acids such as docosahexaenoic acid, eicosapentaenoic acid and ?-linolenic acid at infinite dilution in supercritical (SC) carbon dioxide at temperatures from 308.15 to 343.15K and pressures from 9 to 30MPa.

  2. Spinal Cord Tolerance to Single-Fraction Partial-Volume Irradiation: A Swine Model

    SciTech Connect

    Medin, Paul M., E-mail: Paul.medin@utsouthwestern.ed [Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX (United States); Foster, Ryan D. [Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX (United States); Kogel, Albert J. van der [Department of Radiation Oncology, Radboud University Medical Center Nijmegen, Nijmegen (Netherlands); Sayre, James W. [Department of Biostatistics, University of California, Los Angeles, School of Medicine, Los Angeles, CA (United States); Department of Radiology, University of California, Los Angeles, School of Medicine, Los Angeles, CA (United States); McBride, William H. [Department of Radiation Oncology, University of California, Los Angeles, School of Medicine, Los Angeles, CA (United States); Solberg, Timothy D. [Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX (United States)

    2011-01-01

    Purpose: To determine the spinal cord tolerance to single-fraction, partial-volume irradiation in swine. Methods and Materials: A 5-cm-long cervical segment was irradiated in 38-47-week-old Yucatan minipigs using a dedicated, image-guided radiosurgery linear accelerator. The radiation was delivered to a cylindrical volume approximately 5 cm in length and 2 cm in diameter that was positioned lateral to the cervical spinal cord, resulting in a dose distribution with the 90%, 50%, and 10% isodose lines traversing the ipsilateral, central, and contralateral spinal cord, respectively. The dose was prescribed to the 90% isodose line. A total of 26 pigs were stratified into eight dose groups of 12-47 Gy. The mean maximum spinal cord dose was 16.9 {+-} 0.1, 18.9 {+-} 0.1, 21.0 {+-} 0.1, 23.0 {+-} 0.2, and 25.3 {+-} 0.3 Gy in the 16-, 18-, 20-, 22-, and 24-Gy dose groups, respectively. The mean percentage of spinal cord volumes receiving {>=}10 Gy for the same groups were 43% {+-} 3%, 48% {+-} 4%, 51% {+-} 2%, 57% {+-} 2%, and 59% {+-} 4%. The study endpoint was motor neurologic deficit determined by a change in gait during a 1-year follow-up period. Results: A steep dose-response curve was observed with a median effective dose for the maximum dose point of 20.0 Gy (95% confidence interval, 18.3-21.7). Excellent agreement was observed between the occurrence of neurologic change and the presence of histologic change. All the minipigs with motor deficits showed some degree of demyelination and focal white matter necrosis on the irradiated side, with relative sparing of the gray matter. The histologic findings were unremarkable in the minipigs with normal neurologic status. Conclusions: Our results have indicated that for a dose distribution with a steep lateral gradient, the pigs had a lower median effective dose for paralysis than has been observed in rats and more closely resembles that for rats, mice, and guinea pigs receiving uniform spinal cord irradiation.

  3. A Theoretical Solution to MAP-EM Partial Volume Segmentation of Medical Images

    PubMed Central

    Wang, Su; Lu, Hongyu; Liang, Zhengrong

    2009-01-01

    Voxels near tissue borders in medical images contain useful clinical information, but are subject to severe partial volume (PV) effect, which is a major cause of imprecision in quantitative volumetric and texture analysis. When modeling each tissue type as a conditionally independent Gaussian distribution, the tissue mixture fractions in each voxel via the modeled unobservable random processes of the underlying tissue types can be estimated by maximum a posteriori expectation-maximization (MAP-EM) algorithm in an iterative manner. This paper presents, based on the assumption that PV effect could be fully described by a tissue mixture model, a theoretical solution to the MAP-EM segmentation algorithm, as opposed to our previous approximation which simplified the posteriori cost function as a quadratic term. It was found out that the theoretically-derived solution existed in a set of high-order non-linear equations. Despite of the induced computational complexity when seeking for optimum numerical solutions to non-linear equations, potential gains in robustness, consistency and quantitative precision were noticed. Results from both synthetic digital phantoms and real patient bladder magnetic resonance images were presented, demonstrating the accuracy and efficiency of the presented theoretical MAP-EM solution. PMID:19768123

  4. Partial volume segmentation of brain magnetic resonance images based on maximum a posteriori probability

    SciTech Connect

    Li Xiang; Li Lihong; Lu Hongbing; Liang Zhengrong [Department of Radiology, State University of New York at Stony Brook, Stony Brook, New York, 11794 and Department of Radiation Oncology, Columbia University, New York, New York, 10032 (United States); Department of Radiology, State University of New York at Stony Brook, Stony Brook, New York, 11794 and Department of Engineering Science and Physics, College of Staten Island of the City University of New York, Staten Island, New York 10314 (United States); Department of Radiology, State University of New York at Stony Brook, Stony Brook, New York 11794 and Department of Biomedical Engineering/Computer Application, Fourth Military Medical University, Xi'an, Shaanxi 710032 (China); Department of Radiology, State University of New York at Stony Brook, Stony Brook, New York 11794 (United States)

    2005-07-15

    Noise, partial volume (PV) effect, and image-intensity inhomogeneity render a challenging task for segmentation of brain magnetic resonance (MR) images. Most of the current MR image segmentation methods focus on only one or two of the above-mentioned effects. The objective of this paper is to propose a unified framework, based on the maximum a posteriori probability principle, by taking all these effects into account simultaneously in order to improve image segmentation performance. Instead of labeling each image voxel with a unique tissue type, the percentage of each voxel belonging to different tissues, which we call a mixture, is considered to address the PV effect. A Markov random field model is used to describe the noise effect by considering the nearby spatial information of the tissue mixture. The inhomogeneity effect is modeled as a bias field characterized by a zero mean Gaussian prior probability. The well-known fuzzy C-mean model is extended to define the likelihood function of the observed image. This framework reduces theoretically, under some assumptions, to the adaptive fuzzy C-mean (AFCM) algorithm proposed by Pham and Prince. Digital phantom and real clinical MR images were used to test the proposed framework. Improved performance over the AFCM algorithm was observed in a clinical environment where the inhomogeneity, noise level, and PV effect are commonly encountered.

  5. MRI-based correction for PET partial volume effects in the presence of heterogeneity in gray matter radioactivity

    SciTech Connect

    Meltzer, C.C.; Zubieta, J.K.; Links, J.M. [Johns Hopkins Medical Institutions, Baltimore, MD (United States)] [and others

    1994-05-01

    Quantitation of small structures with PET may be inaccurate due to partial volume averaging of surrounding structures. We have previously described a method of correcting PET data for the effects of partial volume averaging on gray matter quantitation. This method may incompletely correct gray matter structures when local tissue concentrations are highly heterogenous. We present an extension of our previous method that by accounting for gray matter heterogeneity, allows for partial volume correction in small structures that can be delineated on MR images. Spoiled gradient echo MR data were acquired coplanar to the PET imaging plane. For each PET slice, 17 contiguous 1.5 mm-thick MR images were tri-segmented into gray matter, white matter, matter maps were created by and the for gray a second step, the structure of for volume and spill-in from surrounding gray and white matter. PET images simulated from MR data from patients with Alzheimer disease and controls demonstrated full recovery of tracer concentration in the amygdala over a range of contrasts (from that of white matter to 4x gray matter) (error = 0.36{plus_minus}0.29%) and sizes (152-725mm{sup 3}) (error = 0.11{plus_minus}0.17%). The method was validated with sphere phantoms and a 5-compartment brain phantom in actual PET acquisitions. This newly developed and validated MR-based partial volume correction algorithm for PET, accurately derives non-homogeneous gray matter radioactivity concentrations and should improve quantitation of subcortical structures.

  6. When Structure Affects Function – The Need for Partial Volume Effect Correction in Functional and Resting State Magnetic Resonance Imaging Studies

    PubMed Central

    Dukart, Juergen; Bertolino, Alessandro

    2014-01-01

    Both functional and also more recently resting state magnetic resonance imaging have become established tools to investigate functional brain networks. Most studies use these tools to compare different populations without controlling for potential differences in underlying brain structure which might affect the functional measurements of interest. Here, we adapt a simulation approach combined with evaluation of real resting state magnetic resonance imaging data to investigate the potential impact of partial volume effects on established functional and resting state magnetic resonance imaging analyses. We demonstrate that differences in the underlying structure lead to a significant increase in detected functional differences in both types of analyses. Largest increases in functional differences are observed for highest signal-to-noise ratios and when signal with the lowest amount of partial volume effects is compared to any other partial volume effect constellation. In real data, structural information explains about 25% of within-subject variance observed in degree centrality – an established resting state connectivity measurement. Controlling this measurement for structural information can substantially alter correlational maps obtained in group analyses. Our results question current approaches of evaluating these measurements in diseased population with known structural changes without controlling for potential differences in these measurements. PMID:25460595

  7. Partial volume correction of PET-imaged tumor heterogeneity using expectation maximization with a spatially varying point spread function

    PubMed Central

    Barbee, David L; Flynn, Ryan T; Holden, James E; Nickles, Robert J; Jeraj, Robert

    2010-01-01

    Tumor heterogeneities observed in positron emission tomography (PET) imaging are frequently compromised of partial volume effects which may affect treatment prognosis, assessment, or future implementations such as biologically optimized treatment planning (dose painting). This paper presents a method for partial volume correction of PET-imaged heterogeneous tumors. A point source was scanned on a GE Discover LS at positions of increasing radii from the scanner’s center to obtain the spatially varying point spread function (PSF). PSF images were fit in three dimensions to Gaussian distributions using least squares optimization. Continuous expressions were devised for each Gaussian width as a function of radial distance, allowing for generation of the system PSF at any position in space. A spatially varying partial volume correction (SV-PVC) technique was developed using expectation maximization (EM) and a stopping criterion based on the method’s correction matrix generated for each iteration. The SV-PVC was validated using a standard tumor phantom and a tumor heterogeneity phantom, and was applied to a heterogeneous patient tumor. SV-PVC results were compared to results obtained from spatially invariant partial volume correction (SINV-PVC), which used directionally uniform three dimensional kernels. SV-PVC of the standard tumor phantom increased the maximum observed sphere activity by 55 and 40% for 10 and 13 mm diameter spheres, respectively. Tumor heterogeneity phantom results demonstrated that as net changes in the EM correction matrix decreased below 35%, further iterations improved overall quantitative accuracy by less than 1%. SV-PVC of clinically observed tumors frequently exhibited changes of ±30% in regions of heterogeneity. The SV-PVC method implemented spatially varying kernel widths and automatically determined the number of iterations for optimal restoration, parameters which are arbitrarily chosen in SINV-PVC. Comparing SV-PVC to SINV-PVC demonstrated that similar results could be reached using both methods, but large differences result for the arbitrary selection of SINV-PVC parameters. The presented SV-PVC method was performed without user intervention, requiring only a tumor mask as input. Research involving PET-imaged tumor heterogeneity should include correcting for partial volume effects to improve the quantitative accuracy of results. PMID:20009194

  8. A novel neutron computed tomography partial volume voxel water quantification technique

    NASA Astrophysics Data System (ADS)

    Heller, Arthur Kevin

    Since neutrons are attenuated by small amounts of water, but readily penetrate most metals, neutron imaging is ideal for the observation and quantification of water mass in operating hydrogen-powered polymer electrolyte fuel cells (PEFCs). PEFC's have a special need for non-destructive analysis techniques for the imaging of liquid water because the liquid water stored in the porous media can be a source of reduced performance, degradation and cause more lethargic start-up from freezing conditions. Traditional two-dimensional (2D) neutron radioscopy has been successfully applied to the quantification of liquid water in PEFC's, but it suffers from the drawback of making it difficult to determine the exact "depth" within a PEFC the liquid water mass exists. Neutron computed tomography (NCT) produces a three-dimensional (3D) volumetric reconstruction that offers the ability to determine the exact spatial location of a liquid water mass within a PEFC. This makes possible the isolation of liquid water slugs that can block the channels of either the anode or cathode reactant flow fields. Water mass quantification of these slugs would provide insight into improving PEFC design. Thus, a method was developed for the precise quantification of water mass in neutron computed tomography (NCT) reconstructions. A three-dimensional (3D) volumetric reconstruction is comprised of individual volume elements, or voxels. The gray level value of a voxel represents the total macroscopic cross section, Sigmat, of the material present at the voxel's spatial location. For voxels along interfaces, the gray level represents a combination of Sigmats for the various materials present. The fractional amount of water, also known as a partial volume, represented by such a voxel must be quantified for an accurate result. This calculation requires removing or compensating for the influence of other materials on the voxel's gray level. This is accomplished by background normalizing the raw data used to produce the volumetric reconstruction. The resulting volumetric reconstruction contains voxels that represent only water. Normalizing to the gray level value of a voxel of known water mass produces a matrix of voxels with gray levels that now represent fractional amounts of water. These fractional amounts are tallied and multiplied by the known water mass of the normalizing voxel to determine the total. The NCT water quantification technique was tested using MCNP simulations of samples containing liquid phase water and ice phase water. Quantification of the MCNP simulations yielded results within 0.2% of the theoretical. For liquid phase and ice phase water samples at ˜30mm from the detector, results were within 2% of the theoretical. The ability to quantify an ice water mixture to within 2% of the theoretical was also demonstrated. For liquid phase water samples at 140mm from the detector, significant error in the quantified water mass, as large as 47%, was observed and determined to be the result of geometric un-sharpness effects and cupping artifacts. Deconvolution of the imaging system's blurring function was performed to correct for the geometric un-sharpness. Results of the devoncolution showed a reduction in the geometric un-sharpness by ˜14.4% yielding an average increase in quantified water mass of 6.7%. The effects of magnification, cupping artifacts, and geometric unsharpness on the final quantification results were also investigated. Magnification was determined to have no effect while cupping artifacts accounted for 1.4% of the error. Geometric un-sharpness accounted for 45% of the error, making it the dominant source of error.

  9. Partial specific volume of poly[2,2-bis(4-hydroxyphenyl)butane-co-phosgene

    NASA Astrophysics Data System (ADS)

    Wohlfarth, Ch.

    This document is part of Subvolume D2 'Polymer Solutions - Physical Properties and their Relations I (Thermodynamic Properties: PVT -Data and miscellaneous Properties of polymer Solutions) of Volume 6 `Polymers' of Landolt-Börnstein - Group VIII `Advanced Materials and Technologies'.

  10. Partial specific volume of poly[1,1-bis(4-hydroxyphenyl)-1-phenylethane-co-phosgene

    NASA Astrophysics Data System (ADS)

    Wohlfarth, Ch.

    This document is part of Subvolume D2 'Polymer Solutions - Physical Properties and their Relations I (Thermodynamic Properties: PVT -Data and miscellaneous Properties of polymer Solutions) of Volume 6 `Polymers' of Landolt-Börnstein - Group VIII `Advanced Materials and Technologies'.

  11. Solutions : WtPercentToMolarity (4 Variations)

    NSDL National Science Digital Library

    A common concentration unit used commercially is percent weight per volume (%W/V) which is the number of grams of solute in 100 mL of solution. A bottle of vinegar contains 5 %W/V acetic acid (CH 3 COOH). What is the molar concentration of acetic acid in the vinegar?

  12. Volumetric Quantification of Atherosclerotic Plaque in CT Considering Partial Volume Effect

    Microsoft Academic Search

    Jamshid Dehmeshki; Xujiong Ye; Hamdan Amin; Maryam Abaei; Xinyu Lin; Salah D. Qanadli

    2007-01-01

    Coronary artery calcification (CAC) is quantified based on a computed tomography (CT) scan image. A calcified region is identified. Modified expectation maximization (MEM) of a statistical model for the calcified and background material is used to estimate the partial calcium content of the voxels. The algorithm limits the region over which MEM is performed. By using MEM, the statistical properties

  13. Molar Incisor Hypomineralization, Prevalence, and Etiology

    PubMed Central

    Allazzam, Sulaiman Mohammed; Alaki, Sumer Madani; El Meligy, Omar Abdel Sadek

    2014-01-01

    Aim. To evaluate the prevalence and possible etiological factors associated with molar incisor hypomineralization (MIH) among a group of children in Jeddah, Saudi Arabia. Methods. A group of 8-12-year-old children were recruited (n = 267) from the Pediatric Dental Clinics at the Faculty of Dentistry, King Abdulaziz University. Children had at least one first permanent molar (FPM), erupted or partially erupted. Demographic information, children's medical history, and pregnancy-related data were obtained. The crowns of the FPM and permanent incisors were examined for demarcated opacities, posteruptive breakdown (PEB), atypical restorations, and extracted FPMs. Children were considered to have MIH if one or more FPM with or without involvement of incisors met the diagnostic criteria. Results. MIH showed a prevalence of 8.6%. Demarcated opacities were the most common form. Maxillary central incisors were more affected than mandibular (P = 0.01). The condition was more prevalent in children with history of illnesses during the first four years of life including tonsillitis (P = 0.001), adenoiditis (P = 0.001), asthma (P = 0.001), fever (P = 0.014), and antibiotics intake (P = 0.001). Conclusions. The prevalence of MIH is significantly associated with childhood illnesses during the first four years of life including asthma, adenoid infections, tonsillitis, fever, and antibiotics intake. PMID:24949012

  14. New 133Xe Gas Trapping Index for Quantifying Severe Emphysema Before Partial Lung Volume Reduction

    Microsoft Academic Search

    Jeff J. Mathews; Alan H. Maurer; Robert M. Steiner; Nathan Marchetti; Gerald Criner; John P. Gaughan; Harvey O. Coxson

    Lung volume reduction (LVR) is an effective therapy for end- stage emphysema. Preliminary and postprocedure imaging is usually limited to CT for anatomic delineation of the location and severity of the most acutely affected lung zones. The pur- pose of this study was to investigate the potential of using a new quantitative gas trapping index (GTI) derived from a 133Xe

  15. Dependence of the volume and viscosity of naphthalene-ethanol-octane solutions on composition at 298 K

    NASA Astrophysics Data System (ADS)

    Eliseeva, O. V.; Dyshin, A. A.; Kiselev, M. G.

    2013-03-01

    The solubility of naphthalene in ethanol-octane mixtures was measured by the isothermal saturation method. The solution densities were determined and the partial and apparent molar volumes of naphthalene were calculated. The viscosity was measured with an Ubbelohde viscosimeter with a suspended level. All measurements were performed at 298.15 K. The results were discussed based on interactions in solution.

  16. Molar versus as a paradigm clash.

    PubMed Central

    Baum, W M

    2001-01-01

    The molar view of behavior arose in response to the demonstrated inadequacy of explanations based on contiguity. Although Dinsmoor's (2001) modifications to two-factor theory render it irrefutable, a more basic criticism arises when we see that the molar and molecular views differ paradigmatically. The molar view has proven more productive. PMID:11453623

  17. Recovery of partial volume losses in cardiac mouse PET imaging using a combined 1D\\/2D and a combined 1D\\/3D model

    Microsoft Academic Search

    Tyler Dumouchel; Robert A. de Kemp

    2010-01-01

    Micro-PET image resolution is on the order of the left ventricle (LV) wall thickness in a mouse heart. Mouse LV images are thus subject to partial volume (PV) losses, impeding the ability to quantify tracer activity in cardiac muscle. In this study, 2D and 3D PV correction (PVC) models are proposed for mouse imaging. ECG gated PET images are acquired

  18. Intrusion of an overerupted molar using orthodontic miniscrew implant: A preprosthodontic therapy

    PubMed Central

    Sivakumar, Indumathi; Sivakumar, Arunachalam

    2014-01-01

    The purpose of this case report is to demonstrate the use of orthodontic miniscrew implant in the intrusion of overerupted molar as a preprosthodontic therapy. A 37-year-old woman with an overerupted maxillary right first molar encroaching on the opposing mandibular edentulous space was successfully intruded using a single miniscrew implant and partial fixed orthodontic appliance. The prosthodontic clinician may adopt this conservative and cost-effective strategy in their routine practice and avoid clinical crown reduction. PMID:25191088

  19. Densities and apparent molar volumes of atmospherically important electrolyte solutions. 1. The solutes H2SO4, HNO3, HCl, Na2SO4, NaNO3, NaCl, (NH4)2SO4, NH4NO3, and NH4Cl from 0 to 50 °C, including extrapolations to very low temperature and to the pure liquid state, and NaHSO4, NaOH, and NH3 at 25 °C.

    PubMed

    Clegg, S L; Wexler, A S

    2011-04-21

    Calculations of the size and density of atmospheric aerosols are complicated by the fact that they can exist at concentrations highly supersaturated with respect to dissolved salts and supercooled with respect to ice. Densities and apparent molar volumes of solutes in aqueous solutions containing the solutes H(2)SO(4), HNO(3), HCl, Na(2)SO(4), NaNO(3), NaCl, (NH(4))(2)SO(4), NH(4)NO(3), and NH(4)Cl have been critically evaluated and represented using fitted equations from 0 to 50 °C or greater and from infinite dilution to concentrations saturated or supersaturated with respect to the dissolved salts. Using extrapolated densities of high-temperature solutions and melts, the relationship between density and concentration is extended to the hypothetical pure liquid solutes. Above a given reference concentration of a few mol kg(-1), it is observed that density increases almost linearly with decreasing temperature, and comparisons with available data below 0 °C suggest that the fitted equations for density can be extrapolated to very low temperatures. As concentration is decreased below the reference concentration, the variation of density with temperature tends to that of water (which decreases as temperature is reduced below 3.98 °C). In this region below the reference concentration, and below 0 °C, densities are calculated using extrapolated apparent molar volumes which are constrained to agree at the reference concentrations with an equation for the directly fitted density. Calculated volume properties agree well with available data at low temperatures, for both concentrated and dilute solutions. Comparisons are made with literature data for temperatures of maximum density. Apparent molar volumes at infinite dilution are consistent, on a single ion basis, to better than ±0.1 cm(3) mol(-1) from 0 to 50 °C. Volume properties of aqueous NaHSO(4), NaOH, and NH(3) have also been evaluated, at 25 °C only. In part 2 of this work (ref 1 ) an ion interaction (Pitzer) model has been used to calculate apparent molar volumes of H(2)SO(4) in 0-3 mol kg(-1) aqueous solutions of the pure acid and to represent directly the effect of the HSO(4)(-) ? H(+) + SO(4)(2-) reaction. The results are incorporated into the treatment of aqueous H(2)SO(4) density described here. Densities and apparent molar volumes from -20 to 50 °C, and from 0 to 100 wt % of solute, are tabulated for the electrolytes listed in the title and have also been incorporated into the extended aerosol inorganics model (E-AIM, http://www.aim.env.uea.ac.uk/aim/aim.php) together with densities of the solid salts and hydrates. PMID:21438504

  20. Molar Malocclusions in Pine Voles (Microtus pinetorum)

    PubMed Central

    Harvey, Stephen B; Alworth, Leanne C; Blas-Machado, Uriel

    2009-01-01

    Here we describe 5 cases of molar malocclusions in adult pine voles (Microtus pinetorum) used for behavioral endocrinology studies. This species belongs to the subfamily Microtinae, which possess aradicular hypsodont molars. The abnormal molars identified caused apparent difficulty in mastication, resulting in poor body condition necessitating euthanasia. Postmortem examination of the oral cavity revealed grossly elongated mandibular and maxillary molars with abnormal wear at occlusal surfaces. This colony health problem was addressed successfully by adding autoclaved hardwood sticks to each cage as an enrichment tool. PMID:19653952

  1. Mandibular molar root morphology in Neanderthals and Late Pleistocene and recent Homo sapiens.

    PubMed

    Kupczik, Kornelius; Hublin, Jean-Jacques

    2010-11-01

    Neanderthals have a distinctive suite of dental features, including large anterior crown and root dimensions and molars with enlarged pulp cavities. Yet, there is little known about variation in molar root morphology in Neanderthals and other recent and fossil members of Homo. Here, we provide the first comprehensive metric analysis of permanent mandibular molar root morphology in Middle and Late Pleistocene Homo neanderthalensis, and Late Pleistocene (Aterian) and recent Homo sapiens. We specifically address the question of whether root form can be used to distinguish between these groups and assess whether any variation in root form can be related to differences in tooth function. We apply a microtomographic imaging approach to visualise and quantify the external and internal dental morphologies of both isolated molars and molars embedded in the mandible (n=127). Univariate and multivariate analyses reveal both similarities (root length and pulp volume) and differences (occurrence of pyramidal roots and dental tissue volume proportion) in molar root morphology among penecontemporaneous Neanderthals and Aterian H. sapiens. In contrast, the molars of recent H. sapiens are markedly smaller than both Pleistocene H. sapiens and Neanderthals, but share with the former the dentine volume reduction and a smaller root-to-crown volume compared with Neanderthals. Furthermore, we found the first molar to have the largest average root surface area in recent H. sapiens and Neanderthals, although in the latter the difference between M(1) and M(2) is small. In contrast, Aterian H. sapiens root surface areas peak at M(2). Since root surface area is linked to masticatory function, this suggests a distinct occlusal loading regime in Neanderthals compared with both recent and Pleistocene H. sapiens. PMID:20719359

  2. Molar size sequence in Australian Aboriginals.

    PubMed

    Townsend, G C; Brown, T

    1983-01-01

    Percentage frequencies for molar size sequence of first and second molars were calculated in a group of contemporary Australian Aboriginals using mesiodistal and buccolingual dimensions, as well as crown areas. Comparisons were made between sexes, arches, and dimensions within the Aboriginal group and also between Aboriginal data and those published for other populations. The frequencies of the M2 greater than M1 molar size sequence in the Aboriginals fell within the range of frequencies reported for other contemporary populations. Differences in the frequencies of the M2 greater than M1 sequence between the sexes and between arches, together with the relatively high frequency of asymmetry in molar size sequence within Aboriginals, supported the notion that local environmental conditions acting during odontogenesis, together with differential responses to other environmental influences, play an important role in determining observed patterns of molar tooth size. PMID:6869504

  3. Revolution vs status quo? Non-intervention strategy of asymptomatic third molars causes harm.

    PubMed

    Toedtling, V; Yates, J M

    2015-07-10

    The Faculty of Dental Surgery of the Royal College of Surgeons of England has prompted the National Institute for Health and Care Excellence to urgently re-assess the TA1 guidance on extractions of wisdom teeth and highlighted required amendments to the present version in light of published evidence concerning the harm caused by wisdom tooth retention. This article seeks to address the recent concerns relating the increasing frequency of distal-cervical caries in lower second molar teeth when associated with asymptomatic partially erupted mesial or horizontal impacted mandibular third molars. Such acute angle impactions are classified as partially erupted when one of the third molar cusps breached the epithelial attachment of the distal aspect of the second molar, thus prevents the formation of a gingival seal. At its earliest stage the wisdom tooth appears clinically absent or unerupted, yet histologically the architecture of the gingival epithelium has been disrupted allowing ingress of microbes, demineralisation and succeeding cavitation to take place on the distal aspect of the second molar. We hope to highlight the difficulties faced in addressing this growing clinical problem and encourage clinicians to re-evaluate their own caries risk assessment and caries prevention strategy in relation to mesial and horizontal third molar extractions. PMID:26159975

  4. METHODS DEVELOPMENT FOR ASSESSING AIR POLLUTION CONTROL BENEFITS. VOLUME IV. STUDIES ON PARTIAL EQUILIBRIUM APPROACHES TO VALUATION OF ENVIRONMENTAL AMENITIES

    EPA Science Inventory

    The research presented in this volume of a five volume study of the economic benefits of air pollution control explores various facets of the two central project objectives that have not been given adequate attention in the previous volumes. The valuations developed in these prev...

  5. Expressly Fabricated Molar Tube Bases: Enhanced Adhesion

    PubMed Central

    Phull, Tarun Singh; Rana, Tarun; Kumar, Varun

    2014-01-01

    Clinicians, Orthodontists and their patients’ parents often expect the best results in the shortest time span possible. Orthodontic bonding of molar tubes has been an acceptable risk in a modern era of refined biomaterials and instrumentation. Although many orthodontists still prefer banding to bonding, it is the failure rate of the tubes on molars which accounts to an impedance in molar bonding. One of the reasons for molar attachment failures is attributed to improper adaptation of the buccal tube base with or without increased thickness of composite. Merits of banding the second molars especially when these are the terminal teeth for anchorage have been overemphasized in the literature. The present article presents a simple and relatively less time consuming technique of preparing molar tubes to be bonded on tooth surfaces which may be quite difficult to isolate especially for bonding, for example, mandibular second molars. The increased surface area of the composite scaffold helps not only in enhanced bond strength but also serves to reduce the incidence of plaque accumulation given the dexterity of invitro preparation. The removal of the occlusal part of the molar tube scaffold helps in prevention of open / raised bite tendencies. The present innovation, therefore, is not merely serendipity but a structured technique to overcome a common dilemma for the clinical orthodontist. The present dictum of banding being superior to molar tube bonding may prove to be futile with trendsetting molar attachments. It is also an established fact that bonding proves to be a lesser expensive modality when compared to banding procedures. PMID:25121070

  6. A method for partial volume correction of PET-imaged tumor heterogeneity using expectation maximization with a spatially varying point spread function

    NASA Astrophysics Data System (ADS)

    Barbee, David L.; Flynn, Ryan T.; Holden, James E.; Nickles, Robert J.; Jeraj, Robert

    2010-01-01

    Tumor heterogeneities observed in positron emission tomography (PET) imaging are frequently compromised by partial volume effects which may affect treatment prognosis, assessment or future implementations such as biologically optimized treatment planning (dose painting). This paper presents a method for partial volume correction of PET-imaged heterogeneous tumors. A point source was scanned on a GE Discovery LS at positions of increasing radii from the scanner's center to obtain the spatially varying point spread function (PSF). PSF images were fit in three dimensions to Gaussian distributions using least squares optimization. Continuous expressions were devised for each Gaussian width as a function of radial distance, allowing for generation of the system PSF at any position in space. A spatially varying partial volume correction (SV-PVC) technique was developed using expectation maximization (EM) and a stopping criterion based on the method's correction matrix generated for each iteration. The SV-PVC was validated using a standard tumor phantom and a tumor heterogeneity phantom and was applied to a heterogeneous patient tumor. SV-PVC results were compared to results obtained from spatially invariant partial volume correction (SINV-PVC), which used directionally uniform three-dimensional kernels. SV-PVC of the standard tumor phantom increased the maximum observed sphere activity by 55 and 40% for 10 and 13 mm diameter spheres, respectively. Tumor heterogeneity phantom results demonstrated that as net changes in the EM correction matrix decreased below 35%, further iterations improved overall quantitative accuracy by less than 1%. SV-PVC of clinically observed tumors frequently exhibited changes of ±30% in regions of heterogeneity. The SV-PVC method implemented spatially varying kernel widths and automatically determined the number of iterations for optimal restoration, parameters which are arbitrarily chosen in SINV-PVC. Comparing SV-PVC to SINV-PVC demonstrated that similar results could be reached using both methods, but large differences result for the arbitrary selection of SINV-PVC parameters. The presented SV-PVC method was performed without user intervention, requiring only a tumor mask as input. Research involving PET-imaged tumor heterogeneity should include correcting for partial volume effects to improve the quantitative accuracy of results.

  7. A method for partial volume correction of PET-imaged tumor heterogeneity using expectation maximization with a spatially varying point spread function.

    PubMed

    Barbee, David L; Flynn, Ryan T; Holden, James E; Nickles, Robert J; Jeraj, Robert

    2010-01-01

    Tumor heterogeneities observed in positron emission tomography (PET) imaging are frequently compromised by partial volume effects which may affect treatment prognosis, assessment or future implementations such as biologically optimized treatment planning (dose painting). This paper presents a method for partial volume correction of PET-imaged heterogeneous tumors. A point source was scanned on a GE Discovery LS at positions of increasing radii from the scanner's center to obtain the spatially varying point spread function (PSF). PSF images were fit in three dimensions to Gaussian distributions using least squares optimization. Continuous expressions were devised for each Gaussian width as a function of radial distance, allowing for generation of the system PSF at any position in space. A spatially varying partial volume correction (SV-PVC) technique was developed using expectation maximization (EM) and a stopping criterion based on the method's correction matrix generated for each iteration. The SV-PVC was validated using a standard tumor phantom and a tumor heterogeneity phantom and was applied to a heterogeneous patient tumor. SV-PVC results were compared to results obtained from spatially invariant partial volume correction (SINV-PVC), which used directionally uniform three-dimensional kernels. SV-PVC of the standard tumor phantom increased the maximum observed sphere activity by 55 and 40% for 10 and 13 mm diameter spheres, respectively. Tumor heterogeneity phantom results demonstrated that as net changes in the EM correction matrix decreased below 35%, further iterations improved overall quantitative accuracy by less than 1%. SV-PVC of clinically observed tumors frequently exhibited changes of +/-30% in regions of heterogeneity. The SV-PVC method implemented spatially varying kernel widths and automatically determined the number of iterations for optimal restoration, parameters which are arbitrarily chosen in SINV-PVC. Comparing SV-PVC to SINV-PVC demonstrated that similar results could be reached using both methods, but large differences result for the arbitrary selection of SINV-PVC parameters. The presented SV-PVC method was performed without user intervention, requiring only a tumor mask as input. Research involving PET-imaged tumor heterogeneity should include correcting for partial volume effects to improve the quantitative accuracy of results. PMID:20009194

  8. Role of third molars in orthodontics.

    PubMed

    Almpani, Konstantinia; Kolokitha, Olga-Elpis

    2015-02-16

    The role of third molars in the oral cavity has been extensively studied over the years. Literature includes numerous diagnostic and treatment alternatives regarding the third molars. However, an issue that has not been discussed at the same level is their involvement in orthodontic therapy. The aim of this study is to present a review of the contemporary literature regarding the most broadly discussed aspects of the multifactorial role of third molars in orthodontics and which are of general dental interest too. PMID:25685759

  9. Efficiency of a pendulum appliance for molar distalization related to second and third molar eruption stage

    Microsoft Academic Search

    Gero S. M Kinzinger; Ulrike B Fritz; Franz-Günter Sander; Peter R Diedrich

    2004-01-01

    A modified pendulum appliance, including a distal screw and special preactivated pendulum springs (built-in straightening activation and toe-in bending), was used for bilateral maxillary molar distalization in 36 adolescent patients in various stages of the molar dentition. The patients were divided into 3 groups (PG 1-3) according to the stage of eruption of their second and third molars. In PG

  10. Partial specific volume of poly[1,1-bis(4-hydroxy-3-methylphenyl)-1-phenylethane-co-phosgene

    NASA Astrophysics Data System (ADS)

    Wohlfarth, Ch.

    This document is part of Subvolume D2 'Polymer Solutions - Physical Properties and their Relations I (Thermodynamic Properties: PVT -Data and miscellaneous Properties of polymer Solutions) of Volume 6 `Polymers' of Landolt-Börnstein - Group VIII `Advanced Materials and Technologies'.

  11. Partial specific volume of poly[2,2-bis(4-hydroxy-3-methylphenyl)butane-co-phosgene

    NASA Astrophysics Data System (ADS)

    Wohlfarth, Ch.

    This document is part of Subvolume D2 'Polymer Solutions - Physical Properties and their Relations I (Thermodynamic Properties: PVT -Data and miscellaneous Properties of polymer Solutions) of Volume 6 `Polymers' of Landolt-Börnstein - Group VIII `Advanced Materials and Technologies'.

  12. Partial specific volume of poly[2,2-bis(4-hydroxy-3-methylphenyl)propane-co-phosgene

    NASA Astrophysics Data System (ADS)

    Wohlfarth, Ch.

    This document is part of Subvolume D2 'Polymer Solutions - Physical Properties and their Relations I (Thermodynamic Properties: PVT -Data and miscellaneous Properties of polymer Solutions) of Volume 6 `Polymers' of Landolt-Börnstein - Group VIII `Advanced Materials and Technologies'.

  13. Orthodontic extrusion of horizontally impacted mandibular molars

    PubMed Central

    Ma, Zhigui; Yang, Chi; Zhang, Shanyong; Xie, Qianyang; Shen, Yuqing; Shen, Pei

    2014-01-01

    Objective: To introduce and evaluate a novel approach in treating horizontally impacted mandibular second and third molars. Materials and methods: An orthodontic technique was applied for treatment of horizontally impacted mandibular second and third molars, which included a push-type spring for rotation first, and then a cantilever for extrusion. There were 8 mandibular third molars (M3s) and 2 second molars (M2s) in this study. Tooth mobility, extraction time, the inclination and parallelism of the impacted tooth, alveolar bone height of the adjacent tooth, and the relationship of impacted M3 and the inferior alveolar nerve (IAN) were evaluated. Results: Two horizontally impacted M2s could be upright in the arch and good occlusal relationships were obtained after treatment. All impacted M3s were successfully separated from the IAN, without any neurologic consequences. The average extraction time was 5 minutes. There was a significant change in the inclination and parallelism of the impacted tooth after treatment. A new bone apposition with the average height of 3.2 mm was noted distal to the adjacent tooth. Conclusions: This two-step orthodontic technique as presented here may be a safe and feasible alternative in management of severely horizontally impacted mandibular molars, which achieves a successful separation of M3s from the IAN and an excellent position for M2s. PMID:25419364

  14. Measurement of D2 dopamine receptor-specific carbon-11-YM-09151-2 binding in the canine brain by PET: Importance of partial volume correction

    SciTech Connect

    Hatazawa, J.; Hatano, K.; Ishiwata, K.; Itoh, M.; Ido, T.; Kawashima, K.; Meguro, K.; Watanuki, S.; Seo, S. (Tohoku Univ., Sendai (Japan))

    1991-04-01

    Carbon-11-YM-09151-2 binds highly selectively to D2 dopamine receptors in the brain. Using this ligand, D2 dopamine receptor density (Bmax) and affinity (Kd) in canine striatum were measured. After administering various doses of the ligand in nine experiments, regional uptake was followed by repeated PET scanning for up to 80 min. D2 dopamine receptor specific binding at equilibrium was defined as striatal minus occipital activity after partial volume correction. Bmax and Kd were estimated by Scatchard analysis to be 40.3 pmole/ml of tissue and 22.9 nM, respectively. When a low mass dose of the ligand was administered, the bound-to-free ligand ratio in the striatum at equilibrium was consistent with the Bmax/Kd value obtained from the Scatchard analysis. The present study demonstrates the importance of partial volume correction and the Bmax/Kd measurement in a single PET study with carbon-11-YM-09151-2.

  15. Impact of Increasing Margin Around the Lumpectomy Cavity to Define the Planning Target Volume for 3D Conformal External Beam Accelerated Partial Breast Irradiation

    SciTech Connect

    Cox, Brett W. [Department of Radiation Oncology, Stanford University, Stanford, CA (United States); Horst, Kathleen C. [Department of Radiation Oncology, Stanford University, Stanford, CA (United States)], E-mail: kateh@stanford.edu; Thornton, Sherri [Department of Radiation Oncology, Stanford University, Stanford, CA (United States); Dirbas, Frederick M. [Department of Surgery, Stanford University, Stanford, CA (United States)

    2007-01-01

    The purpose of this study was to evaluate the dose to normal tissues as a function of increasing margins around the lumpectomy cavity in accelerated partial breast irradiation (APBI) using 3D-conformal radiotherapy (3DCRT). Eight patients with Stage 0-I breast cancer underwent treatment planning for 3DCRT APBI. The clinical target volume (CTV) was defined as a 15-mm expansion around the cavity limited by the chest wall and skin. Three planning target volumes (PTV1, PTV2, PTV3) were generated for each patient using a 0, 5-, and 10-mm expansion around the CTV, for a total margin of 15, 20, and 25 mm. Three treatment plans were generated for every patient using the 3 PTVs, and dose-volume analysis was performed for each plan. For each 5-mm increase in margin, the mean PTV:total breast volume ratio increased 10% and the relative increase in the mean ipsilateral breast dose was 15%. The mean volume of ipsilateral breast tissue receiving 75%, 50%, and 25% of the prescribed dose increased 6% to 7% for every 5 mm increase in PTV margin. Compared to lesions located in the upper outer quadrant, plans for medially located tumors revealed higher mean ipsilateral breast doses and 20% to 22% more ipsilateral breast tissue encompassed by the 25% IDL. The use of 3DCRT for APBI delivers higher doses to normal breast tissue as the PTV increases around the lumpectomy cavity. Efforts should be made to minimize the overall PTV when this technique is used. Ongoing studies will be necessary to determine the clinical relevance of these findings.

  16. Dependence of the volume characteristics and viscosity of solutions of methanol-octane-naphthalene on composition at 25°C

    NASA Astrophysics Data System (ADS)

    Dyshin, A. A.; Eliseeva, O. V.; Kiselev, M. G.

    2014-10-01

    The limiting solubility of naphthalene in a mixture of methanol-octane at 25°C is determined via isothermal saturation. The kinematic viscosity of a mixture of methanol-octane-naphthalene is measured at 25°C. Data on the density of triple mixtures of methanol-octane-naphthalene, used to calculate the partial and apparent molar volumes of naphthalene, are obtained with a high degree of accuracy. The obtained results are discussed in terms of the interactions that occur in solution.

  17. Dose volume histogram analysis of normal structures associated with accelerated partial breast irradiation delivered by high dose rate brachytherapy and comparison with whole breast external beam radiotherapy fields

    PubMed Central

    Stewart, Alexandra J; O'Farrell, Desmond A; Cormack, Robert A; Hansen, Jorgen L; Khan, Atif J; Mutyala, Subhakar; Devlin, Phillip M

    2008-01-01

    Purpose To assess the radiation dose delivered to the heart and ipsilateral lung during accelerated partial breast brachytherapy using a MammoSite™ applicator and compare to those produced by whole breast external beam radiotherapy (WBRT). Materials and methods Dosimetric analysis was conducted on patients receiving MammoSite breast brachytherapy following conservative surgery for invasive ductal carcinoma. Cardiac dose was evaluated for patients with left breast tumors with a CT scan encompassing the entire heart. Lung dose was evaluated for patients in whom the entire lung was scanned. The prescription dose of 3400 cGy was 1 cm from the balloon surface. MammoSite dosimetry was compared to simulated WBRT fields with and without radiobiological correction for the effects of dose and fractionation. Dose parameters such as the volume of the structure receiving 10 Gy or more (V10) and the dose received by 20 cc of the structure (D20), were calculated as well as the maximum and mean doses received. Results Fifteen patients were studied, five had complete lung data and six had left-sided tumors with complete cardiac data. Ipsilateral lung volumes ranged from 925–1380 cc. Cardiac volumes ranged from 337–551 cc. MammoSite resulted in a significantly lower percentage lung V30 and lung and cardiac V20 than the WBRT fields, with and without radiobiological correction. Conclusion This study gives low values for incidental radiation received by the heart and ipsilateral lung using the MammoSite applicator. The volume of heart and lung irradiated to clinically significant levels was significantly lower with the MammoSite applicator than using simulated WBRT fields of the same CT data sets. Trial registration Dana Farber Trial Registry number 03-179 PMID:19019216

  18. Partial Eval Partial Eval

    E-print Network

    Sumii, Eijiro

    Efficient Onl ine Partial E al ati n Eijiro Sumii o i o i i r i o o o umii o i u o o j #12; Partial/dynamic portions of p(sâ??,d) ¯ spec a e program p sâ?? (d) s p(sâ??,d) = = = = p sâ?? (d) or a am c pu d ope u e r . . . . -- -- -- . . #12; A Naive Onl ine Partial val at r E (expression) ::= x | l l l lx.E | E@E #12; A Naive Onl ine

  19. PET imaging of thin objects: measuring the effects of positron range and partial-volume averaging in the leag of Nicotiana Tabacum

    SciTech Connect

    Alexoff, D.L.; Alexoff, D.L.; Dewey, S.L.; Vaska, P.; Krishnamoorthy, S.; Ferrieri, R.; Schueller, M.; Schlyer, D.; Fowler, J.S.

    2011-03-01

    PET imaging in plants is receiving increased interest as a new strategy to measure plant responses to environmental stimuli and as a tool for phenotyping genetically engineered plants. PET imaging in plants, however, poses new challenges. In particular, the leaves of most plants are so thin that a large fraction of positrons emitted from PET isotopes ({sup 18}F, {sup 11}C, {sup 13}N) escape while even state-of-the-art PET cameras have significant partial-volume errors for such thin objects. Although these limitations are acknowledged by researchers, little data have been published on them. Here we measured the magnitude and distribution of escaping positrons from the leaf of Nicotiana tabacum for the radionuclides {sup 18}F, {sup 11}C and {sup 13}N using a commercial small-animal PET scanner. Imaging results were compared to radionuclide concentrations measured from dissection and counting and to a Monte Carlo simulation using GATE (Geant4 Application for Tomographic Emission). Simulated and experimentally determined escape fractions were consistent. The fractions of positrons (mean {+-} S.D.) escaping the leaf parenchyma were measured to be 59 {+-} 1.1%, 64 {+-} 4.4% and 67 {+-} 1.9% for {sup 18}F, {sup 11}C and {sup 13}N, respectively. Escape fractions were lower in thicker leaf areas like the midrib. Partial-volume averaging underestimated activity concentrations in the leaf blade by a factor of 10 to 15. The foregoing effects combine to yield PET images whose contrast does not reflect the actual activity concentrations. These errors can be largely corrected by integrating activity along the PET axis perpendicular to the leaf surface, including detection of escaped positrons, and calculating concentration using a measured leaf thickness.

  20. The Effect of Dose-Volume Parameters and Interfraction Interval on Cosmetic Outcome and Toxicity After 3-Dimensional Conformal Accelerated Partial Breast Irradiation

    SciTech Connect

    Leonard, Kara Lynne, E-mail: karalynne.kerr@gmail.com [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts (United States); Hepel, Jaroslaw T. [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts (United States) [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts (United States); Department of Radiation Oncology, Rhode Island Hospital, Warren Alpert School of Medicine of Brown University, Providence, Rhode Island (United States); Hiatt, Jessica R. [Department of Radiation Oncology, Rhode Island Hospital, Warren Alpert School of Medicine of Brown University, Providence, Rhode Island (United States)] [Department of Radiation Oncology, Rhode Island Hospital, Warren Alpert School of Medicine of Brown University, Providence, Rhode Island (United States); Dipetrillo, Thomas A. [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts (United States) [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts (United States); Department of Radiation Oncology, Rhode Island Hospital, Warren Alpert School of Medicine of Brown University, Providence, Rhode Island (United States); Price, Lori Lyn [Department of Biostatistics Research Center, Institute of Clinical Research and Health Policy Studies, Tufts Medical Center, Boston, Massachusetts (United States)] [Department of Biostatistics Research Center, Institute of Clinical Research and Health Policy Studies, Tufts Medical Center, Boston, Massachusetts (United States); Wazer, David E. [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts (United States) [Department of Radiation Oncology, Tufts University School of Medicine, Boston, Massachusetts (United States); Department of Radiation Oncology, Rhode Island Hospital, Warren Alpert School of Medicine of Brown University, Providence, Rhode Island (United States)

    2013-03-01

    Purpose: To evaluate dose-volume parameters and the interfraction interval (IFI) as they relate to cosmetic outcome and normal tissue effects of 3-dimensional conformal radiation therapy (3D-CRT) for accelerated partial breast irradiation (APBI). Methods and Materials: Eighty patients were treated by the use of 3D-CRT to deliver APBI at our institutions from 2003-2010 in strict accordance with the specified dose-volume constraints outlined in the National Surgical Adjuvant Breast and Bowel Project B39/Radiation Therapy Oncology Group 0413 (NSABP-B39/RTOG 0413) protocol. The prescribed dose was 38.5 Gy in 10 fractions delivered twice daily. Patients underwent follow-up with assessment for recurrence, late toxicity, and overall cosmetic outcome. Tests for association between toxicity endpoints and dosimetric parameters were performed with the chi-square test. Univariate logistic regression was used to evaluate the association of interfraction interval (IFI) with these outcomes. Results: At a median follow-up time of 32 months, grade 2-4 and grade 3-4 subcutaneous fibrosis occurred in 31% and 7.5% of patients, respectively. Subcutaneous fibrosis improved in 5 patients (6%) with extended follow-up. Fat necrosis developed in 11% of women, and cosmetic outcome was fair/poor in 19%. The relative volume of breast tissue receiving 5%, 20%, 50%, 80%, and 100% (V5-V100) of the prescribed dose was associated with risk of subcutaneous fibrosis, and the volume receiving 50%, 80%, and 100% (V50-V100) was associated with fair/poor cosmesis. The mean IFI was 6.9 hours, and the minimum IFI was 6.2 hours. The mean and minimum IFI values were not significantly associated with late toxicity. Conclusions: The incidence of moderate to severe late toxicity, particularly subcutaneous fibrosis and fat necrosis and resulting fair/poor cosmesis, remains high with continued follow-up. These toxicity endpoints are associated with several dose-volume parameters. Minimum and mean IFI values were not associated with late toxicity.

  1. CANAL MORPHOLOGY OF MAXILLARY MOLARS: Clinical Observations of Canal Configurations

    Microsoft Academic Search

    John J. Stropko

    An examination of 1732 conventionally treated maxillary molars was made in an attempt to deter-mine the percentage of MB2 canals that could be located routinely. The teeth examined were 1096 first molars, 611 second molars, and 25 third mo-lars. The results were recorded on a modified computer program over an 8-yr period of time. An in-teresting trend was noted. The

  2. Reference planes for binary diffusion with variable molar volume

    Microsoft Academic Search

    A. G. Guy

    1985-01-01

    Present-day treatments of diffusion in metallic solid solutions require an accurate, convenient analysis that takes account of the actual variations of atomic size with concentration. Recent research by the author has produced such an analysis, which employs ordinary Cartesian coordinates. The first and second Fick equations are essentially the same as the usual forms (for constant, equal atomic size), differing

  3. Quantitation of Regional Cerebral Blood Flow Corrected for Partial Volume Effect Using O-15 Water and PET: II. Normal Values and Gray Matter Blood Flow Response to Visual Activation

    Microsoft Academic Search

    Ian Law; Hidehiro Iida; Sam Nour; Egill Rostrup; Claus Svarer; Olaf B. Paulson

    2000-01-01

    One of the most limiting factors for the accurate quantification of physiologic parameters with positron emission tomography (PET) is the partial volume effect (PVE). To assess the magnitude of this contribution to the measurement of regional cerebral blood flow (rCBF), the authors have formulated four kinetic models each including a parameter defining the perfusable tissue fraction (PTF). The four kinetic

  4. Molar tubal ectopic pregnancy: Report of two cases.

    PubMed

    Mbarki, Chaouki; Jerbi, Emna; Hsayaoui, Najeh; Zouari, Fatma; Ben Brahim, Ehsen; Oueslati, Hedhili

    2015-06-01

    Ectopic molar pregnancy is a rare occurrence and consequently not often considered as a diagnostic possibility. We report two cases of molar hydatidiform tubal pregnancy. Diagnosis of ectopic pregnancy was confirmed on clinical biological and sonographic investigations. Diagnosis of molar pregnancy was done on histopathology. The clinical course was favorable for both patients. Although rare, molar changes can occur at any site of an ectopic pregnancy. Clinical diagnosis of a molar pregnancy is difficult but histopathology is the gold standard for diagnosis. PMID:25510265

  5. Sinus floor augmentation at the time of maxillary molar extraction: technique and report of preliminary results.

    PubMed

    Fugazzotto, P A

    1999-01-01

    A technique is described for accomplishing both localized sinus augmentation and guided bone regeneration at the time of maxillary molar extraction. One hundred nine sites were treated in 92 patients. Of these, 102 procedures (94.0%) were successful and 7 (6.0%) were partially successful. Success was defined as the ability to ideally position an implant at least 10 mm in length and 4.8 mm in width without perforating the floor of the sinus or generating an implant fenestration or dehiscence. Partially successful procedures required an additional osteotome sinus lift at the time of implant placement. PMID:10453669

  6. Standard molar enthalpy of formation, vapour pressures, and standard molar enthalpy of sublimation of benzanthrone

    Microsoft Academic Search

    Manuel A. V. Ribeiro da Silva; M. Lu??sa C. C. H. Ferrão; Manuel J. S. Monte; Jorge M. Gonçalves; Fang Jiye

    1999-01-01

    The standard (po= 0.1 MPa) molar enthalpy of combustion atT= 298.15 K of crystalline benzanthrone was determined as?cHmo=?(8114.7 ± 2.0)kJ · mol?1by static-bomb calorimetry, and the standard molar enthalpy of formation of the crystal atT= 298.15 K was derived as?fHmo(cr) =?(4.1 ± 3.0)kJ · mol?1. Vapour pressure as a function of temperature was measured using the mass-loss Knudsen effusion technique,

  7. A Prospective Pathologic Study to Define the Clinical Target Volume for Partial Breast Radiation Therapy in Women With Early Breast Cancer

    SciTech Connect

    Nguyen, Brandon T., E-mail: Brandon.Nguyen@act.gov.au [Department of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia); Canberra Hospital, Radiation Oncology Department, Garran, ACT (Australia); Deb, Siddhartha [Department of Anatomical Pathology, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia) [Department of Anatomical Pathology, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia); Victorian Cancer Biobank, Cancer Council of Victoria, Carlton, Victoria (Australia); Fox, Stephen [Department of Anatomical Pathology, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia)] [Department of Anatomical Pathology, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia); Hill, Prudence [Department of Anatomical Pathology, St. Vincent's Hospital Melbourne, Fitzroy, Victoria (Australia)] [Department of Anatomical Pathology, St. Vincent's Hospital Melbourne, Fitzroy, Victoria (Australia); Collins, Marnie [Centre for Biostatistics and Clinical Trials, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia)] [Centre for Biostatistics and Clinical Trials, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia); Chua, Boon H. [Department of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia) [Department of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia); University of Melbourne, Parkville, Victoria (Australia)

    2012-12-01

    Purpose: To determine an appropriate clinical target volume for partial breast radiation therapy (PBRT) based on the spatial distribution of residual invasive and in situ carcinoma after wide local excision (WLE) for early breast cancer or ductal carcinoma in situ (DCIS). Methods and Materials: We performed a prospective pathologic study of women potentially eligible for PBRT who had re-excision and/or completion mastectomy after WLE for early breast cancer or DCIS. A pathologic assessment protocol was used to determine the maximum radial extension (MRE) of residual carcinoma from the margin of the initial surgical cavity. Women were stratified by the closest initial radial margin width: negative (>1 mm), close (>0 mm and {<=}1 mm), or involved. Results: The study population was composed of 133 women with a median age of 59 years (range, 27-82 years) and the following stage groups: 0 (13.5%), I (40.6%), II (38.3%), and III (7.5%). The histologic subtypes of the primary tumor were invasive ductal carcinoma (74.4%), invasive lobular carcinoma (12.0%), and DCIS alone (13.5%). Residual carcinoma was present in the re-excision and completion mastectomy specimens in 55.4%, 14.3%, and 7.2% of women with an involved, close, and negative margin, respectively. In the 77 women with a noninvolved radial margin, the MRE of residual disease, if present, was {<=}10 mm in 97.4% (95% confidence interval 91.6-99.5) of cases. Larger MRE measurements were significantly associated with an involved margin (P<.001), tumor size >30 mm (P=.03), premenopausal status (P=.03), and negative progesterone receptor status (P=.05). Conclusions: A clinical target volume margin of 10 mm would encompass microscopic residual disease in >90% of women potentially eligible for PBRT after WLE with noninvolved resection margins.

  8. Restorative management of severely ankylosed primary molars.

    PubMed

    de Moura, Marcoeli Silva; Pontes, Alessandra Silva; Brito, Maria Hellen Sâmia Fortes; de Deus Moura, Lucia; de Deus Moura de Lima, Marina; de Melo Simplício, Alexandre Henrique

    2015-01-01

    Severe dentoalveolar ankylosis is an etiological factor for malocclusion. When infraocclusion occurs early, it progresses with time, leading to severe consequences in young children because of compensatory supra-eruption of the antagonist tooth and mesialization of adjacent teeth. Early diagnosis allows for interception of the problem and may prevent orthodontic treatment. The purpose of this manuscript is to report two cases of infraocclusion of primary mandibular second molars that were diagnosed early and were treated with composite resin crowns. The use of indirect composite restorations for ankylosed teeth is a good option for primary teeth with a moderate/ severe degree of ankylosis. PMID:25909842

  9. volumes

    Microsoft Academic Search

    B. S. von Ungern-Sternberg; A. Regli; M. C. Schneider; F. Kunz; A. Reber

    Methods. We prospectively studied 161 patients having either breast surgery (Group A, n=80) or lower abdominal laparotomy (Group B, n=81). Premedication and general anaesthesia were standardized. Spirometry was measured with the patient supine, in a 30? head-up position. We measured vital capacity (VC), forced vital capacity, peak expiratory flow and forced expiratory volume in 1 s at preoperative assessment (baseline),

  10. Improving Dynamic Susceptibility Contrast MRI Measurement of Quantitative Cerebral Blood Flow using Corrections for Partial Volume and Nonlinear Contrast Relaxivity: a Xenon CT Comparative Study

    PubMed Central

    Zaharchuk, Greg; Bammer, Roland; Straka, Matus; Newbould, Rexford D; Rosenberg, Jarrett; Olivot, Jean-Marc; Mlynash, Michael; Lansberg, Maarten G; Schwartz, Neil E; Marks, Michael M; Albers, Gregory W; Moseley, Michael E

    2010-01-01

    Purpose To test whether dynamic susceptibility contrast MRI-based CBF measurements are improved with arterial input function (AIF) partial volume (PV) and nonlinear contrast relaxivity correction, using a gold-standard CBF method, xenon computed tomography (xeCT). Materials and Methods 18 patients with cerebrovascular disease underwent xeCT and MRI within 36 hrs. PV was measured as the ratio of the area under the AIF and the venous output function (VOF) concentration curves. A correction was applied to account for the nonlinear relaxivity of bulk blood (BB). Mean CBF was measured with both techniques and regression analyses both within and between patients were performed. Results Mean xeCT CBF was 43.3±13.7 ml/100g/min (mean±SD). BB correction decreased CBF by a factor of 4.7±0.4, but did not affect precision. The least-biased CBF measurement was with BB but without PV correction (45.8±17.2 ml/100 g/min, coefficient of variation [COV]=32%). Precision improved with PV correction, although absolute CBF was mildly underestimated (34.3±10.8 ml/100 g/min, COV=27%). Between patients correlation was moderate even with both corrections (R=0.53). Conclusion Corrections for AIF PV and nonlinear BB relaxivity improve bolus MRI-based CBF maps. However, there remain challenges given the moderate between-patient correlation, which limit diagnostic confidence of such measurements in individual patients. PMID:19787719

  11. Bilateral maxillary fused second and third molars: a rare occurrence

    PubMed Central

    Liang, Rui-Zhen; Wu, Jin-Tao; Wu, You-Nong; Smales, Roger J; Hu, Ming; Yu, Jin-Hua; Zhang, Guang-Dong

    2012-01-01

    This case report describes the diagnosis and endodontic therapy of maxillary fused second and third molars, using cone-beam computed tomography (CBCT). A 31-year-old Chinese male, with no contributory medical or family/social history, presented with throbbing pain in the maxillary right molar area following an unsuccessful attempted tooth extraction. Clinical examination revealed what appeared initially to be a damaged large extra cusp on the buccal aspect of the distobuccal cusp of the second molar. However, CBCT revealed that a third molar was fused to the second molar. Unexpectedly, the maxillary left third molar also was fused to the second molar, and the crown of an unerupted supernumerary fourth molar was possibly also fused to the apical root region of the second molar. Operative procedures should not be attempted without adequate radiographic investigation. CBCT allowed the precise location of the root canals of the right maxillary fused molar teeth to permit successful endodontic therapy, confirmed after 6 months. PMID:23222992

  12. Improved longitudinal [(18)F]-AV45 amyloid PET by white matter reference and VOI-based partial volume effect correction.

    PubMed

    Brendel, Matthias; Högenauer, Marcus; Delker, Andreas; Sauerbeck, Julia; Bartenstein, Peter; Seibyl, John; Rominger, Axel

    2015-03-01

    Amyloid positron-emission-tomography (PET) offers an important research and diagnostic tool for investigating Alzheimer's disease (AD). The majority of amyloid PET studies have used the cerebellum as a reference region, and clinical studies have not accounted for atrophy-based partial volume effects (PVE). Longitudinal studies using cerebellum as reference tissue have revealed only small mean increases and high inter-subject variability in amyloid binding. We aimed to test the effects of different reference regions and PVE-correction (PVEC) on the discriminatory power and longitudinal performance of amyloid PET. We analyzed [(18)F]-AV45 PET and T1-weighted MRI data of 962 subjects at baseline and two-year follow-up data of 258 subjects. Cortical composite volume-of-interest (VOI) values (COMP) for tracer uptake were generated using either full brain atlas VOIs, gray matter segmented VOIs or gray matter segmented VOIs after VOI-based PVEC. Standard-uptake-value ratios (SUVR) were calculated by scaling the COMP values to uptake in cerebellum (SUVRCBL), brainstem (SUVRBST) or white matter (SUVRWM). Mean SUV, SUVR, and changes after PVEC were compared at baseline between diagnostic groups of healthy controls (HC; N=316), mild cognitive impairment (MCI; N=483) and AD (N=163). Receiver operating characteristics (ROC) were calculated for the discriminations between HC, MCI and AD, and expressed as area under the curve (AUC). Finally, the longitudinal [(18)F]-AV45-PET data were used to analyze the impact of quantitation procedures on apparent changes in amyloid load over time. Reference region SUV was most constant between diagnosis groups for the white matter. PVEC led to decreases of COMP-SUV in HC (-18%) and MCI (-10%), but increases in AD (+7%). Highest AUCs were found when using PVEC with white matter scaling for the contrast between HC/AD (0.907) or with brainstem scaling for the contrast between HC/MCI (0.658). Longitudinal increases were greatest in all diagnosis groups with application of PVEC, and inter-subject variability was lowest for the white matter reference. Thus, discriminatory power of [(18)F]-AV45-PET was improved by use of a VOI-based PVEC and white matter or brainstem rather than cerebellum reference region. Detection of longitudinal amyloid increases was optimized with PVEC and white matter reference tissue. PMID:25482269

  13. Partial filling affinity capillary electrophoresis using large-volume sample stacking with an electroosmotic flow pump for sensitive profiling of glycoprotein-derived oligosaccharides.

    PubMed

    Fukushima, Eriko; Yagi, Yuki; Yamamoto, Sachio; Nakatani, Yumi; Kakehi, Kazuaki; Hayakawa, Takao; Suzuki, Shigeo

    2012-07-13

    An online preconcentration technique, large-volume sample stacking with an electroosmotic flow pump (LVSEP) was combined with partial filling affinity capillary electrophoresis (PFACE) to realize highly sensitive analysis of the interaction of glycoprotein-derived oligosaccharides with some plant lectins. Oligosaccharides derivatized with 8-aminopyrene-1,3,6-trisulfonic acid (APTS) were delivered to an entire neutrally-coated capillary and then lectin solution was hydrodynamically introduced from the outlet of the capillary as a short plug. A negative voltage was then applied after immersion of both ends of the capillary in 100 mM Tris-acetate buffer, pH 7.0 containing 0.5% hydroxypropylcellulose as electrophoresis buffers. A low concentration of electrolytes in the sample solution causes a significant flow by electroendosmosis from anode to cathode and the APTS-labeled oligosaccharides move quickly towards the anode and concentrate in the lectin phase. Finally, electroosmotic flow becomes negligible when the capillary is filled with the background electrolyte delivered from the anodic reservoir and APTS-labeled saccharides pass through the lectin plug and are detected at the anodic end. If the APTS-labeled oligosaccharides are recognized by the lectin, the migration profiles should be altered. The sensitivity was enhanced by a factor of ca. 900 compared to typical hydrodynamic injection (3.45 kPa, 10s). By this method, increased residence time of APTS-saccharides in the lectin plug indicates highly efficient interaction with lectins, which differs completely from the results obtained by ordinary lectin PFACE. The run-to-run repeatability (n=18) of the migration time and peak area was high, with relative standard deviations of less than 0.7% and 6.1%, respectively. PMID:22410158

  14. Synthesis and thermal decomposition of tetragonal RbClO4 and volume of fluid O2 from 2 to 9 GPa

    NASA Astrophysics Data System (ADS)

    Walker, David; Hughes, Gwyneth; Cranswick, Lachlan M. D.; Clark, Simon M.; Buhre, Stephan

    2001-10-01

    Orthorhombic (O) RbClO4 transforms to a new tetragonal (T) form at pressures above 20 kbar. Thermal decomposition proceeds through the reversible equilibrium reaction T RbClO4 = B2 RbCl + 2O2 at modestly increasing temperatures centered ˜550°C over the pressure range investigated from 20 to 90 kbar. Cell volumes for T RbClO4 and B2 RbCl were determined by high-pressure, high-temperature, in situ X-ray diffraction on station 16.4 of the Daresbury Synchrotron Radiation Source, from which the partial molar volume of O2 along the decomposition curve was determined. This volume (˜10 cm3/mol) is in close agreement with volumes determined from studies of the thermal decomposition of KClO3 and KClO4 but is difficult to reconcile with fluid O2 volumes determined using shock wave techniques. If these new O2 partial molar volumes are relevant to molten iron solutions, then storage of substantial amounts of O2 in the core becomes feasible.

  15. Calcium chromate synthesis molar ratio and drying studies

    Microsoft Academic Search

    Dillard

    1977-01-01

    The purpose of this study was to determine the effect of varying the molar ratio of reactants and the sample drying temperature on the chemical and physical properties of the calcium chromate product. Calcium chromate samples were prepared using standard operating procedures developed at GEND with molar ratios of reactants ranging from stoichiometric amounts for neutralization of chromic acid to

  16. Functional Patterns of Molar Occlusion in Platyrrhine Primates

    E-print Network

    Rosenberger, Alfred H.

    Functional Patterns of Molar Occlusion in Platyrrhine Primates ALFRED L ROSENBERGERZ AND WARREN G mechanics . Dentition Molars . Occlusion Tooth wear Platyrrhine. ABSTRACT Mechanico-functional features are adapted to loading foods under relatively high occlusal pressure; those of Pithe- cia and Cebus, under

  17. The partial molal volume of silicic acid in 0.725 M NaCl at 1°C determined by the neutralization of Na 2SiO 3

    NASA Astrophysics Data System (ADS)

    Hershey, J. Peter; Duedall, Iver W.

    1983-11-01

    The partial molal volume of silicic acid ( V¯(Si(OH) 4) ) in 0.725 M NaCl at 1°C was calculated from the measured volume change (? V¯n) due to the neutralization of anhydrous sodium metasilicate with HCl and the V¯(HCl) and V¯(NaCl) obtained from the literature. V¯(Si(OH) 4) = 59.0 cm 3mol - 1 , determined under experimental conditions of pH = 2.2, compares favorably with V¯(Si(OH) 4) = 58.9 cm 3 mol -1 calculated from the measured volume change due to the hydrolysis of the meta-silicate salt at pH = 11 and from the partial molal volume due to electrostriction ( V¯elect) of water by charged Si species present in the solution at the high pH. This agreement lends support to a semiempirical model for calculating V¯elect in developed by Millero (1969). V¯(NaOH) = - 5.45 cm 3 mol -1 in 0.725 M NaCl needed for this calculation was also determined in this work. The rate of polymerization of Si(OH) 4 at 1°C was monitored to insure that the monomer Si(OH) 4 was the main Si species present during the determination of V¯(Si(OH) 4) by neutralization of the alkali silicate. V¯(Si(OH) 4) determined in this study compares favorably with the value calculated from high pressure solubility measurements.

  18. Presence of third molars in orthodontic patients from northern Greece

    PubMed Central

    Barka, Georgia; Tretiakov, Georgios; Theodosiou, Theodosios; Ioannidou-Marathiotou, Ioulia

    2012-01-01

    Objective The purpose of the present study was to investigate the frequency of presence of third molar teeth and their distribution in each jaw and each side, according to sex, in a group of orthodontic patients with permanent dentition from northern Greece. Methods The sample included panoramic radiographs from 220 patients with permanent dentition (mean age 13.62 ± 1.81). The ?2 test was used to assess the relationships between the variables, and the Fisher’s exact test was used in cases where the expected frequencies in each cell were <5. Results The frequency of third molar presence was 79.1%, and 20.9% was the frequency of third molar agenesis. Intersexual differences in the number of third molars was not statistically significant. There was a correlation between the distribution of third molars on the right and the left side (Fisher’s exact test = 100.788; P = 0). The two sides showed the same tendency toward the presence or absence of third molars. A correlation was also found between the distribution of maxillary and mandibular third molars (Fisher’s exact test = 24.372; P = 0). In each jaw, the presence or absence of third molars was highly related to the number of third molars found in the other jaw. Conclusion The present results showed that in this orthodontic group of northern Greek patients, presence accounted for 79.1% and agenesis for 20.9%. No significant difference was found between the frequencies of third molar presence on the left and right sides in either the maxilla or mandible. PMID:22701086

  19. Three-dimensional quantitative analysis of adhesive remnants and enamel loss resulting from debonding orthodontic molar tubes

    PubMed Central

    2014-01-01

    Aims Presenting a new method for direct, quantitative analysis of enamel surface. Measurement of adhesive remnants and enamel loss resulting from debonding molar tubes. Material and methods Buccal surfaces of fifteen extracted human molars were directly scanned with an optic blue-light 3D scanner to the nearest 2 ?m. After 20 s etching molar tubes were bonded and after 24 h storing in 0.9% saline - debonded. Then 3D scanning was repeated. Superimposition and comparison were proceeded and shape alterations of the entire objects were analyzed using specialized computer software. Residual adhesive heights as well as enamel loss depths have been obtained for the entire buccal surfaces. Residual adhesive volume and enamel loss volume have been calculated for every tooth. Results The maximum height of adhesive remaining on enamel surface was 0.76 mm and the volume on particular teeth ranged from 0.047 mm3 to 4.16 mm3. The median adhesive remnant volume was 0.988 mm3. Mean depths of enamel loss for particular teeth ranged from 0.0076 mm to 0.0416 mm. Highest maximum depth of enamel loss was 0.207 mm. Median volume of enamel loss was 0.104 mm3 and maximum volume was 1.484 mm3. Conclusions Blue-light 3D scanning is able to provide direct precise scans of the enamel surface, which can be superimposed in order to calculate shape alterations. Debonding molar tubes leaves a certain amount of adhesive remnants on the enamel, however the interface fracture pattern varies for particular teeth and areas of enamel loss are present as well. PMID:25208969

  20. SU-E-J-76: Incorporation of Ultrasound Elastography in Target Volume Delineation for Partial Breast Radiotherapy Planning: A Comparative Study

    SciTech Connect

    Juneja, P; Harris, E; Bamber, J [The Institute of Cancer Research, London (United Kingdom); Royal Marsden NHS Foundation Trust, London (United Kingdom)

    2014-06-01

    Purpose: There is substantial observer variability in the delineation of target volumes for post-surgical partial breast radiotherapy because the tumour bed has poor x-ray contrast. This variability may result in substantial variations in planned dose distribution. Ultrasound elastography (USE) has an ability to detect mechanical discontinuities and therefore, the potential to image the scar and distortion in breast tissue architecture. The goal of this study was to compare USE techniques: strain elastography (SE), shear wave elastography (SWE) and acoustic radiation force impulse (ARFI) imaging using phantoms that simulate features of the tumour bed, for the purpose of incorporating USE in breast radiotherapy planning. Methods: Three gelatine-based phantoms (10% w/v) containing: a stiff inclusion (gelatine 16% w/v) with adhered boundaries, a stiff inclusion (gelatine 16% w/v) with mobile boundaries and fluid cavity inclusion (to mimic seroma), were constructed and used to investigate the USE techniques. The accuracy of the elastography techniques was quantified by comparing the imaged inclusion with the modelled ground-truth using the Dice similarity coefficient (DSC). For two regions of interest (ROI), the DSC measures their spatial overlap. Ground-truth ROIs were modelled using geometrical measurements from B-mode images. Results: The phantoms simulating stiff scar tissue with adhered and mobile boundaries and seroma were successfully developed and imaged using SE and SWE. The edges of the stiff inclusions were more clearly visible in SE than in SWE. Subsequently, for all these phantoms the measured DSCs were found to be higher for SE (DSCs: 0.91–0.97) than SWE (DSCs: 0.68–0.79) with an average relative difference of 23%. In the case of seroma phantom, DSC values for SE and SWE were similar. Conclusion: This study presents a first attempt to identify the most suitable elastography technique for use in breast radiotherapy planning. Further analysis will include comparison of ARFI with SE and SWE. This work is supported by the EPSRC Platform Grant, reference number EP/H046526/1.

  1. Replacement of a first molar and 3 second molars by the mesial inclination of 4 impacted third molars in an adult with a Class II Division 1 malocclusion.

    PubMed

    Tomonari, Hiroshi; Yagi, Takakazu; Kuninori, Takaharu; Ikemori, Takahiro; Miyawaki, Shouichi

    2015-06-01

    This case report presents the successful replacement of 1 first molar and 3 second molars by the mesial inclination of 4 impacted third molars. A woman, 23 years 6 months old, had a chief complaint of crowding of her anterior teeth and linguoclination of a second molar on the left side. The panoramic radiographic images showed that the maxillary and mandibular third molars on both sides were impacted. Root resorption on the distal surfaces of the maxillary second molars was suspected. The patient was given a diagnosis of Angle Class II Division 1 malocclusion with severe crowding of the anterior teeth and 4 impacted third molars. After we extracted the treated maxillary second premolars and the second molars on both sides, the treated mandibular second premolar and the second molar on the left side, and the root canal-filled mandibular first molar on the right side, the 4 impacted third molars were uprighted and formed part of the posterior functional occlusion. The total active treatment period was 39 months. The maxillary and mandibular third molars on both sides successfully replaced the first and second molars. The replacement of a damaged molar by an impacted third molar is a useful treatment option for using sound teeth. PMID:26038080

  2. Determining Molar Combining Ratios Using Radioisotopes--A Student Experiment

    ERIC Educational Resources Information Center

    Sears, Jerry A.

    1976-01-01

    Outlines an experimental procedure in which an iodine radioisotope is used to determine molar combining ratios of lead and silver with the iodine. Tables and graphs show the definitive results that should be attainable. (CP)

  3. Endodontic management of middle mesial canal of the mandibular molar.

    PubMed

    Sundaresh, K J; Srinivasan, Raghu; Mallikarjuna, Rachappa; Rajalbandi, Sandeep

    2013-01-01

    Thorough knowledge of root canal morphology and unusual anatomy of the tooth is critical for successful endodontic treatment. Although the most common configuration is two roots and three root canals, mandibular molars might have many different combinations. In the literature, it is less described about three mesial canals and two distal canals in mandibular second molars, indicating a rare anatomical configuration. A case of unusual root canal morphology is presented to demonstrate anatomical variations in mandibular molars. Endodontic therapy was performed in a mandibular second molar with five separate canals, three mesial and two distal. This report points out the importance of looking for additional canals and unusual canal morphology, because knowledge of their existence might occasionally enable clinicians to treat a case successfully that otherwise might have ended in failure. In conclusion, every attempt should be made to find and treat all root canals of a tooth. PMID:23349182

  4. Endodontic management of middle mesial canal of the mandibular molar

    PubMed Central

    Sundaresh, K J; Srinivasan, Raghu; Mallikarjuna, Rachappa; Rajalbandi, Sandeep

    2013-01-01

    Thorough knowledge of root canal morphology and unusual anatomy of the tooth is critical for successful endodontic treatment. Although the most common configuration is two roots and three root canals, mandibular molars might have many different combinations. In the literature, it is less described about three mesial canals and two distal canals in mandibular second molars, indicating a rare anatomical configuration. A case of unusual root canal morphology is presented to demonstrate anatomical variations in mandibular molars. Endodontic therapy was performed in a mandibular second molar with five separate canals, three mesial and two distal. This report points out the importance of looking for additional canals and unusual canal morphology, because knowledge of their existence might occasionally enable clinicians to treat a case successfully that otherwise might have ended in failure. In conclusion, every attempt should be made to find and treat all root canals of a tooth. PMID:23349182

  5. Hypothetical considerations in the regenerative treatment of molar furcation defects.

    PubMed

    Hutchens, L H

    1996-01-01

    Treatment of the molar furcation defect is a challenge to the dental professional. Responses of molar furcation sites to both closed and open surgical debridement have not been shown to result in significant clinical improvement or bone fill. Regenerative techniques using grafting materials, guided tissue regeneration with resorbable and nonresorbable membranes, coronally positioned flaps, and combination techniques are more frequently used to treat class II molar furcations. The clinical responses to these surgical approaches have shown varied results. This article reviews some of the studies on regeneration in furcation defects as well as some of the uniqueness and complexities of the furcation problem. The bone morphology differences in molar bifurcation and trifurcation defects are discussed, and a bone morphologic classification is presented in an effort to standardize future regenerative studies in class II furcations. PMID:8624561

  6. Evolution of molar enamel microstructure in North American Notharctidae (primates)

    Microsoft Academic Search

    M. C. Maas; M. O'Leary

    1996-01-01

    Evolutionary changes in gross dental morphology and body size of early to middle Eocene North American notharctids is thought to reflect a dietary shift from frugivory to folivory;Cantiusspp. were largely frugivorous, whereasNotharctusspp. andCopelemurwere probably more folivorous. Here we report on the evolution of molar enamel microstructure in the notharctid clade and its relationship to adaptive change. Molar teeth of ten

  7. Recurrent molar pregnancies associated with clomiphene citrate and human gonadotropins.

    PubMed

    Mor-Joseph, S; Anteby, S O; Granat, M; Brzezinsky, A; Evron, S

    1985-04-15

    A 34-year-old patient, gravida 7, para 0, with three consecutive spontaneous abortions followed by four recurrent molar pregnancies is described. The patient conceived only with clomiphene citrate or human gonadotropin treatment. The occurrence of molar pregnancies succeeded spontaneous abortions with one remaining pregnancy progressing to gestational trophoblastic disease. The role of clomiphene citrate and human gonadotropins in the pathogenesis of this disease is discussed. PMID:3920913

  8. Influence of molar ratios on properties of magnesium oxychloride cement

    SciTech Connect

    Li Zongjin [Department of Civil Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong (China)]. E-mail: zongjin@ust.hk; Chau, C.K. [Department of Civil Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong (China)

    2007-06-15

    A parametric study has been conducted to investigate the influences of the molar ratios of MgO/MgCl{sub 2} and H{sub 2}O/MgCl{sub 2} on the properties of magnesium oxychloride (MOC) cement. By an integrated assessment of the experimental studies of strength development and X-ray diffractograms, together with application of the relevant phase diagram, it is recognized that the molar ratios of MgO/MgCl{sub 2} and H{sub 2}O/MgCl{sub 2} can significantly affect the properties of MOC cement. For a MOC cement paste possessing a dominance of 5MgO.MgCl{sub 2}.8H{sub 2}O (phase 5) crystals, the molar ratios of MgO/MgCl{sub 2} of 11-17 and H{sub 2}O/MgCl{sub 2} of 12-18 are found to be the most favorite ranges for design purpose. The choose of the molar ratio of H{sub 2}O/MgCl{sub 2} is, however, largely depends on the molar ratio of MgO/MgCl{sub 2} mainly for controlling workability of paste. Therefore, the most critical parameter to be selected in the design process is the molar ratio of MgO/MgCl{sub 2}, although the reactivity of the MgO powder is also important. Besides, the molar ratio can also be affected by the reactivity of the MgO powder to be employed. It is believed that a molar ratio of MgO/MgCl{sub 2} of 13, the most suitable one shown in this study, can be used as a starting point in the normal practice.

  9. Standardised studies on Molar Incisor Hypomineralisation (MIH) and Hypomineralised Second Primary Molars (HSPM): a need.

    PubMed

    Elfrink, M E C; Ghanim, A; Manton, D J; Weerheijm, K L

    2015-06-01

    In November 2014, a review of literature concerning prevalence data of Molar Incisor Hypomineralisation (MIH) and Hypomineralised Second Primary Molars (HSPM) was performed. A search of PubMed online databases was conducted for relevant articles published until November 2014. The reference lists of all retrieved articles were hand-searched. Studies were included after assessing the eligibility of the full-text article. Out of 1078 manuscripts, a total of 157 English written publications were selected based on title and abstract. Of these 157, 60 were included in the study and allocated as 52 MIH and 5 HSPM, and 3 for both MIH and HSPM. These studies utilised the European Academy of Paediatric Dentistry judgment criteria, the modified index of developmental defects of enamel (mDDE) and self-devised criteria, and demonstrated a wide variation in the reported prevalence (MIH 2.9-44 %; HSPM 0-21.8 %). Most values mentioned were representative for specific areas. More studies were performed in cities compared with rural areas. A great variation was found in calibration methods, number of participants, number of examiners and research protocols between the studies. The majority of the prevalence studies also investigated possible aetiological factors. To compare MIH and HSPM prevalence and or aetiological data around the world, standardisation of such studies seems essential. Standardisation of the research protocol should include a clearly described sample of children (minimum number of 300 for prevalence and 1000 for aetiology studies) and use of the same calibration sets and methods whereas aetiological studies need to be prospective in nature. A standardised protocol for future MIH and HSPM prevalence and aetiology studies is recommended. PMID:25894247

  10. Genetic integration of molar cusp size variation in baboons

    PubMed Central

    Koh, Christina; Bates, Elizabeth; Broughton, Elizabeth; Do, Nicholas T.; Fletcher, Zachary; Mahaney, Michael C.; Hlusko, Leslea J.

    2010-01-01

    Many studies of primate diversity and evolution rely on dental morphology for insight into diet, behavior, and phylogenetic relationships. Consequently, variation in molar cusp size has increasingly become a phenotype of interest. In 2007 we published a quantitative genetic analysis of mandibular molar cusp size variation in baboons. Those results provided more questions than answers, as the pattern of genetic integration did not fit predictions from odontogenesis. To follow up, we expanded our study to include data from the maxillary molar cusps. Here we report on these later analyses, as well as inter-arch comparisons with the mandibular data. We analyzed variation in two-dimensional maxillary molar cusp size using data collected from a captive pedigreed breeding colony of baboons, Papio hamadryas, housed at the Southwest National Primate Research Center. These analyses show that variation in maxillary molar cusp size is heritable and sexually dimorphic. We also estimated additive genetic correlations between cusps on the same crown, homologous cusps along the tooth row, and maxillary and mandibular cusps. The pattern for maxillary molars yields genetic correlations of one between the paracone-metacone and protocone-hypocone. Bivariate analyses of cuspal homologues on adjacent teeth yield correlations that are high or not significantly different from one. Between dental arcades, the non-occluding cusps consistently yield high genetic correlations, especially the metaconid-paracone and metaconid-metacone. This pattern of genetic correlation does not immediately accord with the pattern of development and/or calcification, however these results do follow predictions that can be made from the evolutionary history of the tribosphenic molar. PMID:20034010

  11. The Effect of Prism Orientation in the Indentation Testing of Human Molar Enamel

    PubMed Central

    Braly, A.; Darnell, L.A.; Mann, A.B.; Teaford, M.F.; Weihs, T.P.

    2007-01-01

    Recent nanoindentation studies have demonstrated that the hardness and Young's modulus of human molar enamel decreases by more than 50% on moving from the occlusal surface to the dentin-enamel junction on cross-sectional samples. Possible sources of these variations are changes in local chemistry, microstructure, and prism orientation. This study investigates the latter source by performing nanoindentation tests at two different orientations relative to the hydroxyapatite prisms: parallel and perpendicular. A single sample volume was tested in order to maintain a constant chemistry and microstructure. The resulting data show very small differences between the two orientations for both hardness and Young's modulus. The 1.5 to 3.0% difference is significantly less than the standard deviations found within the data set. Thus, the variations in hardness and Young's modulus on cross-sectional samples of human molar are attributed to changes in local chemistry (varying levels of mineralization, organic matter, and water content) and changes in microstructure (varying volume fractions of inorganic crystals and organic matrix). The impact of prism orientation on mechanical properties measured by nanoindentation appears to be minimal. PMID:17449008

  12. Western Saudi adolescent age estimation utilising third molar development

    PubMed Central

    Alshihri, Amin M.; Kruger, Estie; Tennant, Marc

    2014-01-01

    Objective: The aim of this study was to establish reference data on third molar morphology/development for age estimation in Western Saudi adolescents, between ages 14 and 23 years of old. Materials and Methods: The orthopantomograms of 130 individuals (males and females), were examined, and the stage of third molar development were evaluated. Results: Mean ages, standard deviations, and percentile distributions are presented for each stage of development. The mean estimated age for all participants (n = 130) was 219.7 months, and this differed significantly (P < 0.05) from the mean chronological age (226.5 months). Deviations of predicted age from real age showed 28.5% of all participants had their age estimated within 1 year (±12 months) of their chronological age. Most (43%) had their age underestimated by more than 12 months and the remaining 28.5% had their age overestimated by more than 12 months of their chronological age. Differences in left-right symmetry information of third molars were detected and were higher in the maxilla (92%) than in the mandible (82%). For all molars reaching stage “H” most individuals (males and females) were over the age 18 years of old. Males reach the developmental stages earlier than females. Conclusion: Third molar tooth development can be reliably used to generate mean age and the estimated age range for an individual of unknown chronological age. Further studies with large populations are needed for better statistical results. PMID:25202206

  13. Management of impacted third molars among Nigerian dentists.

    PubMed

    Owotade, F J; Ugboko, V I; Fatusi, O A; Akinmoladun, V I; Obuekwe, O N; Olasoji, H O

    2002-03-01

    Seventy-five Nigerian dentists were interviewed on their approach to the management of impacted third molars. The mean age of the dentists was 34.8 years, with a male/female ratio of 3.4:1. Most of the female dentists were found in the training institutions (p = 0.005). More than half of the dentists (58.7%) practiced in institutions with dental schools (training institutions), majority preferred the buccal approach (92%), and all the dentists (100%) preferred third molar disimpaction under local analgesia. Most dentists (88%) prescribe antibiotics following third molar surgery. Fifty dentists (66.7%) routinely reviewed all patients postoperatively while 12 dentists (16%) were of the opinion that all impacted third molars should be extracted. Only 21 dentists (28%) were aware of any protocol on the management of impacted teeth. More dentists in the training institutions performed third molar surgery less frequently than dentists in other hospitals (p = 0.07) who tend to employ chisels/mallet for bone removal (p = 0.0004). The need for continuing education and the formulation of guidelines in order to assist dentists to make informed decisions is emphasised. This will help conserve scarce resources and enhance the operation of the newly introduced National Health Insurance Scheme. PMID:12061244

  14. Requirement of alveolar bone formation for eruption of rat molars

    PubMed Central

    Wise, Gary E.; He, Hongzhi; Gutierrez, Dina L.; Ring, Sherry; Yao, Shaomian

    2011-01-01

    Tooth eruption is a localized event that requires a dental follicle (DF) to regulate the resorption of alveolar bone to form an eruption pathway. During the intra-osseous phase of eruption, the tooth moves through this pathway. The mechanism or motive force that propels the tooth through this pathway is controversial but many studies have shown that alveolar bone growth at the base of the crypt occurs during eruption. To determine if this bone growth (osteogenesis) was causal, experiments were designed in which the expression of an osteogenic gene in the DF, bone morphogenetic protein-6 (BMP6), was inhibited by injection of the 1st mandibular molar of the rat with an siRNA targeted against BMP6. The injection was followed by electroporation to promote uptake of the siRNA. In 45 first molars injected, eruption either was delayed or completely inhibited (7 molars). In the impacted molars, an eruption pathway formed but bone growth at the base of the crypt was greatly reduced as compared to the erupted first molar controls. These studies show that alveolar bone growth at the base of the crypt is required for tooth eruption and that BMP6 may be an essential gene for promoting this growth. PMID:21896048

  15. Aberration in the palatal root of the maxillary first molar.

    PubMed

    Rajalbandi, Sandeep; Shingte, Sandhya Narayan; Sundaresh, K J; Mallikarjuna, Rachappa

    2013-01-01

    Thorough knowledge of root canal morphology is essential for the endodontic therapy. Variations in the root and root canal morphology, especially in multirooted teeth, are a constant challenge for diagnosis and management. The dentist needs to be familiar with the various root canal configurations and their variations for successful endodontic therapy. There are rare variations in canal number and configuration in maxillary molars, which could affect treatment outcome. Two lingual root structures are occasionally found on human permanent maxillary molars. One of these is the normal lingual root, which is always present, the other is a supernumerary structure which can be located either mesiolingually (radix mesiolingualis) or distolingually (radix distolingualis). The purpose of this paper is to review the literature and to demonstrate a case report which describes the successful non-surgical endodontic management of an unusual maxillary first molar with four separate roots and four canals. PMID:23632609

  16. Sex assessment by molar odontometrics in North Indian population

    PubMed Central

    Narang, Ramandeep Singh; Manchanda, Adesh S.; Singh, Balwinder

    2015-01-01

    Introduction: Human identification is based on scientific principles, mainly involving dental records, fingerprints, estimation of age, postmortem reports, differentiation by blood groups, and DNA comparisons. Sex assessment is one of the prime factors employed to assist with the identification of an individual. Aims and Objective: To investigate univariate sex differences in the dimensions of permanent first molars and to assess sex, based on buccolingual (BL) and mesiodistal (MD) dimensions of permanent first molars in a population of north India. In addition, the study intended to evaluate the reliability of dimensional variation of these teeth in assessment of sex among the population. Materials and Methods: The study sample consists of 410 adult individuals (200 males and 210 females), from a north Indian population. The BL and MD diameters of the permanent first molars were measured using digital vernier callipers. Results: It was observed statistically significant difference between males and females with P < 0.05, in maxillary casts in both BL and MD dimensions; but only in the MD dimension in mandibular casts. A high level of sexual dimorphism of 7.7% was found in the BL dimension of the maxillary right first molar. The accuracy of sex assessment by each dimension was deliberated by univariate analyses with an overall accuracy ranging from 67.5 to 88% for various dimensions. Conclusion: Sexual dimorphism of teeth is population specific and among north Indian population, BL and MD dimensions in maxillary first molar and MD dimension in mandibular first molar can be used for sex assessment. PMID:25709321

  17. Treatment of Ectopic Mandibular Second Permanent Molar with Elastic Separators

    PubMed Central

    Rajesh, R.; Naveen, V.; Amit, S.; Baroudi, Kusai; Sampath Reddy, C.; Namineni, Srinivas

    2014-01-01

    Ectopic eruption is a developmental disturbance in which the tooth fails to follow its normal eruption pathway. Ectopic eruption of the second molar is relatively rare. This paper presents the case of thirteen-year-old male with an ectopic mandibular second permanent molar. The condition was corrected with surgical exposure and placement of elastic separators. This case report lays emphasis on the practice of basic methods to obtain acceptable results rather than extensive surgical or orthodontic corrections. It is advised that ectopic teeth should not be neglected especially when it concerns developing caries and malocclusion. PMID:25050182

  18. LANDSAT-D data format control book. Volume 6, appendix A: Partially processed thematic mapper High Density Tape (HDT-AT)

    NASA Technical Reports Server (NTRS)

    Jai, A.

    1982-01-01

    One of the outputs of the data management system being developed to provide a variety of standard image products from the thematic mapper and the multispectral band scanners on LANDSAT 4, is the partially processed TM data (radiometric corrections applied and geometric correction matrices for two projections appended) which is recorded on a 28-track high density tape. Specifications are presented for the format of the recorded data as well as for the time code and the major and minor frames of the tape. Major frame types, formats, and field definitions are included.

  19. Morphological and clinical considerations of first and second permanent molar eruption disorders.

    PubMed

    Proff, Peter; Bayerlein, Thomas; Fanghänel, Jochen; Allegrini, Sergio; Gedrange, Tomas

    2006-07-01

    Tooth eruption is a complex biological process which starts from the site of development in the jaw bone until the teeth reach their final functional position in the chewing plane. Various factors can disturb this process. Besides mechanical obstacles on the eruption path, a pathological position or axial orientation of the tooth germ, morphological aberrations of the tooth or pathological alterations of the periodontium, primary disorders of the eruption mechanism may lead to complete or partial retention of the tooth in the jaw bone. These morphological features bear upon the prognosis of orthodontic correction which is dependent upon the underlying cause. First and second molars are rarely affected by eruption disorders, with a prevalence of 0.01 to 0.08 per cent, however, marked consequences for function such as posterior open bite or elongation of the antagonists may result. Following an overview of pathogenetic factors of tooth eruption disorders, selected cases of impacted first and second permanent molars are presented with respect to their morphological causes. PMID:16856600

  20. Molar mass characterization of sodium carboxymethyl cellulose by SEC-MALLS.

    PubMed

    Shakun, Maryia; Maier, Helena; Heinze, Thomas; Kilz, Peter; Radke, Wolfgang

    2013-06-01

    Two series of sodium carboxymethyl celluloses (NaCMCs) derived from microcrystalline cellulose (Avicel samples) and cotton linters (BWL samples) with average degrees of substitution (DS) ranging from DS=0.45 to DS=1.55 were characterized by size exclusion chromatography with multi-angle laser light scattering detection (SEC-MALLS) in 100 mmol/L aqueous ammonium acetate (NH4OAc) as vaporizable eluent system. The application of vaporizable NH4OAc allows future use of the eluent system in two-dimensional separations employing evaporative light scattering detection (ELSD). The losses of samples during filtration and during the chromatographic experiment were determined. The scaling exponent as of the relation [Formula: see text] was approx. 0.61, showing that NaCMCs exhibit an expanded coil conformation in solution. No systematic dependencies of as on DS were observed. The dependences of molar mass on SEC-elution volume for samples of different DS can be well described by a common calibration curve, which is of advantage, as it allows the determination of molar masses of unknown samples by using the same calibration curve, irrespective of the DS of the NaCMC sample. Since no commercial NaCMC standards are available, correction factors were determined allowing converting a pullulan based calibration curve into a NaCMC calibration using the broad calibration approach. The weight average molar masses derived using the so established calibration curve closely agree with the ones determined by light scattering, proving the accuracy of the correction factors determined. PMID:23618306

  1. Prognosis of single molar implants: a retrospective study.

    PubMed

    Kim, Young-Kyun; Kim, Su-Gwan; Yun, Pil-Young; Hwang, Jung-Won; Son, Mee-Kyoung

    2010-08-01

    The purpose of this study was to evaluate the short- and mid-term prognosis of maxillary and mandibular single molar implants, prosthetic complications, and factors mediating the effects seen on them. Eighty-seven patients were enrolled consecutively in this study and 96 implants were placed into a single molar defect site by one oral and maxillofacial surgeon from March 2004 to December 2006. Primary osseointegration failure developed in two implants and delayed implant failure occurred at four implants. The fraction surviving interval was 97% to 100%, and at the last follow-up observation, the cumulative survival rate was 91.1%. All failed implants occurred in second molar sites, and the failure rate, according to implant site, showed a significant difference. Prosthetic complications, such as screw loosening, showed a significant correlation to the mesiodistal cantilever. Furthermore, crestal bone loss 3 years after loading was 0.2 mm on average and a very stable result was obtained. Based on the results, the risk of failure for maxillary and mandibular single molar implants is high and the possibility of developing prosthetic complications during loading is also high. Therefore, to minimize the cantilever, implants must be placed precisely and followed carefully and maintained for a long period of time. PMID:20664842

  2. Epilepsy (partial)

    PubMed Central

    2011-01-01

    Introduction About 3% of people will be diagnosed with epilepsy during their lifetime, but about 70% of people with epilepsy eventually go into remission. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of starting antiepileptic drug treatment following a single seizure? What are the effects of drug monotherapy in people with partial epilepsy? What are the effects of additional drug treatments in people with drug-resistant partial epilepsy? What is the risk of relapse in people in remission when withdrawing antiepileptic drugs? What are the effects of behavioural and psychological treatments for people with epilepsy? What are the effects of surgery in people with drug-resistant temporal lobe epilepsy? We searched: Medline, Embase, The Cochrane Library, and other important databases up to July 2009 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 83 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: antiepileptic drugs after a single seizure; monotherapy for partial epilepsy using carbamazepine, gabapentin, lamotrigine, levetiracetam, phenobarbital, phenytoin, sodium valproate, or topiramate; addition of second-line drugs for drug-resistant partial epilepsy (allopurinol, eslicarbazepine, gabapentin, lacosamide, lamotrigine, levetiracetam, losigamone, oxcarbazepine, retigabine, tiagabine, topiramate, vigabatrin, or zonisamide); antiepileptic drug withdrawal for people with partial or generalised epilepsy who are in remission; behavioural and psychological treatments for partial or generalised epilepsy (biofeedback, cognitive behavioural therapy (CBT), educational programmes, family counselling, relaxation therapy (alone or plus behavioural modification therapy, yoga); and surgery for drug-resistant temporal lobe epilepsy ( lesionectomy, temporal lobectomy, vagus nerve stimulation as adjunctive therapy). PMID:21549021

  3. Infected dentigerous cyst of maxillary sinus arising from an ectopic third molar.

    PubMed

    Guruprasad, Yadavalli; Chauhan, Dinesh Singh; Kura, Umashankar

    2013-01-01

    A dentigerous cyst or follicular cyst is a form of odontogenic cyst. It is believed that it forms during the development of the tooth and is associated with pressure exerted by the crown of an unerupted (or partially erupted) tooth on the fluid within the follicular space. Typically, dentigerous cysts are painless and discovered during routine radiographic examination. However, they may be large and result in a palpable mass. Additionally, as they grow they displace adjacent teeth. They almost exclusively occur in permanent dentition. The cyst is lined by stratified squamous non-keratinizing epithelium. About 70% of dentigerous cysts occur in the mandible and 30% in the maxilla. Dentigerous cysts associated with ectopic teeth within the maxillary sinus are very rare. We report radiologic and pathologic features in a rare case of infected dentigerous cyst of maxillary sinus arising from an ectopic third molar in a 21-year-old female patient. PMID:24516770

  4. Characterization of cellulose acetates according to DS and molar mass using two-dimensional chromatography.

    PubMed

    Ghareeb, Hewa Othman; Radke, Wolfgang

    2013-11-01

    A two-dimensional liquid chromatographic method (2D LC) was developed to analyze the heterogeneities of cellulose acetates (CA) in the DS-range DS=1.5-2.9 with respect to both, molar mass and degree of substitution (DS). The method uses gradient liquid chromatography (HPLC) as the first dimension in order to separate by DS followed by separation of the different fractions by size (SEC) in the second dimension. The 2D experiments revealed different correlations between gradient and SEC elution volume. These correlations might arise from differences in the synthetic conditions. The newly developed 2D LC separation therefore provides new insights into the heterogeneity of CAs. PMID:24053824

  5. Spontaneous emergence of overgrown molar teeth in a colony of Prairie voles (Microtus ochrogaster).

    PubMed

    Jheon, Andrew H; Prochazkova, Michaela; Sherman, Michael; Manoli, Devanand S; Shah, Nirao M; Carbone, Lawrence; Klein, Ophir

    2015-03-01

    Continuously growing incisors are common to all rodents, which include the Microtus genus of voles. However, unlike many rodents, voles also possess continuously growing molars. Here, we report spontaneous molar defects in a population of Prairie voles (Microtus ochrogaster). We identified bilateral protuberances on the ventral surface of the mandible in several voles in our colony. In some cases, the protuberances broke through the cortical bone. The mandibular molars became exposed and infected, and the maxillary molars entered the cranial vault. Visualisation upon soft tissue removal and microcomputed tomography (microCT) analyses confirmed that the protuberances were caused by the overgrowth of the apical ends of the molar teeth. We speculate that the unrestricted growth of the molars was due to the misregulation of the molar dental stem cell niche. Further study of this molar phenotype may yield additional insight into stem cell regulation and the evolution and development of continuously growing teeth. PMID:25634121

  6. Molar distalization with the assistance of Temporary Anchorage Devices.

    PubMed

    Palencar, Adrian J

    2015-01-01

    This article describes efficient techniques for distalization of maxillary and mandibular molars with the assistance of Temporary Anchorage Devices (TADs). There are numerous occasions where the distalization of molars is required in lieu of the odontectomy of bicuspids. In the past, extra-oral force has been used, (i.e. Cervical or Combination Head Gear, or intra-oral force, i.e. Posterior Sagittal Appliance, Modified Greenfield Appliance, Williams DMJ 20001, CD Distalizer, Magill Sagittal, Pendulum Appliance, etc.). All the intra-oral appliances have a common denominator the orthodontic clinician has to deal with, the undesirable expression of the Third Law of Newton. The utilization of TADs allows us to circumvent this shortcoming, establishing an absolute anchorage, and thus completely negate the expression of the Third Law of Newton. PMID:25881377

  7. Extrusion of impacted mandibular second molar using removable appliance

    PubMed Central

    Karthikeyan, M. K.; Prabhakar, Ramachandran; Saravanan, R.; Vikram, N. Raj; Kumar, R. Vinoth; Prasath, R. Eshwara

    2014-01-01

    The purpose of this article is to review the principles of case management of impacted mandibular molars and to illustrate their potential to respond well to treatment. Although the scope of treatment may be influenced by the patient's age, past dental history, severity of impaction, dentoalveolar development, and root form, the case reports demonstrate the inherent potential for good treatment outcome even in the most unfavorable circumstances. PMID:25210378

  8. Unrecognised displacement of mandibular molar root into the submandibular space.

    PubMed

    Nusrath, M A; Banks, R J

    2010-09-25

    We describe a case of swelling in the right submandibular and sublingual space caused by displacement of a lower second molar root in the submandibular space. This displacement was not recognised at the time of extraction. The techniques used to minimise the risk of accidental displacement of teeth and roots, during extraction are discussed. The importance of recognising this complication and methods of retrieval are highlighted. PMID:20871549

  9. Fate of the Molar Dental Lamina in the Monophyodont Mouse

    PubMed Central

    Dosed?lová, Hana; Dumková, Jana; Lesot, Hervé; Glocová, Kristýna; Kunová, Michaela; Tucker, Abigail S.; Veselá, Iva; Krej?í, Pavel; Tichý, František; Hampl, Aleš; Buchtová, Marcela

    2015-01-01

    The successional dental lamina (SDL) plays an essential role in the development of replacement teeth in diphyodont and polyphyodont animals. A morphologically similar structure, the rudimental successional dental lamina (RSDL), has been described in monophyodont (only one tooth generation) lizards on the lingual side of the developing functional tooth. This rudimentary lamina regresses, which has been proposed to play a role in preventing the formation of future generations of teeth. A similar rudimentary lingual structure has been reported associated with the first molar in the monophyodont mouse, and we show that this structure is common to all murine molars. Intriguingly, a lingual lamina is also observed on the non-replacing molars of other diphyodont mammals (pig and hedgehog), initially appearing very similar to the successional dental lamina on the replacing teeth. We have analyzed the morphological as well as ultrastructural changes that occur during the development and loss of this molar lamina in the mouse, from its initiation at late embryonic stages to its disappearance at postnatal stages. We show that loss appears to be driven by a reduction in cell proliferation, down-regulation of the progenitor marker Sox2, with only a small number of cells undergoing programmed cell death. The lingual lamina was associated with the dental stalk, a short epithelial connection between the tooth germ and the oral epithelium. The dental stalk remained in contact with the oral epithelium throughout tooth development up to eruption when connective tissue and numerous capillaries progressively invaded the dental stalk. The buccal side of the dental stalk underwent keratinisation and became part of the gingival epithelium, while most of the lingual cells underwent programmed cell death and the tissue directly above the erupting tooth was shed into the oral cavity. PMID:26010446

  10. Fate of the molar dental lamina in the monophyodont mouse.

    PubMed

    Dosed?lová, Hana; Dumková, Jana; Lesot, Hervé; Glocová, Kristýna; Kunová, Michaela; Tucker, Abigail S; Veselá, Iva; Krej?í, Pavel; Tichý, František; Hampl, Aleš; Buchtová, Marcela

    2015-01-01

    The successional dental lamina (SDL) plays an essential role in the development of replacement teeth in diphyodont and polyphyodont animals. A morphologically similar structure, the rudimental successional dental lamina (RSDL), has been described in monophyodont (only one tooth generation) lizards on the lingual side of the developing functional tooth. This rudimentary lamina regresses, which has been proposed to play a role in preventing the formation of future generations of teeth. A similar rudimentary lingual structure has been reported associated with the first molar in the monophyodont mouse, and we show that this structure is common to all murine molars. Intriguingly, a lingual lamina is also observed on the non-replacing molars of other diphyodont mammals (pig and hedgehog), initially appearing very similar to the successional dental lamina on the replacing teeth. We have analyzed the morphological as well as ultrastructural changes that occur during the development and loss of this molar lamina in the mouse, from its initiation at late embryonic stages to its disappearance at postnatal stages. We show that loss appears to be driven by a reduction in cell proliferation, down-regulation of the progenitor marker Sox2, with only a small number of cells undergoing programmed cell death. The lingual lamina was associated with the dental stalk, a short epithelial connection between the tooth germ and the oral epithelium. The dental stalk remained in contact with the oral epithelium throughout tooth development up to eruption when connective tissue and numerous capillaries progressively invaded the dental stalk. The buccal side of the dental stalk underwent keratinisation and became part of the gingival epithelium, while most of the lingual cells underwent programmed cell death and the tissue directly above the erupting tooth was shed into the oral cavity. PMID:26010446

  11. Efficacy of Postoperative Prophylactic Antibiotic Therapy in Third Molar Surgery

    PubMed Central

    Reddy B, Praveen

    2014-01-01

    Introduction: Surgical extraction of mandibular third molar is the most frequently performed procedure in oral surgery. This procedure is associated with significant postoperative sequelae such as trismus, swelling, pain and infection. The need of antibiotic therapy during the removal of mandibular third molar has been a contentious issue. Method: This study investigated a regimen by using amoxycillin and metronidazole in one group and without using antibiotics in the other. Both the groups were assessed postoperatively on the 1st, 2nd, 5th, 7th and 10th days by the same observer for post operative mouth opening (interincisal distance), presence of a purulent discharge at the site of surgery, pain and swelling. Result: Overall, no statistically significant difference was seen between both the treatment groups when interincisal distance, pain, swelling and purulent discharge were considered. Conclusion: The results of this study failed to show any advantage which was associated with the routine postoperative use of antibiotics in asymptomatic third molar surgeries. PMID:24995236

  12. Sub-10-Minute Characterization of an Ultrahigh Molar Mass Polymer by Multi-detector Hydrodynamic Chromatography

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Molar mass averages, distributions, and architectural information of polymers are routinely obtained using size-exclusion chromatography (SEC). It has previously been shown that ultrahigh molar mass polymers may experience degradation during SEC analysis, leading to inaccurate molar mass averages a...

  13. Relationship between mandibular condyle and angle fractures and the presence of mandibular third molars

    PubMed Central

    Mah, Deuk-Hyun; Moon, Seong-Yong; Oh, Ji-Su; You, Jae-Seek

    2015-01-01

    Objectives We retrospectively evaluated the impact of mandibular third molars on the occurrence of angle and condyle fractures. Materials and Methods This was a retrospective investigation using patient records and radiographs. The sample set consisted of 440 patients with mandibular fractures. Eruption space, depth and angulation of the third molar were measured. Results Of the 144 angle fracture patients, 130 patients had third molars and 14 patients did not. The ratio of angle fractures when a third molar was present (1.26 : 1) was greater than when no third molar was present (0.19 : 1; odds ratio, 6.58; P<0.001). Of the 141 condyle fractures patients, the third molar was present in 84 patients and absent in 57 patients. The ratio of condyle fractures when a third molar was present (0.56 : 1) was lower than when no third molar was present (1.90 : 1; odds ratio, 0.30; P<0.001). Conclusion The increased ratio of angle fractures with third molars and the ratio of condyle fractures without a third molar were statistically significant. The occurrence of angle and condyle fractures was more affected by the continuity of the cortical bone at the angle than by the depth of a third molar. These results demonstrate that a third molar can be a determining factor in angle and condyle fractures. PMID:25741462

  14. Anchorage reinforcement with a fixed functional appliance during protraction of the mandibular second molars into the first molar extraction sites.

    PubMed

    Chhibber, Aditya; Upadhyay, Madhur

    2015-07-01

    Protraction of posterior teeth into edentulous spaces is a challenge. This report describes the treatment of a 19-year-old woman with missing mandibular first molars owing to caries. A fixed functional appliance was used for anchorage reinforcement during mandibular second molar protraction. Eight millimeters of bilateral protraction was done with bodily mesial movement of the molars and no lingual tipping of the incisors. PMID:26124039

  15. Applications of tissue heterogeneity corrections and biologically effective dose volume histograms in assessing the doses for accelerated partial breast irradiation using an electronic brachytherapy source.

    PubMed

    Shi, Chengyu; Guo, Bingqi; Cheng, Chih-Yao; Eng, Tony; Papanikolaou, Nikos

    2010-09-21

    A low-energy electronic brachytherapy source (EBS), the model S700 Axxent x-ray device developed by Xoft Inc., has been used in high dose rate (HDR) intracavitary accelerated partial breast irradiation (APBI) as an alternative to an Ir-192 source. The prescription dose and delivery schema of the electronic brachytherapy APBI plan are the same as the Ir-192 plan. However, due to its lower mean energy than the Ir-192 source, an EBS plan has dosimetric and biological features different from an Ir-192 source plan. Current brachytherapy treatment planning methods may have large errors in treatment outcome prediction for an EBS plan. Two main factors contribute to the errors: the dosimetric influence of tissue heterogeneities and the enhancement of relative biological effectiveness (RBE) of electronic brachytherapy. This study quantified the effects of these two factors and revisited the plan quality of electronic brachytherapy APBI. The influence of tissue heterogeneities is studied by a Monte Carlo method and heterogeneous 'virtual patient' phantoms created from CT images and structure contours; the effect of RBE enhancement in the treatment outcome was estimated by biologically effective dose (BED) distribution. Ten electronic brachytherapy APBI cases were studied. The results showed that, for electronic brachytherapy cases, tissue heterogeneities and patient boundary effect decreased dose to the target and skin but increased dose to the bones. On average, the target dose coverage PTV V(100) reduced from 95.0% in water phantoms (planned) to only 66.7% in virtual patient phantoms (actual). The actual maximum dose to the ribs is 3.3 times higher than the planned dose; the actual mean dose to the ipsilateral breast and maximum dose to the skin were reduced by 22% and 17%, respectively. Combining the effect of tissue heterogeneities and RBE enhancement, BED coverage of the target was 89.9% in virtual patient phantoms with RBE enhancement (actual BED) as compared to 95.2% in water phantoms without RBE enhancement (planned BED). About 10% increase in the source output is required to raise BED PTV V(100) to 95%. As a conclusion, the composite effect of dose reduction in the target due to heterogeneities and RBE enhancement results in a net effect of 5.3% target BED coverage loss for electronic brachytherapy. Therefore, it is suggested that about 10% increase in the source output may be necessary to achieve sufficient target coverage higher than 95%. PMID:20720283

  16. Anxiety before extraction of impacted lower third molars

    PubMed Central

    Tarazona, Beatriz; Tarazona-Álvarez, Pablo; Peñarrocha-Oltra, David; Rojo-Moreno, Juan

    2015-01-01

    Objetives: Assess levels of trait anxiety, state anxiety and dental anxiety before extraction of lower third molars and check the correlation and reliability of the scales used for the measurement of preoperative anxiety. Study Design: A prospective study of patients treated with extraction of a lower third molar between September 2010 to December 2010 was carried out. A total of 125 patients were included in the study. All of them were patients of the Oral Surgery and Implantology Department (Valencia University Medical and Dental School, Valencia, Spain). Before surgery, patients had to complete a preoperative protocol with 4 scales: the STAI-T (State-Trait Anxiety Inventory-Trait) for measuring trait anxiety, the STAI-S (State-Trait Anxiety Inventory-State) for measuring state anxiety, and DAS (Dental anxiety Scale of N. Corah) and APAIS (Amsterdam Preoperative anxiety and Information Scale) for measuring dental anxiety. Results: Patients undergoing extractions of an impacted lower third molar showed low levels of trait anxiety and moderate levels of state anxiety and dental anxiety. Higher levels of trait anxiety were obtained for older patients. Women had higher mean levels of dental anxiety and state anxiety that men with a statistically significant difference in STAI-S scales, DAS, and APAIS. Patients with higher trait anxiety and state anxiety showed higher levels of dental anxiety. A significant correlation (p ? 0.01) (p = 0.00) was found between the four scales used to measure anxiety. The scale showed higher correlation was STAI-S scale. The 4 scales showed high reliability (? of C.> 0.80). Conclusions: Patients with highest levels of trait anxiety and state anxiety, had more dental anxiety. The STAI-T, STAI-S, DAS and APAIS scales provided useful information about anxiety before the extraction of lower impacted third molars. The STAI-S is the scale with highest correlation and reliability. Key words:Extraction of impacted lower third molars, preoperative anxiety, dental anxiety, trait anxiety, state anxiety. PMID:25662541

  17. Correlations between FDG PET glucose uptake-MRI gray matter volume scores and apolipoprotein E ?4 gene dose in cognitively normal adults: a cross-validation study using voxel-based multi-modal partial least squares.

    PubMed

    Chen, Kewei; Ayutyanont, Napatkamon; Langbaum, Jessica B S; Fleisher, Adam S; Reschke, Cole; Lee, Wendy; Liu, Xiaofen; Alexander, Gene E; Bandy, Dan; Caselli, Richard J; Reiman, Eric M

    2012-05-01

    We previously introduced a voxel-based, multi-modal application of the partial least square algorithm (MMPLS) to characterize the linkage between patterns in a person's complementary complex datasets without the need to correct for multiple regional comparisons. Here we used it to demonstrate a strong correlation between MMPLS scores to characterize the linkage between the covarying patterns of fluorodeoxyglucose positron emission tomography (FDG PET) measurements of regional glucose metabolism and magnetic resonance imaging (MRI) measurements of regional gray matter associated with apolipoprotein E (APOE) ?4 gene dose (i.e., three levels of genetic risk for late-onset Alzheimer's disease (AD)) in cognitively normal, late-middle-aged persons. Coregistered and spatially normalized FDG PET and MRI images from 70% of the subjects (27 ?4 homozygotes, 36 ?4 heterozygotes and 67 ?4 non-carriers) were used in a hypothesis-generating MMPLS analysis to characterize the covarying pattern of regional gray matter volume and cerebral glucose metabolism most strongly correlated with APOE-?4 gene dose. Coregistered and spatially normalized FDG PET and MRI images from the remaining 30% of the subjects were used in a hypothesis-testing MMPLS analysis to generate FDG PET-MRI gray matter MMPLS scores blind to their APOE genotype and characterize their relationship to APOE-?4 gene dose. The hypothesis-generating analysis revealed covarying regional gray matter volume and cerebral glucose metabolism patterns that resembled those in traditional univariate analyses of AD and APOE-?4 gene dose and PET-MRI scores that were strongly correlated with APOE-?4 gene dose (p<1 × 10(-16)). The hypothesis-testing analysis results showed strong correlations between FDG PET-MRI gray matter scores and APOE-?4 gene dose (p = 8.7 × 10(-4)). Our findings support the possibility of using the MMPLS to analyze complementary datasets from the same person in the presymptomatic detection and tracking of AD. PMID:22348880

  18. Cameriere's third molar maturity index in assessing age of majority.

    PubMed

    Gali?, Ivan; Lauc, Tomislav; Brki?, Hrvoje; Vodanovi?, Marin; Gali?, Elizabeta; Biazevic, Maria Gabriela Haye; Brakus, Ivan; Badrov, Jozo; Cameriere, Roberto

    2015-07-01

    Estimation of chronological age of an individual is one of the main challenges in forensic science. Legally to be able to treat a person as a minor or an adult, it is necessary to determine whether their age of majority (if they are older or younger than 18, in most countries). Methods for estimating age are especially important when an individual in question lacks personal documents or other means of identification. As the dental age differs in various populations, the aim of this study was to evaluate applicability of third molar method for assessing age of majority in Croatia. Cameriere's third molar maturity index (I3M) value of 0.08, measured by the open apices of the teeth, was verified in sample of 1336 panoramic images aged between 14 and 23 years. Chronological age gradually decreased as I3M increased in both genders. Males showed statistically significant advanced maturation when I3M was between 0.0 and 0.3 value. The results indicate that the sensitivity of the test for 0.08 value was 84.3% (95%CI 80.6%, 87.5%) for females and 91.2% (95%CI 88.7%, 93.1) for males. Specificity was 95.4% (95%CI 92.5%, 97.5%) and 91.9% (95%CI 88.8%, 94.3%). The proportions of accurately classified males were 88.8% and that of females 91.5%. The estimated post-test probabilities, of individuals, in other word the probability that a Croatian individual with an I3M<0.08 is 18 years or older is 94.5% for females, and 96.5% for males. With high accuracy, the third molar maturity index should be used as a determinant of the age of majority in Croatia. PMID:26013667

  19. Unilateral single-rooted primary mandibular first molar.

    PubMed

    Chaudhari, Purva; Mallikarjuna, Rachappa; Swadas, Milan; Dave, Bhavna

    2013-01-01

    A 4-year-old boy reported food lodgement and pain in the lower left back tooth region. On examination, a deeply carious tooth with food lodgement was seen. On oral examination, numbers of teeth were found to be carious and required restorations and endodontic treatments according to radiographic evaluation. Radiograph of mandibular left first deciduous molar revealed an unusual morphology of root. It was single-rooted and presented with Vertucci's class I canal. The tooth was treated by pulpectomy followed by a stainless steel crown. All other carious teeth were treated as planned. PMID:23893279

  20. Unilateral single-rooted primary mandibular first molar

    PubMed Central

    Chaudhari, Purva; Mallikarjuna, Rachappa; Swadas, Milan; Dave, Bhavna

    2013-01-01

    A 4-year-old boy reported food lodgement and pain in the lower left back tooth region. On examination, a deeply carious tooth with food lodgement was seen. On oral examination, numbers of teeth were found to be carious and required restorations and endodontic treatments according to radiographic evaluation. Radiograph of mandibular left first deciduous molar revealed an unusual morphology of root. It was single-rooted and presented with Vertucci's class I canal. The tooth was treated by pulpectomy followed by a stainless steel crown. All other carious teeth were treated as planned. PMID:23893279

  1. Effect of the suture technique on postoperative pain, swelling and trismus after removal of lower third molars: A randomized clinical trial

    PubMed Central

    Gómez-Santos, Laila; Sánchez-Torres, Alba; Herráez-Vilas, José-María

    2015-01-01

    Background To evaluate the intensity of pain, swelling and trismus after the removal of impacted lower third molars comparing two different suture techniques of the triangular flap: the complete suture of the distal incision and relieving incision and the partial suture with only one suture knot for closure of the corner of the flap and the closure of the distal incision, without suturing the relieving incision. Material and Methods A prospective, randomized, crossover clinical trial was conducted in 40 patients aged from 18 to 45 years who underwent surgical extraction of impacted lower third molars at the Department of Oral Surgery in the Odontological Hospital of the University of Barcelona during the year 2011. Patients were randomly divided in 2 groups. Two different techniques (hermetical closure and partial closure of the wound) were performed separated by a one month washout period in each patient. Postoperative pain, swelling and trismus were evaluated prior to the surgical procedure and also at 2 and 7 days post operatively. Results No statistically significant differences were observed for pain (p<0.06), trismus (p<0.71) and swelling (p<0.05) between the test and the control group. However, the values of the three parameters related to the test group were lower than those for the control group. Conclusions Partial closure of the flap without suturing the relieving incision after surgical extraction of lower third molars reduces operating time and it does not produce any postoperative complications compared with complete closure of the wound. Key words: Third molar, surgical flaps, suture techniques, postoperative pain, swelling, trismus. PMID:25662551

  2. The CPA Equation of State and an Activity Coefficient Model for Accurate Molar Enthalpy Calculations of Mixtures with Carbon Dioxide and Water/Brine

    E-print Network

    P. C. Myint; Y. Hao; A. Firoozabadi

    2015-04-20

    Thermodynamic property calculations of mixtures containing carbon dioxide (CO$_2$) and water, including brines, are essential in theoretical models of many natural and industrial processes. The properties of greatest practical interest are density, solubility, and enthalpy. Many models for density and solubility calculations have been presented in the literature, but there exists only one study, by Spycher and Pruess, that has compared theoretical molar enthalpy predictions with experimental data. In this report, we recommend two different models for enthalpy calculations: the CPA equation of state by Li and Firoozabadi, and the CO$_2$ activity coefficient model by Duan and Sun. We show that the CPA equation of state, which has been demonstrated to provide good agreement with density and solubility data, also accurately calculates molar enthalpies of pure CO$_2$, pure water, and both CO$_2$-rich and aqueous (H$_2$O-rich) mixtures of the two species. It is applicable to a wider range of conditions than the Spycher and Pruess model. In aqueous sodium chloride (NaCl) mixtures, we show that Duan and Sun's model yields accurate results for the partial molar enthalpy of CO$_2$. It can be combined with another model for the brine enthalpy to calculate the molar enthalpy of H$_2$O-CO$_2$-NaCl mixtures. We conclude by explaining how the CPA equation of state may be modified to further improve agreement with experiments. This generalized CPA is the basis of our future work on this topic.

  3. Partial ceramic crowns. Influence of preparation design and luting material on margin integrity—a scanning electron microscopic study

    Microsoft Academic Search

    Marianne Federlin; C. Sipos; K.-A. Hiller; B. Thonemann; G. Schmalz

    2005-01-01

    This in vitro study examines the effects of three preparation designs and different luting agents on the marginal integrity of partial ceramic crowns. One hundred forty-four extracted human molars were prepared according to the following preparation designs: A. Coverage of functional cusps, B. Horizontal reduction of functional cusps and C. Complete reduction of functional cusps. Partial ceramic crowns (Vita Mark

  4. Pressure, relaxation volume, and elastic interactions in charged simulation cells

    NASA Astrophysics Data System (ADS)

    Bruneval, Fabien; Varvenne, Céline; Crocombette, Jean-Paul; Clouet, Emmanuel

    2015-01-01

    The ab initio calculation of charged supercells within density-functional theory is a necessary step to access several important properties of matter. The relaxation volume of charged point defects or the partial molar volume of ions in solution are two such examples. However, the total energy and therefore the pressure of charged systems is not uniquely defined when periodic boundary conditions are employed. This problem is tightly related to the origin of the electrostatic potential in periodic systems. This effect can be easily observed by modifying the electrostatic convention or modifying the local ionic potential details. We propose an approach to uniquely define the pressures in charged supercells with the use of the absolute deformation potentials. Only with such a definition could the ab initio calculations provide meaningful values for the relaxation volumes and for the elastic interactions for charged defects in semiconductors or ions in solution. The proposed scheme allows one to calculate sensible data even when charge neutrality is not enforced, thus going beyond the classical force-field-based approaches.

  5. Unilateral failure of development of mandibular premolars and molars in an Eastern Grey kangaroo (Macropus giganteus) and its effects on molar progression.

    PubMed

    Barber, D; Campbell, J; Davey, J; Luke, T; Agren, E; Beveridge, I

    2008-01-01

    An adult male Eastern Grey kangaroo from a wildlife reserve near Melbourne was submitted for necropsy examination and was discovered to have abnormal dentition. There was no evidence that any premolars or molars had ever been present on the right mandible, whilst the incisors were normal. The age of the kangaroo was estimated to be 1 year 9 months using the right maxillary molars and 2 years 4 months old using the contralateral side, presumably due to the asymmetry of the dental arcades. 'Lumpy jaw', a common periodontal disease of kangaroos, from which Bacteroides sp was cultured, was present on the base of the vertical ramus of the left mandible. Complete unilateral absence of premolar and molar teeth in the mandible of a kangaroo has not been described. This condition affected molar progression in both sets of maxillary molars. PMID:18271832

  6. Effectiveness of a personalized device in the evaluation of mandibular second molar periodontal healing after surgical extraction of adjacent third molar

    PubMed Central

    Pippi, Roberto

    2013-01-01

    Summary Aim The primary aim of the present study was to validate the effectiveness of a personalized device able to guide periodontal probing in evaluation of second molar periodontal healing after adjacent third molar surgical extraction. Secondarily, the study analyzed if any patient and tooth related factors affected the second molar periodontal healing as well as if they were able to affect the periodontal probing depth performed with or without the personalized device. Materials and methods Thirty-five lower second molars were evaluated after extraction of the adjacent third molar. Pre-operative as well as 3 and 12 month post-operative probing depths of the distal surface of the second molar were evaluated. All measurements were taken by two different methods: standard two-point and four-point probing using a personalized onlay-type guide. Periapical radiographs were also evaluated. The Pearson product moment and the general linear model with backward stepwise procedure were used for inferential statistics. Results The mean 12-month post-operative probing depth/mean pre-operative probing depth ratio obtained with the guided probing method showed a highly significant effect on the 12-month radiographic post-operative/pre-operative radiographic measure ratio. None of the examined patient- or tooth-related factors showed a significant effect on pre-operative/12-month post-operative radiographic measure ratio. Conclusions The use of the proposed personalized device seems to provide a more reliable estimate of second molar periodontal healing after adjacent third molar surgical extraction. No patient-or tooth-related factors seem to be able to affect either second molar periodontal healing or probing depth measures obtained with or without the personalized device in individuals younger than 25 years old. It can be therefore recommended that lower third molar surgical extraction be performed in young adults. PMID:24611086

  7. Nanoparticle counting: towards accurate determination of the molar concentration.

    PubMed

    Shang, Jing; Gao, Xiaohu

    2014-11-01

    Innovations in nanotechnology have brought tremendous opportunities for the advancement of many research frontiers, ranging from electronics, photonics, energy, to medicine. To maximize the benefits of nano-scaled materials in different devices and systems, precise control of their concentration is a prerequisite. While concentrations of nanoparticles have been provided in other forms (e.g., mass), accurate determination of molar concentration, arguably the most useful one for chemical reactions and applications, has been a major challenge (especially for nanoparticles smaller than 30 nm). Towards this significant yet chronic problem, a variety of strategies are currently under development. Most of these strategies are applicable to a specialized group of nanoparticles due to their restrictions on the composition and size range of nanoparticles. As research and uses of nanomaterials are being explored in an unprecedented speed, it is necessary to develop universal strategies that are easy to use and are compatible with nanoparticles of different sizes, compositions, and shapes. This review outlines the theories and applications of current strategies to measure nanoparticle molar concentration, discusses the advantages and limitations of these methods, and provides insights into future directions. PMID:25099190

  8. Solvent-mediated molar conductivity of protic ionic liquids.

    PubMed

    Thawarkar, Sachin; Khupse, Nageshwar D; Kumar, Anil

    2015-01-01

    The molar conductivity, ?m, of protic ionic liquids (PILs) in molecular solvents is measured at 298.15 K. The decrease in the ?m values of PILs is observed with an increase in the concentration of PILs. The limiting molar conductivities, ?m(0), were obtained for each PIL in different molecular solvents using a least squares method. The ?m(0) data for PILs were correlated with the structural aspects of PILs and solvent properties. The polar protic solvents show poor ionic association as compared to the polar aprotic solvents, which is discussed on the basis of the hydrogen bond donating (HBD) ability of solvents and PILs. The alkyl chain substitution of anions plays a significant role in the ionic association of the PILs. The diffusion coefficient D(0) and the transport number t were determined, which were consistent with the ?m(0) values of PILs in water. The ?m(0) and D(0) values are dependent on the hydrodynamic radius of anions of these ionic liquids. The extent of ionic association for each PIL was discussed using temperature dependent ?m data for aqueous PIL systems in terms of the Walden plot. PMID:25406387

  9. An in vitro morphological investigation of the endodontic spaces of third molars.

    PubMed

    Cosi?, Jozo; Gali?, Nada; Vodanovi?, Marin; Njemirovskij, Vera; Segovi?, Sanja; Paveli?, Bozidar; Ani?, Ivica

    2013-06-01

    Aim of this paper was to investigate the particular anatomic features of the endodontic space of third molars in the general population of Croatia. A total of 106 fully developed third molars (56 maxillar and 50 mandibular) has been analyzed. The respective number of roots and of root canals, the structure of the roots, and the curvature and absolute length of the root-canals were analyzed. In most cases, upper third molars had three roots (83.9%), while most of the lower molars were single rooted (56.0%). Upper third molars had mostly three root canals (75.1%), lower third molars two (90.0%). In both jaws, most third molars had curved canals (60.7% in the upper and 84.0% in the lower jaw). 12.5% of upper third molars had lateral and accessory canals, whereas only 4.0% of the lower third molars were found to have them. The Student t-test showed statistically significant differences (p < 0.05) in the length of the root-canals, mesiobuccal and distobuccal canals being significantly shorter than palatinal canals. The same test showed that in the lower third molars the mesial root canals were significantly longer that the distal ones, although slightly. The results obtained are in compliance with similar results by other authors; however, they tend to show some specific population-related features. PMID:23940986

  10. Computing Partial Expectations from Tables

    Microsoft Academic Search

    Jörg Grüner; Klaus Zoller

    1997-01-01

    Many applications in inventory control, reliability engineering and preventive maintenance involve frequent calculations of\\u000a probabilities and partial expectations. In the design of high-volume computer-based applications recourse to internal tables\\u000a may therefore be preferable to an import of statistical packages. While interpolation in tabulated cdf’s will often prove\\u000a sufficiently accurate from the point of view of statistical representation of the underlying

  11. Age estimation using development of third molars in South Indian population: A radiological study

    PubMed Central

    Priyadharshini, K. Indra; Idiculla, Jose Joy; Sivapathasundaram, B.; Mohanbabu, V.; Augustine, Dominic; Patil, Shankargouda

    2015-01-01

    Aim: To assess the estimation of chronological age based on the stages of third molar development following the eight stages (A–H) method of Demirjian et al. in Chennai population of South India. Materials and Methods: A sample consisting of 848 individuals (471 males and 377 females) aged between 14 and 30 years was randomly selected for the clinical evaluation and 323 orthopantomograms with clinically missing third molars were taken for radiological evaluation using Demirjian's method from a Chennai population of known chronological age and sex. Statistical analysis was performed using Pearson's Chi-square test and mean values were compared between the study groups using t-test or analysis of variance (ANOVA) followed by Tukey's highly significant difference (HSD). In the present study, P < 0.05 was considered as the level of significance. Results: The results showed that the mean age of having clinically completely erupted maxillary third molars was 22.41 years in male subjects and 23.81 years in female subjects and that of mandibular third molars was 21.49 years in male subjects and 23.34 years in female subjects. Mandibular third molars were clinically missing more often in females than in males. Eruption of mandibular third molars was generally ahead of the emergence of maxillary third molars into the oral cavity. Third molar development between male and female subjects showed statistically significant differences at calcification stage F and stage G in maxillary third molars and stage F in mandibular third molars (P < 0.05). Conclusion: There are differences indicating that maxillary and mandibular third molar eruption reached Demirjian's formation stages earlier in males than in females. It is suggested that in future studies, to increase the accuracy of age determination, indications of sexual maturity and ossification should also be evaluated in addition to third molar mineralization. PMID:25984465

  12. Standard molar enthalpies of formation of three branched alkyl carboxylic acids

    Microsoft Academic Search

    Manuel A. V. Ribeiro da Silva; M. L. C. C. H. Ferrão; Adelina M. R. O. Alves da Silva

    1999-01-01

    The standard (po= 0.1 MPa) molar enthalpies of combustion in oxygen at T= 298.15 K of three branched alkyl chain carboxylic acids, 2-methylpropanoic, 2,2-dimethylpropanoic, and 3-methylbutanoic, were measured by static bomb combustion calorimetry, from which their standard molar enthalpies of formation were derived.The standard molar enthalpies of formation at T= 298.15 K of the gaseous carboxylic acids were derived using

  13. UPPER VS. LOWER MOLARS FOR CEMENTUM ANNULI AGE DETERMINATION OF DEER

    Microsoft Academic Search

    DALE R. McCULLOUGH; PAUL BEIER

    Ages were determined for 23 black-tailed deer (Odocoileus hemionus columbianus) and 14 white-tailed deer (0. virginianus) by examination of cementum annuli of both upper and lower 1st molars. Although estimated ages were virtually the same for both upper and lower molars, the clarity of annuli was significantly greater in upper molars for both species. Abstract: Ages were determined for 23

  14. Representations of partial derivatives in thermodynamics

    NASA Astrophysics Data System (ADS)

    Thompson, John R.; Manogue, Corinne A.; Roundy, David J.; Mountcastle, Donald B.

    2012-02-01

    One of the mathematical objects that students become familiar with in thermodynamics, often for the first time, is the partial derivative of a multivariable function. The symbolic representation of a partial derivative and related quantities present difficulties for students in both mathematical and physical contexts, most notably what it means to keep one or more variables fixed while taking the derivative with respect to a different variable. Material properties are themselves written as partial derivatives of various state functions (e.g., compressibility is a partial derivative of volume with respect to pressure). Research in courses at the University of Maine and Oregon State University yields findings related to the many ways that partial derivatives can be represented and interpreted in thermodynamics. Research has informed curricular development that elicits many of the difficulties using different representations (e.g., geometric) and different contexts (e.g., connecting partial derivatives to specific experiments).

  15. [The pendulis appliance: a palatal miniscrew supported molar distalization device].

    PubMed

    Nappée-Miévilly, Magali; Nappée, François-Joseph; Kerbrat, Jean-Baptiste; Goudot, Patrick

    2014-09-01

    The maxillary molar distalization is a valuable therapeutic option in some clinical cases. Its biomechanics is challenging and difficult to obtain. Historically, various devices have been described offering successful solutions to this problem such as the Hilgers Pendulum Appliance (1992) and variants linked to mini screws which recently have shown interesting clinical potential. This article presents a new Pendulum variant using a miniscrew, the "pendulis". It follows the original concept (titanium-molybdenum alloy distalization springs and polymethyl-methacrylate pellet) but dental support is replaced by a single palatal miniscrew (median adults, para-median in children) to which the device is fixed by means of a metal welded cap easily positioned and removable by the practitioner. This allows for better control of the oral hygiene and completely controlled extraoral activation. Fabrication steps are described and instruction of use is illustrated with clinical documentation. PMID:25158749

  16. Rotation of rectangular wire in rectangular molar tubes. Part I.

    PubMed

    Raphael, E; Sandrik, J L; Klapper, L

    1981-08-01

    The degree of angular rotation of rectangular orthodontic wires in rectangular molar tubes was measured using a rotatable mechanical stage on a Unitron metallograph and compared to theoretical data. It was found that square 0.016 inch wire did not bind in 0.018 by 0.022 inch or larger mandrel- or inconel-formed tubes, whereas rotations of 11 to 23 degrees were noted in cast tubes of this dimension. Although 0.016 by 0.022 inch wire did bind in these tubes, the degree of rotation was far greater than expected on the basis of theoretical calculations or clinical expectations. The results indicated that it was unrealistic to expect fine control of a few degrees of torque to occur as expected for delicate clinical control. PMID:6943934

  17. Molarity (Aromic Density) of the Elements as Pure Crystals.

    ERIC Educational Resources Information Center

    Pauling, Linus; Herman, Zelek S.

    1985-01-01

    Provides background information for teachers on the atomic density of the elements as pure crystals. Atomic density is defined as the reciprocal of the atomic volume. Includes atomic-density diagrams which were prepared using the atomic-volume values given by Singman, supplemented by additional values for some allotropes. (JN)

  18. Molar uprighting with extrusion for implant site bone regeneration and improvement of the periodontal environment.

    PubMed

    Maeda, Sachiko; Ono, Yoshihiro; Nakamura, Kimio; Kuwahara, Toshiya

    2008-08-01

    This case report describes the treatment of a 55-year-old man who presented with a missing maxillary first molar and mesially inclined neighboring second molar with a severe circumferential bone defect. After bone regeneration therapy with bone grafting, the second molar was uprighted orthodontically to improve the inclination and crown-to-root ratio. These treatments minimized the bone defect and developed a suitable site for an implant in the first molar position. An interdisciplinary approach using periodontal, orthodontic, and prosthodontic treatments can create a more predictable and maintainable situation. PMID:18717376

  19. A rare case of impacted supernumerary premolar causing resorption of mandibular first molar

    PubMed Central

    Murali, R. V.; Gnanashanmugam, K.; Rajasekar, L.; Kularashmi, B. S.; Saravanan, B.

    2015-01-01

    The management of patients with pain in today's general practice has become a major concern and sometimes this pain is related to some rare causes. A male patient aged 26 years reported with pain in the lower left molar region (36) and then an intra-oral periapical radiograph (IOPA), and orthopantomograph was taken. IOPA revealed the presence of supernumerary premolar causing pressure and root resorption of 36. Also, there was missing 21 and proximal decay in 11. Eleven was treated endodontically, and then bridge was done in relation to 11, 21 and 22. Lower anterior crowding was also present. The treatment plan was to extract 36 followed by orthodontic extrusion of the supernumerary premolar and also the correction of lower anterior crowding. Hidden approach (lingual orthodontics) was used as the patient was insisting upon the braces not being seen outside during the course of the treatment. Later all ceramic bridge was done in relation to 11, 21 and 22. Orthodontic tooth extrusion techniques offer excellent treatment options for Partially Impacted tooth. It is a well-documented clinical method for extruding sound tooth material from within the alveolar socket by light forces. The use of lingual technique for forced eruption enhance acceptance of orthodontic treatment by adults. The treatment of a young adult patient illustrates the importance of treatment planning from one discipline to another, communication among team members and the benefits of working together in an interdisciplinary approach PMID:26015740

  20. Dental radiographic features of impacted third molars and some management implications.

    PubMed

    Owotade, F J; Fatusi, O A; Ibitoye, B; Otuyemi, O D

    2003-09-01

    The objective of the study was to determine the principal dental radiographic features of impacted third molars and to highlight some management implications, 255 periapical radiographs belonging to 197 patients with the clinical records were examined. The age of the subjects, sex, and degree of impaction, inclination, depth, mesiodistal space and associated pathology were documented as well as the number of roots and their relationship to the neurovascular bundle. The mean age was 23.4 years with more female teeth (152, 59.6%) than male (103, 40.4%). Majority were partially erupted (223, 91.4%) with vertical impaction most commonly seen in 80 teeth (31.4%). Over half of the teeth (135, 52.9%) had no obvious relationship with the inferior alveolar neuro-vascular bundle and where this existed, darkening of the root was the most common radiographic indicator (55 teeth, 21.6%). Most of the teeth (54.9%) had no obvious pathologic changes associated. In those with pathologic changes, periodontal bone loss and a wide follicle were most commonly observed (44 teeth or 17.3% in both cases). Older subjects had significantly more periodontal bone loss (p = 0.001). Periapical radiographic examination can reveal vital information for treatment planning of impacted teeth and the monitoring of asymptomatic teeth. PMID:14705372

  1. A rare case of impacted supernumerary premolar causing resorption of mandibular first molar.

    PubMed

    Murali, R V; Gnanashanmugam, K; Rajasekar, L; Kularashmi, B S; Saravanan, B

    2015-04-01

    The management of patients with pain in today's general practice has become a major concern and sometimes this pain is related to some rare causes. A male patient aged 26 years reported with pain in the lower left molar region (36) and then an intra-oral periapical radiograph (IOPA), and orthopantomograph was taken. IOPA revealed the presence of supernumerary premolar causing pressure and root resorption of 36. Also, there was missing 21 and proximal decay in 11. Eleven was treated endodontically, and then bridge was done in relation to 11, 21 and 22. Lower anterior crowding was also present. The treatment plan was to extract 36 followed by orthodontic extrusion of the supernumerary premolar and also the correction of lower anterior crowding. Hidden approach (lingual orthodontics) was used as the patient was insisting upon the braces not being seen outside during the course of the treatment. Later all ceramic bridge was done in relation to 11, 21 and 22. Orthodontic tooth extrusion techniques offer excellent treatment options for Partially Impacted tooth. It is a well-documented clinical method for extruding sound tooth material from within the alveolar socket by light forces. The use of lingual technique for forced eruption enhance acceptance of orthodontic treatment by adults. The treatment of a young adult patient illustrates the importance of treatment planning from one discipline to another, communication among team members and the benefits of working together in an interdisciplinary approach. PMID:26015740

  2. Appearance of dentin gamma-carboxyglutamic acid-containing proteins in developing rat molars in vitro

    SciTech Connect

    Finkelman, R.D.; Butler, W.T.

    1985-07-01

    An in vitro model of mineralization was devised in order to study the developmental appearance of dentin gamma-carboxyglutamic acid-containing proteins (DGPs) in relation to the onset of mineralization. Maxillary third molars from 11-day-old rats were cultured with or without fetal calf serum (FCS) as modified from Navia et al. Molars were incubated without radiolabel, or with either /sup 45/CaCl/sub 2/ (5 microCi/ml) for 24 hr at various stages of a ten-day culture period or (/sup 3/H)-leucine (10 microCi/ml) for 24 hr at the eighth day of culture. Molars were lyophilized and extracted with 10% formic acid overnight at 4 degrees C. DGPs in extracts were detected by immunologic and chromatographic techniques; DGPs in molar sections were detected by immunolocalization using indirect immunofluorescence. Molar development was evaluated histologically using the Von Kossa staining technique. Molars cultured with FCS showed histologic evidence for mineralized dentin and enamel and a significant increase in /sup 45/Ca uptake after the sixth day in vitro. Eleven-day-old molars in vivo and molars cultured without FCS showed no evidence of the presence of mineralized tissues. (/sup 3/H)-Leucine-labeled DGPs were isolated and identified by affinity and reversed-phase high-performance liquid chromatography and by gel electrophoresis from both mineralized and unmineralized molars. DGP antigens were localized immunohistochemically using rabbit anti-rat antibodies raised against a highly purified DGP preparation. In the unmineralized molar, antigenicity was seen in odontoblasts but not in predentin matrix, preodontoblasts, or in any other cell type. Antigens in the mineralized molar were localized to odontoblasts and dentin.

  3. The influence of impaction to the third molar mineralization in northwestern Chinese population.

    PubMed

    Guo, Yu-cheng; Yan, Chun-xia; Lin, Xing-wei; Zhang, Wen-tao; Zhou, Hong; Pan, Feng; Wei, Lai; Tang, Zheng; Liang, Feng; Chen, Teng

    2014-07-01

    Age estimation by third molar mineralization has been developed for a period of time. Recent studies showed that impaction status has an influence on the rate of the third molar mineralization in Europids and male Black African populations. In this regard, the present study was conducted to determine whether the impaction status could delay the chronological process of third molar mineralization in northwestern Chinese population too. A total of 3,512 digital orthopantomograms of 1,255 male and 2,257 female northwestern Chinese subjects aged from 11 to 26 years were assessed based on the formation stages described by Demirjian et al. with two modifications. Mineralization stage and impaction status were determined for all third molars. Statistical measures were calculated at stages C-H in the male and female gender for both impacted and non-impacted third molars. It was ascertained that the mean ages with impacted third molars at stages C-H were 0.02-1.42 years higher in males and 0.04-1.52 years higher in females than those with non-impacted third molars, but statistical differences were only found at stages C, D, and E in males and stages D and E in females. The probabilities of being under 14, 16, or 18 years of age with non-impacted third molars were all higher than those with impacted third molars. The results prove that impacted third molars show significant slower mineralization than non-impacted ones at stages D and E in both males and females of northwestern Chinese population. It is recommended to consider the influence of impaction on the rate of third molar mineralization for dental age estimation. PMID:24532176

  4. Influence of cervical preflaring on determinationof apical file size in mandibular molars: SEM analysis

    Microsoft Academic Search

    Marcia da Silva Schmitz; Roberto Santos; Alexandre Capelli; Marcos Jacobovitz; Júlio César Emboava Spanó; Jesus Djalma Pécora

    2008-01-01

    This study investigated the influence of cervical preflaring with different rotary instruments on determination of the initial apical file (IAF) in mesiobuccal roots of mandibular molars. Fifty human mandibular molars whose mesial roots presented two clearly separated apical foramens (mesiobuccal and mesiolingual) were used. After standard access opening and removal of pulp tissue, the working length (WL) was determined at

  5. Phase-separation-induced fractionation in molar mass in aqueous mixtures of gelatin and dextran.

    PubMed

    Edelman, M W; Tromp, R H; van der Linden, E

    2003-02-01

    An overview of the effects of phase separation of aqueous mixtures of gelatin and dextran on the fractionation in molar mass of these two components is given. Molar mass distributions in coexisting phases were investigated using size exclusion chromatography with multiangle laser light scattering. The initial molar mass of the native material, concentration, and temperature were varied. The results show a strong fractionation in molar mass for both components. The molar mass of the native material and concentration appeared to be the only factors that affected the final molar mass distributions, temperature having no effect. The results show that in the molar mass range where fractionation is the strongest, i.e., roughly below the maximum in the distribution, fractionation is governed by a Boltzmann factor e(-deltaG/kT), where deltaG denotes the free energy involved in transferring a polymer with a certain length from the enriched to the depleted phase, and in this case turns out to be proportional to the molar mass. Comparison of the results of phase separation with results on dialysis shows that water affinity is not the driving force for the phase separation of gelatin and dextran in aqueous solution. The gelation properties of gelatin in both phases were also determined. The gelation properties of gelatin in the coexisting phases differ from those of native gelatin. In particular, the gelatin in the gelatin-poor phase shows strong differences compared to the native material. PMID:12636676

  6. 40 CFR 1066.610 - Mass-based and molar-based exhaust emission calculations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Mass-based and molar-based exhaust emission...PROCEDURES Calculations § 1066.610 Mass-based and molar-based exhaust emission calculations. (a) Calculate your total mass of emissions over a test cycle as...

  7. 40 CFR 1066.610 - Mass-based and molar-based exhaust emission calculations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Mass-based and molar-based exhaust emission...PROCEDURES Calculations § 1066.610 Mass-based and molar-based exhaust emission calculations. (a) Calculate your total mass of emissions over a test cycle as...

  8. Molar crown formation in the Late Miocene Asian hominoids, Sivapithecus parvada and Sivapithecus indicus

    E-print Network

    Smith, Tanya M.

    Molar crown formation in the Late Miocene Asian hominoids, Sivapithecus parvada and Sivapithecus and geographic perspective on evolutionary devel- opmental biology in Miocene hominoids. Here we report some for the protocone of S. indicus lie within the range of first molar (M1) formation times for the majority of Miocene

  9. A new method to correct lingual rolling of lower molars (Amini twister).

    PubMed

    Amini, Fariborz; Poosti, Maryam

    2013-01-01

    In this report, we present an uncomplicated approach to overcome lingual rolling of mandibular molars during orthodontic treatment, by using rectangular NiTi arch wire in twist fashion through the molar tube. The sequential steps of the twist manoeuvre on a typodont and a case report are exhibited in this article. PMID:23729138

  10. Second mesiobuccal canal detection in maxillary first molars using microscopy and ultrasonics

    Microsoft Academic Search

    Tayfun Alaçam; Ali Cemal Tinaz; Özgür Genç; Guven Kayaoglu

    2008-01-01

    The aim of this study was to investigate whether the use of operating micro- scope in combination with ultrasonics increased the rate of second mesiobuccal (MB2) canal detection in permanent maxillary first molar teeth. A hundred extracted human maxillary first molars were assessed. After location of the main canals, the MB2 canal was sought in all teeth first without microscopy,

  11. Influence of overlay restorative materials and load cusps on the fatigue resistance of endodontically treated molars

    Microsoft Academic Search

    Pascal Magne; Alena Knezevic

    Objectives: To assess the influence of restorative materials and load cusps on the fatigue resistance of endodontically treated molars. Method and Materials: Thirty extracted molars received root canal treatment followed by a standardized tooth preparation (3-mm cuspal reduction and immediate dentin sealing). Twenty Cerec 3 overlays (Sirona Dental Systems) were milled in the ceramic Vita MKII block (Vident; groups MKIIGL

  12. Regenerative therapy in the treatment of maxillary molar Class II furcations: case reports.

    PubMed

    Rosen, P S; Marks, M H; Bowers, G M

    1997-12-01

    This report demonstrates the use of regenerative therapy in the treatment of maxillary molar Class II furcations. The predominant therapy provided was open debridement in combination with DFDBA, e-PTFE membranes, and citric acid root conditioning. Case reports of consecutively treated patients that include radiographs and reentry photographs demonstrate that maxillary molar furcations can be successfully treated with predictability. PMID:9497738

  13. The third molar controversy: Framing the controversy as a public health policy issue

    Microsoft Academic Search

    William G Flick

    1999-01-01

    Purpose: This article summarizes the current research available concerning the removal of impacted third molars, and provides a background from which practitioners, public health policy advocates, and third-party payers can more objectively assess the the issues of appropriateness of care and overutilization of third molar surgery.Materials and Methods: A literature review was undertaken, with emphasis on noninterventional outcome studies and

  14. Pattern of caries experience in permanent molars in a 15-year-old African population.

    PubMed

    Johnson, A S; Gjermo, P

    1989-01-01

    Some epidemiologic studies from Africa report higher DMF values in second than in first molars. It is generally accepted that the maturation of dental enamel influences the susceptibility of teeth to caries. The purpose of the present study was to test the hypothesis that DMF values of second molars will be higher than those of first molars if the first molars have reached a high degree of maturation before being exposed to increased cariogenic challenge. The study was carried out in a group of 15-year-old students attending secondary schools in Botswana (n = 287). The results showed that in children who assumingly had had a traditional diet during childhood the DMF values were higher in second molars than in first molars. In children who grew up in a more urbanized setting, the results were opposite. The observed differences were due to differences in caries experience in first molars only. The DMF values of second molars did not vary among the groups. Oral hygiene, sugar consumption and knowledge level at age 15 seemed to have no effect upon the caries pattern studied. It is concluded that the results support the hypothesis tested. PMID:2598231

  15. A method for estimating both the solubility parameters and molar volumes of liquids

    NASA Technical Reports Server (NTRS)

    Fedors, R. F.

    1974-01-01

    Development of an indirect method of estimating the solubility parameter of high molecular weight polymers. The proposed method of estimating the solubility parameter, like Small's method, is based on group additive constants, but is believed to be superior to Small's method for two reasons: (1) the contribution of a much larger number of functional groups have been evaluated, and (2) the method requires only a knowledge of structural formula of the compound.

  16. Dietary inference from upper and lower molar morphology in platyrrhine primates.

    PubMed

    Allen, Kari L; Cooke, Siobhán B; Gonzales, Lauren A; Kay, Richard F

    2015-01-01

    The correlation between diet and dental topography is of importance to paleontologists seeking to diagnose ecological adaptations in extinct taxa. Although the subject is well represented in the literature, few studies directly compare methods or evaluate dietary signals conveyed by both upper and lower molars. Here, we address this gap in our knowledge by comparing the efficacy of three measures of functional morphology for classifying an ecologically diverse sample of thirteen medium- to large-bodied platyrrhines by diet category (e.g., folivore, frugivore, hard object feeder). We used Shearing Quotient (SQ), an index derived from linear measurements of molar cutting edges and two indices of crown surface topography, Occlusal Relief (OR) and Relief Index (RFI). Using SQ, OR, and RFI, individuals were then classified by dietary category using Discriminate Function Analysis. Both upper and lower molar variables produce high classification rates in assigning individuals to diet categories, but lower molars are consistently more successful. SQs yield the highest classification rates. RFI and OR generally perform above chance. Upper molar RFI has a success rate below the level of chance. Adding molar length enhances the discriminatory power for all variables. We conclude that upper molar SQs are useful for dietary reconstruction, especially when combined with body size information. Additionally, we find that among our sample of platyrrhines, SQ remains the strongest predictor of diet, while RFI is less useful at signaling dietary differences in absence of body size information. The study demonstrates new ways for inferring the diets of extinct platyrrhine primates when both upper and lower molars are available, or, for taxa known only from upper molars. The techniques are useful in reconstructing diet in stem representatives of anthropoid clade, who share key aspects of molar morphology with extant platyrrhines. PMID:25738266

  17. Joubert syndrome: congenital cerebellar ataxia with the “molar tooth”

    PubMed Central

    Romani, Marta; Micalizzi, Alessia; Valente, Enza Maria

    2013-01-01

    Joubert syndrome (JS) is a congenital cerebellar ataxia with autosomal recessive or X-linked inheritance, which diagnostic hallmark is a unique cerebellar and brainstem malformation recognizable on brain imaging, the “molar tooth sign”. Neurological signs are present from neonatal age and include hypotonia evolving into ataxia, global developmental delay, ocular motor apraxia and breathing dysregulation. These are variably associated with multiorgan involvement, mainly of the retina, kidneys, skeleton and liver. To date, 21 causative genes have been identified, all encoding for proteins of the primary cilium or its apparatus. This is a subcellular organelle that plays key roles in development and in many cellular functions, making JS part of the expanding family of ciliopathies. There is marked clinical and genetic overlap among distinct ciliopathies, which may co-occur even within families. Such variability is likely explained by an oligogenic model of inheritance, in which mutations, rare variants and polymorphisms at distinct loci interplay to modulate the expressivity of the ciliary phenotype. PMID:23870701

  18. Molar crown inner structural organization in Javanese Homo erectus.

    PubMed

    Zanolli, Clément

    2015-01-01

    This contribution investigates the inner organizational pattern (tooth tissue proportions and enamel-dentine junction morphology) of seven Homo erectus permanent molar crowns from the late Lower-early Middle Pleistocene Kabuh Formation of the Sangiran Dome (Central Java, Indonesia). The previous study of their external characteristics confirmed the degree of time-related structural reduction occurred in Javanese H. erectus, and also revealed a combination of nonmetric features which are rare in the Lower and early Middle Pleistocene dental record, but more frequently found in recent humans. In accordance with their outer occlusal morphology, the specimens exhibit a set of derived internal features, such as thick to hyperthick enamel, an incomplete expression of the crest patterns at the enamel-dentine junction (EDJ) level, a sharp EDJ topography. As a whole, these features differ from those expressed in some penecontemporaneous specimens/samples representing African H. erectus/ergaster and H. heidelbergensis, as well as in Neanderthals, but occur in recent human populations. Further research in virtual dental paleoanthropology to be developed at macroregional scale would clarify the polarity and intensity of the intermittent exchanges between continental and insular Southeast Asia around the Lower to Middle Pleistocene boundary, as well as should shed light on the still poorly understood longitudinal evolutionary dynamics across continental Asia. PMID:25209431

  19. Use of opioid pain relievers following extraction of third molars.

    PubMed

    Weiland, Breanna M; Wach, Anthony G; Kanar, Brent P; Castele, Matthew T; Sosovicka, Mark F; Cooke, Matthew R; Moore, Paul A

    2015-02-01

    Following extraction of third molars, it is common practice for oral and maxillofacial surgeons to provide a prescription for an opioid-containing analgesic such as hydrocodone with acetaminophen. Because the instructions for use most often indicate that these analgesics are to be taken "as needed for pain," it is unknown how many of the prescribed postoperative analgesic tablets are needed and actually taken. Therefore, an assessment of patient pain experiences and actual opioid analgesic usage was carried out using structured telephone interviews of patients performed 1 and 7 days following their thirdmolar extraction surgery. Forty-eight adolescents and young adults, ages 15 to 30 years, participated in this assessment. A review of the surgeon's notes indicated that the median number of prescribed opioid-containing analgesics (ie, Vicodin®, Norco®, Lorcet®, Percocet®) was 20 tablets (range 10 to 40). The median consumption during the first 24 hours was reported to be three tablets (range 0 to 10), and the total consumption for all 7 days was eight tablets (range 0 to 34). Four patients reported nausea or vomiting in the first 24 hours, and six patients reported nausea or vomiting during the following 6 days of recovery. The initial prescriptions provided adequate relief for 45 of the 48 patients. Higher consumption of opioid pain relievers (OPRs) was associated with a longer duration of surgery and the occurrence of postoperative infections. PMID:25822637

  20. How many patients have third molars and how many have one or more asymptomatic, disease-free third molars?

    PubMed

    Dodson, Thomas B

    2012-09-01

    The purpose of this report was to summarize the frequencies of third molars (M3s) in general and asymptomatic, disease-free M3s specifically. Estimates of M3 prevalence range so widely (ie, 6.0% to 96%) as to be of little use. The estimates vary depending on definitions, age, clinical versus radiographic assessment, and patient versus population samples. For patient management, it may be more valuable to estimate the prevalence of M3s grouped by clinical rather than anatomic status. Many times, however, M3s are categorized simply as asymptomatic. In many pathologic processes, from cancer to cardiovascular disease, the term asymptomatic does not equal an absence of disease. As such, M3s should be categorized based on symptom and disease status. Subjects with all M3s asymptomatic and absent of disease ranged from 12% in a sample of patients referred for M3 evaluation to 29% in a nonpatient volunteer sample. In the patient sample, 37% of the M3s evaluated were asymptomatic and free of disease. PMID:22916698

  1. Name: Seetin Question: In patients with mixed dentition, who have lost a single primary 2nd molar and require space

    E-print Network

    Goldman, Steven A.

    Name: Seetin Question: In patients with mixed dentition, who have lost a single primary 2nd molar, comparison, outcome) P: Mixed dentition, lost single primary 2nd molar I: Unilateral space maintainer

  2. Analysis of quantitative trait locus effects on the size and shape of mandibular molars in mice.

    PubMed Central

    Workman, Michael Scott; Leamy, Larry J; Routman, Eric J; Cheverud, James M

    2002-01-01

    While >50 genes have been found to influence the development of teeth in mice, we still know very little about the genetic basis for the adaptive characteristics of teeth, such as size and shape. We applied interval mapping procedures to Procrustes size and shape data obtained from 10 morphological landmarks on the mandibular molar row of the F(2) progeny from a cross between the LG/J and SM/J strains of mice. This revealed many more QTL for molar shape (18) than for molar centroid size (3), although levels of dominance effects were comparable among QTL for size and shape. Comparisons of patterns of Procrustes additive and dominance shape effects and ordination of QTL effects by principal components analysis suggested that the effects of the shape QTL were dispersed among the three molars and thus that none of these molars represents a genetically distinct developmental structure. The results of an analysis of co-occurrence of QTL for molar shape, mandible shape, and cranial dimensions in these mice suggested that many of the QTL for molar shape may be the same as those affecting these other sets of characters, although in some cases this could be due to effects of closely linked genes. PMID:11973311

  3. National clinical guidelines for the extraction of first permanent molars in children.

    PubMed

    Cobourne, M T; Williams, A; Harrison, M

    2014-12-01

    This article summarises recently updated guidelines produced by the Clinical Governance Directorate of the British Orthodontic Society through the Clinical Standards Committee of the Faculty of Dental Surgery, Royal College of Surgeons of England (FDSRCS) on the extraction of first permanent molars in children. The first permanent molar is susceptible to chronological enamel defects, molar-incisor hypomineralisation and caries, which may necessitate enforced extraction in the developing dentition. In the right circumstances, the extraction of these teeth can be followed by successful eruption of the second permanent molar and ultimately, third molar eruption to complete the molar dentition. For this reason, elective extraction of first permanent molars with a questionable long-term prognosis should be considered when planning enforced extractions. However, a number of factors can influence the decision-making process, including the necessity for a general anaesthetic to allow extraction, potential cooperation with restorative or orthodontic treatment and likely future preventative practice within the family. Moreover, the presence of any underlying malocclusion also needs to be evaluated within the context of extraction planning. The current available evidence has been evaluated and awarded a grade based upon those recommended by the Scottish Intercollegiate Guidelines Network. PMID:25476643

  4. Medical image registration with partial data

    Microsoft Academic Search

    Senthil Periaswamy; Hany Farid

    2006-01-01

    We have developed a general-purpose registration algorithm for medical images and volumes. The transformation between images is modeled as locally affine but globally smooth, and explicitly accounts for local and global variations in image intensities. An explicit model of missing data is also incorporated, allowing us to simultaneously segment and register images with partial or missing data. The algorithm is

  5. Partial tooth gear bearings

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2010-01-01

    A partial gear bearing including an upper half, comprising peak partial teeth, and a lower, or bottom, half, comprising valley partial teeth. The upper half also has an integrated roller section between each of the peak partial teeth with a radius equal to the gear pitch radius of the radially outwardly extending peak partial teeth. Conversely, the lower half has an integrated roller section between each of the valley half teeth with a radius also equal to the gear pitch radius of the peak partial teeth. The valley partial teeth extend radially inwardly from its roller section. The peak and valley partial teeth are exactly out of phase with each other, as are the roller sections of the upper and lower halves. Essentially, the end roller bearing of the typical gear bearing has been integrated into the normal gear tooth pattern.

  6. Non Syndromic Bilateral Microdontia of Maxillary Second Molars: A Very Rare Finding

    PubMed Central

    Chander, Subhash; Ahluwalia, Amrit Singh; Chinna, Harleen

    2015-01-01

    Dental anomalies are the formative defects caused by genetic disturbances or environmental factors during tooth morphogenesis. The term microdontia is defined as the condition of having abnormally small teeth. Clinically, microdontia in the permanent dentition, excluding the third molars, is found in 0.8-8.4% of the population. One of the commonest forms of localized microdontia is that which affects the maxillary lateral incisor, a condition called Peg laterals. The next tooth which can be affected is the third molars. Few cases of microdontia in canines have been reported. Localised microdontia of maxillary second molar has never been reported in literature before. PMID:26023663

  7. Endodontic Management of Maxillary First Molar with Type I Canal Configuration– A Rare Case Report

    PubMed Central

    Desai, Niranjan; Raghavendra, Srinidhi Surya; Mittal, Priya; Patil, Gururaj

    2015-01-01

    Thorough knowledge about the root canal variations is essential for the predictable endodontic treatment outcome. The root and root canal anatomy of maxillary first molar varies greatly. A Pub-med literature search about single rooted single canalled maxillary first molar was done to know its details such as incidence, diagnostic method used, age, sex and ethnic background of patient. This article presented report of a single rooted single canalled maxillary first molar in a 27-year-old healthy Asian female. PMID:26023655

  8. Non syndromic bilateral microdontia of maxillary second molars: a very rare finding.

    PubMed

    Hans, Manoj Kumar; Chander, Subhash; Ahluwalia, Amrit Singh; Chinna, Harleen

    2015-04-01

    Dental anomalies are the formative defects caused by genetic disturbances or environmental factors during tooth morphogenesis. The term microdontia is defined as the condition of having abnormally small teeth. Clinically, microdontia in the permanent dentition, excluding the third molars, is found in 0.8-8.4% of the population. One of the commonest forms of localized microdontia is that which affects the maxillary lateral incisor, a condition called Peg laterals. The next tooth which can be affected is the third molars. Few cases of microdontia in canines have been reported. Localised microdontia of maxillary second molar has never been reported in literature before. PMID:26023663

  9. Endodontic management of maxillary first molar with type I canal configuration- a rare case report.

    PubMed

    Desai, Niranjan; Jadhav, Ganesh Ranganath; Raghavendra, Srinidhi Surya; Mittal, Priya; Patil, Gururaj

    2015-04-01

    Thorough knowledge about the root canal variations is essential for the predictable endodontic treatment outcome. The root and root canal anatomy of maxillary first molar varies greatly. A Pub-med literature search about single rooted single canalled maxillary first molar was done to know its details such as incidence, diagnostic method used, age, sex and ethnic background of patient. This article presented report of a single rooted single canalled maxillary first molar in a 27-year-old healthy Asian female. PMID:26023655

  10. Age at first molar emergence in early Miocene Afropithecus turkanensis and life-history evolution in the Hominoidea

    Microsoft Academic Search

    Jay Kelley; Tanya M. Smith

    2003-01-01

    Among primates, age at first molar emergence is correlated with a variety of life history traits. Age at first molar emergence can therefore be used to broadly infer the life histories of fossil primate species. One method of determining age at first molar emergence is to determine the age at death of fossil individuals that were in the process of

  11. 40 CFR 1065.642 - SSV, CFV, and PDP molar flow rate calculations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...use its respective mean C d and other constants you determined according to § 1065.640 and calculate its molar flow rate n...venturis, you may use its respective mean, K v , and other constants you determined...

  12. Influence of the carrier gas molar mass on the particle formation in a vapor phase.

    PubMed

    Braun, S; Römer, F; Kraska, T

    2009-08-14

    The influence of the molar mass of a carrier gas on the formation of nanoparticles in the vapor phase is investigated. The function of the carrier gas atmosphere is the regulation of the particle temperature by collisions with the cluster surface. The aim of this work is to optimize the carrier gas in a simulation in order to mimic a large amount of carrier gas atoms by few gas atoms with effective parameters. In this context the efficiency of the heat exchange with the carrier gas depending on its molar mass is analyzed. As a result one finds for varying molar masses and unchanged interaction parameters a competition between the efficiency and the number of the collisions. For too small molar masses the energy exchange per collision is too small while for too high masses the carrier gas atoms become very slow, decreasing the number of collisions. PMID:19691389

  13. 40 CFR 1065.642 - SSV, CFV, and PDP molar flow rate calculations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...s (c) CFV molar flow rate. Some CFV flow meters consist of a single venturi and some consist of multiple venturis, where different combinations of venturis are used to meter different flow rates. If you use multiple venturis and...

  14. 40 CFR 1065.642 - SSV, CFV, and PDP molar flow rate calculations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...s (c) CFV molar flow rate. Some CFV flow meters consist of a single venturi and some consist of multiple venturis, where different combinations of venturis are used to meter different flow rates. If you use multiple venturis and...

  15. Accidental Displacement of Third Molar into the Sublingual Space: a Case Report

    PubMed Central

    Garcia, Robson Rodrigues; Botelho, Tessa Lucena; Franco, Ademir; Silva, Rhonan Ferreira

    2014-01-01

    ABSTRACT Background Successful extraction of third molars depends on preoperative diagnosis and planning. Gold standard preoperative examinations are performed through computed tomography, decreasing risks and avoiding potential accidents. The present report highlights the value of preoperative examinations in face of accidentally displaced third molars. Methods An 18-years-old female patient underwent a third mandibular molar extraction with a general dentist. Accidentally, the mandibular left third molar was displaced into the sublingual space, making necessary a second surgical step. The surgery was interrupted and the patient was referred to an expert in maxillofacial surgery. Results After 21 days awaiting an asymptomatic health status, the second surgical step was successfully performed using multislice computed tomography as preoperative imaging guide. Conclusions The present case report highlights the clinical usefulness of imaging planning and informed consents in face of legal and ethic potential complaints. PMID:25386232

  16. How Many Digits Should We Use in Formula or Molar Mass Calculations?

    ERIC Educational Resources Information Center

    Svensson, Christer

    2004-01-01

    The calculations of uncertainties in the formula or molar masses of compounds are streamlined. Three rules of increasing complexity are proposed, which overestimate the uncertainty so there is little if any risk that the true values are missed.

  17. Identification of a nonsense mutation in the PAX9 gene in molar oligodontia.

    PubMed

    Nieminen, P; Arte, S; Tanner, D; Paulin, L; Alaluusua, S; Thesleff, I; Pirinen, S

    2001-10-01

    Development of dentition is controlled by numerous genes, as has been shown by experimental animal studies and mutations that have been identified by genetic studies in man. Here we report a nonsense mutation in the PAX9 gene that is associated with molar tooth agenesis in a Finnish family. The A340T transversion creates a stop codon at lysine 114, and truncates the coded PAX9 protein at the end of the DNA-binding paired-box. All the affected members of the family were heterozygous for the mutation. The tooth agenesis phenotype involves all permanent second and third molars and most of the first molars and resembles the earlier reported phenotype that was also associated with a PAX9 mutation. The phenotype is presumably a consequence of haploinsufficiency of PAX9. In another Finnish family with molar tooth agenesis, we could not find similar sequence changes in PAX9. PMID:11781684

  18. Influence of the carrier gas molar mass on the particle formation in a vapor phase

    NASA Astrophysics Data System (ADS)

    Braun, S.; Römer, F.; Kraska, T.

    2009-08-01

    The influence of the molar mass of a carrier gas on the formation of nanoparticles in the vapor phase is investigated. The function of the carrier gas atmosphere is the regulation of the particle temperature by collisions with the cluster surface. The aim of this work is to optimize the carrier gas in a simulation in order to mimic a large amount of carrier gas atoms by few gas atoms with effective parameters. In this context the efficiency of the heat exchange with the carrier gas depending on its molar mass is analyzed. As a result one finds for varying molar masses and unchanged interaction parameters a competition between the efficiency and the number of the collisions. For too small molar masses the energy exchange per collision is too small while for too high masses the carrier gas atoms become very slow, decreasing the number of collisions.

  19. A geometric morphometric analysis of hominin lower molars: Evolutionary implications and overview of postcanine dental variation.

    PubMed

    Gómez-Robles, Aida; Bermúdez de Castro, José María; Martinón-Torres, María; Prado-Simón, Leyre; Arsuaga, Juan Luis

    2015-05-01

    Lower molars have been extensively studied in the context of hominin evolution using classic and geometric morphometric analyses, 2D and 3D approaches, evaluations of the external (outer enamel surface) and internal anatomy (dentine, pulp chamber, and radicular canals), and studies of the crown and root variation. In this study, we present a 2D geometric morphometric analysis of the crown anatomy of lower first, second, and third molars of a broad sample of hominins, including Pliocene and Lower, Middle, and Upper Pleistocene species coming from Africa, Asia, and Europe. We show that shape variability increases from first to second and third molars. While first molars tend to retain a relatively stable 5-cusped conformation throughout the hominin fossil record, second and third molars show marked distal reductions in later Homo species. This trend to distal reduction is similar to that observed in previous studies of premolars and upper second and third molars, and points to a correlated reduction of distal areas across the whole postcanine dentition. Results on lower molar variation, as well as on other postcanine teeth, show certain trends in European Pleistocene populations from the Atapuerca sites. Middle Pleistocene hominins from Sima de los Huesos show Neanderthal affinities and strong dental reduction, especially in the most distal molars. The degree of dental reduction in this population is stronger than that observed in classic Neanderthals. Homo antecessor hominins from Gran Dolina-TD6 have primitive lower teeth that contrast with their more derived upper teeth. The evolutionary implications of these dental affinities are discussed in light of recent paleogenetic studies. PMID:25840859

  20. Third molars in the establishment of adult status--a case report.

    PubMed

    Nambiar, P; Yaacob, H; Menon, R

    1996-12-01

    Teeth are the most durable structures in the human body. The timing and sequence of their development, as contained in dental development charts, have been used as valid criteria for age determination. The third molars however are the last teeth to erupt and are regarded as the most variable in the dentition. Age estimation in a legal context, using developing third molars must be carefully applied otherwise justice may miscarry. A case of wrongful use of the technique is presented here. PMID:9227080

  1. Standard molar enthalpy of formation of 4-iodobenzoic acid by static and rotating-bomb calorimetry

    Microsoft Academic Search

    M. A. V. Ribeiro da Silva; M. L. C. C. H. Ferrão; I. M. S. Costa

    1999-01-01

    The standard (po= 0.1 MPa) molar enthalpy of combustion of 4-iodobenzoic acid, at T= 298.15 K, was measured by static-bomb and rotating-bomb calorimetry, from which the standard molar enthalpy of formation, in the crystalline state, was derived.The values obtained confirm that 4-iodobenzoic acid is a satisfactory test substance for combustion of organo-iodine compounds. Using a literature value for its standard

  2. MOLAR: adaptive runtime support for high-end computing operating and runtime systems

    Microsoft Academic Search

    Christian Engelmann; Stephen L. Scott; David E. Bernholdt; Narasimha R. Gottumukkala; Chokchai Leangsuksun; Jyothish S. Varma; Chao Wang; Frank Mueller; Aniruddha G. Shet; Ponnuswamy Sadayappan

    2006-01-01

    http:\\/\\/www.fastos.org\\/molar ABSTRACT MOLAR is a multi-institutional research eort that con- centrates on adaptive, reliable, and ecient operating and runtime system (OS\\/R) solutions for ultra-scale, high-end scientific computing on the next generation of supercom- puters. This research addresses the challenges outlined in FAST-OS (forum to address scalable technology for runtime and operating systems) and HECRTF (high-end computing revitalization task force) activities

  3. Sinus augmentation at the time of molar tooth removal: modification of jensen technique.

    PubMed

    Block, Michael S

    2015-06-01

    When a maxillary molar tooth needs to be removed, the treatment plan often includes subsequent dental implant placement. However, there may be less than 5 mm of bone available in the central fossa region of the proposed implant site. This report describes a technique to use a precise osteotomy within the maxillary molar socket to mobilize a segment of bone and superiorly raise it to provide increased alveolar bone height using grafting. This technique eliminates the need for lateral window surgery. PMID:25659359

  4. Determination of the anti-inflammatory effects of methylprednisolone on the sequelae of third molar surgery

    Microsoft Academic Search

    Emin Esen; Ferda Ta?ar; Okan Akhan

    1999-01-01

    Purpose: The anti-inflammatory effect and adrenal suppressive side effect of methylprednisolone sodium succinate (MP) on the postoperative sequelae of third molar surgery were evaluated using objective methods in a double-blind, crossover study.Patients and Methods: Twenty patients who were to undergo surgical removal of bilateral, symmetrically placed lower third molars were studied. Each patient was given 125 mg MP intravenously before

  5. Investigation on the utility of permanent maxillary molar cusp areas for sex estimation

    Microsoft Academic Search

    P. James Macaluso Jr

    2011-01-01

    Digital photogrammetric methods were employed to assess the level of sexual dimorphism present in permanent maxillary molar\\u000a cusp areas of black South Africans (130 males, 105 females). Odontometric standards were then developed for diagnosing sex,\\u000a based on the cusp area data derived for these teeth. Results demonstrated that all cusp area measurements of both the first\\u000a and second maxillary molars

  6. Occlusal morphology of permanent mandibular first and second molars in Gujarati population

    PubMed Central

    Dholia, Bhavik; Manjunatha, Bhari Sharanesha

    2015-01-01

    Background: Dental identification has been used since long time for disaster victim identification protocol. There is a difference of opinion regarding whether ethnicity influences dental morphology or not. Few studies have shown the associations between these dental features and crown traits in humans using quantitative methods. The present study is an attempt to find correlation of occlusal morphology of Gujarati population with forensic Odontology. Aim: To study different occlusal morphology of permanent mandibular first and second molars in Gujarati Population. Materials and Methods: This study comprised of a total of 100 participants of Gujarati origin, selected by random sampling method. Total number of cusps and groove patterns of mandibular first and second molar were examined clinically and photographs of the same were taken. A descriptive statistics, Chi-square test and Student t-test were used for analysis of data. Results: Mandibular first molar with 5 cusps in 71%, 4 cusps in 18% and 6 cusps in 11% were noted in the study. Mandibular first molars with “+” groove pattern in 39.5% and “Y” groove pattern in 60.5% were recorded. Mandibular second molar with 5 cusps in 6.5% and 4 cusps in 93.5% were recorded in the study. Mandibular second molars with “+” groove pattern in 93.5% and “Y” groove pattern in 6.5% were recorded. Conclusion: The most common occlusal morphology in permanent mandibular first molar is “5 cusp” and “Y” groove pattern in about 47% and for second molar is “4 cusp” and “+” groove pattern in 88.5% of Gujarati population. It may be concluded that variation in degree of expression and frequency of teeth in dentitions of different populations is different, which may help in forensic identification. PMID:26005303

  7. Yeast Genomic Library Genomic DNA Sau3AI partial digestion

    E-print Network

    Odorizzi, Greg

    Yeast Genomic Library Concept: Genomic DNA ­ Sau3AI partial digestion Vector DNA ­ BamHI full digestion partial Ligate and transform above products Vector Information: · use centromeric plasmid to avoid of the mcs Preparing Vector: 1) digest 3-4ug of library vector with BamHI for 2-4hrs in a total volume of 20

  8. Chiral and continuum extrapolation of partially quenched lattice results

    SciTech Connect

    C.R. Allton; W. Armour; D.B. Leinweber; A.W. Thomas; R.D. Young

    2005-04-01

    The vector meson mass is extracted from a large sample of partially quenched, two-flavor lattice QCD simulations. For the first time, discretization, finite-volume and partial quenching artifacts are treated in a unified chiral effective field theory analysis of the lattice simulation results.

  9. A novel chitin binding crayfish molar tooth protein with elasticity properties.

    PubMed

    Tynyakov, Jenny; Bentov, Shmuel; Abehsera, Shai; Khalaila, Isam; Manor, Rivka; Katzir Abilevich, Lihie; Weil, Simy; Aflalo, Eliahu D; Sagi, Amir

    2015-01-01

    The molar tooth of the crayfish Cherax quadricarinatus is part of the mandible, and is covered by a layer of apatite (calcium phosphate). This tooth sheds and is regenerated during each molting cycle together with the rest of the exoskeleton. We discovered that molar calcification occurs at the pre-molt stage, unlike calcification of the rest of the new exoskeleton. We further identified a novel molar protein from C. quadricarinatus and cloned its transcript from the molar-forming epithelium. We termed this protein Cq-M13. The temporal level of transcription of Cq-M13 in an NGS library of molar-forming epithelium at different molt stages coincides with the assembly and mineralization pattern of the molar tooth. The predicted protein was found to be related to the pro-resilin family of cuticular proteins. Functionally, in vivo silencing of the transcript caused molt cycle delay and a recombinant version of the protein was found to bind chitin and exhibited elastic properties. PMID:26010981

  10. A reliable method for evaluating upper molar distalization: Superimposition of three-dimensional digital models

    PubMed Central

    Nalcaci, Ruhi; Bicakci, Ali Altug; Ozturk, Firat; Babacan, Hasan

    2015-01-01

    Objective The aim of this study was to evaluate the reliability of measurements obtained after the superimposition of three-dimensional (3D) digital models by comparing them with those obtained from lateral cephalometric radiographs and photocopies of plaster models for the evaluation of upper molar distalization. Methods Data were collected from plaster models and lateral cephalometric radiographs of 20 Class II patients whose maxillary first molars were distalized with an intraoral distalizer. The posterior movements of the maxillary first molars were evaluated using lateral cephalometric radiographs (group CP), photocopies of plaster models (group PH), and digitized 3D models (group TD). Additionally, distalization and expansion of the other teeth and the degrees of molar rotation were measured in group PH and group TD and compared between the two groups. Results No significant difference was observed regarding the amount of molar distalization among the three groups. A comparison of the aforementioned parameters between group PH and group TD did not reveal any significant difference. Conclusions 3D digital models are reliable to assess the results of upper molar distalization and can be considered a valid alternative to conventional measurement methods. PMID:25798414

  11. Evaluation of radius of gyration and intrinsic viscosity molar mass dependence and stiffness of hyaluronan.

    PubMed

    Mendichi, Raniero; Soltés, Ladislav; Giacometti Schieroni, Alberto

    2003-01-01

    Nine hyaluronan (HA) samples were fractionated by size-exclusion chromatography, and molar mass (M), radius of gyration (Rg), and intrinsic viscosity ([eta]) were measured in 0.15 M NaCl at 37 degrees C by on-line multiangle light scattering and viscometer detectors. Using such method, we investigated the Rg and [eta] molar mass dependence for HA over a very wide range of molar masses: M ranging from 4 x 10(4) to 5.5 x 10(6) g/mol. The Rg and the [eta] molar mass dependence found for HA showed a meaningful difference. The Rg = f(M) power law was substantially linear in the whole range of molar masses explored with a constant slope of 0.6. In contrast, the [eta] = f(M) power law (Mark-Houwink-Sakurada plot) showed a marked curve shape, and a linear regression over the whole range of molar masses does not make sense. Also the persistence length (stiffness) for HA was estimated. The persistence length derived by using both the Odijk's model (7.5 nm from Rg vs M data) and the Bohdanecky's plot (6.8 nm from [eta] vs M data) were quite similar. These persistence length values are congruent with a semistiff conformation of HA macromolecules. PMID:14606912

  12. An in vitro assessment of type, position and incidence of isthmus in human permanent molars

    PubMed Central

    de LIMA, Fernando José Camello; MONTAGNER, Francisco; JACINTO, Rogério Castilho; AMBROSANO, Glaucia Maria Bovi; GOMES, Brenda Paula Figueiredo de Almeida

    2014-01-01

    Root canal anatomical complexities, such as isthmus, may limit the action of the endodontic instruments, irrigant solutions and intracanal medications, leading to endodontic treatment failure. Objectives This in vitro study assessed the type, position and incidence of isthmus in human permanent molars. Material and Methods One hundred and twenty eight upper and lower first and second permanent molars were analyzed. The roots were embedded in transparent resin, and then split at different distances from the apex (1.0-2.5-4.0-5.5-7.0 mm). Following the sample examination in stereomicroscope, the data were submitted to chi-square statistical test at a 5% significance level. Results The highest isthmus incidence was at 7.0 mm from the root apex in all samples, except the distal root of lower molars (at 5.5 mm). In upper and lower molars, type V (complete isthmus with a continuous opening between the two main root canals) was the most common classification of isthmus (28.8%). In the mesial root of first and second mandibular molars, type IV had the highest incidence (36% and 23.9%, respectively). Conclusion It was concluded that isthmus was widely found in flat roots, with a low percentage in areas close to the apex. In upper and lower molars, these structures were most frequently found at 7 mm from the apex. PMID:25141198

  13. Sharp mandibular bone irregularities after lower third molar extraction: Incidence, clinical features and risk factors

    PubMed Central

    Alves-Pereira, Daniela; Valmaseda-Castellón, Eduard; Laskin, Daniel M.; Berini-Aytés, Leonardo; Gay-Escoda, Cosme

    2013-01-01

    Objectives: The purpose of this study was to determine the incidence and clinical symptoms associated with sharp mandibular bone irregularities (SMBI) after lower third molar extraction and to identify possible risk factors for this complication. Study Design: A mixed study design was used. A retrospective cohort study of 1432 lower third molar extractions was done to determine the incidence of SMBI and a retrospective case-control study was done to determine potential demographic and etiologic factors by comparing those patients with postoperative SMBI with controls. Results: Twelve SMBI were found (0.84%). Age was the most important risk factor for this complication. The operated side and the presence of an associated radiolucent image were also significantly related to the development of mandibular bone irregularities. The depth of impaction of the tooth might also be an important factor since erupted or nearly erupted third molars were more frequent in the SMBI group. Conclusions: SMBI are a rare postoperative complication after lower third molar removal. Older patients having left side lower third molars removed are more likely to develop this problem. The treatment should be the removal of the irregularity when the patient is symptomatic. Key words:Third molar, postoperative complication, bone irregularities, age. PMID:23524429

  14. A Novel Chitin Binding Crayfish Molar Tooth Protein with Elasticity Properties

    PubMed Central

    Tynyakov, Jenny; Bentov, Shmuel; Abehsera, Shai; Khalaila, Isam; Manor, Rivka; Katzir Abilevich, Lihie; Weil, Simy; Aflalo, Eliahu D.; Sagi, Amir

    2015-01-01

    The molar tooth of the crayfish Cherax quadricarinatus is part of the mandible, and is covered by a layer of apatite (calcium phosphate). This tooth sheds and is regenerated during each molting cycle together with the rest of the exoskeleton. We discovered that molar calcification occurs at the pre-molt stage, unlike calcification of the rest of the new exoskeleton. We further identified a novel molar protein from C. quadricarinatus and cloned its transcript from the molar-forming epithelium. We termed this protein Cq-M13. The temporal level of transcription of Cq-M13 in an NGS library of molar-forming epithelium at different molt stages coincides with the assembly and mineralization pattern of the molar tooth. The predicted protein was found to be related to the pro-resilin family of cuticular proteins. Functionally, in vivo silencing of the transcript caused molt cycle delay and a recombinant version of the protein was found to bind chitin and exhibited elastic properties. PMID:26010981

  15. Implant-connected versus tooth-connected implant-supported partial dentures: 2-year clinical and radiographic comparative evaluation.

    PubMed

    Mostafa, Tamer Mohamed; El-Sheikh, Mohamed M; Abd El-Fattah, Fadel

    2015-01-01

    The purpose of this study was to clinically and radiographically compare implant-connected and tooth-connected implant-supported fixed-detachable mandibular partial dentures. Twenty partially edentulous patients (age range: 25 to 50 years) with mandibular Kennedy Class II configurations were equally divided into two groups receiving a three-unit, fixed-detachable, screw-retained partial denture. Group 1 comprised patients with unilateral missing mandibular molars and premolars. Two implants were placed at the mandibular first premolar and first molar areas. Group 2 comprised patients with missing mandibular molars and second premolars. An implant was placed at the mandibular first molar area, the first premolar was prepared, and a coping was cemented to the tooth with permanent cement. Each case was evaluated clinically and radiographically at baseline (partial denture insertion) and after 6, 12, and 24 months. Data were collected and statistically analyzed using repeated-measures one-way and two-way analysis of variance tests. There was no statistically significant difference between the two groups (P > .05). The implant-tooth-supported prosthesis provided an equally predictable treatment option compared to the totally implant-supported prosthesis in terms of implant survival and loss of marginal bone. PMID:25909533

  16. Partial Derivative Visualization Gallery

    NSDL National Science Digital Library

    Roberts, Lila F.

    2004-11-11

    This resource is a small gallery of demos for illustrating partial derivatives geometrically. These animations can be used by instructors in a classroom setting or by students to aid in acquiring a visualization background for partial derivatives. Two file formats, gif and QuickTime files are used for the animations which can be downloaded.

  17. Classification of partial discharges

    Microsoft Academic Search

    F. H. Kreuger; E. Gulski; A. Krivda

    1993-01-01

    For a long time, classification of partial discharges was performed by eye, by studying discharge patterns at the ellipse of an oscilloscope screen. The introduction of digital processing techniques allowed automation of the recognition procedure. These procedures are reported and applied to a number of actual HV constructions which suffer from partial discharges. The results of these tests show that

  18. Partially Linear Models

    Microsoft Academic Search

    Wolfgang Hardle; Hua LIang; Jiti Gao

    2000-01-01

    In the last ten years, there has been increasing interest and activity in the general area of partially linear regression smoothing in statistics. Many methods and techniques have been proposed and studied. This monograph hopes to bring an up-to-date presentation of the state of the art of partially linear regression techniques. The emphasis of this monograph is on methodologies rather

  19. Partial Oxidation of Methane

    Microsoft Academic Search

    R. Pitchai; K. Klier

    1986-01-01

    Partial oxidation is a widely used process to convert hydrocarbons and alcohols to valuable oxygen-containing chemicals. Although methane is the simplest hydrocarbon which gives formaldehyde and methanol as partial oxidation products, the direct utilization of these reactions for the manufacture of formaldehyde and methanol has remained extremely difficult. During the 1940s, two processes for the conversion of methane to formaldehyde

  20. Initial Clinical Experience With the Strut-Adjusted Volume Implant (SAVI) Breast Brachytherapy Device for Accelerated Partial-Breast Irradiation (APBI): First 100 Patients With More Than 1 Year of Follow-Up

    SciTech Connect

    Yashar, Catheryn M., E-mail: cyashar@ucsd.edu [Department of Radiation Oncology, University of California San Diego, La Jolla, CA (United States); Scanderbeg, Daniel [Department of Radiation Oncology, University of California San Diego, La Jolla, CA (United States); Kuske, Robert [Arizona Breast Cancer Specialists, Phoenix, AZ (United States); Wallace, Anne [Department of Surgery, University of California San Diego, La Jolla, CA (United States); Zannis, Victor [Breast Care Center of the Southwest, Phoenix, AZ (United States); Blair, Sarah [Department of Surgery, University of California San Diego, La Jolla, CA (United States); Grade, Emily; Swenson, Virginia H. [Arizona Oncology Services Foundation, Phoenix, AZ (United States); Quiet, Coral [Arizona Breast Cancer Specialists, Phoenix, AZ (United States)

    2011-07-01

    Purpose: The Strut-Adjusted Volume Implant (SAVI; Cianna Medical, Aliso Viejo, CA) is a multichannel single-entry brachytherapy device designed to allow dose modulation to minimize normal tissue dose while simultaneously maximizing target coverage. This is the first report on the initial 102 patients with nearly 2 years of median follow-up. Methods and Materials: One hundred two patients were treated at two institutions. Data were collected on eligibility and dosimetry and followed for toxicity and recurrence. Results: The median follow-up is 21 months. Overall dosimetry is outstanding (median percent of target volume receiving 90% of the prescription dose was 95.9%, volume of target receiving 150% of the prescription dose was 27.8 mL, and volume of target receiving 200% of the prescription dose was 14.0 cm{sup 3}). No devices were pulled prior to treatment completion. For patients with a skin bridge of less than 7 mm, the maximum median skin dose was 280 cGy (median percent of target volume receiving 90% of the prescription dose was 95.2%, volume of target receiving 150% of the prescription dose was 25.8 cm{sup 3} and volume of target receiving 200% of the prescription dose was 12.7 mL). For patients with both chest wall and skin of less than 7 mm, the maximum median lung dose was 205 cGy with simultaneous skin dose of 272 cGy. The rate of telangiectasia was 1.9%. Grade 1 hyperpigmentation developed in 10 patients (9.8%) and Grade 2 fibrosis in 2 patients (1.9%). There were 2 symptomatic seromas and 2 cases of asymptomatic fat necrosis (1.9%). Of the patients, 27% were not eligible for MammoSite balloon brachytherapy (Hologic, Inc., Marlborough, MA) and 5% were not eligible for any balloon brachytherapy. The recurrence rate was 1%. Conclusions: The SAVI appears to safely allow an increase in eligibility for APBI over balloon brachytherapy or three-dimensional conformal radiation, highlighting the outstanding device flexibility to maximize the target dose and minimize the normal tissue dose. The device was well tolerated by patients.

  1. Dose–volume analysis of radiotherapy for T1N0 invasive breast cancer treated by local excision and partial breast irradiation by low-dose-rate interstitial implant

    Microsoft Academic Search

    Brian D Lawenda; Alphonse G Taghian; Lisa A Kachnic; Hanaa Hamdi; Barbara L Smith; Michele A Gadd; Thomas Mauceri; Simon N Powell

    2003-01-01

    PurposeTo evaluate the toxicity of partial breast irradiation (RT) using escalating doses of low-dose-rate interstitial implant as the sole adjuvant local therapy for selected T1N0 breast cancer patients treated by wide local excision. The results of a European Organization for Research and Treatment of Cancer study have demonstrated a significant local control benefit using external beam RT to 65 Gy

  2. Morphologic and Demographic Predictors of Third Molar Agenesis: A Systematic Review and Meta-analysis.

    PubMed

    Carter, K; Worthington, S

    2015-07-01

    We aimed to consolidate all available data on worldwide third molar agenesis frequencies, with a particular emphasis on exploring the factors leading authors to find contradictory results for the demographic and morphologic predictors of this anomaly. A total of 12,376 studies were originally identified, then narrowed down to 1,312 for title/abstract screening. On the basis of our inclusion and exclusion criteria, we selected 92 studies, containing 100 effect sizes and 63,314 subjects, for systematic review and metaregression. The worldwide rate of agenesis was found to be 22.63% (95% confidence interval = 20.64% to 24.76%), although the estimates ranged from 5.32% to 56.0%. Our subgroup analyses revealed that women are 14% more likely than men to have agenesis of ?1 third molars and that maxillary agenesis was 36% more likely than mandibular agenesis in both sexes. Furthermore, we found that having agenesis of 1 or 2 molars was most common, while agenesis of 3 or 4 molars was least common. Finally, we found large differences among agenesis frequency depending on geographic region. This information is expected to be of use not only to clinicians and patients but also to policy makers, given the implications for third molar extraction protocols. PMID:25883107

  3. Gender Determination Using Diagonal Measurements of Maxillary Molar and Canine Teeth in Davangere Population

    PubMed Central

    Tarigoppula, Ratna Kumari V. N.; Kulkarni, Pavan G; BS, Anil

    2014-01-01

    Background: Mesiodistal and buccolingual measurements of the teeth have been the traditional means of determining gender which sometimes are difficult to measure. Aims and Objectives: To assess the degree of sexual dimorphism in upper permanent canines and first molars using diagonal diameters and to evaluate the applicability of diagonal measurements in sex determination. Materials and Methods: Mesiobuccal-distolingual (MBDL) and distobuccal-mesiolingual (DBML) measurements of the crown and cervix of maxillary canine and maxillary molar were taken using digital vernier callipers in 100 upper dental casts obtained from 50 males and 50 females of the age group of 17-25 y. Results: With step wise discriminant function analysis, results were statistically significant with males showing higher diagonal measurement values. The classification accuracy for males was 69% and in females was 73% with overall accuracy of 71%. Results showed that canines exhibited highest accuracy with cervical measurements being more dimorphic. MBDL measurements were found to be more reliable. Most dimorphicmeasurements included right molar cervical MBDL, left molar cervical MBDL followed by right and left molar crown MBDL. Conclusion: In cases of tooth rotations, crowding, certain fillings and attritions where traditional mesio-distal and bucco-lingual measurements are not applicable, diagonal measurements could be of help in predicting gender. PMID:25584308

  4. Cysts in Periradicular Region of Deciduous Molars in Mixed Dentition: Retrospective Study of Five Cases

    PubMed Central

    Chavan, Ankush; Wadde, Kavita; Dewalwar, Vishal

    2014-01-01

    ABSTRACT% The cyst in mixed dentition stage cause expansion of buccal cortex, displacement of teeth and may present as case of infection. The cyst in periradicular region of deciduous molar are of frequent occurrence. The differential diagnosis of this lesion is radicular cysts of deciduous molar: developmental or infammatory dentigerous cyst of corresponding unerupted premolar. After going through the available literature of radicular cyst of deciduous molars and dentigerous cysts of developing premolars in mixed dentition we studied the five cases of cyst in periradicular region of deciduous molars in mixed dentition retrospectively for the diagnostic dilemma of radicular cyst verses dentigerous cyst. In conclusion, we can set some criteria for the diagnosis which is particularly important for treatment and for conservation of developing premolar. How to cite this article: Manekar VS, Chavan A, Wadde K, Dewalwar V. Cysts in Periradicular Region of Deciduous Molars in Mixed Dentition: Retrospective Study of Five Cases. Int J Clin Pediatr Dent 2014;7(3):229-235. PMID:25709310

  5. Containing the cost of third-molar extractions: a dilemma for health insurance.

    PubMed Central

    Friedman, J W

    1983-01-01

    No known scientific studies support the extraction of third molars (wisdom teeth) to prevent future disease. Yet, third-molar surgery for this purpose has become so common that in at least one major U.S. health insurance plan, the cumulative cost exceeds that for every other kind of major surgery. Many third molars that are developing normally in adolescents are classified as impacted and removed before they erupt, a practice that results in large expenditures for unnecessary surgery. In addition, the difficulty of the extractions is frequently exaggerated, so that patients and insurance plans are overcharged. Third molar surgery is not without risk of iatrogenic injury. Fracture of the jaw, permanent numbness of the lip (paresthesia), and injury to other teeth may occur. This paper presents a mechanism for containing the cost of third-molar surgery by elimination of payment for nonessential extractions and of the related overcharges. Adoption of this policy by administrators of dental insurance plans would save millions of dollars each year, money that could be better used in providing care for more people with real dental disease. PMID:6611824

  6. Endodontic treatment of mandibular molars with atypical root canal anatomy: reports of 4 cases.

    PubMed

    Chauhan, Raju; Singh, Shweta

    2015-01-01

    The variations in root canal anatomy of multirooted teeth represent a continuous challenge to endodontic diagnosis and treatment. Although the most common configuration of mandibular molars is one containing 2 roots and 3 root canals, there are many different combinations. Very rarely, an additional third (supernumerary) root is seen. When it is located distolingually to the main distal root, this third root is called radix entomolaris (RE), and when it is located mesiobuccally to the mesial root, it is called radix paramolaris (RP). Variations of root canal systems need not always be in the form of extra roots or extra canals. Single roots with single canals can also occur. A general dentist should be aware of these unusual root canal morphologies in mandibular molars for the success of endodontic treatment. These case reports describe the root canal treatment of a case of RE in the mandibular first molar, 2 rare cases of RP (1 each in the mandibular first and second molars), and a mandibular second molar with a single root and root canal. PMID:25945768

  7. Studies of the chronological course of third molars eruption in a northern Chinese population.

    PubMed

    Guo, Yu-cheng; Yan, Chun-xia; Lin, Xing-wei; Zhou, Hong; Pan, Feng; Wei, Lai; Tang, Zheng; Liang, Feng; Chen, Teng

    2014-09-01

    Dental age estimation is of great importance for individual identification in forensic medicine and many other fields of study. Among them, tooth eruption is a parameter developmental morphology that can be determined by clinical examinations or by dental X-rays. The purpose of present research is to study the chronological course of third molars eruption in a Chinese population and compare that with other ethnic population for age estimation. A total of 1135 conventional orthopantomograms from 506 male and 629 female northern Chinese subjects aged between 11 and 26 years were analyzed. The eruption status of the third molars was assessed using the developmental stages described by Olze et al. Results showed that the third molars 18, 28, 38 and 48 in the stage A showed significant younger average age in males than in females. The Olze's stage A could be used as a reference stage to determine whether a male or female northern Chinese is likely to be equal or above age 16, with 99.6-100% and 97.4-98.1% of correct predictions, respectively. The stage D was found to be a useful marker for diagnosing age under 16 years, with 98.9-100% and 100% of correct predictions in males and females, respectively. There were some significant differences of the chronological course of the third molars eruption in different ethnic groups, which indicated that population-specific standards could enhance the accuracy of forensic age estimation based on third molar eruption. PMID:24907520

  8. Evc regulates a symmetrical response to Shh signaling in molar development.

    PubMed

    Nakatomi, M; Hovorakova, M; Gritli-Linde, A; Blair, H J; MacArthur, K; Peterka, M; Lesot, H; Peterkova, R; Ruiz-Perez, V L; Goodship, J A; Peters, H

    2013-03-01

    Tooth morphogenesis involves patterning through the activity of epithelial signaling centers that, among other molecules, secrete Sonic hedgehog (Shh). While it is known that Shh responding cells need intact primary cilia for signal transduction, the roles of individual cilia components for tooth morphogenesis are poorly understood. The clinical features of individuals with Ellis-van Creveld syndrome include various dental anomalies, and we show here that absence of the cilial protein Evc in mice causes various hypo- and hyperplasia defects during molar development. During first molar development, the response to Shh signaling is progressively lost in Evc-deficient embryos and, unexpectedly, the response consistently disappears in a buccal to lingual direction. The important role of Evc for establishing the buccal-lingual axis of the developing first molar is also supported by a displaced activity of the Wnt pathway in Evc mutants. The observed growth abnormalities eventually manifest in first molar microdontia, disruption of molar segmentation and symmetry, root fusions, and delayed differentiation. Analysis of our data indicates that both spatially and temporally disrupted activities of the Shh pathway are the primary cause for the variable dental anomalies seen in patients with Ellis-van Creveld syndrome or Weyers acrodental dysostosis. PMID:23315474

  9. The incidence of cysts and tumors associated with impacted third molars

    PubMed Central

    Vigneswaran, A. T.; Shilpa, S.

    2015-01-01

    Incidence of cysts and tumors associated with lower impacted third molars are very low prevalence, which might be because of the fact that most pathologies go unnoticed as many practitioners discard the erupted tissue after surgical removal of the impacted teeth rather than sending the tissue for histopathological examination. Our aim was to evaluate the patients who came for third molar surgical removal with due therapeutic prophylacis and an incidental finding. A proper study protocol both inclusion and exclusion criteria was strictly followed for all the cases, which were included in the study. The period of study was 6 years and the total number of cases assessed were 2778 patients out of which 70 cases reported pathology associated with the impacted third molars. Among 70 cases 61.4% were reported as cyst and tumors and 38.6% of the cases had chronic inflammatory reaction, including two cases with normal dental follicle. High incidence rate of pathology associated with third molar occurred between age group of 20 and 30 years older age groups showed very low incidence. Most common site of impaction was found to be left side of mandible and positions were vertical and distoangular impactions. Thus was male predominance in the younger groups. The examination is necessary whether the third molars impacted cases were symptomatic or asymptomatic PMID:26015725

  10. The chronological age estimation of third molar mineralization of Han population in southwestern China.

    PubMed

    Qing, Maofeng; Qiu, Lihua; Gao, Zhi; Bhandari, Kishor

    2014-05-01

    The purpose of the study was to estimate the chronology of third molar mineralization in Han population of southwestern China and find its unique characteristics so that it would provide a reference in several legal cases like forensic age estimation. The study used Demirjian's staging method to study 2192 orthopantomograms of 984 male and 1208 female subjects aged between 8 and 25 years. The statistical data was analyzed by Student's t test and ANOVA. The conclusions of the study are: (1) The chronological mineralization age of third molars of Han population in Southwestern China is similar to the Turkish and the Japanese, was earlier than the Austrian and Han of South China, but later than the Spanish. (2) The mineralization timing of the third molars between two sides in maxilla or mandible has no significant differences in the same gender group. (3) There is no significant difference in mineralization of third molars between male and female, except for tooth 48 in Demirjian's stage E. (4) The mineralization of third molar in maxilla is earlier than mandible. PMID:24794846

  11. Demirjian's method in the estimation of age: A study on human third molars

    PubMed Central

    Lewis, Amitha J.; Boaz, Karen; Nagesh, K. R; Srikant, N; Gupta, Neha; Nandita, K. P; Manaktala, Nidhi

    2015-01-01

    Aim: The primary aim of the following study is to estimate the chronological age based on the stages of third molar development following the eight stages (A to H) method of Demirjian et al. (along with two modifications-Orhan) and secondary aim is to compare third molar development with sex and age. Materials and Methods: The sample consisted of 115 orthopantomograms from South Indian subjects with known chronological age and gender. Multiple regression analysis was performed with chronological age as the dependable variable and third molar root development as independent variable. All the statistical analysis was performed using the SPSS 11.0 package (IBM ® Corporation). Results: Statistically no significant differences were found in third molar development between males and females. Depending on the available number of wisdom teeth in an individual, R2 varied for males from 0.21 to 0.48 and for females from 0.16 to 0.38. New equations were derived for estimating the chronological age. Conclusion: The chronological age of a South Indian individual between 14 and 22 years may be estimated based on the regression formulae. However, additional studies with a larger study population must be conducted to meet the need for population-based information on third molar development. PMID:26005306

  12. Partially coherent lensfree tomographic microscopy?

    PubMed Central

    Isikman, Serhan O.; Bishara, Waheb; Ozcan, Aydogan

    2012-01-01

    Optical sectioning of biological specimens provides detailed volumetric information regarding their internal structure. To provide a complementary approach to existing three-dimensional (3D) microscopy modalities, we have recently demonstrated lensfree optical tomography that offers high-throughput imaging within a compact and simple platform. In this approach, in-line holograms of objects at different angles of partially coherent illumination are recorded using a digital sensor-array, which enables computing pixel super-resolved tomographic images of the specimen. This imaging modality, which forms the focus of this review, offers micrometer-scale 3D resolution over large imaging volumes of, for example, 10–15 mm3, and can be assembled in light weight and compact architectures. Therefore, lensfree optical tomography might be particularly useful for lab-on-a-chip applications as well as for microscopy needs in resource-limited settings. PMID:22193016

  13. Polarization volume holograms in layers of polymethylmethacrylate with phenanthrenequinone

    NASA Astrophysics Data System (ADS)

    Marmysh, D. N.; Mahilny, U. V.

    2013-11-01

    Polarization volume holograms are recorded in the polymethylmethacrylate layers that contain phenanthrenequinone at a molar content of 2.5-3%. The effect of the polarization of recording beams on the kinetics of diffraction efficiency and properties of holograms is analyzed. Polarization hologram recording in the polymethylmethacrylate layers with phenanthrenequinone and a relatively high optical stability of the holograms are demonstrated.

  14. Tuning of magnetic properties in cobalt ferrite by varying Fe+2 and Co+2 molar ratios

    NASA Astrophysics Data System (ADS)

    Biswal, Dipti; Peeples, Brianna N.; Peeples, Caryn; Pradhan, Aswini K.

    2013-11-01

    Different grades of magnetic cobalt ferrite (CoFe2O4) nanoparticles were synthesized with various molar ratios of Fe+2 to Co+2 ions in the initial salt solutions by the co-precipitation method. The crystal structure and morphology of the nanoparticles are obtained from X-ray diffraction and transmission electron microscopy studies. Fourier transform infrared spectroscopy analysis exhibited the Fe-O stretching vibration ~540 cm-1, confirming the formation of metal oxide. The magnetic studies demonstrate that all of the nanoparticles are superparamagnetic at 300 K. The saturation magnetization and coercivity of the CoFe2O4 nanoparticles are affected by the molar ratios of Fe+2 to Co+2 ions. Among all the synthesized nanoparticles, the system with 75:25 molar ratio of Fe+2 to Co+2 ions with a particle size of 13 nm showed a high magnetization of 90 emu/g.

  15. Formation of polyelectrolyte complexes with diethylaminoethyl dextran: charge ratio and molar mass effect.

    PubMed

    Le Cerf, Didier; Pepin, Anne Sophie; Niang, Pape Momar; Cristea, Mariana; Karakasyan-Dia, Carole; Picton, Luc

    2014-11-26

    The formation of polyelectrolyte complexes (PECs) between carboxymethyl pullulan and DEAE Dextran, was investigated, in dilute solution, with emphasis on the effect of charge density (molar ratio or pH) and molar masses. Electrophoretic mobility measurements have evidenced that insoluble PECs (neutral electrophoretic mobility) occurs for charge ratio between 0.6 (excess of polycation) and 1 (stoichiometry usual value) according to the pH. This atypical result is explained by the inaccessibility of some permanent cationic charge when screened by pH dependant cationic ones (due to the Hoffman alkylation). Isothermal titration calorimetry (ITC) indicates an endothermic formation of PEC with a binding constant around 10(5) L mol(-1). Finally asymmetrical flow field flow fractionation coupled on line with static multi angle light scattering (AF4/MALS) evidences soluble PECs with very large average molar masses and size around 100 nm, in agreement with scrambled eggs multi-association between various polyelectrolyte chains. PMID:25256478

  16. Description, Nomenclature, and Mapping of a Novel Cerebello-Renal Syndrome with the Molar Tooth Malformation

    PubMed Central

    Valente, Enza Maria; Salpietro, Damiano Carmelo; Brancati, Francesco; Bertini, Enrico; Galluccio, Tiziana; Tortorella, Gaetano; Briuglia, Silvana; Dallapiccola, Bruno

    2003-01-01

    Cerebello-oculo-renal syndromes (CORSs) and Joubert syndrome (JS) are clinically and genetically heterogeneous autosomal recessive syndromes that share a complex neuroradiological malformation resembling a molar tooth on brain axial images, a condition referred to as “molar tooth on imaging” (MTI) or the “molar tooth sign.” The current literature on these syndromes is complex, with overlapping and incomplete phenotypes that complicate the selection of clinically homogeneous cases for genetic purposes. So far, only one locus (JBTS1 on 9q34) has been mapped, in two families with JS. Here, we describe a large consanguineous family with JS and nephronophthisis, representing a novel cerebello-renal phenotype. We have mapped this condition to the pericentromeric region of chromosome 11 and have named the locus “CORS2.” The acronym “CORS” is proposed for all loci associated with JS, CORSs, and related phenotypes sharing the MTI, because this neuroradiological sign seems to be the unifying feature of these clinically heterogeneous syndromes. PMID:12908130

  17. Iatrogenic mandibular fractures following removal of impacted third molars: an analysis of 130 cases.

    PubMed

    Ethunandan, M; Shanahan, D; Patel, M

    2012-02-01

    Immediate and late mandibular fractures are a rare complication of third molar removal. We analysed 130 cases of mandibular fractures following removal of impacted third molars reported in the literature, including four managed in the maxillofacial unit and identified potential risk factors. Its occurrence is likely to be multi-factorial, with age, gender, angulation, laterality, extent and degree of impaction and associated pathologies contributing to the risk of fracture. Postoperative fractures were more common than intra-operative fractures (2.7:1) and occurred most frequently in the second and third weeks (57%). A 'cracking' noise was the most frequent presentation (77%). Intra-operative fractures were more frequent among females (M:F - 1:1.3), and differed from postoperative fractures (M:F - 3.9:1). This study analyses the results, providing suggestions to minimise the risk and to manage a mandibular fracture following removal of a third molar. PMID:22361547

  18. Accessory Central Cusp in the Maxillary Second Primary Molars: A Rare Entity among the Rare

    PubMed Central

    Das, Monalisa

    2014-01-01

    ABSTRACT% Central accessory cusp in primary molars is an extremely rare condition which is due to abnormal proliferation and folding of inner enamel epithelium during morphodifferentiation stage of tooth development. The extension of the pulp in the cuspal area is often the reason for early involvement of pulp by the caries process. Therefore, early diagnosis and treatment planning is necessary to maintain the integrity of primary dental arch. This article reports such a case of central accessory cusps involving maxillary second primary molars. How to cite this article: Chandra B, Das M. Accessory Central Cusp in the Maxillary Second Primary Molars: A Rare Entity among the Rare. Int J Clin Pediatr Dent 2014;7(3):202-205. PMID:25709302

  19. An Evaluation of Pathologic Changes in the Follicle of Impacted Mandibular Third Molars

    PubMed Central

    Tambuwala, Aruna Azhar; Oswal, Rakesh Gulabchand; Desale, Rushikesh Suresh; Oswal, Nitin Prakash; Mall, Prashant Edwin; Sayed, Aatif Riyaz; Pujari, Aniket Tarachand

    2015-01-01

    Background: The purpose of this study was to evaluate the early pathologic changes in the follicular tissue of completely impacted mandibular third molar. Materials and Methods: 52 patients, between 18 and 52 years of age of which 25 were males and 27 were females, were selected. They had impacted mandibular third molars, which were indicated for extraction. After extraction, the follicle was sent for a histopathological evaluation to two different oral pathologists. Results: The results showed that 80.8% of the specimen had normal follicles. 11.5% specimen suggested cystic changes while 7.7% suggested infected follicle. Conclusion: It is desirable to consider prophylactic removal of impacted mandibular third molar presenting at a younger age, whereas their removal remains an enigma for the older age group and should only be considered appropriate in those cases where frank causes for its removal are established. PMID:25954073

  20. In vitro comparison of laser fluorescence performance with visual examination for detection of occlusal caries in permanent and primary molars

    Microsoft Academic Search

    Jonas A. Rodrigues; Michele B. Diniz; Érika B. Josgrilberg; Rita C. L. Cordeiro

    2009-01-01

    The aim of this study was to compare the performance of the DIAGNOdent 2095 with visual examination for occlusal caries detection\\u000a in permanent and primary molars. The sample comprised 148 permanent human molars and 179 primary human molars. The samples\\u000a were measured and visually examined three times by two examiners. After measurement, the teeth were histologically prepared\\u000a and assessed for

  1. Radiographic assessment of third molars development and it's relation to dental and chronological age in an Iranian population

    PubMed Central

    Monirifard, Mohamad; Yaraghi, Navid; Vali, Ava; Vali, Asana; Vali, Amrita

    2015-01-01

    Background: The aim of the present study was to estimate chronological age based on third molar development and to determine the association between dental age and third molar calcification stages. Materials and Methods: In this cross-sectional study, 505 digital panoramic radiographs of 223 males (44.2%) and 282 females (55.8%) between the age of 6 and 17 were selected from patients who were treated in Departments of Pediatrics and Orthodontics of Isfahan University of Medical Sciences between the years of 2009 and 2013. Correlation between chronological age and third molar development was analyzed with SPSS 21 using Spearman's Rank correlation coefficient, Chi-square test and multiple regression statistical tests (P < 0.05). Results: All third molars demonstrated a highly significant correlation with dental age (P < 0.001). The teeth showing the highest relationship with dental age were mandibular left third molar in males and mandibular right third molar in females (rs = 0.072). When multiple regression was used to predict dental age based on molar calcification stage, the only significant correlation was between maxillary left third molar in males (P < 0.05). There was no statistically significant correlation for any of third molars in females. Relationship between chronological age and molars development stage was significant in all age subgroups and in both gender (P < 0.001). Conclusion: Strong correlation was observed between left third molars and dental age in males. Results showed that third molar calcification stage can be used as an age predictor and in general mandibular teeth seems to be more reliable for this purpose in both genders and in all ages. PMID:25709677

  2. Classification of impacted mandibular third molars on cone-beam CT images

    PubMed Central

    Maglione, Michele; Bazzocchi, Gabriele

    2015-01-01

    Background Neurological involvement is a serious complication associated to the surgical removal of impacted mandibular third molars and the radiological investigation is the first mandatory step to assess the risk of a possible post-operative injury to the inferior alveolar nerve (IAN). The aim of this study was to introduce a new radiological classification that could be normally used in clinical practice to assess the relationship between an impacted third molar and mandibular canal on cone beam CT (CBCT) images. Material and Methods CBCT images of 80 patients (133 mandibular third molars) were independently studied by three members of the surgical team to draw a classification that could describe all the possible relationships between third molar and IAN on the cross-sectional images. Subsequently, the study population was subdivided according to this classification. The SPSS software, version 15.0 (SPSS® Inc., Chicago, Illinois, USA) was used for the statistical analysis. Results Eight different classes were proposed (classes 0-7) and six of them (classes 1-6) were subdivided in two subtypes (subtypes A-B). The distribution of classes showed a prevalence of buccal or apical course of the mandibular canal followed by lingual position and inter-radicular one. No differences have resulted in terms of anatomic relationship between males and females apart from a higher risk of real contact without corticalization of the canal when the IAN had a lingual course for female group. Younger patients showed an increased rate of direct contact with a reduced calibre of the canal and/or without corticalization. Conclusions The use of this classification could be a valid support in clinical practice to obtain a common language among operators in order to define the possible relationships between an impacted third molar and the mandibular canal on CBCT images. Key words:CBCT, classification, inferior alveolar nerve, third molars.

  3. The influence of impaction on the rate of third molar mineralisation in male black Africans.

    PubMed

    Olze, Andreas; van Niekerk, Piet; Schulz, Ronald; Ribbecke, Sebastian; Schmeling, Andreas

    2012-11-01

    One of the main criteria used in dental age diagnostics in living adolescents and young adults is assessment of the mineralisation stage of the third molars. In the case of Europid populations, it has been established that impaction status has an influence on the rate of mineralisation of the third molars. In view of this, a study was undertaken to determine whether the chronological process of wisdom tooth mineralisation is dependent upon impaction status in black Africans too. Orthopantomograms (553) of 437 male and 116 female black South Africans with verified birth dates in the age group between 10 and 26 years were studied. Mineralisation stage and impaction status were determined for all third molars. Statistical measures were calculated for the mandibular wisdom teeth at stages F, G and H and for the maxillary wisdom teeth at stage H in the male gender for both impacted and non-impacted third molars. It was ascertained that the minimum age in persons with impacted third molars, depending on the wisdom tooth observed, was 0.19-2.57 years higher than in those with non-impacted wisdom teeth. Test persons with impacted mandibular wisdom teeth at stage F or G were on average between 0.32 and 1.88 years older than those with non-impacted mandibular wisdom teeth. The 50 % probability values of impacted wisdom teeth at stage H were 1.85-3.31 years higher than those in non-impacted wisdom teeth. The conclusion was drawn that in male black Africans, impacted mandibular wisdom teeth mineralise more slowly than non-impacted lower third molars. The presence of impacted mandibular wisdom teeth in mineralisation stage H in male black Africans does not, however, furnish proof of completion of the 18(th) year of life beyond reasonable doubt. PMID:22885908

  4. The distribution and ultrastructure of the forming blood capillaries and the effect of apoptosis on vascularization in mouse embryonic molar mesenchyme

    PubMed Central

    Yuan, Guohua; Zhang, Li; Yang, Guobin; Yang, Jingwen; Wan, Chunyan; Zhang, Lu; Song, Guangtai

    2014-01-01

    Vascularization is essential for organ and tissue development. Teeth develop through interactions between epithelium and mesenchyme. The developing capillaries in the enamel organ, the dental epithelial structure, occur simultaneously by mechanisms of vasculogenesis and angiogenesis at the onset of dentinogenesis. The vascular neoformation in the dental mesenchyme has been reported to start from the cap stage. However, the mechanisms of vascularization in the dental mesenchyme remain unknown. In the hope of understanding the mechanisms of the formation of dental mesenchymal vasculature, mouse lower molar germs from embryonic day (E) 13.5 to E16.5 were processed for immunostaining of CD31 and CD34, terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) and transmission electron microscopy (TEM). In addition, the role of apoptosis for the vascularization in dental mesenchyme was examined by in vitro culture of E14.0 lower molars in the presence of the apoptosis inhibitor (z-VAD-fmk) and a subsequent subrenal culture. Our results showed that CD31- and CD34-positive cells progressively entered the central part of the dental papilla from the peridental mesenchyme. For TEM, angioblasts, young capillaries with thick endothelium and endothelial cells containing vacuoles were observed in peripheral dental mesenchyme, suggesting vasculogenesis was taking place. The presence of lateral sprouting, cytoplasmic filopodia and transluminal bridges in the dental papilla suggested angiogenesis was also occurring. Inhibition of apoptosis delayed the angiogenic vascularization of the dental papilla. Therefore, these data demonstrated that molar mesenchyme is progressively vascularized by mechanisms of both vasculogenesis and angiogenesis and apoptosis partially contributes to the vascularization of the dental papilla. PMID:24477797

  5. Molar-Mass Characterization of Cationic Polymers for Gene Delivery by Aqueous Size-Exclusion Chromatography

    Microsoft Academic Search

    Xulin Jiang; Aschwin van der Horst; Mies J. van Steenbergen; Niels Akeroyd; Cornelus F. van Nostrum; Peter J. Schoenmakers; Wim E. Hennink

    2006-01-01

    \\u000a Purpose  This study was performed to develop a reliable aqueous size-exclusion chromatography (SEC) method to obtain the absolute molar\\u000a masses and distributions of various cationic polymers used in gene delivery.\\u000a \\u000a \\u000a \\u000a Methods  Water-soluble cationic [2-(dimethylamino) ethyl methacrylate] polymers (PDEs) with different molar masses and low polydispersities\\u000a were synthesized by living polymerization and these were used to optimize the SEC conditions. Online coupled multiangle

  6. The magnitude of a human bite measured exactly at the molar Intercuspidation using FBG

    NASA Astrophysics Data System (ADS)

    Marin, Gabriela Costa; Milczewski, Maura S.; Abe, Ilda; Lopes, Stephani C. P. S.; Camargo, Elisa S.; Kalinowski, Hypolito J.

    2014-05-01

    The aim of the study is to develop a new punctual method to determine the human bite force, between uppers and lowers first molars, at the moment of occlusion in maximum intercuspation. Fibre optic Bragg gratings are encapsulated in an acetate splint made by casting of a volunteer lower dentition. Splint sensor was positioned into the mouth to be pressured with minimal occlusal interference. The transversal pressure on the FBG was acquired at the moment of before occlusion (free), occlusion and biting. The measured forces were 12N during occlusion and 28N bite force, between right uppers and lowers first molars.

  7. Modified lingual split technique for extraction of impacted mandibular third molars.

    PubMed

    Lewis, J E

    1980-08-01

    Critical evaluation of existing chisel and bur techniques for removal of impacted mandibular third molars reveals a high incidence of complications. Both approaches require creation of a buccal defect immediately distal to the second molar for the insertion of an elevator, which may cause pocketing to occur postoperatively. The method described here minimizes periosteal reflection, almost completely avoids loss of bone, and effectively reduces the use of rotary instrumentation. The planning of the soft tissue flaps and bony cuts assists in primary wound closure, obliteration of dead space, and reduction of postoperative morbidity. PMID:6930459

  8. Upper molar distalization on palatal miniscrews: an easy to manage palatal appliance.

    PubMed

    Huanca Ghislanzoni, Luis Tomas; Piepoli, Claudio

    2012-05-01

    Upper molar distalization supported by miniscrews has become increasingly popular in the last years. A detailed clinical and lab procedure for the realization of a distalization appliance (fast back or distal jet) connected to miniscrews inserted in the anterior region of the palate is presented. A case report illustrates the use of a fast back appliance supported by miniscrews to correct the mesial shift of the molars and of the premolars as a consequence of an early loss of the maxillary deciduous canines. PMID:22583590

  9. Maxillary first molar with 8 root canals detected by CBCT scanning: a case report.

    PubMed

    Almeida, Gustavo; Machado, Ricardo; Sanches Cunha, Rodrigo; Vansan, Luiz Pascoal; Neelakantan, Prasanna

    2015-01-01

    Maxillary molars are prone to exhibit some of the most complex root canal configurations in endodontics. These complexities can result in diagnostic dilemmas, as well as management challenges. This case report illustrates how a cone beam computed tomography (CBCT) scan confirmed an unusual maxillary first molar with 3 root canals each in the mesiobuccal and distobuccal roots and 2 canals in the palatal root. This article illustrates how CBCT scanning and a dental operating microscope can facilitate a better understanding of complex root canal anatomies, ultimately allowing the dentist to clean, shape, and obturate root canal systems more efficiently. PMID:25734290

  10. The molar enthalpies of solution and vapour pressures of saturated aqueous solutions of some ammonium salts

    Microsoft Academic Search

    Alexander Apelblat; Eli Korin

    2003-01-01

    Vapour pressures of water over saturated solutions of ammonium bromide, ammonium dihydrogen phosphate, ammonium thiosulfate, ammonium persulfate, ammonium acetate, ammonium oxalate and ammonium tartrate were determined as a function of temperature. These vapour pressures were used to evaluate the water activities, osmotic coefficients and molar enthalpies of vaporization. Molar enthalpies of solution of ammonium bromide ?solHm(NH4Br, T=293.97K, m=0.1030mol·kg?1)=(17.4±0.5)kJ·mol?1; ammonium hydrogen

  11. The molar enthalpies of solution and vapour pressures of saturated aqueous solutions of some cesium salts

    Microsoft Academic Search

    Alexander Apelblat; Eli Korin

    2006-01-01

    Vapour pressures of water over saturated solutions of cesium chloride, cesium bromide, cesium nitrate, cesium sulfate, cesium formate, and cesium oxalate were determined as a function of temperature. These vapour pressures were used to evaluate the water activities, osmotic coefficients and molar enthalpies of vapourization. Molar enthalpies of solution of cesium chloride, ?solHm(T=295.73 K; m=0.0622 mol·kg?1)=(17.83±0.50) kJ·mol?1; cesium bromide, ?solHm(T=293.99

  12. Laparoscopic Partial Nephrectomy

    Microsoft Academic Search

    \\u000a Laparoscopic partial nephrectomy is an excellent management option for small, superficial renal masses. With experience, larger\\u000a and deeper tumors can be addressed as well. Intermediate-term follow-up (3- and 5-year) suggests cancer control similar to\\u000a that of open surgery. The benefit of laparoscopy over open surgery is a briefer and less intense convalescence. The disadvantage\\u000a of laparoscopic partial nephrectomy, at least

  13. 'Partial-Birth Abortion\\

    Microsoft Academic Search

    Samuel W. Calhoun

    2010-01-01

    In explaining his constitutional objection to Wisconsin’s partial-birth abortion ban, Judge Richard Posner contrasts killing during “normal labor” with partial-birth abortion. The former can be constitutionally prohibited, but the latter cannot. Why the distinction? For Posner, the former involves “killing a live baby that is half-born,” whereas the latter does not. This article will show that Judge Posner is correct

  14. Partial antibiotic decontamination.

    PubMed Central

    Guiot, H F; Furth, R

    1977-01-01

    Partial antibiotic decontamination and reverse isolation were carried out in nine patients undergoing bone marrow transplantation. The aim of this approach was to eradicate the patient's endogenous potentially pathogenic bacteria while preserving the anaerobic flora of the gut, which help to prevent recolonisation. No exogenous infections developed, and only one patient developed an infection associated with endogenous recolonisation. Colonisation resistance seemed normal in patients during partial antibiotic decontamination. This form of decontamination deserves further study in patients with immunodepression. PMID:322798

  15. Partially-Bent Functions

    Microsoft Academic Search

    Claude Carlet; A Rocquencourt

    1993-01-01

    We study a conjecture stated in [6] about the numbers of non-zeros of, respectively, the auto-correlation function and the Walsh transform of the function (-1)f(x), wheref(x) is any boolean function on {0, 1}n. The result that we obtain leads us to introduce the class of partially-bent functions. We study within these functions the propagation criterion. We characterize those partially-bent functions

  16. Partial Differential Equation Analysis in

    E-print Network

    Gilchrist, James F.

    Partial Differential Equation Analysis in Biomedical Engineering PartialDifferentialEquationAnalysisin BiomedicalEngineering Partial Differential Equation Analysis in Biomedical Engineering Case Studies in biomedical engineering. Taking an applied approach, rather than using abstract mathematics, the reader

  17. Endodontic management of a mandibular second molar with radix entomolaris: a case report.

    PubMed

    Hannah, Rosaline; Kandaswamy, Deivanayagam; Jayaprakash, Nachimuthu

    2014-05-01

    The presence of radix entomolaris (RE) in a mandibular first molar is a common occurrence in certain ethnic groups, but the presence of RE in a mandibular second molar is a rare occurrence. In the present case, RE was identified from preoperative radiographs and confirmed using cone-beam computed tomography (CBCT). The access cavity was modified to locate the RE. Cleaning and shaping were performed with nickel-titanium rotary instruments. Obturation was completed with gutta-percha cones using AH Plus (Dentsply Detrey GmbH) as sealer. From the CBCT axial images, the RE was determined to have a Type III curvature by the De Moor classification, Type B separate RE by the Carlsen and Alexandersen classification, and radiographically, a Type i image by the Wang classification. The presence of RE in the mandibular second molar makes it essential to anticipate and treat the distolingual root canal. This case report highlights the usefulness of CBCT for assessing RE in the mandibular second molar, which can help the clinician in making a confirmatory diagnosis and assessing the morphology of the root canal. PMID:24790927

  18. A familial case of recurrent hydatidiform molar pregnancies with biparental genomic contribution

    Microsoft Academic Search

    Mazen N. Helwani; Muhieddine Seoud; Laila Zahed; Ghazi Zaatari; Ali Khalil; Rima Slim

    1999-01-01

    Hydatidiform mole is a benign trophoblastic neoplasia characterized by an abnormal development of the embryo and proliferation of placental villi. Using microsatellite markers amplified by the polymerase chain reaction, we have performed a genetic study on eight independent molar tissues occurring in two sisters. Karyotype and genotype data demonstrate a diploid and biparental constitution in seven of the analyzed moles

  19. Cemento-osseous dysplasia-like lesion and complex odontoma associated with an impacted third molar.

    PubMed

    Prodromidis, Georgios I; Tosios, Konstantinos I; Koutlas, Ioannis G

    2011-12-01

    We present a case of a 36-year-old female with a benign fibro-osseous lesion consistent with cemento-osseous dysplasia (COD) that was located coronally to the crown of an impacted mandibular third molar tooth and was associated with a complex odontoma. The pathogenesis of this unusual association is discussed and the odontogenic origin of COD is suggested. PMID:21505851

  20. Femto-Molar Sensitive Field Effect Transistor Biosensors Based on Silicon Nanowires and

    E-print Network

    Dalang, Robert C.

    (SiNW- FETs) for high sensitive detection of vascular endothelial growth factor (VEGF) molecules. Si with VEGF monoclonal antibodies in order to sense VEGF. Increasing concentrations of VEGF in the femto molar with antibodies has been developed and used to sense vascular endothelial growth factor (VEGF). VEGF is a promoter

  1. Corrosion of a zinc rotating disk in one molar hydrochloric acid

    Microsoft Academic Search

    Hauser

    1984-01-01

    The corrosion of a zinc rotating disk in one molar hydrochloric acid has been studied using a potentiodynamic polarization method. Experimental rotating-disk data at a rotation speed of 1600 rpm are presented. The polarization curves are analyzed to determine the transfer coefficients and rate constants for the anodic zinc dissolution and cathodic hydrogen evolution reactions. A modified Butler-Volmer equation is

  2. Evaluation of root canal morphology of maxillary molars using cone beam computed tomography

    PubMed Central

    Alrahabi, Mothanna; Sohail Zafar, Muhammad

    2015-01-01

    Objectives: The success of endodontic treatment is based on cleaning and shaping of the root canals. The root canals have complex morphology and wide individual variations. The objective of this study was to analyze root canals morphology and existence of extra canals in maxillary molars in Saudi subpopulation. Methods: Freshly extracted maxillary first molars (n=100) were included in this study. All teeth were examined for morphology of roots, root canals and apical foramen by Cone Beam Computed Tomography (CBCT). The root canals configuration was classified using Vertucci’s classification. Results: The majority of maxillary first molars (94%) were having three distinctly separated roots and 6% had four roots. Palatal and distobuccal roots were observed to contain one root canal (100%) and Vertucci’s type I configuration. The mesiobuccal root had one (29.4%; type I) or two canals (70.6%; type II, III or IV). Conclusions: The occurrence of second canal in the mesiobuccal root of upper first molar is very much likely (>70%). The mesiobuccal roots are more likely to have Vertucci’s type I or II configuration (>76%). The palatal and distobuccal roots always have a Vertucci’s type I canal configuration.

  3. Temporomandibular joint loading generated during bilateral static bites at molars and premolars

    Microsoft Academic Search

    Makoto Abe; Raul U. Medina-Martinez; Ken-ichi Itoh; Shoji Kohno

    2006-01-01

    The aim of this study was to investigate the features of the loading vectors of the temporomandibular joint (TMJ) generated during bilateral static bites at the molars and at the premolars, and to determine the major factors affecting the difference between the two loading vectors. We computed the subjects’ estimated and theoretical minimum TMJ loadings under the two different bite

  4. Estimation of legal age using calcification stages of third molars in living individuals.

    PubMed

    Streckbein, Philipp; Reichert, Isabelle; Verhoff, Marcel A; Bödeker, Rolf-Hasso; Kähling, Christopher; Wilbrand, Jan-Falco; Schaaf, Heidrun; Howaldt, Hans-Peter; May, Andreas

    2014-12-01

    The increased number of adolescents and young adults with unknown or inaccurately given date of birth is a current issue in justice and legal medicine. The objective of this study was to determine the extent to which third molar calcification stages assessed on panoramic X-rays could be useful as additional criteria for forensic age estimation in living individuals, focusing on the legally important ages 17 and 18. In a retrospective multi-center study, the developmental stage of each individual's third molar was analyzed using Demirjian's scale in 2360 cases. Additionally, sex, age and ancestry were assessed. Individuals with the lowest calcification stage of all present molars in stage H were ?18 years with a likelihood of ?99.05% in the female (n=388), and ?99.24% in the male (n=482) population. The lowest calcification stage of all present third molars proved to be useful as an additional reliable criterion for the determination of an age ?18 years. PMID:25498932

  5. Molar Functional Relations and Clinical Behavior Analysis: Implications for Assessment and Treatment

    ERIC Educational Resources Information Center

    Waltz, Thomas J.; Follette, William C.

    2009-01-01

    The experimental analysis of behavior has identified several molar functional relations that are highly relevant to clinical behavior analysis. These include matching, discounting, momentum, and variability. Matching provides a broader analysis of how multiple sources of reinforcement influence how individuals choose to allocate their time and…

  6. Materials and techniques for restoration of primary molars by pediatric dentists in Florida

    Microsoft Academic Search

    Marcio Guelmann; Ivar A. Mjör

    2002-01-01

    Purpose: The purpose of this study was to obtain an overview of materials and tech- niques used by pediatric dentistry clinicians for posterior restorations in primary molars and to compare the results to what is being taught in dental schools. Methods: A form with questions in different formats was mailed to all 180 members of the American Academy of Pediatric

  7. Postoperative Analgesia in Impacted Third Molar Surgery: The Role of Preoperative Diclofenac Sodium, Paracetamol and Lornoxicam

    Microsoft Academic Search

    Aysegul Mine Tuzuner Oncul; Duygu Yazicioglu; Zekeriyya Alanoglu; Samimi Demiralp; Adnan Ozturk; Cahit Ucok

    2011-01-01

    Objective: The aim of this study was to compare the postoperative analgesic effects of preoperative intravenous (i.v.) paracetamol, diclofenac sodium and lornoxicam (nonsteroidal anti-inflammatory drugs). Subjects and Methods: Sixty patients with impacted third molar who underwent surgical removal were randomly allocated into three groups: group P (n = 20), group D (n = 20) and group L (n = 20).

  8. Distal movement of mandibular molars in adult patients with the skeletal anchorage system

    Microsoft Academic Search

    Junji Sugawara; Takayoshi Daimaruya; Mikako Umemori; Hiroshi Nagasaka; Ichiro Takahashi; Hiroshi Kawamura; Hideo Mitani

    2004-01-01

    The skeletal anchorage system (SAS) consists of titanium anchor plates and monocortical screws that are temporarily placed in either the maxilla or the mandible, or in both, as absolute orthodontic anchorage units. Distalization of the molars has been one of the most difficult biomechanical problems in traditional orthodontics, particularly in adults and in the mandible. However, it has now become

  9. Differential Evolvability Along Lines of Least Resistance of Upper and Lower Molars in Island House Mice

    PubMed Central

    Renaud, Sabrina; Pantalacci, Sophie; Auffray, Jean-Christophe

    2011-01-01

    Variation within a population is a key feature in evolution, because it can increase or impede response to selection, depending on whether or not the intrapopulational variance is correlated to the change under selection. Hence, main directions of genetic variance have been proposed to constitute “lines of least resistance to evolution” along which evolution would be facilitated. Yet, the screening of selection occurs at the phenotypic level, and the phenotypic variance is not only the product of the underlying genetic variance, but also of developmental processes. It is thus a key issue for interpreting short and long term evolutionary patterns to identify whether main directions of phenotypic variance indeed constitute direction of facilitated evolution, and whether this is favored by developmental processes preferably generating certain phenotypes. We tackled these questions by a morphometric quantification of the directions of variance, compared to the direction of evolution of the first upper and lower molars of wild continental and insular house mice. The main phenotypic variance indeed appeared as channeling evolution between populations. The upper molar emerged as highly evolvable, because a strong allometric component contributed to its variance. This allometric relationship drove a repeated but independent evolution of a peculiar upper molar shape whenever size increased. This repeated evolution, together with knowledge about the molar development, suggest that the main direction of phenotypic variance correspond here to a “line of least developmental resistance” along which evolution between population is channeled. PMID:21589657

  10. Complication rates in patients using absorbable collagen sponges in third molar extraction sockets: a retrospective study

    PubMed Central

    Cho, Hoon; Jung, Hwi-Dong; Kim, Bok-Joo; Kim, Chul-Hoon

    2015-01-01

    Objectives The purpose of this study is to retrospectively evaluate the postoperative complication rates for absorbable type-I collagen sponge (Ateloplug; Bioland) use in third molar extraction. Materials and Methods From January to August 2013, 2,697 total patients undergoing third molar extraction and type-I collagen sponge application in the Department of Oral and Maxillofacial Surgery at Yonsei University Dental Hospital (1,163 patients) and Dong-A University Hospital (1,534 patients) were evaluated in a retrospective study using their operation and medical records. Results A total of 3,869 third molars in 2,697 patients were extracted and the extraction sockets packed with type-I collagen sponges to prevent postoperative complications. As a result, the overall complication rate was 4.52%, with 3.00% experiencing surgical site infection (SSI), 1.14% showing alveolar osteitis, and 0.39% experiencing hematoma. Of the total number of complications, SSI accounted for more than a half at 66.29%. Conclusion Compared to previous studies, this study showed a relatively low incidence of complications. The use of type-I collagen sponges is recommended for the prevention of complications after third molar extraction. PMID:25741465

  11. [Dental health of first molars among Westphalian immigrants and German students].

    PubMed

    Heinrich-Weltzien, R; Walther, M; Goddon, I; Kühnisch, J

    2014-01-01

    The aim of this study was to assess the health status of the occlusal surface on the first molars of Westphalian students, of whom 41.0% were immigrants. The prevalence and retention of fissure sealants (FS) and caries experience was scored for 161 students aged 8 and 10 years. Logistic regression analysis was used to predict the influence of sex, ethnicity, and retention of FS on the occlusal caries risk of the first molars. There was no difference in caries prevalence and experience in 8-year-old German students and immigrants (5.6%/10.5%; 0.07 DMFT/0.21 DMFT), both parameters were significantly higher in 10-year-old immigrants than in German students (25.5%/9.5%; 0.55 DMFT/0.11 DMFT). The prevalence and number of molars with FS was not different between German students and immigrants at 8 years (39.1%, 1.28 FS; 33.8%, 0.94 FS) and at 10 years of age (47.4%, 1.68 FS; 39.4%, 1.17 FS). The occlusal caries risk of first molars without FS was significantly higher in 8-year-old immigrants than in German students (OR 4.62). FS should be used more frequently in daily dental practice. To improve the quality of FS, stricter implementation of guideline-based standards is required. PMID:24297452

  12. A combined endodontic retrofill and periodontal guided tissue regeneration technique for the repair of molar endodontic furcation perforations: report of a case.

    PubMed

    Duggins, L D; Clay, J R; Himel, V T; Dean, J W

    1994-02-01

    This is a report of a case in which the techniques of endodontic retrofill and guided tissue regeneration were used together to treat a perforation of the mesiofacial root of a maxillary left first molar (a strip perforation). After full-thickness flap reflection, the root received a retrograde filling and a large fenestration defect was surgically created to allow access to the furcal (distal) surface of the mesiofacial root. The roots were treated with tetracycline, the defect was filled with freeze-dried, demineralized, irradiated human cadaver bone, and the access fenestration was covered with a piece of barrier membrane. Healing was uneventful and the defect showed 100% bone fill at the time of reentry to retrieve the membrane 7 months after the initial surgery. Fifteen months after surgery the area appears clinically and radiographically healthy and the tooth has been employed as an abutment for a fixed partial denture. PMID:8183975

  13. Partially Pumped Random Lasers

    NASA Astrophysics Data System (ADS)

    Andreasen, Jonathan; Bachelard, Nicolas; Bhaktha, Shivakiran B. N.; Cao, Hui; Sebbah, Patrick; Vanneste, Christian

    2014-01-01

    Conventional lasers consist of two components: a gain material that is pumped in order to provide amplification of light and a cavity to provide feedback. Random lasers replace the traditional laser cavity with a random, multiple-scattering medium. This can give rise to complex lasing behavior, such as unpredictable multidirectional and multifrequency output. Controlling these systems has proved difficult and, until now, has consisted of material and structural manipulations. In random lasers, the most common pumping mechanism is an optical field, which can be applied uniformly or partially across the scattering medium. Partial pumping, referring to the restricted spatial extent of the pump applied to the gain material, is therefore quite ubiquitous in such systems. In contrast to conventional lasers, however, the impact of partial pumping can be significant in random lasers as a subset of the scattering medium is probed. In this review, we discuss state-of-the-art investigations of partially pumped random lasers. Numerical and experimental investigations of how even a simple spot profile of the pump can dramatically alter random laser output are presented. First, the simple case of partial pumping in strongly scattering systems where laser modes are spatially confined is described. Then the most common but more difficult case of weakly scattering random lasers is considered. Here, modes are spatially extended, forcing greater mode interaction and making the random laser output more difficult to predict. Finally, we review recent works that show how the pumping degree of freedom allows a general increase in control over random lasers.

  14. A histological and micro-CT investigation in to the effect of NGF and EGF on the periodontal, alveolar bone, root and pulpal healing of replanted molars in a rat model - a pilot study

    PubMed Central

    2014-01-01

    Background This study aims to investigate, utilising micro-computed tomography (micro-CT) and histology, whether the topical application of nerve growth factor (NGF) and/or epidermal growth factor (EGF) can enhance periodontal, alveolar bone, root and pulpal tissue regeneration while minimising the risk of pulpal necrosis, root resorption and ankylosis of replanted molars in a rat model. Methods Twelve four-week-old male Sprague-Dawley rats were divided into four groups: sham, collagen, EGF and NGF. The maxillary right first molar was elevated and replanted with or without a collagen membrane impregnated with either the growth factors EGF or NGF, or a saline solution. Four weeks after replantation, the animals were sacrificed and the posterior maxilla was assessed using histological and micro-CT analysis. The maxillary left first molar served as the control for the corresponding right first molar. Results Micro-CT analysis revealed a tendency for all replanted molars to have reduced root length, root volume, alveolar bone height and inter-radicular alveolar bone volume. It appears that the use of the collagen membrane had a negative effect while no positive effect was noted with the incorporation of EGF or NGF. Histologically, the incorporation of the collagen membrane was found to negatively affect pulpal, root, periodontal and alveolar bone healing with pulpal inflammation and hard tissue formation, extensive root resorption and alveolar bone fragmentation. The incorporation of EGF and NGF did not improve root, periodontal or alveolar bone healing. However, EGF was found to improve pulp vascularisation while NGF-improved pulpal architecture and cell organisation, although not to the level of the control group. Conclusions Results indicate a possible benefit on pulpal vascularisation and pulpal cell organisation following the incorporation of EGF and NGF, respectively, into the alveolar socket of replanted molars in the rat model. No potential benefit of EGF and NGF was detected in periodontal or root healing, while the use of a collagen membrane carrier was found to have a negative effect on the healing response. PMID:24393534

  15. Root Canal Morphology of Permanent Three-rooted Mandibular First Molars: Part II—Measurement of Root Canal Curvatures

    Microsoft Academic Search

    Yongchun Gu; Qun Lu; Ping Wang; Longxing Ni

    2010-01-01

    IntroductionThe distolingual (DL) roots of three-rooted mandibular molars often challenge clinicians during root canal therapy. This study investigated canal curvatures in permanent three-rooted mandibular first molars by using micro–computed tomography (micro-CT) scans.

  16. Analysis of stress in the periodontium of the maxillary first molar with a three-dimensional finite element model

    Microsoft Academic Search

    Peter D. Jeon; Patrick K. Turley; Hong B. Moon; Kang Ting

    1999-01-01

    The aim of this study was to simulate the stress response in the periodontium of the maxillary first molar to different moment to force ratios, and to determine the moment to force ratio for translational movement of the tooth by means of the finite element method. The three-dimensional finite element model of the maxillary first molar consisted of 3097 nodes

  17. Loss of molar occlusion and mandibular morphology in adults in an ancient human population consuming a coarse diet.

    PubMed

    Mays, Simon A

    2013-11-01

    The purpose of the study is to investigate the link between number of molar teeth retained in occlusion and mandibular morphology in adults in an ancient, high dental wear human population. The study material comprises skeletons from Mediaeval Wharram Percy, England (N = 50 female, 69 male adults). It was hypothesized that adults retaining fewer occluding molars would show reduction in mandibular dimensions, particularly in the ascending ramus and gonial regions where the main muscles of mastication have their insertions. Molar occlusal status is assessed using the concept of functional units. Mandibular morphology is assessed using a suite of ten linear measurements plus the mandibular angle. Results show no evidence for any association between number of molars retained in occlusion and mandibular angle. There was an association between mandibular size and number of molars retained in occlusion, with smaller mandibular dimensions in those retaining fewer occluding molars. Some measurements were affected more than others so that there was also some shape alteration. Alteration of mandibular dimensions was more clearly demonstrable in females than in males. Only in females could significant reduction in the ascending ramus and gonial regions be demonstrated. Reasons for the apparent difference in response to loss of molar occlusion between male and female mandibles are unclear, but sex differences in bony metabolism mediated by hormonal factors may be implicated. Results suggest that care should be exercised when including mandibles from individuals showing loss of molar occlusion in morphological studies. PMID:24104725

  18. Changes in the pattern of horseradish peroxidase diffusion into predentin and dentin after cavity preparation in rat molars

    Microsoft Academic Search

    Toshio Izumi; Hiroshi Inoue; Hiroshi Matsuura; Fumihiko Mukae; Hiromichi Osoegawa; Hirofumi Hirano; Naoharu Tamura

    2001-01-01

    Objective: The purpose of this study was to examine the process of reducing dentin permeability in adult rat molars after cavity preparation with horseradish peroxidase as a tracer. Study Design: Class V cavities were prepared on the upper first molars of 18 rats. Horseradish peroxidase was injected into the vascular system at intervals of 3 hours and 3, 5, 7,

  19. Estimation of band broadening in size-exclusion chromatography. I. A method based on analyzing narrow standards with a molar mass-sensitive detector.

    PubMed

    Yossen, Mariana M; Vega, Jorge R; Meira, Gregorio R

    2006-09-22

    A method is proposed for estimating the (asymmetrical and non-uniform) band broadening function (BBF) in size-exclusion chromatography (SEC). The following data are required: the molar mass calibration and the concentration- and molar mass chromatograms of a set of narrow standards. In the narrow range of each standard, the BBF is uniform but skewed. Each uniform BBF is estimated through a nonlinear optimization procedure that compares one (of the two) measured chromatograms with its theoretical prediction based on the other chromatogram. The method is validated with numerical examples that simulate the analyses of narrow standards exhibiting log-normal and Poisson weight chain length distributions. The BBF can be assumed of arbitrary shape, or represented by an exponentially-modified Gaussian (EMG). From the uniform BBF estimate, the true polydispersity of the standard can be determined. The global non-uniform BBF is obtained by interpolation between a set of uniform BBFs covering a wide range of elution volumes. PMID:16828786

  20. GENERAL: Low-temperature heat capacities and standard molar enthalpy of formation of 4-(2-aminoethyl)-phenol (C8H11NO)

    NASA Astrophysics Data System (ADS)

    Di, You-Ying; Kong, Yu-Xia; Yang, Wei-Wei; Tan, Zhi-Cheng

    2008-09-01

    This paper reports that low-temperature heat capacities of 4-(2-aminoethyl)-phenol (C8H11NO) are measured by a precision automated adiabatic calorimeter over the temperature range from 78 to 400 K. A polynomial equation of heat capacities as a function of the temperature was fitted by the least square method. Based on the fitted polynomial, the smoothed heat capacities and thermodynamic functions of the compound relative to the standard reference temperature 298.15 K were calculated and tabulated at the interval of 5 K. The energy equivalent, ?calor, of the oxygen-bomb combustion calorimeter has been determined from 0.68 g of NIST 39i benzoic acid to be ?calor = (14674.69±17.49)J.K-1. The constant-volume energy of combustion of the compound at T = 298.15 K was measured by a precision oxygen-bomb combustion calorimeter to be ?cU = -(32374.25±12.93)J.g-1. The standard molar enthalpy of combustion for the compound was calculated to be ?cHmominus = -(4445.47 ± 1.77) k. J · mol-1 according to the definition of enthalpy of combustion and other thermodynamic principles. Finally, the standard molar enthalpy of formation of the compound was derived to be ?fHmominus(C8H11NO, s) = -(274.68 ± 2.06) kJ · mol-1, in accordance with Hess law.

  1. Methanol partial oxidation reformer

    DOEpatents

    Ahmed, Shabbir (Bolingbrook, IL); Kumar, Romesh (Naperville, IL); Krumpelt, Michael (Naperville, IL)

    1999-01-01

    A partial oxidation reformer comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell.

  2. Methanol partial oxidation reformer

    DOEpatents

    Ahmed, S.; Kumar, R.; Krumpelt, M.

    1999-08-24

    A partial oxidation reformer is described comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell. 7 figs.

  3. Methanol partial oxidation reformer

    DOEpatents

    Ahmed, S.; Kumar, R.; Krumpelt, M.

    1999-08-17

    A partial oxidation reformer is described comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell. 7 figs.

  4. Methanol partial oxidation reformer

    DOEpatents

    Ahmed, Shabbir (Bolingbrook, IL); Kumar, Romesh (Naperville, IL); Krumpelt, Michael (Naperville, IL)

    2001-01-01

    A partial oxidation reformer comprising a longitudinally extending chamber having a methanol, water and an air inlet and an outlet. An igniter mechanism is near the inlets for igniting a mixture of methanol and air, while a partial oxidation catalyst in the chamber is spaced from the inlets and converts methanol and oxygen to carbon dioxide and hydrogen. Controlling the oxygen to methanol mole ratio provides continuous slightly exothermic partial oxidation reactions of methanol and air producing hydrogen gas. The liquid is preferably injected in droplets having diameters less than 100 micrometers. The reformer is useful in a propulsion system for a vehicle which supplies a hydrogen-containing gas to the negative electrode of a fuel cell.

  5. Partially strong WW scattering

    SciTech Connect

    Cheung Kingman [Department of Physics, National Tsing Hua University, Hsinchu, Taiwan (China); Physics Division, National Center for Theoretical Sciences, Hsinchu, Taiwan (China); Chiang Chengwei [Department of Physics and Center for Mathematics and Theoretical Physics, National Central University, Chung-Li, Taiwan (China); Institute of Physics, Academia Sinica, Taipei, Taiwan (China); Yuan Tzuchiang [Physics Division, National Center for Theoretical Sciences, Hsinchu, Taiwan (China); Institute of Physics, Academia Sinica, Taipei, Taiwan (China)

    2008-09-01

    What if only a light Higgs boson is discovered at the CERN LHC? Conventional wisdom tells us that the scattering of longitudinal weak gauge bosons would not grow strong at high energies. However, this is generally not true. In some composite models or general two-Higgs-doublet models, the presence of a light Higgs boson does not guarantee complete unitarization of the WW scattering. After partial unitarization by the light Higgs boson, the WW scattering becomes strongly interacting until it hits one or more heavier Higgs bosons or other strong dynamics. We analyze how LHC experiments can reveal this interesting possibility of partially strong WW scattering.

  6. Laparoscopic partial adrenalectomy

    Microsoft Academic Search

    T. Imai; Y. Tanaka; T. Kikumori; M. Ohiwa; N. Matsuura; T. Mase; H. Funahashi

    1999-01-01

    Background: Most laparoscopic adrenalectomies involve total removal of the whole adrenal gland, and reports of laparoscopic partial adrenalectomies\\u000a have been very few. The criteria for performing a laparoscopic partial adrenalectomy have not been described.\\u000a \\u000a \\u000a \\u000a \\u000a Methods: (a) Patients with functioning adrenal tumors smaller than 3 cm in diameter were selected. (b) The solitary adrenal tumors\\u000a were evaluated by preoperative thin-slice computed

  7. Partial gravity habitat study

    NASA Technical Reports Server (NTRS)

    Capps, Stephen; Lorandos, Jason; Akhidime, Eval; Bunch, Michael; Lund, Denise; Moore, Nathan; Murakawa, Kiosuke

    1989-01-01

    The purpose of this study is to investigate comprehensive design requirements associated with designing habitats for humans in a partial gravity environment, then to apply them to a lunar base design. Other potential sites for application include planetary surfaces such as Mars, variable-gravity research facilities, and a rotating spacecraft. Design requirements for partial gravity environments include locomotion changes in less than normal earth gravity; facility design issues, such as interior configuration, module diameter, and geometry; and volumetric requirements based on the previous as well as psychological issues involved in prolonged isolation. For application to a lunar base, it is necessary to study the exterior architecture and configuration to insure optimum circulation patterns while providing dual egress; radiation protection issues are addressed to provide a safe and healthy environment for the crew; and finally, the overall site is studied to locate all associated facilities in context with the habitat. Mission planning is not the purpose of this study; therefore, a Lockheed scenario is used as an outline for the lunar base application, which is then modified to meet the project needs. The goal of this report is to formulate facts on human reactions to partial gravity environments, derive design requirements based on these facts, and apply the requirements to a partial gravity situation which, for this study, was a lunar base.

  8. On Partially Sparse Recovery

    E-print Network

    2011-04-14

    Apr 14, 2011 ... applications in sparse quadratic polynomial interpolation. ... that m(z) has a representation in terms of ?1 and ?2 with ?1 a sparse vector ... of quadratic models [2] in interpolation-based trust-region methods for. Derivative-Free Optimization [8]. One of the key applications of partially sparse recovery is image

  9. The every partial denture

    Microsoft Academic Search

    Andrew Ganly

    1954-01-01

    HE Every denture may be described as a precision plastic partial upper denture, so designed that it is free of the immediate supporting tissues of the remaining teeth. It has no clasps or occlusal rests. Retention is obtained primarily by atmospheric pressure as in a ~ull denture, but through a modified peripheral seal. Secondarily, retention is obtained by the accuracy

  10. Generalized partial spreads

    Microsoft Academic Search

    Claude Carlet

    1995-01-01

    We exhibit a simple condition under which the sum (modulo 2) of characteristic functions of (n\\/2)-dimensional vector subspaces of (GF(2))n (n even) is a Bent function. The “Fourier” transform of such a Bent function is the sum of the characteristic functions of the duals of these spaces. The class of Bent functions that we obtain contains the whole partial spreads

  11. Partial Difference Triples

    Microsoft Academic Search

    Ka Hin Leung; Siu Lun Ma

    1993-01-01

    It is known that a strongly regular semi-Cayley graph (with respect to a group G) corresponds to a triple of subsets (C, D, D') of G. Such a triple (C, D, D') is called a partial difference triple. First, we study the case when D ? D' is contained in a proper normal subgroup of G. We basically determine all

  12. General Feed Forward Architectures: Volume 1: Theory

    E-print Network

    Peterson, James K

    General Feed Forward Architectures: Volume 1: Theory James K. Peterson Generated February 7, 2010: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2 Matrix Feed Forward Networks 17 2.1 Introduction: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 4 Partial Calculations in Generalized Chains: 43 5 Chained Feed Forward Architectures: 49 5

  13. Comparison of Buccal Infiltration of 4% Articaine With 1?:?100,000 and 1?:?200,000 Epinephrine for Extraction of Maxillary Third Molars With Pericoronitis: A Pilot Study

    PubMed Central

    Lima, José Lacet; Dias-Ribeiro, Eduardo; Ferreira-Rocha, Julierme; Soares, Ramon; Costa, Fábio Wildson Gurgel; Fan, Song; Sant'ana, Eduardo

    2013-01-01

    We compared the buccal infiltration of 4% articaine with 1?:?100,000 or 1?:?200,000 epinephrine without a palatal injection for the extraction of impacted maxillary third molars with chronic pericoronitis. This prospective, double-blind, controlled clinical trial involved 30 patients between the ages of 15 and 46 years who desired extraction of a partially impacted upper third molar with pericoronitis. Group 1 (15 patients) received 4% articaine with 1?:?100,000 epinephrine and group 2 (15 patients) received 4% articaine with 1?:?200,000 epinephrine by buccal infiltration. None of the patients in group 1 reported pain, but 3 patients in group 2 reported pain, which indicated a need for a supplementary palatal injection. The palatal injections were all successful in eliminating the pain. Two additional patients in group 2 experienced pain when the suture needle penetrated their palatal mucosa. Based on these results, 4% articaine with 1?:?100,000 epinephrine was found to be more effective for the removal of upper third molars in the presence of pericoronitis than 4% articaine hydrochloride with 1?:?200,000 epinephrine when only a buccal infiltration was used. PMID:23763558

  14. Furcation canals of the maxillary fourth premolar and the mandibular first molar teeth in cats.

    PubMed

    Negro, Viviana B; Hernández, Sabás Z; Maresca, Beatriz M; Lorenzo, Cesar E

    2004-03-01

    The furcation region morphology was evaluated in 103 mature feline carnassial teeth (54 maxillary fourth premolar and 49 mandibular first molar teeth). Patent furcation canals were present in 27.2% of teeth. No significant difference (p = 0.88) in distribution of this anatomical variation was found between maxillary fourth premolar and mandibular first molar teeth. The mean width of these furcation canals was 104.0 microns with two-thirds of the canals having a buccal orientation. The presence of furcation canals could be a factor in the etiopathogenesis of feline dental resorptive lesions, as well as a characteristic to be considered in the diagnosis, prognosis, and treatment of endodontic or periodontic-endodontic lesions in cat teeth. PMID:15108397

  15. Endodontic treatment of a mandibular first molar with 8 canals: a case report.

    PubMed

    Arora, Ankit; Acharya, Shashi Rashmi; Sharma, Padmaja

    2015-02-01

    Presented here is a case where 8 canals were located in a mandibular first molar. A patient with continuing pain in mandibular left first molar even after completion of biomechanical preparation was referred by a dentist. Following basic laws of the pulp chamber floor anatomy, 8 canals were located in three steps with 4 canals in each root. In both of the roots, 4 separate canals commenced which joined into two canals and exited as two separate foramina. At 6 mon follow-up visit, the tooth was found to be asymptomatic and revealed normal radiographic periapical area. The case stresses on the fact that understanding the laws of pulp chamber anatomy and complying with them while attempting to locate additional canals can prevent missing canals. PMID:25671216

  16. Antibiotic prophylaxis for third molar extraction in healthy patients: Current scientific evidence.

    PubMed

    Rodrigues, Willian Caetano; Okamoto, Roberta; Pellizzer, Eduardo Piza; dos Carrijo, Ana Cláudia Nazareno; de Almeida, Rafael Santiago; de Melo, Willian Morais

    2015-02-01

    Third molar extraction is one of the most frequently performed procedures in the dental clinic, and it is associated with innumerable trans- and postoperative complications, such as pain, trismus, edema, localized alveolar osteitis, and surgical site infection. Some authors advocate the use of local or systemic antibiotics to reduce the incidence of these postoperative complications. However, several studies have revealed an insignificant gain after using antibiotics. Despite the risks of allergic reactions, toxicity, and the development of resistant microorganisms, about 50% of dentists routinely prescribe the use of prophylactic antibiotics for this purpose. The goal of this paper is to evaluate the scientific evidence that justifies antibiotic prescription to healthy patients undergoing third molar extraction. PMID:25279397

  17. Degradation of high-molar-mass hyaluronan and characterization of fragments.

    PubMed

    Soltés, L; Kogan, G; Stankovska, M; Mendichi, R; Rychlý, J; Schiller, J; Gemeiner, P

    2007-09-01

    A sample of high-molar mass hyaluronan was oxidized by seven oxidative systems involving hydrogen peroxide, cupric chloride, ascorbic acid, and sodium hypochlorite in different concentrations and combinations. The process of the oxidative degradation of hyaluronan was monitored by rotational viscometry, while the fragments produced were investigated by size-exclusion chromatography, matrix-assisted laser desorption ionization-time-of-flight mass spectrometry, and non-isothermal chemiluminometry. The results obtained imply that the degradation of hyaluronan by these oxidative systems, some of which resemble the chemical combinations present in vivo in the inflamed joint, proceeds predominantly via hydroxyl radicals. The hyaluronan fragmentation occurred randomly and produced species with rather narrow and unimodal distribution of molar mass. Oxidative degradation not only reduces the molecular size of hyaluronan but also modifies its component monosaccharides, generating polymer fragments that may have properties substantially different from those of the original macromolecule. PMID:17691842

  18. Acute cervical artery dissection after a dental procedure due to a second inferior molar infection.

    PubMed

    Delgado, Montserrat G; Riesco, Nuria; Murias, Eduardo; Calleja, Sergio

    2015-01-01

    Periodontal infections might represent one of the causative factors for cervical artery dissection. We present a case of a 49-year-old woman admitted due to headache. The patient had been suffering from a right second inferior molar infection with a cervical phlegmon for 1?week prior to admission. On 2 October 2014, the patient went to the dentist and a molar extraction was performed in the morning. In the afternoon, the patient began to experience right hemifacial pain that progressed towards an intense and bilateral headache. Neurological status at the time of admission revealed right miosis, ptosis and conjuntival hyperaemia. A CT angiography showed a right internal carotid artery dissection provoking a high-degree stenosis. The relationship between periodontal infection and vascular disease has been previously presented. Microbial agents may directly, and inflammatory and immunological host response indirectly, influence inflammatory changes in cervical arteries favouring dissections with minor traumas. PMID:26038385

  19. Molar mass and temperature dependence of the thermodiffusion of polyethylene oxide in water/ethanol mixtures.

    PubMed

    Wang, Zilin; Afanasenkau, Dzmitry; Dong, Minjie; Huang, Danni; Wiegand, Simone

    2014-08-14

    In this work, we study the molar mass dependence of the thermodiffusion of polyethylene oxide at different temperatures in ethanol, water/ethanol mixture (c(water) = 0.7), and water in a molar mass range up to M(w) = 180,000 g/mol. Due to the low solubility of polyethylene oxide oligomers in ethanol the measurements are limited up to M(w) = 2200 g/mol. The specific water/ethanol concentration 0.7 has been chosen, because at this weight fraction the thermal diffusion coefficient, D(T), of water/ethanol vanishes so that the system can be treated as a pseudo binary mixture. The addition of ethanol will degrade the solvent quality, so that we expect a change of the interaction energies between polymer and solvent. The analysis of the experimental data within a theoretical model shows the need of a refined model, which takes specific interactions into account. PMID:25134596

  20. Mini-implant-borne Pendulum B appliance for maxillary molar distalisation: design and clinical procedure.

    PubMed

    Wilmes, Benedict; Katyal, Vandana; Drescher, Dieter

    2014-11-01

    A treatment objective of upper molar distalisation may often be required during the correction of a malocclusion. Distalisation is not only indicated for the management of Class II patients, but also for Class III surgery patients who require decompensation in the upper arch if upper incisor retrusion is needed. Unfortunately, most conventional intra-oral devices for non-compliance maxillary molar distalisation experience anchorage loss. A Pendulum type of appliance and a mini-implant-borne distalisation mechanism have been designed which can be inserted at chair-side, without a prior laboratory procedure and immediately after mini-implant placement. For re-activation purposes, a distal screw may be added to the Pendulum B appliance. PMID:25549527

  1. A quantitative investigation of irregular cuspules in human maxillary permanent molars.

    PubMed

    Kanazawa, E; Sekikawa, M; Ozaki, T

    1990-10-01

    The frequency of occurrence of anomalous cusps or tubercles on human upper first molars was investigated in seven racial populations using moiré contourography, which permits the three-dimensional measurement of minute cusps. Tubercles on the mesial marginal ridge were more frequently found in Mongoloid populations (Japanese and Eskimo) than in others. The frequency of the protoconule was high in Eskimos and Negroids (Bantu and San). The lingual paracone tubercle (mesial cusp) showed a particularly high frequency in Australian aborigines. The metaconule was rare or absent in all of the populations. Caucasoid groups (Dutch White and Asiatic Indian) showed generally low frequencies of all these abnormal tubercles, especially the distal accessory cusp (C5). Racial differences in the frequencies of occurrence may offer a key to understanding the adaptive significance of these traits and human microevolution. Confusion in nomenclature for upper molar tubercles is also discussed. PMID:2248376

  2. Endodontic Retreatment of a Mandibular Second Molar with four Separate Roots: A Case Report.

    PubMed

    Idris, Mohamed; Sakkir, Nasil; Kj, Nandakishore; Kini, Annapurna

    2014-03-01

    Aberrations in the root canal anatomy are a commonly occurring phenomenon. Although the mandibular second molar is commonly a bi-rooted tooth with an uncomplicated endodontic anatomy, variations have to be considered every time endodontic therapy is performed. This case report describes the non-surgical endodontic retreatment performed on a mandibular second molar with four seperate roots and canals. ProTaper Universal rotary nickel-titanium instruments (Dentsply Maillefer, Ballaigues, Switzerland) for treatment and retreatment were used to remove the old gutta percha and to clean and shape all root canals, followed by the complete obturation of root canal system. Post-operative CBCT scan was taken to confirm the quality of the performed treatment. PMID:24783160

  3. Severe impaction of the primary mandibular second molar accompanied by displacement of the permanent second premolar.

    PubMed

    Matsuyama, Junko; Kinoshita-Kawano, Shoko; Hayashi-Sakai, Sachiko; Mitomi, Tomoe; Sano-Asahito, Tomiko

    2015-01-01

    Tooth impaction is defined as any tooth that fails to erupt into a normal functional position and remains unerupted beyond the time at which it should normally erupt. Reports of impaction and eruption failure in primary teeth are relatively rare compared to permanent teeth. We report 2 rare cases where the second premolar was located on the occlusal side of the impacted mandibular second primary molar. In the first case, the succedaneous permanent tooth erupted after extraction of the primary tooth, fenestration, and traction. In the second case, the succedaneous permanent tooth erupted without fenestration or traction. Although the etiology of the tooth displacement was unknown in both cases, inhibition of the eruptive movement of the primary molar may have been associated with displacement of the succedaneous permanent premolar. PMID:25810929

  4. Polymer Reference Materials: Round-Robin Tests for the Determination of Molar Masses

    Microsoft Academic Search

    U. Just; S. Weidner; P. Kilz; T. Hofe

    2005-01-01

    This article reports round-robin tests dealing with static light scattering (LS), size exclusion chromatography (SEC), and viscometry measurements of 10 reference materials of various polymer classes: poly(styrene)s (PS), poly(methyl methacrylate)s (PMMA), poly(ethylene oxide)s (PEO), and poly(lactide)s (PLA).In the certificates, molar masses and intrinsic viscosities as well as their uncertainties are specified. Additional values from nuclear magnetic resonance (NMR), infrared spectroscopy

  5. Near-UV molar absorptivities of alachlor, mecroprop-p, pendimethalin, propanil and trifluralin in methanol

    Microsoft Academic Search

    Eneida Reyes Perez; Stéphane Le Calvé; Philippe Mirabel

    2008-01-01

    An experimental set-up consisting of two parallel absorption cells coupled to a CCD detector was used to determine absolute values of molar absorptivity coefficients ? of five herbicides (alachlor, mecoprop-p, pendimethalin, propanil and trifluralin) in methanol. The absorption spectra were measured using a deuterium lamp at room temperature (298±2K) over the wavelength range 240–340nm, except for pendimethalin and trifluralin where

  6. Antibiotics in third molar extraction; are they really necessary: A non-inferiority randomized controlled trial

    PubMed Central

    Arora, Ankit; Roychoudhury, Ajoy; Bhutia, Ongkila; Pandey, Sandeep; Singh, Surender; Das, Bimal K.

    2014-01-01

    Introduction: Antibiotic resistance is now a serious problem, although it was not so only a few years ago. The need of the hour is to give clear evidence of the efficacy of antibiotic use, or lack thereof, to the surgeon for a procedure as common as mandibular third molar surgery. Aim: This study aimed to evaluate whether postoperative combined amoxicillin and clavulanic acid in mandibular third molar extraction is effective in preventing inflammatory complications. Study and Design: The study was structured as a prospective randomized double-blind placebo-controlled clinical trial. Materials and Methods: A study was designed wherein the 96 units (two bilaterally similar impacted mandibular third molars per head in 48 patients) were randomly assigned to two treatment groups (Group I and Group II). Each patient served as his/her own control. Each patient received 625 mg of combined amoxicillin and clavulanic acid 1 h before surgery. In the case of third molars belonging to Group I, 625 mg of combined amoxicillin and clavulanic acid TDS was continued for 3 days; in Group II, placebo in similar-looking packs was continued for 3 days. The patients were evaluated on the third and seventh postoperative days for signs of clinical infection and for microbial load evaluation. Statistical Analysis: The data between the two groups were statistically analyzed by the two-tailed Fisher's exact test, with a 95% confidence interval. Results: The difference was not statistically significant between the test group and the control group with regard to erythema, dehiscence, swelling, pain, trismus, and infection based on microbial load. The data were statistically significant for alveolar osteitis, with the occurrence of alveolar osteitis (14.58%) in the placebo group. Conclusion: Postoperative antibiotics are recommended only for patients undergoing contaminated, long-duration surgery. PMID:25937728

  7. Administration of bisphosphonate (ibandronate) impedes molar tooth movement in rabbits: A radiographic assessment

    PubMed Central

    Venkataramana, V.; Kumar, S. Sathesh; Reddy, B. Vishnuvardhan; Cherukuri, A. Sreekanth; Sigamani, K. Raja; Chandrasekhar, G.

    2014-01-01

    Introduction: Bisphosphonate (Bp)-ibandronate is a pharmacological agent, exhibits antiosteoclastic or antiresorptive activity and used to treat osteolytic or osteopenic disorders. BP-ibandronate may also interfere during orthodontic tooth movement. The aim of this study was to examine the influence of locally administered Bp-ibandronate on experimental tooth movement in rabbits. Materials and Methods: Twenty rabbits were divided into two groups- “10” served as Group-1 (control) and other “10” as Group-2 (experimental). Both groups received nickel-titanium closed coil springs with 100 g force between mandibular molar and incisors. Group-1 animals received 1 ml normal saline and Group-2 animals received ibandronate solution (0.3 mg/kg body weight) locally, mesial to the mandibular molar on the 1st, 7th, and 14th day of the experiment. A total of “40” lateral cephalograms were taken from both groups on the 1st and 21st day using a digital X-ray unit (Siemens X-ray systems, 300 mA Pleomophos analog, 2008, Germany). Individually, each animal's radiograph was traced manually and superimposed. The molar tooth movement was measured with the help of a standard metric scale. Results: The Student's t-test has been done to compare the mean values of Group-1 (4.650 ± 0.363) and Group-2 (2.030 ± 0.291) and the difference was statistically significant (P < 0.001). Conclusion: The retarded molar tooth movement was noticed in local drug administered rabbits, which could be beneficial in orthodontics to control the undesired tooth movement. PMID:25210364

  8. Morphology of the enamel-dentine junction in sections of anthropoid primate maxillary molars

    Microsoft Academic Search

    Anthony J. Olejniczak; Christopher C. Gilbert; Lawrence B. Martin; Tanya M. Smith; Lilian Ulhaas; Frederick E. Grine

    2007-01-01

    The shape of the enamel-dentine junction (EDJ) in primate molars is regarded as a potential indicator of phylogenetic relatedness because it may be morphologically more conservative than the outer enamel surface (OES), and it may preserve vestigial features (e.g., cuspules, accessory ridges, and remnants of cingula) that are not manifest at the OES. Qualitative accounts of dentine-horn morphology occasionally appear

  9. Proliferation of rat molar pulp cells after direct pulp capping with dentine adhesive and calcium hydroxide

    Microsoft Academic Search

    Till Dammaschke; Udo Stratmann; Rudolf-Josef Fischer; Darius Sagheri; Edgar Schäfer

    2011-01-01

    The aim was to evaluate the proliferation of pulp cells 1, 3 and 7 days after direct pulp capping with the dentine adhesive\\u000a Gluma Comfort Bond (GCB) and to compare it with calcium hydroxide (Ca(OH)2). An occlusal cavity was prepared in 72 molar teeth of 36 Wistar rats. Then GCB or Ca(OH)2 was placed on the exposed pulp. All cavities were

  10. Parvalbumin and calretinin-immunoreactive trigeminal neurons innervating the rat molar tooth pulp

    Microsoft Academic Search

    Hiroyuki Ichikawa; Toru Deguchi; Tadao Nakago; David M. Jacobowitz; Tomosada Sugimoto

    1995-01-01

    Calcium-binding proteins and neuropeptides were examined in trigeminal neuronal cell bodies retrogradely labeled with Fast blue (FB) from the maxillary molar tooth pulp of the rat. FB-labeled cells were located in the maxillary division of the trigeminal ganglion. ? 30 and 50% of the labeled cells were immunoreactive for parvalbumin and calcitonin gene-related peptide (CGRP), respectively. The coexpression of these

  11. Fracture Resistance of Non-Metallic Molar Crowns Manufactured with CEREC 3D

    Microsoft Academic Search

    Dalia A. Madani

    2010-01-01

    Objectives. To compare fracture strength and fatigue resistance of ceramic (ProCAD, Ivoclar-Vivadent) (C) and resin composite (Paradigm MZ100, 3M\\/ ESPE) (R) crowns made with CEREC-3D. Methods. A prepared ivorine molar tooth was duplicated to produce 40 identical prepared specimens made of epoxy resin (Viade). Twenty (C) crowns and 20 (R) were cemented to their dies using resin cement. Ten of

  12. Guided tissue regeneration in the treatment of degree III furcation defects in maxillary molars.

    PubMed

    Pontoriero, R; Lindhe, J

    1995-10-01

    11 subjects with generalized periodontitis and advanced lesions in the maxillary molar regions, including bilateral mesial-distal, but not buccal, degree III furcation defects in the 1st and/or 2nd molars, were recruited for the present clinical trial. The patients were given oral hygiene instruction and full-mouth scaling and root planing. A re-examination was performed after 3 months of healing, after which the furcation involved molars were randomly selected for a GTR or conservative treatment modality. An informed consent form was signed by each participating patient. The GTR procedure involved the elevation of mucoperiostal flaps, root surface debridement, and the placement of an e-PFTE membrane at the 2 entrances of the furcation defect. The flaps were repositioned and secured. The contralateral molar was treated in an identical manner but without the placement of the teflon membrane. The patients received amoxicillin (1g x 2/day for 8 days), were placed on chlorhexidine mouth rinsing and were recalled for prophylaxis 1x every 2 weeks. The teflon membranes were removed at a 2nd stage procedure after 6 weeks. All subjects were re-examined 6 months after the regenerative procedure, and in addition, all sites were evaluated following a reentry procedure. The final examination and measurements made during the reentry procedure documented that, although some reduction in probing pocket depth and some gain in probing attachment had occurred at both test and control sites, none of the furcation defects had closed, but retained the characteristics of a degree-III furcation involvement. PMID:8682929

  13. Excess molar enthalpies of binary mixtures containing mono- and polybromoalkanes at 298.15 K

    SciTech Connect

    Blanco, S.T.; Munoz, J.; Velasco, I.; Otin, S. [Univ. de Zaragoza (Spain). Dept. de Quimica Organica y Quimica Fisica

    1995-05-01

    An isobaric and quasi-isothermic calorimeter has been used to determine excess molar enthalpies, H{sub m}{sup E}, at 298.15 K and atmospheric pressure for 10 binary mixtures containing dibromomethane, tribromomethane, 1,2-dibromoethane, 1,1,2,2-tetrabromoethane, and 1-bromopropane. H{sub m}{sup E} values for these mixtures are negative except for 1,2-dibromoethane or dibromomethane + 1-bromopropane and 1,1,2,2-tetrabromoethane + tribromomethane.

  14. Electrical Conductance of Fissure Enamel in Recently Erupted Molar Teeth as Related to Caries Status

    Microsoft Academic Search

    Y. L. Ie; E. H. A. M. Verdonschot; M. J. M. Schaeken; M. A. van’t Hof

    1995-01-01

    Pit-and-fissure caries lesions contribute greatly to the caries incidence in permanent molar teeth in children. To date, the diagnosis of occlusal caries is still performed mainly by visual inspection, periodically aided by bite-wing radiography. However, in detecting small occlusal carious lesions, these methods perform inadequately, especially in low caries prevalence populations or individuals. The use of electrical conductance measurements (ECMs)

  15. Bone sialoprotein-induced reparative dentinogenesis in the pulp of rat’s molar

    Microsoft Academic Search

    F. Decup; B. Palmier; D. Buch; J. J. Lasfargues; E Salih; M. Goldberg

    2000-01-01

    Bone sialoprotein (BSP), an osteogenic protein (OP), mixed with a carrier, was implanted in the pulp of rat first upper molars\\u000a (OP group). Cavities were prepared with dental burs and pulp perforation was carried out by pressure with the tip of a steel\\u000a probe. After 8, 14, and 30 days, the rats were killed and the pulps of the OP

  16. A scanning electron microscope study of vascular development in the dental papilla of prenatal rat molars

    Microsoft Academic Search

    Shigemitsu Yoshida

    1991-01-01

    Prenatal development of the vascular supply to the dental papilla was studied in the maxillary first molar teeth of rats from 18.5 to 22.0 days gestation, using the vascular casting\\/scanning electron microscope method. Five pulp horns developed in order, central, distal, mesial, disto-lingual and mesio-lingual with the development of the dental papilla. The first vessels that invaded each pulp horn

  17. Partially coherent ultrafast spectrography

    PubMed Central

    Bourassin-Bouchet, C.; Couprie, M.-E.

    2015-01-01

    Modern ultrafast metrology relies on the postulate that the pulse to be measured is fully coherent, that is, that it can be completely described by its spectrum and spectral phase. However, synthesizing fully coherent pulses is not always possible in practice, especially in the domain of emerging ultrashort X-ray sources where temporal metrology is strongly needed. Here we demonstrate how frequency-resolved optical gating (FROG), the first and one of the most widespread techniques for pulse characterization, can be adapted to measure partially coherent pulses even down to the attosecond timescale. No modification of experimental apparatuses is required; only the processing of the measurement changes. To do so, we take our inspiration from other branches of physics where partial coherence is routinely dealt with, such as quantum optics and coherent diffractive imaging. This will have important and immediate applications, such as enabling the measurement of X-ray free-electron laser pulses despite timing jitter. PMID:25744080

  18. Partially Strong WW Scattering

    E-print Network

    Kingman Cheung; Cheng-Wei Chiang; Tzu-Chiang Yuan

    2008-04-14

    What if only a light Higgs boson is discovered at the CERN LHC? Conventional wisdom tells us that the scattering of longitudinal weak gauge bosons would not grow strong at high energies. We show that this is not always true. In some composite models, two-Higgs-doublet models, or even supersymmetric models, the presence of a light Higgs boson does not guarantee the complete unitarization of the $WW$ scattering. After the partial unitarization by the light Higgs boson, the $WW$ scattering becomes strongly interacting until it hits one or more heavier Higgs bosons or other strong dynamics. We analyze how the LHC experiments can reveal this interesting possibility of partially strong $WW$ scattering.

  19. Partial and Total Differentiation

    Microsoft Academic Search

    Sudhir R. Ghorpade; Balmohan V. Limaye

    \\u000a The notion of derivative of a function of one-variable does not really have a solitary analogue for functions of several variables.\\u000a Indeed, for a function of two (or more) variables, there is a plethora of derivatives depending on whether we choose to become\\u000a partial to one of the variables, or opt to move about in a specific direction, or prefer

  20. Partial trisomy 21

    Microsoft Academic Search

    A. Hagemeijer; E. M. E. Smit

    1977-01-01

    Cytogenetic analysis of a 6-year-old girl with moderate mental retardation revealed 46 chromosomes with a tandem translocation (21;21) resulting in a partial trisomy 21. Only the terminal band 21q22 was not in triplicate. G-, Q-, R-, and C-banding techniques and silver nitrate staining of the nucleolus organizer regions (NORs) were used to identify this chromosome fully.

  1. Partially-Bent Functions

    Microsoft Academic Search

    Claude Carlet

    1992-01-01

    We study a conjecture stated in [6] about the numbers of non-zeros of, respectively, the auto-correlation function and the Walsh transform of the function (?1)\\u000a f(x), where f(x) is any boolean function on {0, 1}n. The result that we obtain leads us to introduce the class of partially-bent functions. We study within these functions the\\u000a propagation criterion. We characterize those

  2. Replantation of Displaced Underlying Successor and Marsupialization of Radicular Cyst associated with a Primary Molar

    PubMed Central

    Ravi, GR

    2015-01-01

    ABSTRACT Radicular cysts are by far the most common cystic lesions of the jaw. However, those arising from primary teeth are comparatively rare, comprising only 0.5 to 3.3%. The aim of this paper is to present clinical, radiographic and histopathological characteristics of radicular cyst associated with a primary mandibular molar causing unusual displacement of the permanent successor. Extraction of primary tooth along with extirpation of cyst was done under local anesthesia. The displaced premolar was also extracted and then replanted in the socket after proper alignment. Healing was uneventful and the space of missing primary molar was maintained by band and loop space maintainer. The relationship between intracanal medicaments and rapid growth of cyst, as mentioned in literature was observed in our case too. Thus, pulpotomy treated primary teeth should receive periodic postoperative radiographic examination and absence of clinical symptoms does not mean that a pulpotomy treated tooth is healthy. How to cite this article: Lamba G, Ravi GR. Replantation of Displaced Underlying Successor and Marsupialization of Radicular Cyst associated with a Primary Molar. Int J Clin Pediatr Dent 2015;8(1):70-74.

  3. Histopathological and radiographic evaluation of rat molar teeth after traumatic injury-a pilot study

    PubMed Central

    Prasanth, T; Saraswathi, TR

    2012-01-01

    Objective: Radiographic and histopathological evaluation of mechanical trauma on the development of maxillary molars in rat. Materials and Methods: Experimental study with 7-day-old five new born Wistar rats. Trauma induced on 7th postnatal day with #55 K file. Right first molar region of the maxilla was the experimental side, and the left side as control. Each animal was sacrificed for histopathological observation on 8th day (immediately next day of injury), 10th day (after 3 days of injury), 13th day (Enamel completion), 19th day (Emergence into oral cavity) and 42nd day when all the teeth came into functional occlusion. Results: On the 42nd day experimental side of the study, the 1st molar tooth had not erupted and the radiographs taken revealed conglomerate mass suggestive of complex odontome. Reduced tooth size, altered enamel and dentin formation, abscess formation and complex odontome like structure were observed histopathologically. Conclusion: The diversity of morphlogical and histopathological changes to intrusive force implies intricate mechanism involved in tooth development. PMID:23248457

  4. A new 3-d approach to determine functional morphology of cercopithecoid molars.

    PubMed

    Ulhaas, Lilian; Kullmer, Ottmar; Schrenk, Friedemann; Henke, Winfried

    2004-12-01

    Functional relationships between diet and tooth morphology form an integral part of primatological and paleontological research. Previously, mostly two-dimensional parameters have been used to compare and interpret the complex crown morphology of cercopithecine and colobine molars. However, as teeth are three-dimensional objects, any dimensional reduction in describing their morphology must result in loss of information. In the current study we use a high resolution optical topometric system to record crown morphology in different wear stages in order to extract three-dimensional (3-d) parameters from virtual 3-d models. Structural parameters such as relief index, occlusal surface area, enamel area and strike and dip of cusp slopes as well as wear facets can be calculated, reflecting the changing occlusal topography of molars due to attrition and abrasion. By comparing mostly fruit-eating cercopithecines and leaf-eating colobines, functional implications of tooth wear, occlusal jaw movement and resulting relief can be inferred. Our analyses show that the main differences in occlusal relief between these genera do not change with wear. Colobines maintain higher occlusal relief, whereas in cercopithecines all cusps wear flat quite rapidly. Detailed models of wear for cercopithecoid molars will be used to reconstruct diet and will enhance our knowledge of the paleoecology of Cercopithecoidea. PMID:15646282

  5. Articaine versus lidocaine for third molar surgery: A randomized clinical study

    PubMed Central

    Santos, Thiago-de-S; Santos, Jadson-A.; Maia, Marcelo-C; Mendonça, Carla-G

    2012-01-01

    Objective: Pain reduction has been the subject of continuous research in the field of oral and maxillofacial surgery since postoperative pain with ranging of intensity and duration may affects the patient submitted in an oral surgical procedure. The aim of present study was to compare the analgesic effectiveness between two different anesthetic solutions (articaine and lidocaine) in third molar surgery. Study Design: A prospective, randomized and clinical study with patients submitted to third molar surgery at two distinct times. The visual analogue scale, the McGill Pain Questionnaire and the analgesic consumption record were used to measure the pain after each surgical time. Results: Duration of surgery, latency, the amount of anesthetic used and analgesic consumption showed clinical differences with highlights of articaine, though statistical significance was not observed (P<0.05). The pain scores indicated similar anesthetic efficacy with both solutions. Conclusion: In the present study no significant differences were observed between lidocaine and articaine in the control of postoperative pain. Key words: Articaine, lidocaine, pain control, lower third molar. PMID:22157664

  6. Randomized Split-Mouth Study on Postoperative Effects of Palmitoylethanolamide for Impacted Lower Third Molar Surgery

    PubMed Central

    Bacci, Christian; Cassetta, Giulia; Emanuele, Bruno; Berengo, Mario

    2011-01-01

    The aim of this study was to assess the efficacy of Normast 300?mg in reducing swelling and pain after the surgical extraction of impacted lower third molars. Materials and Methods. A randomized, split-mouth, single-blind study was conducted on 30 patients between 18 and 30 years of age requiring lower third molar extraction. Patients underwent bilateral extractions in a randomized sequence, one extraction being performed under Normast treatment. The Normast treatment involved 2 tablets a day for 15 days. The parameters assessed at each procedure were trismus, swelling, pain, NSAID consumption, postoperative complications, drug tolerability, and safety. The results obtained were processed using repeated measures analysis of variance. Results. Perceived postoperative pain was reportedly significantly milder on Normast treatment than control. The trend of the means differed over time (P < .0001) and between the two extraction groups (P < .0221). On the other hand, for edema and trismus, the trend differed over time for both groups but did not differ between the two groups. Discussion. Our analyses indicate that patients experienced significantly less postoperative pain when they were treated with Normast. Conclusions. Administering Normast improves the postoperative course—in terms of pain—after lower third molar extraction. PMID:22084787

  7. Classifying stages of third molar development: crown length as a predictor for the mature root length.

    PubMed

    Altalie, Salem; Thevissen, Patrick; Willems, Guy

    2015-01-01

    Multiple tooth development staging techniques were reported based on arbitrarily set borderlines between succeeding stages. Anatomic tooth features or predictions of future tooth part dimensions were described to identify the thresholds between the established stages. The need to predict mature tooth dimensions, while the tooth considered is still in development, is a drawback to use this staging technique for dental age estimations. Using the fully mature crown length as a predictor for the future root length could provide a tool for undisputable staging. The aim of this study was first to measure the crown and root length of fully mature third molars and second to investigate whether the crown length could be used as a predictor of the root length, in order to classify the observed root length as a proportion of the future mature root. The crown and root lengths of all present third molars were digitally measured on dental panoramic radiographs of 1,000 subjects. The included subjects were equally distributed in gender, and their age ranged between 22 and 40 years. Two occlusal borders, the cement enamel junction and the root apices, were defined as landmarks for standardized measurements. Regression models with root length as response and crown length as predictor were established and revealed low R (2) and high RMSE values. Due to the small explained variance by the prediction models and the high variation in prediction errors, the observed crown length cannot be used to predict the final root length of a developing third molar. PMID:24801360

  8. Incidence, Management, and Outcome of Molar Pregnancies at a Tertiary Care Hospital in Quetta, Pakistan

    PubMed Central

    Fatima, Mahrukh; Kasi, Pashtoon Murtaza; Baloch, Shahnaz Naseer; Kassi, Masoom; Marri, Shah Muhammad; Kassi, Mahwash

    2011-01-01

    Molar pregnancies represent a significant burden of disease on the spectrum of gestational trophoblastic diseases. The incidence appears to be higher in women from South Asia. The purpose of our prospective study was to determine the incidence, presentation, and outcomes of all molar pregnancies at our institution. During the study period, there were a total of 16,625 patients admitted to our department; out of whom 85 patients were diagnosed with a molar pregnancy. Vaginal bleeding was the commonest symptom (94.2%); theca lutein cysts were noted in 39% of the cases. Suction, dilatation, and curettage were noted to be the preferred method in almost all cases; hysterectomy was done in 12 (14.1%) patients. Single-agent chemotherapy was employed in high-risk patients and was well tolerated. Mean followup for these patients was 5.7?months (range 1–24 months). None of these patients developed persistent trophoblastic disease, invasive mole, or choriocarcinoma during the follow-up period. PMID:22028979

  9. Incidence, management, and outcome of molar pregnancies at a tertiary care hospital in quetta, pakistan.

    PubMed

    Fatima, Mahrukh; Kasi, Pashtoon Murtaza; Baloch, Shahnaz Naseer; Kassi, Masoom; Marri, Shah Muhammad; Kassi, Mahwash

    2011-01-01

    Molar pregnancies represent a significant burden of disease on the spectrum of gestational trophoblastic diseases. The incidence appears to be higher in women from South Asia. The purpose of our prospective study was to determine the incidence, presentation, and outcomes of all molar pregnancies at our institution. During the study period, there were a total of 16,625 patients admitted to our department; out of whom 85 patients were diagnosed with a molar pregnancy. Vaginal bleeding was the commonest symptom (94.2%); theca lutein cysts were noted in 39% of the cases. Suction, dilatation, and curettage were noted to be the preferred method in almost all cases; hysterectomy was done in 12 (14.1%) patients. Single-agent chemotherapy was employed in high-risk patients and was well tolerated. Mean followup for these patients was 5.7?months (range 1-24 months). None of these patients developed persistent trophoblastic disease, invasive mole, or choriocarcinoma during the follow-up period. PMID:22028979

  10. Molar ratio S/In effect on properties of sprayed In2S3 films

    NASA Astrophysics Data System (ADS)

    Bouguila, Nourredine; Timoumi, Abdelmajid; Bouzouita, Hassen; Lacaze, Emmanuelle; Bouchriha, Habib; Rezig, Bahri

    2013-08-01

    We have studied the structural, morphological and optical properties of In2S3 layers deposited on glass substrate by the spray pyrolysis method with the molar ratio S/In varies from 1 to 4. The substrate temperature was maintained at 613 K. The characteristics of these films have been determined by X-ray diffraction (XRD), optical absorption-transmission and atomic force microscopy (AFM). Their structure is strongly dependent on the molar ratio. The deposit is mainly constituted by the ? phase towards (4 0 0) direction. No characteristic peaks were observed for other impurities such as In2O3, S or In2(OH)3. The best crystallinity and surface morphology are obtained at molar ratio equal to 2.5. At this ratio, the crystallites coalesce and the local roughness is of the order of 1 nm. Optical transmission of 80% has been achieved in the visible spectrum. In2S3 band gap energy reached 2.63 eV from layers with x = 2 and deposited at Ts = 613 K.

  11. Highly Efficient Hyperbranched CNT Surfactants: Influence of Molar Mass and Functionalization

    E-print Network

    Ellen Bertels; Kevin Bruyninckx; Mert Kurttepeli; Mario Smet; Sara Bals; Bart Goderis

    2015-05-18

    End-group-functionalized hyperbranched polymers were synthesized to act as a carbon nanotube (CNT) surfactant in aqueous solutions. Variation of the percentage of triphenylmethyl (trityl) functionalization and of the molar mass of the hyperbranched polyglycerol (PG) core resulted in the highest measured surfactant efficiency for a 5000 g/mol PG with 5.6% of the available hydroxyl end-groups replaced by trityl functions, as shown by UV-vis measurements. Semiempirical model calculations suggest an even higher efficiency for PG5000 with 2.5% functionalization and maximal molecule specific efficiency in general at low degrees of functionalization. Addition of trityl groups increases the surfactant-nanotube interactions in comparison to unfunctionalized PG because of pi-pi stacking interactions. However, at higher functionalization degrees mutual interactions between trityl groups come into play, decreasing the surfactant efficiency, while lack of water solubility becomes an issue at very high functionalization degrees. Low molar mass surfactants are less efficient compared to higher molar mass species most likely because the higher bulkiness of the latter allows for a better CNT separation and stabilization. The most efficient surfactant studied allowed dispersing 2.85 mg of CNT in 20 mL with as little as 1 mg of surfactant. These dispersions, remaining stable for at least 2 months, were mainly composed of individual CNTs as revealed by electron microscopy.

  12. Partially Reflected Diffusion

    E-print Network

    A. Singer; Z. Schuss; D. Holcman

    2007-09-02

    The radiation (reaction, Robin) boundary condition for the continuum diffusion equation is widely used in chemical and biological applications to express reactive boundaries. The underlying trajectories of the diffusing particles are believed to be partially absorbed and partially reflected at the reactive boundary, however, the relation between the reaction (radiation) constant in the Robin boundary condition and the reflection probability is still unclear. In this paper we clarify the issue by finding the relation between the reaction (radiation) constant and the absorption probability of the diffusing trajectories at the boundary. We analyze the Euler scheme for the underlying It\\^o dynamics, which is assumed to have variable drift and diffusion tensor, with partial reflection at the boundary. Trajectories that cross the boundary are terminated with a given probability and otherwise are reflected in a normal or oblique direction. We use boundary layer analysis of the corresponding Wiener path integral to resolve the non-uniform convergence of the probability density function of the numerical scheme to the solution of the Fokker-Planck equation with the Robin boundary condition, as the time step is decreased. We show that the Robin boundary condition is recovered in the limit iff trajectories are reflected in the co-normal direction. We find the relation of the reactive constant to the termination probability. We show the effect of using the new relation in numerical simulations.

  13. Diagnostic CBCT in Dentigerous Cyst with Ectopic Third Molar in the Maxillary Sinus–A Case Report

    PubMed Central

    Krishnamoorthy, Bhuvana; J K, Savitha; Bhai, Pankaja

    2014-01-01

    Dentigerous cyst is the second most common odontogenic cyst after radicular cyst. This report describes a case of a dentigerous cyst associated with an impacted maxillary third molar. Patient presented with foul smelling discharge through nose and oral cavity. Cone beam computed tomography revealed maxillary third molar displaced to lateral wall of the nose and a unilocular radiolucency obliterating the entire maxillary sinus. A provisional diagnosis of infected dentigerous cyst was made. The cyst was enucleated along with removal of third molar. Histopathological examination confirmed the diagnosis of dentigerous cyst. The patient recovery was uneventful. PMID:25121067

  14. Furnace brazing under partial vacuum

    NASA Technical Reports Server (NTRS)

    Mckown, R. D.

    1979-01-01

    Brazing furnace utilizing partial-vacuum technique reduces tooling requirements and produces better bond. Benefit in that partial vacuum helps to dissociate metal oxides that inhibit metal flow and eliminates heavy tooling required to hold parts together during brazing.

  15. A Prescription for Partial Synchrony 

    E-print Network

    Sastry, Srikanth

    2012-07-16

    Algorithms in message-passing distributed systems often require partial synchrony to tolerate crash failures. Informally, partial synchrony refers to systems where timing bounds on communication and computation may exist, ...

  16. A Bibliography of Recreational Mathematics, Volume 3.

    ERIC Educational Resources Information Center

    Schaaf, William L.

    This book is a partially annotated bibliography of books, articles and periodicals concerned with mathematical games, puzzles, tricks, amusements, and paradoxes. Because the literature in recreational mathematics has proliferated to amazing proportions since Volume 2 of this series (ED 040 874), Volume 3 is more than just an updating of the…

  17. [Epidemiology of third molar extractions: the experience of the S.G.C. Fatebenefratelli Hospital in Rome (Italy)].

    PubMed

    Gilardi, Francesco; Maurici, Massimo; Capozzi, Claudio; Di Dio, Marco; Ferrante, Maurizio; Arcuri, Claudio; Paulon, Luca

    2014-01-01

    The extraction of third molars (wisdom teeth) is one of the main surgical procedures performed in dentistry. The aim of this study was to describe the characteristics of patients undergoing the procedure in the SGC Fatebenefratelli Hospital, a large hospital in Rome (Italy), where about 20% of all third molar extractions in the Lazio Region are performed. Hospital discharge forms were analysed for patients discharged in the years 2010 and 2011 with a Diagnosis Related Group (DRG) code 169, used for the procedure. Study results indicate that the extraction of third molars is a relevant public health issue considering its frequency and associated yearly costs at the national level. The appropriateness of third molar extraction, especially when performed prophylactically in young persons, should be further explored. PMID:25715894

  18. Free alg's via partial alg's

    E-print Network

    van Suijlekom, Walter

    Free alg's via functor on partial alg's Dion Coumans and Sam van Gool Free algebra step-by-step Free image-total functor Application to KB Free algebras via a functor on partial algebras Dion Coumans / 16 #12;Free alg's via functor on partial alg's Dion Coumans and Sam van Gool Free algebra step

  19. Quantitative Three-Dimensional Analysis of Root Canal Curvature in Maxillary First Molars Using Micro-Computed Tomography

    Microsoft Academic Search

    Jong-Ki Lee; Byung-Hyun Ha; Jeong-Ho Choi; Seok-Mo Heo; Hiran Perinpanayagam

    2006-01-01

    In endodontic therapy, access and instrumentation are strongly affected by root canal curvature. However, the few studies that have actually measured curvature are mostly from two-dimensional radiographs. The purpose of this study was to measure the three-dimensional (3D) canal curvature in maxillary first molars using micro-computed tomography (microCT) and mathematical modeling. Extracted maxillary first molars (46) were scanned by microCT

  20. Quantitative Three-Dimensional Analysis of Root Canal Curvature in Maxillary First Molars Using Micro-Computed Tomography

    Microsoft Academic Search

    Jong-Ki Lee; Byung-Hyun Ha; Jeong-Ho Choi; Seok-Mo Heo; Hiran Perinpanayagam

    In endodontic therapy, access and instrumentation are strongly affected by root canal curvature. However, the few studies that have actually measured curvature are mostly from two-dimensional radiographs. The purpose of this study was to measure the three-dimensional (3D) canal curvature in maxillary first molars using micro-computed tomography (microCT) and mathemat- ical modeling. Extracted maxillary first molars (46) were scanned by

  1. Compositional dependence of molar absorptivities of near-infrared OH and H 2O bands in rhyolitic to basaltic glasses

    Microsoft Academic Search

    Susanne Ohlhorst; Harald Behrens; François Holtz

    2001-01-01

    Molar absorption coefficients (molar absorptivities) of the near infrared combination bands at 4500 and 5200 cm?1 assigned to OH groups and H2O molecules, respectively, were determined for glasses of dacitic, andesitic and basaltic compositions. Total water contents (range 1.5–6.3 wt.%) of the samples used in the calibration were determined by pyrolysis and subsequent Karl–Fischer Titration. Different combinations of baseline types

  2. Comparison of molar intrusion efficiency and bone density by CT in patients with different vertical facial morphology.

    PubMed

    Ding, W H; Li, W; Chen, F; Zhang, J F; Lv, Y; Chen, X Y; Lin, W W; Fu, Z; Shi, J J

    2015-05-01

    The purpose of this study is to examine the relationship between molar intrusion efficiency and bone density in patients with different vertical facial morphology. Thirty-six female patients, with overerupted upper first molars, were divided into two groups according to mandiblular plane angle (FH-MP): hyperdivergent, FH-MP>30° (G1), hypodivergent, FH-MP<22° (G2). Mini-screw implants with elastic chains were used to intrude upper first molars. Spiral CT was used to measure the intrusion degree of upper first molar and bone density, and molar intrusion efficiency was calculated as amount/duration (mm month(-1) ). In addition, each tooth was divided into three portions (cervical, furcation and apical) to measure the bone density. It was found in this study that treatment duration was 3·13 and 4·71 months in G1 and G2 and that the intrusion efficiency was 1·57 and 0·81 in G1 and G2 with significant difference (P < 0·05). There were significant differences in cervical, furcation and apical bone density between two groups (P < 0·05). The bone density was significantly reduced after molar intrusion. In addition, the bone density change was greater in G1 than in G2 (P < 0·05). It was concluded that molars were more easily to be intruded in hyperdivergent than in hypodivergent patients. The difference of bone density and bone density changes during intrusion may account for the variation of molar intrusion efficiency. PMID:25515652

  3. Simulated fatigue resistance of composite resin versus porcelain CAD\\/CAM overlay restorations on endodontically treated molars

    Microsoft Academic Search

    Pascal Magne; Alena Knezevic

    Objective: To assess the influence of material selection (porcelain versus composite resin) for overlay-type restoration of endodontically treated molars and its effect on the in vitro fatigue resistance and failure mode. Method and Materials: A standardized tooth prepara- tion was applied to 30 extracted molars, including root canal treatment, 3-mm coverage of all cusps, a mesial box 1.5 mm below

  4. State and trait related predictors of serum cortisol to DHEA(S) molar ratios and hormone concentrations in schizophrenia patients

    Microsoft Academic Search

    Michael Ritsner; Anatoly Gibel; Rachel Maayan; Yael Ratner; Eduard Ram; Ilan Modai; Abraham Weizman

    2007-01-01

    Objective:In previous studies we have demonstrated high serum molar ratios of cortisol to dehydroepiandrosterone (DHEA) and its sulfate ester (DHEAS) [together abbreviated DHEA(S)], and the value of both cortisol\\/DHEA(S) molar ratios for prediction of responsivity to antipsychotic treatment in schizophrenia patients. The present study aimed to examine the contribution of anxiety, and severity of symptoms to the prediction of serum

  5. Influence of molar ratios of precursor, catalyst, solvent and water on monolithicity and physical properties of TMOS silica aerogels

    Microsoft Academic Search

    A. Venkateswara Rao; G. M. Pajonk; N. N. Parvathy

    1994-01-01

    In continuation to our earlier work on aerogels, the experimental results on the monolithicity and physical properties of silica aerogels as a function of the molar ratios of tetramethoxysilane (TMOS) precursor, catalyst (NH4OH), methanol (MeOH) solvent and water, are reported. The molar ratios of NH4OH\\/TMOS, MeOH\\/TMOS and H2O\\/TMOS were varied from 7.1 × 10-6 to 9.6 × 10-1, 1 to

  6. Unique inhibitory cascade pattern of molars in canids contributing to their potential to evolutionary plasticity of diet

    PubMed Central

    Asahara, Masakazu

    2013-01-01

    Developmental origins that guide the evolution of dental morphology and dental formulae are fundamental subjects in mammalian evolution. In a previous study, a developmental model termed the inhibitory cascade model was established. This model could explain variations in relative molar sizes and loss of the lower third molars, which sometimes reflect diet, in murine rodents and other mammals. Here, I investigated the pattern of relative molar sizes (inhibitory cascade pattern) in canids, a taxon exhibiting a wide range of dietary habits. I found that interspecific variation in canid molars suggests a unique inhibitory cascade pattern that differs from that in murine rodents and other previously reported mammals, and that this variation reflects dietary habits. This unique variability in molars was also observed in individual variation in canid species. According to these observations, canid species have greater variability in the relative sizes of first molars (carnassials), which are functionally important for dietary adaptation in the Carnivora. In conclusion, an inhibitory cascade that differs from that in murine rodents and other mammals may have contributed to diverse dietary patterns and to their parallel evolution in canids. PMID:23467478

  7. Construction of a cDNA library for miniature pig mandibular deciduous molars

    PubMed Central

    2014-01-01

    Background The miniature pig provides an excellent experimental model for tooth morphogenesis because its diphyodont and heterodont dentition resembles that of humans. However, little information is available on the process of tooth development or the exact molecular mechanisms controlling tooth development in miniature pigs or humans. Thus, the analysis of gene expression related to each stage of tooth development is very important. Results In our study, after serial sections were made, the development of the crown of the miniature pigs’ mandibular deciduous molar could be divided into five main phases: dental lamina stage (E33-E35), bud stage (E35-E40), cap stage (E40-E50), early bell stage (E50-E60), and late bell stage (E60-E65). Total RNA was isolated from the tooth germ of miniature pig embryos at E35, E45, E50, and E60, and a cDNA library was constructed. Then, we identified cDNA sequences on a large scale screen for cDNA profiles in the developing mandibular deciduous molars (E35, E45, E50, and E60) of miniature pigs using Illumina Solexa deep sequencing. Microarray assay was used to detect the expression of genes. Lastly, through Unigene sequence analysis and cDNA expression pattern analysis at E45 and E60, we found that 12 up-regulated and 15 down-regulated genes during the four periods are highly conserved genes homologous with known Homo sapiens genes. Furthermore, there were 6 down-regulated and 2 up-regulated genes in the miniature pig that were highly homologous to Homo sapiens genes compared with those in the mouse. Conclusion Our results not only identify the specific transcriptome and cDNA profile in developing mandibular deciduous molars of the miniature pig, but also provide useful information for investigating the molecular mechanism of tooth development in the miniature pig. PMID:24750690

  8. Radiographic Evaluation of Third Molar Development in 5- to 25 Year Olds in Tehran, Iran

    PubMed Central

    Jafari, A.; Mohebbi, SZ.; Khami, MR.; Shahabi, M. Shakur; Naseh, M.; Elhami, F.; Shamshiri, AR.

    2012-01-01

    Objective: Radiographic evaluation of the third molar tooth to determine its position and degree of development is an important part in diagnosis and treatment planning, as well as in forensic dentistry procedures. The objective was to investigate the developmental stages of third molars in relation to chronologic age, gender and location (maxillary/mandibular) in an Iranian population. Materials and Methods: The data were collected in departments of pediatric dentistry and orthodontics, Tehran Faculty of Dentistry and four private offices. Three calibrated observers visited the centers to examine panoramic radiographs and corresponded patients documents in each age cohort in the range of 5- to-25-years old. Data were analyzed by Generalized Estimating Equation (GEE) in the linear mode and exchangeable correlation structure. The significance level was defined as 0.05. Results: The mean age of emerging third molars’ follicle was 9.29±1.65 years. Early calcification was seen at the mean age of 10.28±1.66 years. The GEE model controlling for age, gender and tooth location (maxillary/mandibular) revealed that besides age (?=0.43, p<0.001), the tooth location had association with the developmental stage (?=0.11, p<0.001) so that maxillary teeth were prior in calcification stages, but no relationship between gender and developmental stages was seen (?=0.03, p=0.69). Conclusion: Maxillary teeth were ahead of mandibular teeth in calcification stages with no gender difference. The present study may provide a reference for oral surgeons, pediatric dentists and orthodontists practicing in Iran and may have implications for the neighboring countries especially those with Caucasian populations. PMID:23066475

  9. Enamel thickness variation of deciduous first and second upper molars in modern humans and Neanderthals.

    PubMed

    Fornai, Cinzia; Benazzi, Stefano; Svoboda, Ji?í; Pap, Ildikó; Harvati, Katerina; Weber, Gerhard W

    2014-11-01

    Enamel thickness and dental tissue proportions have been recognized as effective taxonomic discriminators between Neanderthal and modern humans teeth. However, most of the research on this topic focused on permanent teeth, and little information is available for the deciduous dentition. Moreover, although worn teeth are more frequently found than unworn teeth, published data for worn teeth are scarce and methods for the assessment of their enamel thickness need to be developed. Here, we addressed this issue by studying the 2D average enamel thickness (AET) and 2D relative enamel thickness (RET) of Neanderthal and modern humans unworn to moderately worn upper first deciduous molars (dm(1)s) and upper second deciduous molars (dm(2)s). In particular, we used 3D ?CT data to investigate the mesial section for dm(1)s and both mesial and buccal sections for dm(2)s. Our results confirmed previous findings of an Neanderthal derived condition of thin enamel, and thinner enamel in dm(1)s than dm(2)s in both Neanderthal and modern humans. We demonstrated that the Neanderthal 2D RET indices are significantly lower than those of modern humans at similar wear stages in both dm(1)s and dm(2)s (p < 0.05). The discriminant analysis showed that using 2D RET from dm(1) and dm(2) sections at different wear stages up to 93% of the individuals are correctly classified. Moreover, we showed that the dm(2) buccal sections, although non-conventionally used, might have an advantage on mesial sections since they distinguish as well as mesial sections but tend to be less worn. Therefore, the 2D analysis of enamel thickness is suggested as a means for taxonomic discrimination between modern humans and Neanderthal unworn to moderately worn upper deciduous molars. PMID:25282273

  10. Age estimation using lower permanent first molars on a panoramic radiograph: A digital image analysis

    PubMed Central

    Talabani, Ranjdar M.; Baban, Mohammed T.; Mahmood, Mohammed A.

    2015-01-01

    Objective: A study was carried out to analyze the efficacy and practical application for age estimation using digital panoramic radiograph to exploit image analysis to obtain metric measurement of morphological parameters of permanent mandibular first molar on Sulaimani population. Materials and Methods: In the present study a population of known age and sex was studied and subjected to digital panoramic radiographic examination. The correlation between the reduction of coronal pulp cavity and chronological age was examined in a sample of 96 individuals distributed into four age groups: 20-29 years (29 cases), 30-39 years (29 cases), 40-49 years (26 cases) and 50-59 years (12 cases). The height (mm) of the crown (CH = coronal height) and the height (mm) of coronal pulp cavity (CPCH = coronal pulp cavity height) of 96 of first molars from all subjects was measured. The tooth–coronal index (TCI) after Ikeda et al. was computed for each tooth and regressed on real age. Results: ANOVA was used to show the strength of relation between the age and TCI (P = 0.0000). The correlation coefficient (r2) was 0.49, which mean there is strong negative linear regression between age and TCI with the r2, regarding predicting age using TCI value, after the following equation calculated, Predicted age = 3.78 – (0.064 TCI) showed that there is no significant difference between real age and estimated age. Conclusion: There is a strong negative liner relationship between TCIs of mandibular first molars with chronological age of Sulaimani population, and age of individuals can therefore be estimated with a good degree of accuracy using regression equations. PMID:26005307

  11. Biometric study of the prefurcation area of human mandibular first molars.

    PubMed

    Barboza, Carlos Alberto; Rodrigues, Diogo Moreira; Petersen, Rodrigo; Trisão, Gilson Coutinho; Barboza, Eliane Porto

    2014-01-01

    This study analyzed the length of the root trunk (RT) as well as the width and depth of the prefurcation area (PFA) of human mandibular first molars. Ninety-six human mandibular first molars that were extracted after being observed to be in poor condition both clinically and radiographically were used in this study. A contour-measuring instrument was used, and profiles of the buccal and lingual root surfaces of these teeth were traced on a millimeter-scaled paper. The profiles were recorded from the cementoenamel junction, millimeter by millimeter, up to the entrance of the furcation of each tooth. The width and depth of the PFA as well as the length of the RT were studied. After statistical analysis it was concluded that the mean widths of the PFA on the buccal and lingual surfaces were 3.68 ± 0.66 and 3.48 ± 0.51 mm, respectively; mean depths of the PFA on the buccal and lingual surfaces were 0.89 ± 0.42 and 0.82 ± 0.28 mm, respectively; and mean lengths of the RT on the buccal and lingual surfaces were 3.07 ± 0.82 and 3.54 ± 0.73 mm. Of the samples, the lengths of the RT and the PFA were coincident in 39.58% on the buccal surface and in 46.87% on the lingual surface. There is a concavity (PFA) in the RT region of all mandibular first molars, showing larger width and depth on the buccal surface. The RT was longer on the lingual surface in comparison with the buccal surface. PMID:25411742

  12. Molar mass, surface tension, and droplet growth kinetics of marine organics from measurements of CCN activity

    NASA Astrophysics Data System (ADS)

    Moore, R. H.; Ingall, E. D.; Sorooshian, A.; Nenes, A.

    2008-04-01

    The CCN-relevant properties and droplet growth kinetics are determined for marine organic matter isolated from seawater collected near the Georgia coast. The organic matter is substantially less CCN active than (NH4)2SO4, but droplet growth kinetics are similar. Köhler Theory Analysis (KTA) is used to determine the average organic molar masses of two samples, which are 4370 +/- 24% and 4340 +/- 18% kg kmol-1. KTA is used to infer surface tension depression, which is in excellent agreement with direct measurements. For the first time it is shown that direct measurements of surface tension are relevant for CCN activation, and this study highlights the power of KTA.

  13. Clinical and radiographic diagnosis of underlying dark shadow from dentin (ICDAS 4) in permanent molars.

    PubMed

    Bertella, N; Moura, Dos S; Alves, L S; Damé-Teixeira, N; Fontanella, V; Maltz, M

    2013-01-01

    This study investigated the radiographic pattern of underlying dark shadow from dentin (ICDAS 4) in permanent molars and assessed the association between enamel breakdown and radiographic features. Ninety-five teeth (54 patients) were clinically and radiographically assessed. The majority of ICDAS 4 caries lesions presented enamel breakdown (n = 78, 82.1%) and no radiographic image (n = 64, 67.4%) or a radiolucent zone restricted to the enamel-dentin junction (n = 17, 17.9%). No association was found between enamel breakdown and radiographic features. This study suggests that a radiographic examination is needed prior to the decision making process for underlying dark shadows from dentin. PMID:23712062

  14. Prevalence of molar incisor hypomineralization in the city of Buenos Aires.

    PubMed

    Biondi, Ana M; Cortese, Silvina G; Martínez, Karina; Ortolani, Andrea M; Sebelli, Patricia M F; Ienco, Melisa; Paván, Verónica H; Mendel, Nancy; Bertolino, Mariana; Hecht, Pedro

    2011-01-01

    The prevalence of Molar Incisor Hypomineralization (MIH) still remains unknown in Argentina. The objectives of this work were to: estimate prevalence of MIH in a group of children seeking dental care in the city of Buenos Aires, analyze distribution according to year of birth and compare prevalence and severity of MIH in children with different access to health care services. A prospective, observational, transversal, descriptive study was designed, to be conducted on children seeking attention at Department of Comprehensive Children's Dentistry at the School of Dentistry of Buenos Aires University and at 3 pediatric dentistry offices attended by members of the team, located in Buenos Aires city (Kappa 0.933 0.911-0.952), from April to August 2010. The study included all children born between 1993 and 2003, whose 4 first molars and 8 permanent incisors had erupted. After prophylaxis and drying, the teeth were clinically evaluated and specially designed charts were used to record sex, year of birth, type of access to dental care, presence of MIH, number of affected incisors and molars, and maximum degree of severity for each tooth. The data obtained were analyzed using percentages, Fisher's Exact Test and Linear regression. 1098 children, mean age 11.3 years (11.08-11.39) were evaluated. Prevalence of MIH in this study was 15.9% (13.8-18.2). A highly significant positive correlation was obtained between MIH and year of birth (p<0.0001). Group A (private sector: prepaid medical insurance) was made up of 586 children (age: 10.92 6.22-15.62) while group B (public sector: university hospital) was made up of 512 children (age: 11.59 5.31-16.90). In Group A, MIH prevalence was 24.40% (20.9-27.9) while in Group B it was 6.44% (4.31-8.56) (p<0.0001). Of the affected molars, 37% (32.2-42) in A and 13.7% (6.7-23.8) in B had grade 3 lesions, with loss of enamel (p<0.0001). In this study, MIH was a frequent pathology (15.9%) and a significant increase was found according to year of birth during the study period. Patients with better access to health care had greater prevalence and degree of severity of MIH. PMID:22010411

  15. Partially segmented deformable mirror

    DOEpatents

    Bliss, E.S.; Smith, J.R.; Salmon, J.T.; Monjes, J.A.

    1991-05-21

    A partially segmented deformable mirror is formed with a mirror plate having a smooth and continuous front surface and a plurality of actuators to its back surface. The back surface is divided into triangular areas which are mutually separated by grooves. The grooves are deep enough to make the plate deformable and the actuators for displacing the mirror plate in the direction normal to its surface are inserted in the grooves at the vertices of the triangular areas. Each actuator includes a transducer supported by a receptacle with outer shells having outer surfaces. The vertices have inner walls which are approximately perpendicular to the mirror surface and make planar contacts with the outer surfaces of the outer shells. The adhesive which is used on these contact surfaces tends to contract when it dries but the outer shells can bend and serve to minimize the tendency of the mirror to warp. 5 figures.

  16. Partially segmented deformable mirror

    DOEpatents

    Bliss, Erlan S. (Danville, CA); Smith, James R. (Livermore, CA); Salmon, J. Thaddeus (Livermore, CA); Monjes, Julio A. (San Ramon, CA)

    1991-01-01

    A partially segmented deformable mirror is formed with a mirror plate having a smooth and continuous front surface and a plurality of actuators to its back surface. The back surface is divided into triangular areas which are mutually separated by grooves. The grooves are deep enough to make the plate deformable and the actuators for displacing the mirror plate in the direction normal to its surface are inserted in the grooves at the vertices of the triangular areas. Each actuator includes a transducer supported by a receptacle with outer shells having outer surfaces. The vertices have inner walls which are approximately perpendicular to the mirror surface and make planar contacts with the outer surfaces of the outer shells. The adhesive which is used on these contact surfaces tends to contract when it dries but the outer shells can bend and serve to minimize the tendency of the mirror to warp.

  17. A Bibliography of Recreational Mathematics, Volume 1. Fourth Edition.

    ERIC Educational Resources Information Center

    Schaaf, William L.

    This book is a partially annotated bibliography of books, articles, and periodicals concerned with mathematical games, puzzles, and amusements. It is a reprinting of Volume 1 of a three-volume series. This volume, originally published in 1955, treats problems and recreations which have been important in the history of mathematics as well as some…

  18. Seismic velocity decrement ratios for regions of partial melt in the lower mantle

    Microsoft Academic Search

    James G. Berryman

    2000-01-01

    For regions of partial melt in the lower mantle, both compressional and shear wave velocities decrease monotonically with increasing melt volume fraction. Those regions close to the core-mantle boundary thought to contain partial melt have a velocity decrement ratio (relative change in shear velocity over relative change of compressional velocity) of about 3. Arguments based on effective medium theories have

  19. Seismic velocity decrement ratios for regions of partial melt near the core-mantle boundary

    Microsoft Academic Search

    James G. Berryman

    1999-01-01

    For regions of partial melt in the lower mantle, both compressional and shear wave ve- locities decrease monotonically with increasing melt volume fraction. It has been ob- served that regions close to the core-mantle boundary thought to contain partial melt have a velocity decrement ratio (relative change in shear velocity over relative change of com- pressional velocity) of about 3.

  20. Brief communication: Comparative patterns of enamel thickness topography and oblique molar wear in two Early Neolithic and medieval population samples.

    PubMed

    Le Luyer, Mona; Rottier, Stéphane; Bayle, Priscilla

    2014-09-01

    Enamel thickness has been linked to functional aspects of masticatory biomechanics and has been demonstrated to be an evolutionary plastic trait, selectively responsive to dietary changes, wear and tooth fracture. European Late Paleolithic and Mesolithic hunter-gatherers mainly show a flat wear pattern, while oblique molar wear has been reported as characteristic of Neolithic agriculturalists. We investigate the relationships between enamel thickness distribution and molar wear pattern in two Neolithic and medieval populations. Under the assumption that dietary and/or non-dietary constraints result in directional selective pressure leading to variations in enamel thickness, we test the hypothesis that these two populations will exhibit significant differences in wear and enamel thickness patterns. Occlusal wear patterns were scored in upper permanent second molars (UM2) of 64 Neolithic and 311 medieval subadult and adult individuals. Enamel thickness was evaluated by microtomography in subsamples of 17 Neolithic and 25 medieval individuals. Eight variables describing enamel thickness were assessed. The results show that oblique molar wear is dominant in the Neolithic sample (87%), while oblique wear affects only a minority (42%) of the medieval sample. Moreover, in the Neolithic molars, where buccolingually directed oblique wear is dominant and greatest enamel lost occurs in the distolingual quadrant, thickest enamel is found where occlusal stresses are the most important-on the distolingual cusp. These results reveal a correlation between molar wear pattern and enamel thickness that has been associated to dietary changes. In particular, relatively thicker molar enamel may have evolved as a plastic response to resist wear. PMID:24961878

  1. NLRP7, Involved in Hydatidiform Molar Pregnancy (HYDM1), Interacts with the Transcriptional Repressor ZBTB16

    PubMed Central

    Singer, Heike; Biswas, Arijit; Nuesgen, Nicole; Oldenburg, Johannes; El-Maarri, Osman

    2015-01-01

    Mutations in the maternal effect gene NLRP7 cause biparental hydatidiform mole (HYDM1). HYDM1 is characterized by abnormal growth of placenta and lack of proper embryonic development. The molar tissues are characterized by abnormal methylation patterns at differentially methylated regions (DMRs) of imprinted genes. It is not known whether this occurs before or after fertilization, but the high specificity of this defect to the maternal allele indicates a possible maternal germ line-specific effect. To better understand the unknown molecular mechanism leading to HYDM1, we performed a yeast two-hybrid screen against an ovarian library using NLRP7 as bait. We identified the transcriptional repressor ZBTB16 as an interacting protein of NLRP7 and verified this interaction in mammalian cells by immunoprecipitation and confocal microscopy. Native protein analysis detected NLRP7 and ZBTB16 in a 480kD protein complex and both proteins co-localize in the cytoplasm in juxtanuclear aggregates. HYDM1-causing mutations in NLRP7 did not show altered patterns of interaction with ZBTB16. Hence, the biological significance of the NLRP7-ZBTB16 interaction remains to be revealed. However, a clear effect of harvesting ZBTB16 to the cytoplasm when the NLRP7 protein is overexpressed may be linked to the pathology of the molar pregnancy disease. PMID:26121690

  2. Growth-Associated Changes in the Periodontal Bone and Molar Teeth of Male Rats

    PubMed Central

    García, María F; Moreno, Hilda; Rigalli, Alfredo; Puche, Rodolfo C

    2009-01-01

    Here we report quantitative data associating periodontal bone variables of young conventional rats with the growth process. The hemimandibles of male rats (IIM/Fm stock, 2 to 15 wk of age.) were excised and submitted to conventional morphologic, radiologic, and histologic evaluation. The length, area, or X-ray absorbance of various regions or structures was measured on digital images of radiographs by using an image-analysis program. The sum of periodontal bone areas undergoing resorption (interproximal + intraradicular) increased until 9 or 10 wk of age and decreased thereafter. Mineral accretion rates and mineral density asymptotes were not significantly different among molars. The mineral density of resorption areas in alveolar bone fitted sinusoidal kinetics, indicative of the ‘instability’ of the tissue due to its high metabolic activity. Mineral accretion rates and mineral density asymptotes were not significantly different among molars. The proportion of root length within alveolar bone exhibited a biphasic curve (minimum at 5 wk of age), due to differences in the growth rates of variables involved in its calculation (distance between the cementoenamel junction to the apex and height of the resorption areas). The distance between the cementoenamel junction and alveolar bone crest over time fitted a sigmoidal function with a point of inflection that did not differ significantly from that of body or mandible dry weight. In summary, the growth process appears to affect periodontal bone support and the distance between the cementoenamel junction and alveolar bone crest in male rats. PMID:19807966

  3. Evaluation of intra-alveolar chlorhexidine dressings after removal of impacted mandibular third molars.

    PubMed

    Fotos, P G; Koorbusch, G F; Sarasin, D S; Kist, R J

    1992-03-01

    Chlorhexidine gluconate (CHX) has been investigated for its possible benefit in the prevention of alveolar osteitis complicating third molar removal. In a double-blind, placebo-controlled clinical study, 70 randomly selected healthy patients were subjected to uncomplicated mandibular third molar removal followed by CHX-gelatin sponge and saline solution-gelatin sponge intra-alveolar dressings. Each patient was followed for 6 days for postoperative discomfort and complications, and scored accordingly. The results demonstrated that patients receiving 0.2% CHX intra-alveolar dressings exhibited a significant reduction in postoperative discomfort and complications when compared with saline solution-treated control sites (p less than 0.005). Further, this phenomenon was not found to be related to patient factors including age, sex, and race, nor did any correlation exist between treated or control sites, and surgical factors including performing surgeon, surgeon's dominant hand, time of surgery, surgical site, and difficulty of the removal. These findings warrant further studies concerning the apparent clinical benefit of postextraction intra-alveolar CHX dressings for the reduction of postoperative alveolar osteitis. PMID:1545974

  4. Accuracy of Cameriere's cut-off value for third molar in assessing 18 years of age.

    PubMed

    De Luca, S; Biagi, R; Begnoni, G; Farronato, G; Cingolani, M; Merelli, V; Ferrante, L; Cameriere, R

    2014-02-01

    Due to increasingly numerous international migrations, estimating the age of unaccompanied minors is becoming of enormous significance for forensic professionals who are required to deliver expert opinions. The third molar tooth is one of the few anatomical sites available for estimating the age of individuals in late adolescence. This study verifies the accuracy of Cameriere's cut-off value of the third molar index (I3M) in assessing 18 years of age. For this purpose, a sample of orthopantomographs (OPTs) of 397 living subjects aged between 13 and 22 years (192 female and 205 male) was analyzed. Age distribution gradually decreases as I3M increases in both males and females. The results show that the sensitivity of the test was 86.6%, with a 95% confidence interval of (80.8%, 91.1%), and its specificity was 95.7%, with a 95% confidence interval of (92.1%, 98%). The proportion of correctly classified individuals was 91.4%. Estimated post-test probability, p was 95.6%, with a 95% confidence interval of (92%, 98%). Hence, the probability that a subject positive on the test (i.e., I3M<0.08) was 18 years of age or older was 95.6%. PMID:24365729

  5. Evaluation of formocresol, calcium hydroxide, ferric sulfate, and MTA primary molar pulpotomies

    PubMed Central

    Yildiz, Esma; Tosun, Gul

    2014-01-01

    Objective: The aim of this study is to evaluate four different pulpotomy medicaments in primary molars. Materials and Methods: A total of 147 primary molars with deep caries were treated with four different pulpotomy medicaments (FC: formocresol, FS: ferric sulfate, CH: calcium hydroxide, and MTA: mineral trioxide aggregate) in this study. The criteria for tooth selection for inclusion were no clinical and radiographic evidence of pulp pathology. During 30 months of follow-up at 6-month intervals, clinical and radiographic success and failures were recorded. The differences between the groups were statistically analyzed using the Chi-square test and Kaplan-Meier analysis. Results: At 30 months, clinical success rates were 100%, 95.2%, 96.4%, and 85% in the FC, FS, MTA, and CH groups, respectively. In radiographic analysis, the MTA group had the highest (96.4%), and the CH group had the lowest success rate (85%). There were no clinical and radiographic differences between materials (P > 0.05). Conclusions: Although there were no differences between materials, only in the CH group did three teeth require extraction due to further clinical symptoms of radiographic failures during the 30-month follow-up period. None of the failed teeth in the other groups required extraction during the 30-month follow-up period. PMID:24966776

  6. Primary and secondary closure technique following removal of impacted mandibular third molars: A comparative study

    PubMed Central

    Chaudhary, Manoj; Singh, Manpreet; Singh, Sanjay; Singh, S. P.; Kaur, Gagandeep

    2012-01-01

    Aim: The purpose of this study was to evaluate and compare the post operative healing, using primary versus second closure techniques after impacted mandibular third molar removal. Materials and Methods: The study consisted of twelve patients, Seven males and five females under 30 years of age were divided into two groups as Group A and Group B in the randomized fashion. In the Group A, closure was done by primary intention and in the Group B, by secondary closure. A comparison between both groups was done with a follow-up period of 6 h to 6 days with regards to postoperative pain and swelling. Results: The statistical analysis (analysis of variance for repeated measures, P < 0.05) showed that pain was greater in Group A, although it decreased over time similarly in the two groups. Pain and swelling was less severe with secondary healing than with primary healing. Conclusion: The outcome of this study suggested that secondary closure technique is better than primary closure technique for removal of impacted mandibular third molar with regards to postoperative pain and swelling. PMID:23251051

  7. Identification of possible factors impacting dental students' ability to locate MB2 canals in maxillary molars.

    PubMed

    Park, Ellen; Chehroudi, Babak; Coil, Jeffrey M

    2014-05-01

    This study examined the effect of the access size and straight-line path of access on third-year dental students' ability to locate a second mesiobuccal (MB2) canal in maxillary first and second molars. One hundred and six third-year dental students at one Faculty of Dentistry performed simulated root canal treatment with the aid of 2x magnification loupes on extracted teeth. A postgraduate endodontic student subsequently made a reasonable search for an untreated MB2 canal with the aid of a dental operating microscope. The mesiobuccal roots were then sectioned horizontally for determination of the canal configuration. The dental students were able to treat an MB2 canal in 15.8 percent of the teeth, but this was not associated with satisfactory access criteria. The postgraduate endodontic student identified an MB2 canal in 54.7 percent of the remaining tooth samples excluding those where the MB2 canal was found by the dental students; this represented 94.3 percent of those teeth confirmed by horizontal sectioning of the root to have an MB2 canal. The postgraduate student troughed, on average, 2.6 mm before negotiating the MB2 canal. As satisfactory access criteria and straight-line path of access did not correlate with the dental students' ability to find a second mesiobuccal canal, this result has important implications for educational goals with respect to endodontic treatment of maxillary molar teeth. PMID:24789839

  8. Refractive index, molar refraction and comparative refractive index study of propylene carbonate binary liquid mixtures.

    PubMed

    Wankhede, Dnyaneshwar Shamrao

    2012-06-01

    Refractive indices (n) have been experimentally determined for the binary liquid-liquid mixtures of Propylene carbonate (PC) (1) with benzene, ethylbenzene, o-xylene and p-xylene (2) at 298.15, 303.15 and 308.15 K over the entire mole fraction range. The experimental values of n are utilised to calculate deviation in refractive index (?n), molar refraction (R) and deviation in molar refraction (?R). A comparative study of Arago-Biot (A-B), Newton (NW), Eyring and John (E-J) equations for determining refractive index of a liquid has been carried out to test their validity for all the binary mixtures over the entire composition range at 298.15 K. Comparison of various mixing relations is represented in terms of average deviation (AVD). The ?n and ?R values have been fitted to Redlich-Kister equation at 298.15 K and standard deviations have been calculated. The results are discussed in terms of intermolecular interactions present amongst the components. PMID:24061238

  9. Molar tooth sign of the midbrain-hindbrain junction: occurrence in multiple distinct syndromes.

    PubMed

    Gleeson, Joseph G; Keeler, Lesley C; Parisi, Melissa A; Marsh, Sarah E; Chance, Phillip F; Glass, Ian A; Graham Jr, John M; Maria, Bernard L; Barkovich, A James; Dobyns, William B

    2004-03-01

    The Molar Tooth Sign (MTS) is defined by an abnormally deep interpeduncular fossa; elongated, thick, and mal-oriented superior cerebellar peduncles; and absent or hypoplastic cerebellar vermis that together give the appearance of a "molar tooth" on axial brain MRI through the junction of the midbrain and hindbrain (isthmus region). It was first described in Joubert syndrome (JS) where it is present in the vast majority of patients with this diagnosis. We previously showed that the MTS is a component of several other syndromes, including Dekaban-Arima (DAS), Senior-Löken, and COACH (cerebellar vermis hypoplasia (CVH), oligophrenia, ataxia, coloboma, and hepatic fibrosis). Here we present evidence that the MTS is seen together with polymicrogyria, Váradi-Papp syndrome (Orofaciodigital VI (OFD VI)), and a new syndrome with encephalocele and cortical renal cysts. We also present a new patient with COACH syndrome plus the MTS. We propose that the MTS is found in multiple distinct clinical syndromes that may share common developmental mechanisms. Proper classification of patients with these variants of the MTS will be essential for localization and identification of mutant genes. PMID:14981712

  10. Morphometric study of the root anatomy in furcation area of mandibular first molars

    PubMed Central

    MARCACCINI, Andréa Marcia; PAVANELO, Ângela; NOGUEIRA, Andressa Vilas Boas; de SOUZA, João Antonio Chaves; PORCIÚNCULA, Hélio Ferraz; CIRELLI, Joni Augusto

    2012-01-01

    Furcation involvement in periodontal disease has been a challenge for the dentist. Objective The aim of this study was to investigate root dimensions in the furcation area of 233 mandibular first molars. Material and Methods Digital photomicrographs were used to obtain the following measurements on the buccal and lingual surfaces of each tooth: root trunk height (RT), horizontal interadicular distance obtained 1 mm (D1) and 2 mm (D2) below the fornix and interadicular angle (IA). Results Mean± standard deviation of buccal and lingual furcation measurements were, respectively, 1.37±0.78 mm and 2.04±0.89 mm for RT; 0.86±0.39 mm and 0.71±0.42 mm for D1; 1.50±0.48 mm and 1.38±0.48 mm for D2; 41.68±13.20º and 37.78±13.18º for IA. Statistically significant differences were found between all measured parameters for buccal and lingual sides (p<0.05, paired t test). Conclusions In conclusion, the lingual furcation of mandibular first molars presented narrower entrance and longer root trunk than the buccal furcation, suggesting more limitation for instrumentation and worse prognosis to lingual furcation involvements in comparison to buccal lesions. PMID:22437682

  11. Hemisection: A Treatment Option for an Endodontically treated Molar with Vertical Root Fracture.

    PubMed

    Anitha, S; Rao, Deepika Sc

    2015-01-01

    Vertical root fractures (VRF) in endodontically treated teeth have long been reported and pose diagnostic difficulties. A hemisection/root resection procedures removes the fractured fragments completely, and retains a portion of the compromized tooth offers a predictable treatment option. The key to this rests in ideal case selection involving balancing all indications and contraindications. The success of the treatment depends on careful case selection based on a firm set of guidelines. This article presents a case with VRF in an endodontic treated molar. This article describes the case of a 65-year-old man with a VRF on the mesial root and a healthy periodontium supporting the distal root making it ideal for retention as well as restoration and support of the final prosthesis. Also, the patient was motivated to try and save as much of the tooth as possible. Postoperatively no untoward complication was reported making it an alternative treatment option in patients with VRF in a molar, willing to retain the remaining tooth portion. With all other factors balanced, it allows for retaining the remaining intact portion of the tooth structure. PMID:25906809

  12. The effects of informed consent format on preoperative anxiety in patients undergoing inferior third molar surgery

    PubMed Central

    Heras-Meseguer, Marisa; Azcárate-Velázquez, Francisco; Hita-Iglesias, Pilar; Ruiz-de-León-Hernández, Gonzalo; Hernández-Pacheco, Esther; Gutiérrez-Pérez, José L.

    2014-01-01

    Objectives: To evaluate the effect of informed consent format on preoperative anxiety of patients. Material and Methods: We performed a prospective study (91 patients) undergoing lower third molar extraction. Patients were distributed into three groups. Informed consent for surgery was obtained through a written document, an oral interview or a video recording. Afterwards, patients were asked about their anxiety level and the effect the informed consent had had on it. Results: Whereas the information conveyed both in oral and written formats relieved the patient to some extent (in a scale of -3 to +3) 0.97±1.21 and 0.29±0.97, respectively), the video recording increased patient’s anxiety in a statistically significant way (in a scale of -3 to +3, -0.57±1.43). The difference obtained between the values obtained in oral and written information was not statistically significant. Discussion: The most adequate format, according to our study, would be the oral format. Key words:Anxiety, satisfaction, third molar surgery, Spielberger State-Trait Anxiety Inventory. PMID:24316709

  13. Computer-assisted intraosseous anaesthesia for molar and incisor hypomineralisation teeth. A preliminary study.

    PubMed

    Cabasse, C; Marie-Cousin, A; Huet, A; Sixou, J L

    2015-03-01

    Anesthetizing MIH (Molar and Incisor Hypomineralisation) teeth is one of the major challenges in paediatric dentistry. Computer-assisted IO injection (CAIO) of 4% articaine with 1:200,000 epinephrine (Alphacaine, Septodont) has been shown to be an efficient way to anesthetize teeth in children. The aim of this study was to assess the efficacy of this method with MIH teeth. This preliminary study was performed using the Quick Sleeper system (Dental Hi Tec, Cholet, France) that allows computer-controlled rotation of the needle to penetrate the bone and computer-controlled injection of the anaesthetic solution. Patients (39) of the department of Paediatric Dentistry were included allowing 46 sessions (including 32 mandibular first permanent molars) to be assessed. CAIO showed efficacy in 93.5% (43/46) of cases. Failures (3) were due to impossibility to reach the spongy bone (1) and to achieve anaesthesia (2). This prospective study confirms that CAIO anaesthesia is a promising method to anesthetize teeth with MIH that could therefore be routinely used by trained practitioners. PMID:26058304

  14. Molar Incisor Hypomineralization: A Study of Prevalence and Etiology in a Group of Iranian Children

    PubMed Central

    Ahmadi, Rahil; Ramazani, Nahid; Nourinasab, Rahmatollah

    2012-01-01

    Objective The aim of this study was to investigate the prevalence of molar incisor hypomineralization (MIH) and its relationship with systemic conditions in a group of Iranian children. Methods The study population comprised of 433 7-9 year olds, from four schools in Zahedan, Iran. Subjects were evaluated clinically by one examiner, and at a separate session, their mothers completed a coded medical history questionnaire. Hypo-mineralized molars and incisors were recorded based on DDE (developmental defects of enamel) index and DMFT (number of decayed, filled and missing teeth) was determined. Statistical analyses were performed using Chi-square and independent sample t-tests. Findings Fifty-five (12.7%) children showed MIH. The overall mean number of affected teeth was 0.2. The mean value of DMFT in MIH children was greater than in normal children. Demarcated opacities were the most frequent (76%) enamel defect. Mother's and child's medical problems during prenatal, perinatal and post natal period were significantly remarkable in MIH children. Conclusion The prevalence of MIH in a group of Iranian children was 12.7%. Prenatal, perinatal and post natal medical conditions were more prevalent in children affected by MIH. PMID:23056894

  15. Determination of sexual dimorphism via maxillary first molar teeth in Himachali population

    PubMed Central

    Singla, Swati; Gupta, Rakhi; Puri, Abhiney; Bansal, Sucheta; Singla, Smita; Nangia, Rajat

    2015-01-01

    Context: Sex determination of skeletal remains forms part of archaeological and medicolegal examinations. It is an aspect of forensic odontology. Forensic odontology primarily deals with identification, based on recognition of unique features present in an individual's dental structures. Correct sex determination limits the pool of missing persons to just one half of the population. Aim of Study: Purpose of this study is to evaluate the existence of sexual dimorphism and variation in left and right maxillary first molars using bucco-lingual and mesio-distal dimensions in population of Sirmour District, H.P. Materials and Methods: Base sample comprised 100 subjects (50 males and 50 females) of an age group ranging from 17 to 25 years. Statistical Analysis Used: Unpaired t-test. Results: It was observed that the comparison of mean values of bucco-lingual and mesio-distal parameters showed highly statistically significant differences between males and females, measured both intraorally and on study casts. There were no significant differences between the mean values of both the parameters on the left side as compared to right side. Conclusion: The study concludes that sexual dimorphism is population specific. Among Himachali people, mesio-distal dimensions and bucco-lingual dimensions of first molar can aid in sex determination. PMID:26005295

  16. Aminoacid Composition and Partial Specific Volume of Citrate Oxaloacetate Lyase

    Microsoft Academic Search

    T. J. Bowen

    1965-01-01

    STUDIES of the amino-acid composition of citrate oxaloacetate lyase (citrate lyase) from Aerobacter aerogenes were made using the pure enzyme prepared by methods previously described1,2. The amino-acid composition of the enzyme was determined using the technique of high-voltage electrophoresis to separate the amino-acids in a protein hydrolysate3. Hydrolysates of two quantities of enzyme (5.0 mg), by `AnalaR' hydrochloric acid (6

  17. Trigonometric Integrals via Partial Fractions

    ERIC Educational Resources Information Center

    Chen, H.; Fulford, M.

    2005-01-01

    Parametric differentiation is used to derive the partial fractions decompositions of certain rational functions. Those decompositions enable us to integrate some new combinations of trigonometric functions.

  18. Low partial discharge vacuum feedthrough

    NASA Technical Reports Server (NTRS)

    Benham, J. W.; Peck, S. R.

    1979-01-01

    Relatively discharge free vacuum feedthrough uses silver-plated copper conductor jacketed by carbon filled silicon semiconductor to reduce concentrated electric fields and minimize occurrence of partial discharge.

  19. Generalized quantum partial adiabatic evolution

    NASA Astrophysics Data System (ADS)

    Sun, Jie; Lu, Songfeng; Liu, Fang

    2014-04-01

    Due to the intrinsic similarity between partial adiabatic evolution and global adiabatic evolution, we generalize the partial adiabatic evolution proposed recently to its local adiabatic algorithm version. However, unlike that the local adiabatic evolution can speed up the global adiabatic algorithm quadratically, we prove that this new quantum algorithm presented here just has the same time complexity as the original partial adiabatic evolution. This may imply the optimality of the original partial adiabatic evolution or its generalized version. Additionally, a concrete example is given to further support our conclusion.

  20. Approach for determination of ATP:ADP molar ratio in mixed solution by surface-enhanced Raman scattering.

    PubMed

    Fang, Hui; Yin, Hong Jun; Lv, Ming Yang; Xu, Hai Jun; Zhao, Yong Mei; Zhang, Xin; Wu, Zheng Long; Liu, Luo; Tan, Tian Wei

    2015-07-15

    The ATP:ADP molar ratio is an important physiological factor. However, in previous literatures, ATP and ADP could not be distinguished by Raman spectroscopy due to the high similarity of molecular structure. To challenge this problem, also considering that the ? phosphate group may interact with adenine group and cause a different variation of the Raman spectrum than that of ADP, a highly sensitive, low-cost, environment protecting, flexible and super-hydrophobic Au nanoparticles/cicada wing (Au/CW) substrate with three-dimension structure was fabricated and employed as an active surface-enhanced Raman scattering (SERS) substrate to detect the ATP:ADP molar ratios. The concentration as low as 10(-8)M for ATP and ADP was analyzed to determine the limit of detection. This SERS study on various ATP:ADP molar ratios demonstrates that ATP:ADP could be distinguished and the quantitative determination of ATP content was achieved. Moreover, a principle was speculated based on the molecular structures of ATP and ADP of the Raman peaks centered at ~685 and ~731cm(-1) to explain the linear relationship between the area ratio and the molar ratio. A new method has been developed for quantitative determination of ATP:ADP molar ratio based on Au/CW substrate by the SERS method. PMID:25703730

  1. Accuracy of identifying juvenile/adult status from third molar development using prediction probabilities derived from logistic regression analysis.

    PubMed

    Acharya, Ashith B; Bhowmik, Biyas; Naikmasur, Venkatesh G

    2014-05-01

    The use of third molars in predicting juvenile/adult status (molar development was assessed using Köhler's grading on 268 orthopantomograms of Indian subjects. Logistic regression analysis was applied to determine allocation accuracy of juvenile/adult status and the level of probability that is "reliable" in predicting juvenile/adult status. Allocation accuracies ranged between 75.8% and 78.2% for the sexes combined, with minimal male-female differences. Adults were categorized more accurately than juveniles, suggesting that Köhler's grading puts Indian juveniles at greater risk of unwarranted punishment. In both sexes, juvenile/adult status was "reliably" predicted when the probability was >80% using individual third molars (excepting the lower right third molar in males); combining upper and lower third molars on the left/right sides, "reliable" predictions were possible when the probability was >80% and >90% for females and males, respectively. Overall, "reliable" juvenile/adult status prediction was achieved in c. 36% of subjects. PMID:24313875

  2. Backstepping and Partial Asymptotic Stabilization: Applications to Partial Attitude Control

    Microsoft Academic Search

    Chaker Jammazi

    2008-01-01

    In this paper, the problem of partial asymptotic stabilization of nonlinear control cascaded systems with integrators is considered. Unfortunately, many controllable control systems present an anomaly, which is the non complete stabilization via continuous pure-state feedback. This is due to Brockett necessary condition. In order to cope with this difficulty we propose in this work the partial asymptotic stabilization. For

  3. Guided tissue regeneration in the treatment of degree II furcations in maxillary molars.

    PubMed

    Pontoriero, R; Lindhe, J

    1995-10-01

    he present clinical trial was designed to evaluate the clinical effect of GTR in the treatment of degree II furcation defects in maxillary molars. 28 patients, 21 to 59 years of age, referred for treatment of advanced periodontal disease were included. They presented with similar periodontal lesions in the right and the left maxillary molar regions, but had only one surface which exhibited furcation involvement. A total of 28 pairs of contralateral furcation defects of degree II including 18 interproximal pairs (10 mesial, 8 distal) and 10 buccal pairs, were available for the study. After the completion of basic therapy, the furcation involved molars in the right and left quadrants in each patient were randomly assigned to either a test or a control treatment procedure. Following flap elevation, scaling, root planing and granulation tissue removal, an e-PTFE membrane at the test site was adjusted to cover the entrance to the furcation defect and adjacent bone and was retained in this position with sling sutures. The mucoperiostal flaps were subsequently adjusted and positioned to cover the entire surface of the membrane and were secured in this position. An identical surgical procedure was performed in the control tooth regions with the exception of the placement of a teflon membrane. No periodontal dressing was used. Starting the day before surgery and continuing for 7 days, the patients received 1 + 1 g of Amoxicillin per day; morning and evening. The sutures were removed after 10 days. At the test sites, the membranes were removed after 6 weeks of healing. The treated sites were examined and re-entry procedures performed 6 months after reconstructive surgery. Open flap debridement at maxillary furcations of degree II resulted in some gingival recession and probing depth reduction, but no change occurred in parameters describing probing attachment or bone levels. The addition of GTR at buccal furcations enhanced the treatment result by promoting probing attachment and bone gain and reduced the amount of soft tissue recession above what was accomplished by flap debridement alone. No such benefit of membrane therapy was observed at mesial and distal furcations. PMID:8682922

  4. Economic modeling of sealing primary molars using a "value of information" approach.

    PubMed

    Ney, J P; van der Goes, D N; Chi, D L

    2014-09-01

    The objective was to evaluate 2 primary molar sealant strategies for publicly insured children using an "expected value of perfect information" (EVPI) approach. We converted a 10,000-observation tooth-level cost-effectiveness simulation model comparing 2 primary molar sealant strategies - always seal (AS) and standard care (SC) - with a 1,250-observation child-level model. Costs per child per restoration or extraction averted were estimated. Opportunity losses under the AS strategy were determined for children for whom SC was the optimal choice. We determined the EVPI by multiplying mean opportunity losses by the projected incident population of publicly insured 3-year-olds in the US over 10 years with costs discounted at 2%. All analyses were conducted under assumptions of high and low intrachild correlations between at-risk teeth. The AS strategy cost $43.68 over SC (95% CI: -$5.50, $92.86) per child per restoration or extraction averted under the high intrachild correlation assumption and $15.54 (95% CI $7.86, $23.20) under the low intrachild correlation. Under high intrachild correlation, mean opportunity losses were $80.28 (95% CI: $76.39, $84.17) per child, and AS was the optimal strategy in 31% of children. Under low correlation, mean opportunity losses were $14.61 (95% CI: $12.20, $17.68) and AS was the optimal strategy in 87% of children. The EVPI was calculated at $530,813,740 and $96,578,389 (for high and low intrachild correlation, respectively), for a projected total incident population of 8,059,712 children. On average, always sealing primary molars is more effective than standard care, but widespread implementation of this preventive approach among publicly insured children would result in large opportunity losses. Additional research is needed to identify the subgroups of publicly insured children who would benefit the most from this effective and potentially cost-saving public health intervention. PMID:25056993

  5. A Novel Approach for Restoration of Hemisectioned Mandibular Second Molar with Modified Tunnel Restoration: A Case Report

    PubMed Central

    Varma K, Madhu; Satish R, Kalyan; Kumar M, Sita Rama; Sajjan, Girija S

    2014-01-01

    Hemisection refers to sectioning of a mandibular molar into two halves followed by removal of the diseased root and its coronal portion. Hemisection of a mandibular molar may be a suitable treatment option when the decay is restricted to one root and the other root is healthy. The retained root is endodontically treated and the furcation area is made self-cleansable. Retained tooth structure is restored as premolar which helps to reduce the masticatory load. Hemisection of mandibular molar was often referred to as premolarization. Studies showed that the remaining coronal structure influenced the fracture resistance of endodontically treated maxillary first premolars. Clinical experience showed the viability of tunnel restoration as an alternative to class II conventional cavity preparation in initial proximal lesion. This article discusses a case that presents the novel technique involved in restoration of the remaining hemisected tooth using modified tunnel restoration. PMID:25478460

  6. Dental age estimation utilizing third molar development: A review of principles, methods, and population studies used in the United States.

    PubMed

    Lewis, James M; Senn, David R

    2010-09-10

    When an individual reaches the age of legal majority, their treatment within the criminal and civil legal systems is changed dramatically in the United States. Forensic odontologists are often asked to assist government agencies in estimating the ages of persons who may or may not have reached that legally important age. The third molars are the only teeth useful as forensic estimators of chronological age in the target age group. This study reviews the principles, methodology, and population data of the most commonly used technique in the United States, the analysis of the third molar development based on modified Demirjian staging. The method analyzes the developing third molar to estimate mean age, age intervals and the empirical probability that an individual has reached the anniversary of her or his eighteenth birthday. PMID:20493649

  7. Molar-mass measurement of a 28Si-enriched silicon crystal for determination of the Avogadro constant

    NASA Astrophysics Data System (ADS)

    Narukawa, Tomohiro; Hioki, Akiharu; Kuramoto, Naoki; Fujii, Kenichi

    2014-06-01

    The molar mass of a 28Si-enriched crystal was measured at the National Metrology Institute of Japan to determine the Avogadro constant by the x-ray crystal density method as part of the International Avogadro Coordination project. The molar mass was determined by isotope ratio measurements using a multicollector inductively coupled plasma mass spectrometer combined with an isotope dilution technique. The 28Si-enriched crystal was dissolved in tetramethylammonium hydroxide and three different blended solutions were used to correct for mass bias in the measurement. The molar mass of the 28Si-enriched crystal was determined to be 27.976?970 09 g mol-1 with a standard uncertainty of 0.000?000 14 g mol-1. This corresponds to a relative standard uncertainty of 5.2 × 10-9. This result is consistent with measurements reported by the Physikalisch-Technische Bundesanstalt, Germany.

  8. On partially static Kaplan turbines

    Microsoft Academic Search

    H. Grassmann; M. L. Ganis

    2005-01-01

    Recently, it was shown that it is possible to increase the power of a wind turbine by a factor of 5 by operating it in a partially static mode. In this paper, we explore whether also Kaplan turbines can be made partially static in order to increase their power or in order to operate them under a smaller head. As

  9. Partial drought conditions in Nepal

    Microsoft Academic Search

    CHANDRA K. SHARMA; Babar Mahal

    In a mountainous country like Nepal, where precipitation from the monsoon (July) and the westerlies (January) occurs yearly, it is surprising to find partial drought conditions in space and time. This paper deals with the partial drought conditions and also the measures to combat them.

  10. Partial discharge measurement and interpretation

    Microsoft Academic Search

    David A. Nattrass

    1988-01-01

    An overview is given of partial discharge patterns, their evaluation, and determination of their origin. Some brief comparisons of test equipment considered to be of general interest are made. The intent is to assist practitioners in the interpretation of results as well as in the accurate discrimination between true partial discharges within an insulating structure and other unwanted conduction or

  11. Accuracy of predicting 18 years of age from mandibular third molar development in an Indian sample using Demirjian’s ten-stage criteria

    Microsoft Academic Search

    Ashith B. Acharya

    2011-01-01

    Predicting 18 years of age can be crucial in forensic contexts. The third molar is the only tooth developing during this chronological\\u000a period and has been used to estimate minority\\/majority status (<\\/?18 years). Conventionally, Demirjian’s grading has been\\u000a used to assess third molar development although the method was not originally intended for evaluating this tooth. Demirjian\\u000a incorporated third molar assessment in a

  12. Biogeography and molar morphology of Pleistocene African elephants: new evidence from Elandsfontein, Western Cape Province, South Africa

    NASA Astrophysics Data System (ADS)

    Smith, Kathlyn M.; Stynder, Deano D.

    2015-05-01

    Elandsfontein (EFT) is a Middle Pleistocene archaeological/paleontological site located in the Western Cape Province of South Africa. The largest herbivore in the assemblage is Loxodonta atlantica zulu, an extinct member of the genus that includes modern African elephants. No Elephas recki specimens were recovered at EFT, despite their common occurrence in other regions of Africa at the same time. Because E. recki and L. atlantica molars are similar in appearance, but the two species are traditionally viewed as dominating different regions of Africa during the Pleistocene, isolated molars may on occasions have been assessed to species level on the basis of geography rather than morphology. The last morphologic evaluation of EFT elephants was conducted in the 1970s, and revisiting this issue with new specimens provides added insight into the evolution of elephants in Africa. Reevaluating morphological characteristics of EFT elephant molars, through qualitative and quantitative description and comparison with Middle Pleistocene E. recki recki, L. atlantica atlantica, and L. atlantica zulu molar morphology, corroborates assessment of EFT elephants as L. a. zulu. Two recently discovered, previously undescribed molars from EFT show that molars of L. a. zulu exhibit greater variation in enamel thickness, lamellar frequency, and occlusal surface morphology than previously reported. An update of the Pleistocene biogeography of Loxodonta and Elephas indicates that fossil remains of both are often found at the same localities in eastern Africa. Their rare co-occurrences in the north and south, however, suggest geographic separation of the two genera in at least some regions of Africa, which may have been based on habitat preference.

  13. Comparative evaluation of Ferric Sulfate, Electrosurgical and Diode Laser on human primary molars pulpotomy: an “in-vivo” study

    PubMed Central

    Yadav, P; Indushekar, KR; Saraf, BG; Sheoran, N; Sardana, D

    2014-01-01

    Background and aims: Despite modern advances in the prevention of dental caries and increased understanding of the importance of maintaining the natural primary dentition, many teeth are still lost prematurely. This can lead to malocclusion with aesthetic, phonetic and functional problems that may be transient or permanent. Therefore, maintaining the integrity and health of the oral tissues is the primary objective of pulp treatment. Pulpotomy has remained an acceptable and mainstay treatment in preserving the vitality of primary tooth and prolonging its life till the permanent successor erupts. Various materials and techniques are available for pulpotomy on primary molars; all with some advantages and disadvantages. The present study was carried out on 45 primary molars to evaluate and compare the clinical and radiographic success of diode laser, electrosurgical and ferric sulfate pulpotomy over a period of 9 months. Materials (Subjects) and Methods: The forty five primary molars were randomly and equally divided into three treatment groups which were as follows: Group A: 15 primary molars treated with 15.5% Ferric sulfate Group B: 15 primary molars treated with electrosurgical unit and Group C: 15 primary molars treated with diode laser. All teeth in three categories were followed up clinically and radiographically at 1, 3, 6 and 9 months post treatment and the findings were recorded on the prepared proforma Results: Clinically, 86.6% success rate was found in ferric sulfate group whereas 100% success rate was found in electrosurgical and diode laser groups. Radiographically, 80% success rate was found in all the three groups at the end of 9 months with internal resorption being the most common cause of failure after pulpotomy. Conclusions: Thus, electrosurgery and diode lasers appear to be acceptable alternative to pharmacotherapeutic pulpotomy agents. PMID:24771970

  14. Immunohistochemical demonstration of exocytosis-regulating proteins within rat molar dentinal tubules.

    PubMed

    Norlin, T; Hilliges, M; Brodin, L

    1999-03-01

    No morphologically defined synaptic structures have so far been detected between nerve terminals and the dentine-producing odontoblasts. Recent studies of the molecular mechanisms in neuronal exocytosis have identified several proteins that participate in synaptic-vesicle exocytosis. By localizing these proteins with immunohistochemical methods, information about the capacity for synaptic exocytosis should be obtained. Here, antibodies directed against some of the exocytosis-related proteins were used to investigate whether they are present in nerve fibers within the dentinal tubules in rat molars. Antibodies against synaptosome-associated protein of 25 kDa, Rab 3, synaptotagmin and synapsin all produced a punctuate staining pattern, suggesting that the proteins are accumulated in bouton-like elements. The results demonstrate that a set of exocytosis-related proteins is accumulated in the dentinal tubules, most probably within the intradentinal nerves. This finding is consistent with the hypothesis that intradentinal nerves can mediate efferent signals. PMID:10217513

  15. Solution properties of high-molar-mass hyaluronans: the biopolymer degradation by ascorbate.

    PubMed

    Soltés, Ladislav; Valachová, Katarína; Mendichi, Raniero; Kogan, Grigorij; Arnhold, Juergen; Gemeiner, Peter

    2007-06-11

    An accurate molecular characterization, molar mass and size distributions, of 10 hyaluronan (HA) samples was performed by using a multi-angle light scattering detector connected on-line to a size exclusion chromatographic system. The dynamic viscosity eta of the HA solutions was investigated using a rotational viscometer. On monitoring the sample dynamic viscosity for up to 5h, a small however constant increase of the eta value was observed, indicating rheopectic behavior of all 10 HA solutions. Addition of ascorbic acid to the HA solutions caused significant changes in the rheological properties of the samples investigated. The change of eta values in the course of time was explained by the redox reactions (caused by the added ascorbate) that occur during the dynamic viscosity monitoring. PMID:17362893

  16. Coumarin-bearing triarylamine sensitizers with high molar extinction coefficient for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Zhong, Changjian; Gao, Jianrong; Cui, Yanhong; Li, Ting; Han, Liang

    2015-01-01

    Coumarin unit is introduced into triarylamine and three organic sensitizers are designed and synthesized with triarylamine bearing coumarin moiety as the electron donor, conjugated system containing thiophene unit as the ?-bridge, and cyanoacetic acid moiety as the electron acceptor. The light-harvesting capabilities and photovoltaic performance of these dyes are investigated systematically with the comparison of different ?-bridges. High molar extinction coefficients are observed in these triarylamine dyes and the photocurrent and photovoltage are increased with the introduction of another thiophene or benzene. Optimal photovoltaic performance (? = 6.24%, Voc = 690 mV, Jsc = 14.33 mA cm-2, and ff = 0.63) is observed in the DSSC based on dye with thiophene-phenyl unit as the ?-conjugated bridge under 100 mW cm-2 simulated AM 1.5 G solar irradiation.

  17. Fracture Resistance of Non-Metallic Molar Crowns Manufactured with CEREC 3D

    NASA Astrophysics Data System (ADS)

    Madani, Dalia A.

    Objectives. To compare fracture strength and fatigue resistance of ceramic (ProCAD, Ivoclar-Vivadent) (C) and resin composite (Paradigm MZ100, 3M/ ESPE) (R) crowns made with CEREC-3D. Methods. A prepared ivorine molar tooth was duplicated to produce 40 identical prepared specimens made of epoxy resin (Viade). Twenty (C) crowns and 20 (R) were cemented to their dies using resin cement. Ten of each group were subjected to compressive loading to fracture. The remaining 10 of each group were subjected to mechanical cyclic loading for 500,000 cycles. The survivors were subjected to compressive loading to fracture. Results. No significant difference in mean fracture load was found between the two materials. However, only 30% of the (C) crowns vs. 100% of the (R) crowns survived the cyclic loading test. Conclusions. (R) crowns demonstrated higher fatigue Resistance than (C) crowns in-vitro and might better resist cracking in-vivo.

  18. Joubert Syndrome: The Molar Tooth Sign of the Mid-Brain

    PubMed Central

    Nag, C; Ghosh, M; Das, K; Ghosh, TN

    2013-01-01

    Joubert syndrome (JS) is a very rare, autosomal-recessive condition. It is characterized by agenesis of cerebellar vermis, abnormal eye movements with nystagmus, episodes of hyperpnea and apnea, delayed generalized motor development, retinal coloboma and dystrophy and, sometimes, multicystic kidney disease. The importance of recognizing JS is related to the outcome and its potential complications. Prenatal diagnosis by ultarsonography and antenatal magnetic resonance imaging (MRI) is also possible. We have diagnosed a case of JS in a male infant with history of delayed mental and motor milestone development, history of abnormal breathing pattern, abnormal limb movement, generalized hypotonia and abnormal head movements with nystagmus. MRI showed hypoplastic cerebellar vermis with hypoplasia of the superior cerebellar peduncle resembling the “Molar Tooth Sign” in the mid-brain. PMID:23919210

  19. Maxillary first molar with seven root canals diagnosed with cone-beam computed tomography scanning.

    PubMed

    Munavalli, Anil; Kambale, Sharnappa; Bandekar, Siddhesh; Ajgaonkar, Nishant

    2015-01-01

    Nonsurgical endodontic therapy of a right maxillary first molar with three roots and seven root canals. This unusual morphology was diagnosed using a dental operating microscope (DOM) and confirmed with the help of cone-beam computed tomography (CBCT) images. CBCT axial images showed that both the palatal and distobuccal root have a Vertucci type II canal pattern, whereas the mesiobuccal root showed a Sert and Bayirli type XVIII canal configuration. The use of a DOM and CBCT imaging in endodontically challenging cases can facilitate a better understanding of the complex root canal anatomy, which ultimately enables the clinician to explore the root canal system and clean, shape, and obturate it more efficiently. PMID:25961622

  20. Comparative study of the upper molar occlusal table morphology among seven human populations.

    PubMed

    Kanazawa, E; Morris, D H; Sekikawa, M; Ozaki, T

    1988-10-01

    Three-dimensional morphology of the occlusal table of the upper first molars was compared in seven racial populations. Materials were moiré contourograms collected by ourselves over 5 years. Intercuspal distances and cuspal heights were comparatively studied in this analysis. When the populations were arranged in the order of these sizes, their arrangements based on intercuspal distances and cuspal heights were quite different from each other. When intercuspal distances were scaled by protocone-paracone distance, the distances connecting distal cusps were significantly smaller in Mongoloids (Japanese and Eskimo) than in Caucasoids (Dutch and Asiatic Indian), which suggests a reduction tendency of distal cusps in Mongoloids. This tendency was intermediate in Negroids and Australoid. Principal coordinate analysis was carried out on the basis of a similarity matrix including both intercuspal distances and cuspal heights. The result suggested that the three-dimensional shape of the occlusal table was distinguishable in four representative racial populations. PMID:3207172

  1. Correction of the occlusal and functional sequelae of mandibular condyle fractures using orthodontic mini-implant molar intrusion.

    PubMed

    Cousley, Richard R J; Gibbons, Andrew J

    2014-09-01

    We report on the non-surgical management of an adult female whose bilateral mandibular condylar fractures had resulted in a clockwise (posterior) mandibular rotation, limitation of mandibular movements and increased occlusal loading on the molar teeth. She refused maxillary surgery and was treated with a minimally-invasive approach, involving orthodontic fixed appliances and mini-implant intrusion of the maxillary molar teeth. This provided both occlusal and functional improvements, including a significant increase in the inter-incisal distance, which were stable after one year of retention. PMID:24521751

  2. Molar Distalization with Different Pendulum Appliances: In Vitro Registration of Orthodontic Forces and Moments in the Initial Phase

    Microsoft Academic Search

    Gero Kinzinger; Christian Syrée; Ulrike Fritz; Peter Diedrich

    2004-01-01

    \\u000a Abstract.\\u000a \\u000a Aim:\\u000a   Registration of the orthodontic forces and moments acting with different types of pendulum appliance for non-compliance upper molar distalization in an in vitro study.\\u000a Material and Methods:\\u000a   The purpose-designed test set-up comprised the following components: artificial maxilla with anchorage unit and two electrothermodynamic (ETD) molars, electronic measuring unit for temperature control and regulation, and a sensor unit with

  3. Mandibular first molars with disto-lingual roots: review and clinical management.

    PubMed

    Abella, F; Patel, S; Durán-Sindreu, F; Mercadé, M; Roig, M

    2012-11-01

    The purpose of this review was (i) to conduct a literature review on the prevalence and morphologic classification of mandibular first molars with disto-lingual (DL) roots, and (ii) to discuss the clinical approach to diagnosis and root canal treatment of these teeth. A search was carried out on electronic (MEDLINE, PubMed and Cochrane) and hand databases, which covered all publications from 1970 to December 2011. Two reviewers independently assessed the studies and recorded type of study, origin and sample sizes, number of teeth with three roots and type of root canal configuration. Forty-five studies were identified with a total of 19,056 mandibular first molar teeth. The frequency of DL roots was 14.4% and was associated with certain ethnic populations. The most common canal configuration of mesial and distal roots was Vertucci types IV and I, respectively. No significant differences were observed in the prevalence of DL roots according to gender. Variable results related to side were observed as well as a trend in bilateral occurrence. The root length of the DL roots was in general shorter than that of the disto-buccal roots (DB). Most DL roots had a greater angle of curvature and a smaller radius of curvature in a bucco-lingual orientation. The best methods to identify DL roots are a 25° mesial parallax periapical radiograph or cone-beam computed tomography (CBCT). A trapezoidal shape access cavity is desirable to locate the orifice of the DL canal. Clinicians should be aware of the variable furcation levels during coronal pre-flaring or post-space preparation to avoid furcal/strip perforations and a weakening of DL roots. PMID:22681628

  4. Reliability of CBCT as an assessment tool for mandibular molars furcation defects

    NASA Astrophysics Data System (ADS)

    Marinescu, Adrian George; Boariu, Marius; Rusu, Darian; Stratul, Stefan-Ioan; Ogodescu, Alexandru

    2014-01-01

    Introduction. In numerous clinical situations it is not possible to have an exact clinical evaluation of the furcation defects. Recently the use of CBCT in periodontology has led to an increased precision in diagnostic. Aim. To determine the accuracy of CBCT as diagnostic tool of the furcation defects. Material and method. 19 patients with generalised advanced chronic periodontitis were included in this study, presenting a total of 25 lower molars with different degrees of furcation defects. Clinical and digital measurements (in mm) were performed on all the molars involved. The data obtained has been compared and statistically analysed. Results. The analysis of primary data has demonstrated that all the furcation grade II and III defects were revealed using the CBCT technique. Regarding the incipient defects (grade I Hamp < 3mm), the dimensions measured on CBCT images were slightly bigger. The results have shown that 84% of the defects detected by CBCT have been confirmed by clinical measurements. These data are similar to those revealed by other studies1. Conclusions. The use of CBCT technique in evaluation and diagnosis of human mandibular furcation defects can provide many important information regarding the size and aspect of the interradicular defect, efficiently and noninvasively. CBCT technique is used more effectively in detection of advanced furcation degree compared to incipient ones. However, the CBCT examination cannot replace, at least in this stage of development, the clinical measurements, especially the intraoperative ones, which are considered to represent the „golden standard" in this domain.

  5. Lipid concentration and molar ratio boundaries for the use of isotropic bicelles.

    PubMed

    Beaugrand, Maïwenn; Arnold, Alexandre A; Hénin, Jérôme; Warschawski, Dror E; Williamson, Philip T F; Marcotte, Isabelle

    2014-06-01

    Bicelles are model membranes generally made of long-chain dimyristoylphosphatidylcholine (DMPC) and short-chain dihexanoyl-PC (DHPC). They are extensively used in the study of membrane interactions and structure determination of membrane-associated peptides, since their composition and morphology mimic the widespread PC-rich natural eukaryotic membranes. At low DMPC/DHPC (q) molar ratios, fast-tumbling bicelles are formed in which the DMPC bilayer is stabilized by DHPC molecules in the high-curvature rim region. Experimental constraints imposed by techniques such as circular dichroism, dynamic light scattering, or microscopy may require the use of bicelles at high dilutions. Studies have shown that such conditions induce the formation of small aggregates and alter the lipid-to-detergent ratio of the bicelle assemblies. The objectives of this work were to determine the exact composition of those DMPC/DHPC isotropic bicelles and study the lipid miscibility. This was done using (31)P nuclear magnetic resonance (NMR) and exploring a wide range of lipid concentrations (2-400 mM) and q ratios (0.15-2). Our data demonstrate how dilution modifies the actual DMPC/DHPC molar ratio in the bicelles. Care must be taken for samples with a total lipid concentration ?250 mM and especially at q ? 1.5-2, since moderate dilutions could lead to the formation of large and slow-tumbling lipid structures that could hinder the use of solution NMR methods, circular dichroism or dynamic light scattering studies. Our results, supported by infrared spectroscopy and molecular dynamics simulations, also show that phospholipids in bicelles are largely segregated only when q > 1. Boundaries are presented within which control of the bicelles' q ratio is possible. This work, thus, intends to guide the choice of q ratio and total phospholipid concentration when using isotropic bicelles. PMID:24797658

  6. Manual and rotary instrumentation ability to reduce Enterococcus faecalis associated with photodynamic therapy in deciduous molars.

    PubMed

    Pinheiro, Sérgio Luiz; Silva, Josianne Neres da; Gonçalves, Rafael Orro; Villalpando, Karina Teixeira

    2014-12-01

    This aim of this study was to assess the ability of manual or rotary instrumentation associated with photodynamic therapy (PDT) to reduce Enterococcus faecalis using three combinations of light/photosensitizers: toluidine blue O/laser, fuchsin/halogen light and fuchsin/LED. Twenty deciduous molars were selected and contaminated with Enterococcus faecalis (McFarland 0.5 scale). Working length determination was performed by visual method. The teeth were randomly divided into two groups: G1 (n=10): manual instrumentation (Kerr-type files) and G2 (n=10): rotary instrumentation (ProTaper system). The bacteria were collected three times using sterile paper cones compatible with the anatomic diameter of the root canal for 30 s before and after instrumentation and after PDT. The samples were diluted in peptone water, seeded on blood agar plates and incubated in an oven at 37 °C for colony-forming units counting. The decrease of E. faecalis counts after instrumentation and after PDT was compared using the Wilcoxon test, t-test and Kruskal Wallis test. A significant reduction of E. faecalis occurred after manual and rotary instrumentation and after PDT using the three combinations of light/photosensitizer (p<0.05). It may be concluded that both rotary and manual instrumentation reduced E. faecalis. Fuchsin with halogen light or LED irradiation and toluidine blue O with laser irradiation can be used to reduce E. faecalis in root canals of primary molars. PDT can be used as an adjuvant to conventional endodontic treatment. PMID:25590196

  7. The Annotated Mina, Volume Two

    E-print Network

    2014-03-10

    1 Mina de Malfois Volume Two Disclaimer: This is a work of fiction. No resemblance is intended to any person or persons living, dead, or online. No BNFs were harmed in the making of this fic. Permissions: These stories... and characters are the sole property of the author, but she lends them out for fanfic and fanart. A partial list of Mina de Malfois/Sanguinity things by other people can be found at the back of this volume. For further Minaverseness, try tracking down...

  8. The Annotated Mina, Volume Two 

    E-print Network

    2014-03-10

    1 Mina de Malfois Volume Two Disclaimer: This is a work of fiction. No resemblance is intended to any person or persons living, dead, or online. No BNFs were harmed in the making of this fic. Permissions: These stories... and characters are the sole property of the author, but she lends them out for fanfic and fanart. A partial list of Mina de Malfois/Sanguinity things by other people can be found at the back of this volume. For further Minaverseness, try tracking down...

  9. Excess Gibbs free energies at several temperatures and excess enthalpies and volumes at 298.15 K of butanenitrile with 2-methyl-1-propanol or 2-methyl-2-propanol

    Microsoft Academic Search

    Rosa Garriga; Francisco Sánchez; Pascual Pérez; Mariano Gracia

    1997-01-01

    Vapour pressures of butanenitrile +2-methyl-1-propanol or +2-methyl-2-propanol at several temperatures between 278.15 and 323.15 K were measured by a static method. Excess molar enthalpies and volumes were also measured at T = 298.15 K. Reduction of the vapour pressures to obtain activity coefficients and excess molar Gibbs free energies was carried out by fitting the vapour pressure data to the

  10. High Productivity Implantation ''PARTIAL IMPLANT''

    SciTech Connect

    Hino, Masayoshi; Miyamoto, Naoki; Sakai, Shigeki; Matsumoto, Takao [Nissin Ion Equipment Co., LTD., Kyoto (Japan)

    2008-11-03

    The patterned ion implantation 'PARTIAL IMPLANT' has been developed as a productivity improvement tool. The Partial Implant can form several different ion dose areas on the wafer surface by controlling the speed of wafer moving and the stepwise rotation of twist axis. The Partial Implant system contains two implant methods. One method is 'DIVIDE PARTIAL IMPLANT', that is aimed at reducing the consumption of the wafer. The Divide Partial Implant evenly divides dose area on one wafer surface into two or three different dose part. Any dose can be selected in each area. So the consumption of the wafer for experimental implantation can be reduced. The second method is 'RING PARTIAL IMPLANT' that is aimed at improving yield by correcting electrical characteristic of devices. The Ring Partial Implant can form concentric ion dose areas. The dose of wafer external area can be selected to be within plus or minus 30% of dose of wafer central area. So the electrical characteristic of devices can be corrected by controlling dose at edge side on the wafer.

  11. Report on ISS Oxygen Production, Resupply, and Partial Pressure Management

    NASA Technical Reports Server (NTRS)

    Schaezler, Ryan; Ghariani, Ahmed; Leonard, Daniel; Lehman, Daniel

    2011-01-01

    The majority of oxygen used on International Space Station (ISS) is for metabolic support and denitrogenation procedures prior to Extra-Vehicular Activities. Oxygen is supplied by various visiting vehicles such as the Progress and Shuttle in addition to oxygen production capability on both the United States On-Orbit Segment (USOS) and Russian Segment (RS). To maintain a habitable atmosphere the oxygen partial pressure is controlled between upper and lower bounds. The full range of the allowable oxygen partial pressure along with the increased ISS cabin volume is utilized as a buffer allowing days to pass between oxygen production or direct addition of oxygen to the atmosphere from reserves. This paper summarizes amount of oxygen supplied and produced from all of the sources and describes past experience of managing oxygen partial pressure along with the range of management options available to the ISS.

  12. Clinical application of partial splenic embolization.

    PubMed

    Guan, Yong-Song; Hu, Ying

    2014-01-01

    Partial splenic embolization (PSE) is one of the intra-arterial therapeutic approaches of diseases. With the development of interventional radiology, the applications of PSE in clinical practice are greatly extended, while various materials are developed for embolization use. Common indications of PSE include hypersplenism with portal hypertension, hereditary spherocytosis, thalassemia, autoimmune hemolytic anemia, splenic trauma, idiopathic thrombocytopenic purpura, splenic hemangioma, and liver cancer. It is also performed to exclude splenic artery aneurysms from the parent vessel lumen and prevent aneurysm rupture, to treat splenic artery steal syndrome and improve liver perfusion in liver transplant recipients, and to administer targeted treatment to areas of neoplastic disease in the splenic parenchyma. Indicators of the therapeutic effect evaluation of PSE comprise blood routine test, changes in hemodynamics and in splenic volume. Major complications of PSE include the pulmonary complications, severe infection, damages of renal and liver function, and portal vein thrombosis. The limitations of PSE exist mainly in the difficulties in selecting the arteries to embolize and in evaluating the embolized volume. PMID:25538966

  13. A Review on Prediction Methods for Molar Enthalpies of Vaporization of Hydrocarbons: The ELBA Method as the Best Answer

    NASA Astrophysics Data System (ADS)

    Santos, Rui C.; Leal, João P.

    2012-12-01

    A review on prediction methods for molar enthalpies of vaporization at T = 298.15 K of hydrocarbons is presented. A new method is proposed and compared with six of the most common used ones from the literature. This new method, the extended Laidler bond additivity (ELBA), was applied to the prediction of standard molar enthalpies of vaporization of hydrocarbons (alkanes, alkenes, alkynes, polyenes, poly-ynes, cycloalkanes, cycloalkenes, benzene compounds, biphenyl compounds, and polyphenyl compounds) at T = 298.15 K. A total of 260 experimental standard molar enthalpies of vaporization at T = 298.15 K were used for the parameters optimization. Comparison between the experimental values and those calculated using ELBA led to an average absolute difference of 0.35 kJ mol-1, corresponding to an average relative error of 0.92%. In addition, this new method proves to be better than the ones used for comparison with an independent set of 83 experimental standard molar enthalpies of vaporization at T = 298.15 K.

  14. Panoramic radiographs do not accurately detect curvature of or close association with the mandibular canal of mandibular third molar roots

    Microsoft Academic Search

    S. Thomas Deahl

    2003-01-01

    Original ArticleBell GW, Rodgers JM, Grime RJ, Edwards KL, Hahn MR, Dorman ML, et al. The accuracy of dental panoramic tomographs in determining the root morphology of mandibular third molar teeth before surgery. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2003;95(1):119–25.

  15. Lost and found: The third molars of Callimico goeldii and the evolution of the callitrichine postcanine dentition.

    PubMed

    Scott, Jeremiah E

    2015-06-01

    This study tests the hypothesis that the third molars of Callimico goeldii represent a reversal in evolutionary tooth loss within the Callitrichinae. Loss of third molars is part of a suite of unusual characters that has been used to unite marmosets and tamarins in a clade to the exclusion of Callimico. However, molecular phylogenetic studies provide consistent support for the hypothesis that marmosets are more closely related to Callimico than to tamarins, raising the possibility that some or all of the features shared by marmosets and tamarins are homoplastic. Here, I use the binary-state speciation and extinction (BiSSE) model and a sample of 249 extant primate species to demonstrate that, given the shape of the primate phylogenetic tree and the distribution of character states in extant taxa, models in which M3 loss is constrained to be irreversible are much less likely than models in which reversals are allowed to occur. This result provides support for the idea that the last common ancestor of Callimico and marmosets was characterized by the two-molared phenotype. The M3s of Callimico therefore appear to be secondarily derived rather than plesiomorphic. This conclusion may also apply to the other apparently plesiomorphic traits found in Callimico. Hypotheses regarding the re-evolution of M3 in the callitrichine clade and the origin and maintenance of the two-molared phenotype are discussed. PMID:25887279

  16. Endodontic Treatment of the Mandibular First Molar with Six Roots Canals – Two Case Reports and Literature Review

    PubMed Central

    Anderson, Craig

    2015-01-01

    The most common configuration of the mandibular first molar is the presence of two roots and three root canals. The objective of this work is to present two rare anatomic configurations with six root canals on two mandibular left first molars diagnosed during endodontic therapy. Root canal therapy was performed using a dental operating microscope. Ultrasonic troughing in the grooves in between the mesial root canals and in between the distal root canals was able to show the middle root canals. Large samples population characterization researches and systematic reviews were unable to detect a single case of six root canals configuration in a mandibular first molar in their investigations. Although it is a rare configuration, a six root canal configuration is possible to be found in the mandibular first molar. Three different pulp chamber configurations are possible to be found. Two or three roots may be present and the root configuration more common in the mesial root is the Type 8 and Type 12 for the distal root. Some concepts about the required technique to approach these cases are also debated. PMID:26023651

  17. Treatment of a maxillary molar in a patient presenting with florid cemento-osseous dysplasia: a case report.

    PubMed

    Tonioli, Matthew B; Schindler, William G

    2004-09-01

    A case report of a 49-year-old black woman with florid cemento-osseous dysplasia is presented. Endodontic treatment of a maxillary first molar and a general review of florid cemento-osseous dysplasia are presented. Treatment considerations including diagnosis, difficulty in radiographic interpretation, working length determination, and postoperative concerns are discussed. PMID:15329574

  18. Age at first molar emergence in early Miocene Afropithecus turkanensis and life-history evolution in the Hominoidea

    E-print Network

    Smith, Tanya M.

    Age at first molar emergence in early Miocene Afropithecus turkanensis and life-history evolution by Sivapithecus parvada (Function, Phylogeny, and Fossils: Miocene Hominoid Evolution and Adaptations, 1997, 173. 2003 Elsevier Science Ltd. All rights reserved. Keywords: Miocene hominoid; dentition; dental eruption

  19. The Presence of Mandibular Third Molars During Sagittal Split Osteotomies Does not Increase the Risk of Complications

    Microsoft Academic Search

    Jean-Charles Doucet; Archibald D. Morrison; Benjamin R. Davis; Curtis E. Gregoire; Reginald Goodday; David S. Precious

    PurposeThe purpose of this study was to prospectively investigate the effects of the presence or absence of third molars during sagittal split osteotomies (SSOs) on the frequency of unfavorable fractures, degree of entrapment and manipulation of the inferior alveolar nerve (IAN), and procedural time.

  20. Molar concentration on k2so4 and soil ph estimation of extractable c with chloroform fumigation-extraction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methods of determining soil microbial biomass need to be reliable and produce consistent results across soils with a wide range of properties. We investigated the effect of extractant molarity (distilled water and 0.001, 0.01, 0.1, and 0.5 M K2SO4) on the flush of C (i.e., the difference between fum...

  1. Effect of traumatic occlusion on CGRP and SP immunoreactive nerve fibre morphology in rat molar pulp and periodontium

    Microsoft Academic Search

    I. Kvinnsland; K. J. Heyeraas

    1992-01-01

    Traumatic occlusion provides a trauma that affects the whole tooth and its supporting tissues. To study the effect of this trauma on CGRP and SP immunoreactive nerve morphology in pulp and periodontium, traumatic occlusion was induced in 2-months-old rats. The occlusal surface of the first maxillary molar in 30 rats were unilaterally raised 1 mm with a composite material. At

  2. Clinical performance of a new laser fluorescence device for detection of occlusal caries lesions in permanent molars

    Microsoft Academic Search

    K. C. Huth; K. W. Neuhaus; M. Gygax; K. Bücher; A. Crispin; E. Paschos; R. Hickel; A. Lussi

    2008-01-01

    ObjectivesTo determine the clinical performance of a laser fluorescence device (DIAGNOdent pen, KaVo) to discriminate between different occlusal caries depths (D0–D1–4; D0–2–D3,4) in permanent molars.

  3. Inferior alveolar nerve damage after lower third molar surgical extraction: A prospective study of 1117 surgical extractions

    Microsoft Academic Search

    Eduard Valmaseda-Castellón; Leonardo Berini-Aytés; Cosme Gay-Escoda

    2001-01-01

    Purpose: The purpose of this study was to determine the incidence of inferior alveolar nerve (IAN) damage after surgical removal of lower third molars, to identify the causes, and to construct a predictive model to assess the risk of IAN injury. Study Design: We performed a nonrandomized forward prospective study of 946 consecutive outpatients subjected to surgical extraction of 1117

  4. Efficacy of platelet-rich plasma applied to post-extraction retained lower third molar alveoli. A systematic review

    PubMed Central

    Barona-Dorado, Cristina; González-Regueiro, Iria; Martín-Ares, María; Arias-Irimia, Oscar; Martínez-González, José M.

    2014-01-01

    Dental retentions have a high prevalence among the general population and their removal can involve multiple complications. The use of platelet rich plasma has been proposed in an attempt to avoid these complications, as it contains high growth factors and stimulates diverse biological functions that facilitate the healing of soft and hard tissues. Objectives: To evaluate the available scientific evidence related to the application of platelet-rich plasma in the post-extraction alveoli of a retained lower third molars. Material and Methods: A systematic review of published literature registered in the Medline, EMBASE, Cochrane and NIH databases. The following categories were included: human randomized clinical studies. Key search words were: platelet rich plasma; platelet rich plasma and oral surgery; platelet rich in growth factors and third molar. Results: Of 101 potentially valid articles, seven were selected, of which four were rejected as they failed to meet quality criteria. Three studies fulfilled all selection and quality criteria: Ogundipe et al.; Rutkowski et al.; Haraji et al. The studies all measured osteoblast activity by means of sintigraphy, and also registered pain, bleeding, inflammation, temperature, numbness as perceived by the patients, radiological bone density and the incidence of alveolar osteitis. Conclusions: Scientific evidence for the use of PRP in retained third molar surgery is poor. For this reason randomized clinical trials are needed before recommendations for the clinical application of PRP can be made. Key words:Platelet rich plasma, lower third molar surgery, postoperative. PMID:24316707

  5. Effect of Tooth Preparation on Microleakage of Stainless Steel Crowns Placed on Primary Mandibular First Molars with Reduced Mesiodistal Dimension

    PubMed Central

    Ramazani, Nahid; Ranjbar, Mina

    2015-01-01

    Objectives: Incomplete adaptation of stainless steel crown margins leads to microleakage. The aim of this study was to evaluate the effect of tooth preparation on microleakage of stainless steel crowns (SSCs) placed on mesiodistally reduced primary mandibular first molars. Materials and Methods: In this In vitro study, 60 primary mandibular first molars with reduced mesiodistal dimension were selected. Pulp cavities were filled with amalgam and occlusal surfaces were reduced. The samples were randomly divided into two groups (groups P and BLP). Standard preparation was done in group P with only proximal reduction. In group BLP, after reducing the proximal undercuts, buccal and lingual surfaces were slightly reduced. Occlusal one-third of the buccal surfaces was beveled in both groups. Then, the SSCs of the primary maxillary and mandibular first molars were fitted and cemented in P and BLP groups, respectively. After immersing the samples into deionized water, thermo-cycling, and immersion in 2% basic fuchsin, the samples were sectioned buccolingually. The mesial halves were evaluated microscopically for microleakage in both buccal and lingual margins. Data were analyzed using Mann-Whitney U test in SPSS 19 at the significant level of 0.05. Results: There was a significant difference in microleakage of the buccal margin (P=0.003); whereas, the difference observed in the lingual margin was not significant (P=0.54). Conclusion: We suggest reduction of buccal and lingual surfaces of mesiodistally reduced primary mandibular first molars and placing lower (mandibular) crowns. PMID:26005450

  6. Providing an environment for reparative dentine induction in amputated rat molar pulp by high molecular-weight hyaluronic acid

    Microsoft Academic Search

    Takahisa Sasaki; Hidemi Kawamata-Kido

    1995-01-01

    To study provision of this environment, wound healing was examined by light and electron microscopy following pulp amputation and direct capping with hyaluronic acid. Molar pulps of female Sprague-Dawley rats were mechanically exposed and directly capped; the cavities were then restored with glass-ionomer cement. As an experimental control, Calvital (a commercial preparation of calcium hydroxide paste) was used as the

  7. Efficacy of methylprednisolone injected into the masseter muscle following the surgical extraction of impacted lower third molars

    Microsoft Academic Search

    E. Vegas-Bustamante; J. Micó-Llorens; J. Gargallo-Albiol; M. Satorres-Nieto; L. Berini-Aytés; C. Gay-Escoda

    2008-01-01

    The aim of this study was to demonstrate the efficacy of methylprednisolone, as a single 40-mg dose, injected into the masseter muscle upon completion of extraction of impacted lower third molars. A prospective, randomized cross-over study was made of 35 healthy patients. The difficulty of extraction was similar in all cases. The study group received 40mg of methylprednisolone injected into

  8. Age estimation using the radiographic visibility of the periodontal ligament in lower third molars in a Portuguese population

    PubMed Central

    Sequeira, Catarina-Dourado; Teixeira, Alexandra; Afonso, Américo; Pérez-Mongiovi, Daniel

    2014-01-01

    Objectives: The mineralization of third molars has been used repeatedly as a method of forensic age estimation. However, this procedure is of little use beyond age 18, especially to determinate if an individual is older than 21 years of age; thus, the development of new approaches is essential. The visibility of the periodontal ligament has been suggested for this purpose. The aim of this work was to determine the usefulness of this methodology in a Portuguese population. Study Design: Periodontal ligament visibility was assessed in the lower third molars, using a sample of 487 orthopantomograms, 228 of which belonging to females and 259 to males, from a Portuguese population aged 17 to 31 years. A classification of four stages based on the visual phenomenon of disappearance of the periodontal ligament of fully mineralized third molars was used. For each stage, median, variance, minimal and maximal age were assessed. Results: The relationship between age and stage of periodontal ligament had a statistical significance for both sexes. In this population, stage 3 can be used to state that a male person is over 21 years-old; for females, another marker should be used. Conclusions: This technique can be useful for determining age over 21, particularly in males. Differences between studies are evident, suggesting that specific population standards should be used when applying this technique. Key words:Forensic sciences, forensic odontology, age estimation, third molar, periodontal ligament. PMID:25674324

  9. Evaluation of skeletal and dental age using third molar calcification, condylar height and length of the mandibular body

    PubMed Central

    Kedarisetty, Sunil Gupta; Rao, Guttikonda Venkateswara; Rayapudi, Naveen; Korlepara, Rajani

    2015-01-01

    Aim: To identify the most reliable method for age estimation among three variables, that is, condylar height, length of mandibular body and third molar calcification by Demirjian's method. Materials and Methods: Orthopantomograms and lateral cephalograms of 60 patients with equal gender ratio were included in the study, among each gender 15 subjects were below 18 years and 15 subjects were above 18 years. Lateral cephalograms were traced, height of condyle and mandibular body are measured manually on the tracing paper, OPG's were observed on radiographic illuminator and maturity score of third molar calcification was noted according to Demirjian's method. All the measurements were subjected to statistical analysis. Results: The results obtained are of no significant difference between estimated age and actual age with all three parameters (P > 0.9780 condylar height, P > 0.9515 length of mandibular body, P > 0.8611 third molar calcification). Among these three, length of mandibular body shows least standard error test (i.e. 0.188). Conclusion: Although all three parameters can be used for age estimation, length of mandibular body is more reliable followed by height of condyle and third molar calcification. PMID:26005300

  10. Endodontic treatment of the mandibular first molar with six roots canals - two case reports and literature review.

    PubMed

    Martins, Jorge N R; Anderson, Craig

    2015-04-01

    The most common configuration of the mandibular first molar is the presence of two roots and three root canals. The objective of this work is to present two rare anatomic configurations with six root canals on two mandibular left first molars diagnosed during endodontic therapy. Root canal therapy was performed using a dental operating microscope. Ultrasonic troughing in the grooves in between the mesial root canals and in between the distal root canals was able to show the middle root canals. Large samples population characterization researches and systematic reviews were unable to detect a single case of six root canals configuration in a mandibular first molar in their investigations. Although it is a rare configuration, a six root canal configuration is possible to be found in the mandibular first molar. Three different pulp chamber configurations are possible to be found. Two or three roots may be present and the root configuration more common in the mesial root is the Type 8 and Type 12 for the distal root. Some concepts about the required technique to approach these cases are also debated. PMID:26023651

  11. Partial belief and expert testimony

    E-print Network

    Briggs, Rachael (Rachael Amy)

    2009-01-01

    My dissertation investigates two questions from within a partial belief framework: First, when and how should deference to experts or other information sources be qualified? Second, how closely is epistemology related to ...

  12. Partial blocking and associative learning

    Microsoft Academic Search

    Anton Benz

    2006-01-01

    We are going to explain partial blocking as the result of diachronic processes based on what we will call associative learning. Especially, we argue that the task posed by partial blocking phenomena is to explain their emergence from unambiguous and\\u000a fully expressive languages. This contrasts with approaches that presuppose underspecified semantic meanings or ineffability\\u000a like Bidirectional Optimality Theory (Bi–OT) and

  13. [Genetics of the partial epilepsy].

    PubMed

    Serratosa, J M

    1996-12-01

    Until recently, research in the field of genetics of the epilepsies had mainly focused on the idiopathic generalized epilepsies and the progressive myoclonic epilepsies. Interest in the genetics of the partial epilepsies has now increased due to the identification of several forms of partial epilepsies with a strong genetic component. The genetic partial epilepsies appear to be more common than expected and each description of a new syndrome is followed by reports of more patients and families. Understanding the clinical and genetic characteristics of the new familial partial epilepsy syndromes and identifying informative families will accelerate the discovery of the basic mechanisms implicated in the production of partial seizures. The recent description of the syndrome of autosomal dominant nocturnal frontal lobe epilepsy, its localization to chromosome 20, and the identification of the responsible gene and mutation in the alpha 4 subunit of the nicotinic cholinergic receptor in an Australian family are a good example. Future discoveries in the genetics of the partial epilepsies will have important diagnostic, prognostic and therapeutic implications and will allow us to apply more specific treatments for each syndrome, offer a prognosis to patients and develop novel forms of therapy. PMID:9052957

  14. Comparison of the efficacy of two anesthetic techniques of mandibular primary first molar: A randomized clinical trial

    PubMed Central

    Tudeshchoie, Davood Ghasemi; Rozbahany, Neda Ahmadi; Hajiahmadi, Maryam; Jabarifar, Ebrahim

    2013-01-01

    Background: The most common technique to anesthetize mandibular primary teeth is inferior alveolar (I.A) nerve block injection which induces a relatively sustained anesthesia and in turn may potentially traumatize soft-tissues. Therefore, the need of having an alternative technique of anesthesia with a shorter term but the same efficacy is reasonable. The aim of this study was a comparison of the efficacy of two anesthetic techniques of mandibular primary first molar. Materials and Methods: In this randomized crossover clinical trial, 40 children with ages ranged from 5 years to 8 years whose mandibular primary first molars were eligible for pulpotomy, were selected and divided randomly into two groups. The right and left mandibular first molars of group A were anesthetized with infiltration and I. A nerve block techniques in the first and second sessions respectively. The left and right mandibular first molars of group B were anesthetized with I.A nerve block and infiltration techniques in the first and second sessions respectively. The severity of pain were measured and recorded according to sound-eye-motor scale by a certain person. Data was analyzed using Wilcoxon Signed Rank and Mann-Whitney U tests (P > 0.05). Results: The severity of pain was lower in infiltration technique versus I.A nerve block. There were no significant differences between the severities of pain on pulpal exposure of two techniques. Conclusion: It seems that infiltration technique is more favorable to anesthetize the mandibular primary first molar compared to I.A nerve block. PMID:24348619

  15. Comparison of clinical efficacy of methylprednisolone and serratiopeptidase for reduction of postoperative sequelae after lower third molar surgery

    PubMed Central

    Chappi D., Mouneshkumar; Patil, Manisha R.; Desai, Rajendra; Tauro, David P.; Bharani K.N.S., Shiva; Parkar, Mushtaq I.; Babaji, Harsha V.

    2015-01-01

    Background Surgical removal of mandibular third molars results in some degree of post-operative pain, swelling and trismus. These can be controlled by proper administration of local anesthesia, careful bone removal, minimal trauma to adjacent soft tissues and administration of methylprednisolone and serratiopeptidase drugs. The aim of the present study was to compare the efficacy of methylprednisolone and serratiopeptidase in controlling post-operative pain, swelling and trismus after surgical removal of impacted mandibular third molars. Material and Methods The subjects were divided into two groups of 50 patients each undergoing surgical removal of mandibular third molars. Group A was given methylprednisolone 4mg orally every 8th hourly and Group B was given serratiopeptidase 10 mg every 12th hourly orally. Post-operatively pain, swelling and trismus were evaluated at the end of 1st, 3rd and 5thday. Results The results of this study showed that methylprednisolone is an effective analgesic, while serratiopeptidase has moderate analgesic activity. Serratiopeptidase is more effective than methylprednisolone in controlling post surgical swelling and trismus. Hence combination of these two drugs would be very effective than individual drug when widespread post-operative sequelae are expected after surgical removal of impacted lower third molars. Conclusions We conclude that methylprednisolone affords better pain relief while serratiopeptidase exerts better anti-inflammatory and anti-swelling effects in the post-operative period. Synergistic combinations of these two drugs would however prove to be more effective when extensive post-operative sequelae are expected. Key words:Methylprednisolone, serratiopeptidase, pain, swelling, trismus, third molar.

  16. Corneal Stromal Cell Growth on Gelatin/Chondroitin Sulfate Scaffolds Modified at Different NHS/EDC Molar Ratios

    PubMed Central

    Lai, Jui-Yang

    2013-01-01

    A nanoscale modification strategy that can incorporate chondroitin sulfate (CS) into the cross-linked porous gelatin materials has previously been proposed to give superior performance for designed corneal keratocyte scaffolds. The purpose of this work was to further investigate the influence of carbodiimide chemistry on the characteristics and biofunctionalities of gelatin/CS scaffolds treated with varying N-hydroxysuccinimide (NHS)/1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride (EDC) molar ratios (0–1) at a constant EDC concentration of 10 mM. Results of Fourier transform infrared spectroscopy and dimethylmethylene blue assays consistently indicated that when the NHS to EDC molar ratio exceeds a critical level (i.e., 0.5), the efficiency of carbodiimide-mediated biomaterial modification is significantly reduced. With the optimum NHS/EDC molar ratio of 0.5, chemical treatment could achieve relatively high CS content in the gelatin scaffolds, thereby enhancing the water content, glucose permeation, and fibronectin adsorption. Live/Dead assays and interleukin-6 mRNA expression analyses demonstrated that all the test samples have good cytocompatibility without causing toxicity and inflammation. In the molar ratio range of NHS to EDC from 0 to 0.5, the cell adhesion ratio and proliferation activity on the chemically modified samples significantly increased, which is attributed to the increasing CS content. Additionally, the materials with highest CS content (0.143 ± 0.007 nmol/10 mg scaffold) showed the greatest stimulatory effect on the biosynthetic activity of cultivated keratocytes. These findings suggest that a positive correlation is noticed between the NHS to EDC molar ratio and the CS content in the biopolymer matrices, thereby greatly affecting the corneal stromal cell growth. PMID:23337203

  17. Characterization of mandibular molar root and canal morphology using cone beam computed tomography and its variability in Belgian and Chilean population samples

    PubMed Central

    Jacobs, Reinhilde; Lambrechts, Paul; Brizuela, Claudia; Cabrera, Carolina; Concha, Guillermo; Pedemonte, María Eugenia

    2015-01-01

    Purpose This study used cone-beam computed tomography (CBCT) to characterize mandibular molar root and canal morphology and its variability in Belgian and Chilean population samples. Materials and Methods We analyzed the CBCT images of 515 mandibular molars (257 from Belgium and 258 from Chile). Molars meeting the inclusion criteria were analyzed to determine (1) the number of roots; (2) the root canal configuration; (3) the presence of a curved canal in the cross-sectional image of the distal root in the mandibular first molar and (4) the presence of a C-shaped canal in the second mandibular molar. A descriptive analysis was performed. The association between national origin and the presence of a curved or C-shaped canal was evaluated using the chi-squared test. Results The most common configurations in the mesial root of both molars were type V and type III. In the distal root, type I canal configuration was the most common. Curvature in the cross-sectional image was found in 25% of the distal canals of the mandibular first molars in the Belgian population, compared to 11% in the Chilean population. The prevalence of C-shaped canals was 10% or less in both populations. Conclusion In cases of unclear or complex root and canal morphology in the mandibular molars, CBCT imaging might assist endodontic specialists in making an accurate diagnosis and in treatment planning.

  18. Estimation of band broadening in size-exclusion chromatography. I. A method based on analyzing narrow standards with a molar mass-sensitive detector

    Microsoft Academic Search

    Mariana M. Yossen; Jorge R. Vega; Gregorio R. Meira

    2006-01-01

    A method is proposed for estimating the (asymmetrical and non-uniform) band broadening function (BBF) in size-exclusion chromatography (SEC). The following data are required: the molar mass calibration and the concentration- and molar mass chromatograms of a set of narrow standards. In the narrow range of each standard, the BBF is uniform but skewed. Each uniform BBF is estimated through a

  19. Isolation and characterization of stem cells derived from human third molar tooth germs of young adults: implications in neo-vascularization, osteo-, adipo- and neurogenesis

    Microsoft Academic Search

    M E Yalvac; M Ramazanoglu; A A Rizvanov; F Sahin; O F Bayrak; U Salli; A Palotás; G T Kose

    2010-01-01

    A number of studies have reported in the last decade that human tooth germs contain multipotent cells that give rise to dental and peri-odontal structures. The dental pulp, third molars in particular, have been shown to be a significant stem cell source. In this study, we isolated and characterized human tooth germ stem cells (hTGSCs) from third molars and assessed

  20. Free volume of mixed cation borosilicate glass sealants elucidated by positron annihilation lifetime spectroscopy and its correlation with glass properties

    NASA Astrophysics Data System (ADS)

    Ojha, Prasanta K.; Rath, Sangram K.; Sharma, Sandeep K.; Sudarshan, Kathi; Pujari, Pradeep K.; Chongdar, Tapas K.; Gokhale, Nitin M.

    2015-01-01

    The role of La+3/Sr+2 ratios, which is varied from 0.08 to 5.09, on density, molar volume, packing fraction, free volume, thermal and electrical properties in strontium lanthanum aluminoborosilicate based glass sealants intended for solid oxide fuel cell (SOFC) applications is evaluated. The studies reveal expansion of the glass network evident from increasing molar volume and decreasing packing fraction of glasses with progressive La+3 substitutions. The molecular origin of these macroscopic structural features can be accounted for by the free volume parameters measured from positron annihilation lifetime spectroscopy (PALS). The La+3 induced expanded glass networks show increased number of subnanoscopic voids with larger sizes, as revealed from the ortho-positronium (o-Ps) lifetime and its intensity. A remarkably direct correspondence between the molar volume and fractional free volume trend is established with progressive La2O3 substitution in the glasses. The effect of these structural changes on the glass transition temperature, softening temperature, coefficient of thermal expansion, thermal stability as well as electrical conductivity has been studied.

  1. Subacromial volume and rotator cuff tears

    PubMed Central

    Yi, Anthony; Avramis, Ioannis A; Argintar, Evan H; White, Eric R; Villacis, Diego C; Hatch III, George F Rick

    2015-01-01

    Background: Rotator cuff pathology occurs commonly and its cause is likely multifocal in origin. The development and progression of rotator cuff injury, especially in relation to extrinsic shoulder compression, remain unclear. Traditionally, certain acromial morphologies have been thought to contribute to rotator cuff injury by physically decreasing the subacromial space. The relationship between subacromial space volume and rotator cuff tears (RCT) has, however, never been experimentally confirmed. In this study, we retrospectively compared a control patient population to patients with partial or complete RCTs in an attempt to quantify the relationship between subacromial volume and tear type. Materials and Methods: We retrospectively identified a total of 46 eligible patients who each had shoulder magnetic resonance imaging (MRI) performed from January to December of 2008. These patients were stratified into control, partial RCT, and full-thickness RCT groups. Subacromial volume was estimated for each patient by averaging five sequential MRI measurements of subacromial cross-sectional areas. These volumes were compared between control and experimental groups using the Student's t-test. Results: With the numbers available, there was no statistically significant difference in subacromial volume measured between: the control group and patients diagnosed partial RCT (P > 0.339), the control group and patients with complete RCTs (P > 0.431). Conclusion: We conclude that subacromial volumes cannot be reliably used to predict RCT type. PMID:26015629

  2. The Ti/Al molar ratio as a new proxy for tracing sediment transportation processes and its application in aeolian events and sea level change in East Asia

    NASA Astrophysics Data System (ADS)

    Chen, Huei-Fen; Yeh, Po-Yi; Song, Sheng-Rong; Hsu, Shih-Chieh; Yang, Tien-Nan; Wang, Yong; Chi, Zhenqing; Lee, Teh-Quei; Chen, Min-Te; Cheng, Chien-Liang; Zou, Jianjun; Chang, Yuan-Pin

    2013-09-01

    Ti/Al molar ratios of sediments in various sedimentary environments are used to explain sediment transportation from source regions to sink areas. Samples were collected from outcrops, soils, fluvial, lake, and marine sediment environments. Initial Ti/Al molar ratios of sediments are controlled by those of parent soils or rocks. These ratios tend to decline gradually as a result of heavy-mineral gravity fractionation during transportation. Sedimentary Ti/Al molar ratios in sink areas such as lakes and pelagic environments are lower than those in source regions. In this study, for the Changjiang River, Huanghe River, and Kaoping River, Ti/Al molar ratios decline considerably from downstream to estuary environments. Additionally, well sorted aeolian sands have extremely low Ti/Al molar ratios in northern China. The Ti/Al molar ratios of aerosol particles found in Taiwan and the East China Sea show reduced ratios as a result of Asia Dust Storm episodes. Furthermore, lower Ti/Al molar ratios in deep ocean sediments were discovered by tracing the distribution of sedimentary Ti/Al molar ratios in the South China Sea. When sea levels dropped during glacial periods, the river estuary was closer to deep marine areas and carried more terrestrial sediments into deep marine environments. The closer estuary with relatively higher Ti/Al ratio would lead increase of Ti/Al molar ratios in deep sea sediments. In this study, Ti/Al molar ratio is promoted as a new proxy to help with understanding changes in sedimentary environments.

  3. Endodontic treatment of mandibular molar with root dilaceration using Reciproc single-file system.

    PubMed

    Meireles, Daniely Amorin; Bastos, Mariana Mena Barreto; Marques, André Augusto Franco; Garcia, Lucas da Fonseca Roberti; Sponchiado, Emílio Carlos

    2013-08-01

    Biomechanical preparation of root canals with accentuated curvature is challenging. New rotatory systems, such as Reciproc, require a shorter period of time to prepare curved canals, and became a viable alternative for endodontic treatment of teeth with root dilaceration. Thus, this study aimed to report a clinical case of endodontic therapy of root with accentuated dilaceration using Reciproc single-file system. Mandibular right second molar was diagnosed as asymptomatic irreversible pulpitis. Pulp chamber access was performed, and glide path was created with #10 K-file (Dentsply Maillefer) and PathFile #13, #16 and #19 (Dentsply Maillefer) up to the temporary working length. The working length measured corresponded to 20 mm in the mesio-buccal and mesio-lingual canals, and 22 mm in the distal canal. The R25 file (VDW GmbH) was used in all the canals for instrumentation and final preparation, followed by filling with Reciproc gutta-percha cones (VDW GmbH) and AH Plus sealer (Dentsply Maillefer), using thermal compaction technique. The case has been receiving follow-up for 6 mon and no painful symptomatology or periapical lesions have been found. Despite the difficulties, the treatment could be performed in a shorter period of time than the conventional methods. PMID:24010084

  4. Single C-shaped canal in mandibular first molar: A case report

    PubMed Central

    Raghavendra, Srinidhi Surya; Napte, Bandu D.; Desai, Niranjan N.; Hindlekar, Ajit N.

    2015-01-01

    The variability of root canal system morphology presents a continuous challenge to endodontic diagnosis and therapeutics. There have been reports of teeth with multiple roots and canals as also those with lesser number of root and root canals. Variations of root canal systems need not always be in the form of extra canals. Clinicians should be aware that there is a possibility of existence of fewer numbers of roots and root canals than normal, which presents varied canal anatomy and poses a challenge to the clinician's expertise. This case report deals with the management of an unusual case of C-shaped canal in mandibular molar with two buccally fused roots. Cone-beam computed tomography (CBCT) was employed to confirm the extension of the unusual anatomy. The Self Adjusting File (SAF) system was used to ensure complete cleaning of the canal system. One-year follow-up of the case showed good healing. The clinician should expect to encounter unusual features when performing endodontic treatment. Use of diagnostic aids like CBCT, improved magnification with dental operating microscope, and the use of novel file systems like SAF ensure success. PMID:25829700

  5. Radiographic Estimation of Chronological Age using Mineralization of Third Molars in Coastal Andhra, India

    PubMed Central

    Babburi, Suresh; Nelakurthi, Hasini; Aparna, V; Soujanya, P; Kotti, Ajay Benarji; Ganipineni, Kiranmai

    2015-01-01

    Background: Age estimation is an important factor in establishing the identity of a person. Among various techniques, dental age estimation is helpful in estimating the age in children above 16 years of age. Determination of age using developmental stages of teeth is more useful than using tooth eruption. Materials and Methods: A total of 550 orthopantomographs of 248 males and 302 females aged between 15 and 22 years were taken and evaluated by Demirjian’s tooth mineralization stages. Statistical assessment was done using logistic regression analysis. Results: Complete apical closure of third molars was observed at the age of 20.4 years in 50% of males. Gender is also thought to influence mineralization and males showed early apical closure than females. Mean value testing is also done but showed influence of high and lower end age groups on age estimation. Conclusion: Finally, we conclude that, though the exact age of a person cannot be determined, the Demirjian’s stage at which 18 years of age is attained can be found out. PMID:26028903

  6. Hertwig’s Epithelial Root Sheath Fate during Initial Cellular Cementogenesis in Rat Molars

    PubMed Central

    Yamamoto, Tsuneyuki; Yamada, Tamaki; Yamamoto, Tomomaya; Hasegawa, Tomoka; Hongo, Hiromi; Oda, Kimimitsu; Amizuka, Norio

    2015-01-01

    To elucidate the fate of the epithelial root sheath during initial cellular cementogenesis, we examined developing maxillary first molars of rats by immunohistochemistry for keratin, vimentin, and tissue non-specific alkaline phosphatase (TNALP) and by TdT-mediated dUTP nick end labeling (TUNEL). The advancing root end was divided into three sections, which follow three distinct stages of initial cellular cementogenesis: section 1, where the epithelial sheath is intact; section 2, where the epithelial sheath becomes fragmented; and section 3, where initial cellular cementogenesis begins. After fragmentation of the epithelial sheath, many keratin-positive epithelial sheath cells were embedded in the rapidly growing cellular cementum. A few unembedded epithelial cells located on the cementum surface. Dental follicle cells, precementoblasts, and cementoblasts showed immunoreactivity for vimentin and TNALP. In all three sections, there were virtually no cells possessing double immunoreactivity for vimentin-keratin or TNALP-keratin and only embedded epithelial cells showed TUNEL reactivity. Taken together, these findings suggest that: (1) epithelial sheath cells divide into two groups; one group is embedded in the cementum and thereafter dies by apoptosis, and the other survives on the cementum surface as epithelial cell rests of Malassez; and (2) epithelial sheath cells do not undergo epithelial-mesenchymal transition during initial cellular cementogenesis.

  7. Clinical evaluation of guided tissue regeneration in the treatment of maxillary class II molar furcation invasions.

    PubMed

    Metzler, D G; Seamons, B C; Mellonig, J T; Gher, M E; Gray, J L

    1991-06-01

    This investigation assessed and compared the clinical efficacy of combined open flap debridement/occlusive membrane therapy versus open flap debridement therapy alone, in the treatment of maxillary periodontal furcation defects. Seventeen patients presenting with advanced adult periodontitis, including at least one pair of Class II maxillary furcal defects, comprised the study group. Following completion of a hygienic phase of treatment, measurements were made with calibrated periodontal probes to determine soft tissue recession, probing pocket depths, and attachment levels. Each pair of furcation defects was surgically exposed and hard tissue measurements obtained. Defects were treated with either open flap debridement and a polytetrafluoroethylene periodontal membrane or open flap debridement alone. Membranes were removed at 4 to 6 weeks. Six months postsurgery, soft tissue measurements were repeated and all sites were surgically re-entered to obtain hard tissue measurements. No statistically significant differences were found in recession, probing depth reductions, clinical attachment gains, or resorption of alveolar crest height between test and control groups. Results for these parameters were inconsistent and unpredictable. Statistically significant improvements were found, however, in horizontal open probing attachment (HOPA) and vertical open probing attachment (VOPA) between experimental and control sites. The GTR procedure as used in this study likely has limited application as a therapeutic modality for Class II furcations of maxillary molars. Modifications or improvements in the procedure may result in more predictable healing of these lesions. PMID:1870064

  8. CBCT evaluation of multiple idiopathic internal resorptions in permanent molars: case report

    PubMed Central

    2014-01-01

    Background Internal inflammatory root resorption is a rare condition in permanent teeth, which requires the presence of necrotic and infected pulp tissue within the coronal portion of the root canal system as well as inflamed pulp tissue apical to the resorptive defect. The aetiology of internal root resorption is not completely understandable, trauma and chronic pulpitis are considered the main risk factors. Case presentation We report a rare case of the multiple idiopathic resorption in the permanent maxillary and mandibular molars in a healthy 33-year-old female patient. In addition to clinical examination the patient was imaged using conventional radiography techniques and cone beam computed tomography (CBCT).The patient had recurrent throbbing pain in her # 46. The radiographic examination including “panoramic radiography and CBCT” revealed that radiographic evidence of internal resorption in #37 #36 #35 #34 #33 #47 #46 #45 #44 #43 #16 #15 #14 #13 and also including in unerupted #17, #26, #27, #28 teeth. The definitive diagnosis was made with the histopathological examination of the extracted tooth. Conclusions Internal root resorption is a rare clinical process that should be examined using different radiographic modalities. CBCT seems to be useful in evaluation of the lesions with superior diagnostic performance. PMID:24739085

  9. Localization and density of myeloid leucocytes in the periodontal ligament of normal rat molars.

    PubMed

    Kan, L; Okiji, T; Kaneko, T; Suda, H

    2001-06-01

    The phenotypic distribution and density of macrophage-associated antigen-expressing cells in the periodontal ligament (PDL) of normal rat mandibular first molars was evaluated by immunohistochemistry, and an attempt made to identify dendritic cells (DCs) by immunoelectron microscopy. Cells immunopositive to ED1 (a general macrophage marker) were widely distributed throughout the PDL and were most common around blood vessels. A small number of T lymphocytes and OX62 (anti-veiled cells and gammadelta T cells)-positive DC-like cells were also found. The relative density of cells immunopositive to ED9 (CD14), OX42 (CD11b), OX6 (anti-class II MHC molecules), ED2 (anti-tissue-resident macrophages), 8A2 (CD11c) and WT.1 (CD11a) varied in the mesial, distal and periapical regions of the distal root and the furcal region. This finding suggests that there are several subpopulations of ED1-positive cells which express various combinations of these markers. Immunoelectron microscopy revealed that a small, but distinct, subpopulation of ED1- and OX6-positive cells did have a DC-like ultrastructure, although the majority of these cells were identified as macrophages. The DC-like cells were characterized by poorly developed lysosomal structures and an absence of phagocytic vesicles. It was concluded that the normal rat PDL is equipped with heterogeneous populations of macrophages with regional variations in density. The DC-like cells may function as antigen-presenting cells. PMID:11311198

  10. Management of a massive resorptive lesion with multiple perforations in a molar: case report.

    PubMed

    Borkar, Swati; de Noronha de Ataide, Ida

    2015-05-01

    Internal resorption is usually asymptomatic. Large resorption defects may result in penetration of the root dentin leading to perforation. In this case report, we describe the diagnosis and nonsurgical repair of a large resorptive lesion with multiple perforations in a mandibular first molar using cone-beam computed tomographic technology. The 3 different root perforations were located in the mesial root and repaired using Biodentine (Septodont, Saint-Maur des Fossés, France). The mesial root weakened from resorption was reinforced by replacing the lost root dentin with calcium silicate-based cement and placement of a glass fiber post. The 18-month follow-up confirmed remineralization of the osseous defect and asymptomatic function of the tooth. A further follow-up at 43 months revealed retention of the tooth and absence of root fracture. Usually, a tooth with multiple perforations and such a severe tooth material loss would have been destined for extraction. However, with contemporary diagnostic techniques such as cone-beam computed tomography and use of advanced biomaterials and root reinforcement methods, such teeth can be salvaged. PMID:25728818

  11. Single C-shaped canal in mandibular first molar: A case report.

    PubMed

    Raghavendra, Srinidhi Surya; Napte, Bandu D; Desai, Niranjan N; Hindlekar, Ajit N

    2015-01-01

    The variability of root canal system morphology presents a continuous challenge to endodontic diagnosis and therapeutics. There have been reports of teeth with multiple roots and canals as also those with lesser number of root and root canals. Variations of root canal systems need not always be in the form of extra canals. Clinicians should be aware that there is a possibility of existence of fewer numbers of roots and root canals than normal, which presents varied canal anatomy and poses a challenge to the clinician's expertise. This case report deals with the management of an unusual case of C-shaped canal in mandibular molar with two buccally fused roots. Cone-beam computed tomography (CBCT) was employed to confirm the extension of the unusual anatomy. The Self Adjusting File (SAF) system was used to ensure complete cleaning of the canal system. One-year follow-up of the case showed good healing. The clinician should expect to encounter unusual features when performing endodontic treatment. Use of diagnostic aids like CBCT, improved magnification with dental operating microscope, and the use of novel file systems like SAF ensure success. PMID:25829700

  12. Photoelastic stress analysis of different designs of cement-retained fixed partial dentures on Morse taper oral implants.

    PubMed

    Menani, Luiz Ricardo; Tiossi, Rodrigo; de Torres, Érica Miranda; Ribeiro, Ricardo Faria; de Almeida, Rossana Pereira

    2011-03-01

    There is no consensus in literature regarding the best plan for prosthetic rehabilitation with partial multiple adjacent implants to minimize stress generated in the bone-implant interface. The aim of this study was to evaluate the biomechanical behavior of cemented fixed partial dentures, splinted and nonsplinted, on Morse taper implants and with different types of coating material (ceramic and resin), using photoelastic stress analysis. A photoelastic model of an interposed edentulous space, missing a second premolar and a first molar, and rehabilitated with 4 different types of cemented crowns and supported by 2 adjacent implants was used. Groups were as follows: UC, splinted ceramic crowns; IC, nonsplinted ceramic crowns; UR, splinted resin crowns; and IR, nonsplinted resin crowns. Different vertical static loading conditions were performed: balanced occlusal load, 10 kgf; simultaneous punctiform load on the implanted premolar and molar, 10 kgf; and alternate punctiform load on the implanted premolar and molar, 5 kgf. Changes in stress distribution were analyzed in a polariscope, and digital photographs were taken of each condition to allow comparison of stress pattern distribution around the implants. Cementation of the fixed partial dentures generated stresses between implants. Splinted restorations distributed the stresses more evenly between the implants than nonsplinted when force was applied. Ceramic restorations presented better distribution of stresses than resin restorations. Based on the results obtained, it was concluded that splinted ceramic restorations promote better stress distribution around osseointegrated implants when compared with nonsplinted crowns; metal-ceramic restorations present less stress concentration and magnitude than metal-plastic restorations. PMID:21415635

  13. Restoration of the partially edentulous mouth — a comparison of overdentures, removable partial dentures, fixed partial dentures and implant treatment

    Microsoft Academic Search

    E. Budtz-Jörgensen

    1996-01-01

    Objectives: Loss of posterior teeth may result in the loss of neuromuscular stability of the mandible, reduced masticatory efficiency, loss of vertical dimension of occlusion and poor aesthetics. Prosthetic rehabilitation should aim at restoring the vertical dimension and increasing the occlusal contact area in the premolar\\/molar region. Overdentures are particularly indicated in patients with a severe loss of periodontal attachment,

  14. Partial discharge. XIII. Acoustic partial discharge detection-fundamental considerations

    Microsoft Academic Search

    L. E. Lundgaard

    1992-01-01

    An overview of the basic acoustics theory required to understand the finer points of acoustic partial discharge (PD) detection systems is given. PD and acoustic test methods are discussed, and acoustic wave motion, impedance, and intensity are described. Wave propagation and signal absorption, and the velocity of sound are discussed. Acoustic characteristics of media gases, liquids, and solid materials are

  15. Partial pressure analysis of plasmas

    SciTech Connect

    Dylla, H.F.

    1984-11-01

    The application of partial pressure analysis for plasma diagnostic measurements is reviewed. A comparison is made between the techniques of plasma flux analysis and partial pressure analysis for mass spectrometry of plasmas. Emphasis is given to the application of quadrupole mass spectrometers (QMS). The interface problems associated with the coupling of a QMS to a plasma device are discussed including: differential-pumping requirements, electromagnetic interferences from the plasma environment, the detection of surface-active species, ion source interactions, and calibration procedures. Example measurements are presented from process monitoring of glow discharge plasmas which are useful for cleaning and conditioning vacuum vessels.

  16. Partial lipodystrophy in a girl.

    PubMed

    Shamsadini, Sadollah; Ahmadi, Akbar

    2004-01-01

    A 9-year old girl presented with a 2-year history of severe loss of subcutaneous fat in her face. Her medical history included a self-limited episode of jaundice and mild fever 2 years prior. Laboratory examination revealed low serum C3 but normal serum C4. Renal function tests were normal. Low C3 can be a warning sign in patients partial lipodystrophy; it may be a harbinger of renal insufficiency. Patients with partial lipodystrophy may be predisposed to renal failure, especially after pregnancy or the use oral contraceptive pills. PMID:15530307

  17. Full and partial gauge fixing

    SciTech Connect

    Shirzad, A. [Institute for Studies in Theoretical Physics and Mathematics, P. O. Box 5531, Tehran 19395 (Iran, Islamic Republic of) and Department of Physics, Isfahan University of Technology, Isfahan (Iran, Islamic Republic of)

    2007-08-15

    Gauge fixing may be done in different ways. We show that using the chain structure to describe a constrained system enables us to use either a full gauge, in which all gauged degrees of freedom are determined, or a partial gauge, in which some first class constraints remain as subsidiary conditions to be imposed on the solutions of the equations of motion. We also show that the number of constants of motion depends on the level in a constraint chain in which the gauge fixing condition is imposed. The relativistic point particle, electromagnetism, and the Polyakov string are discussed as examples and full or partial gauges are distinguished.

  18. Sculpture All Ways ISSUE 2 VOLUME 4

    E-print Network

    Scherer, Norbert F.

    of painted wood, partially painted glass, and colored (blue, red, yellow) fluorescent tubes. Smart MuseumCARVED, CAST, CRUMPLED Sculpture All Ways FALL 2014 ISSUE 2 VOLUME 4 AT THE SMART #12;The Smart Museum of Art at the University of Chicago opens the world through art and ideas. MISSION 2 So Smart

  19. Walk the line: 600000 years of molar evolution constrained by allometry in the fossil rodent Mimomys savini.

    PubMed

    Firmat, Cyril; Lozano-Fernández, Iván; Agustí, Jordi; Bolstad, Geir H; Cuenca-Bescós, Gloria; Hansen, Thomas F; Pélabon, Christophe

    2014-08-19

    The allometric-constraint hypothesis states that evolutionary divergence of morphological traits is restricted by integrated growth regulation. In this study, we test this hypothesis on a time-calibrated and well-documented palaeontological sequence of dental measurements on the Pleistocene arvicoline rodent species Mimomys savini from the Iberian Peninsula. Based on 507 specimens representing nine populations regularly spaced over 600 000 years, we compare static (within-population) and evolutionary (among-population) allometric slopes between the width and the length of the first lower molar. We find that the static allometric slope remains evolutionary stable and predicts the evolutionary allometry quite well. These results support the hypothesis that the macroevolutionary divergence of molar traits is constrained by static allometric relationships. PMID:25002706

  20. Dandy-Walker malformation masking the molar tooth sign: an illustrative case with magnetic resonance imaging follow-up.

    PubMed

    Sartori, Stefano; Ludwig, Kathrin; Fortuna, Manuela; Marzocchi, Cinzia; Calderone, Milena; Toldo, Irene; Salviati, Leonardo; Laverda, Anna Maria; Tenconi, Romano

    2010-11-01

    Joubert syndrome is a disorder characterized by ataxia, developmental delay, oculomotor anomalies, and breathing irregularities, with cerebellar vermian and midbrain dysgenesis. The molar tooth sign, reflecting the midbrain dysgenesis of Joubert syndrome, is the neuroradiological hallmark and is an essential sign in the identification of this condition. Variable vermian agenesis, an expanded fourth ventricle, and a large posterior cranial fossa with a normal brainstem are typical of Dandy-Walker malformation. The authors report a case in which a Dandy-Walker malformation coexisted with Joubert syndrome, but initially prevented the ''molar tooth sign'' from being recognized because of an important cystic dilatation of the fourth ventricle. In this article, they discuss the importance of the re-examination of brain magnetic resonance features after decompression of the posterior cranial fossa in a patient with Dandy-Walker malformation and additional clinical neurological or systemic abnormalities typical of Joubert syndrome, to not miss the correct diagnosis. PMID:20823032

  1. The molar enthalpies of solution and vapour pressures of saturated aqueous solutions of aluminium chloride, aluminium nitrate and aluminium sulphate

    Microsoft Academic Search

    Alexander Apelblat; Eli Korin

    2002-01-01

    Vapour pressures of water over saturated solutions of aluminium chloride, aluminium nitrate and aluminium sulphate were determined as a function of temperature. The vapour pressures served to evaluate the water activities, osmotic coefficients and molar enthalpies of vaporization. Molar enthalpies of solution of aluminium chloride hexahydrate, ?solHm(AlCl3·6H2O, T=295.02K, m=0.02084mol·kg?1)=?(54.6±2.1)kJ·mol?1, aluminium nitrate nonahydrate, ?solHm(Al(NO3)3·9H2O; T=296.62K, m=0.01342mol·kg?1)=(30.7±1.0)kJ·mol?1 and aluminium sulphate octadecahydrate, ?solHm(Al2(SO4)3·18H2O,

  2. Molar mass, entanglement, and associations of the biofilm polysaccharide of Staphylococcus epidermidis.

    PubMed

    Ganesan, Mahesh; Stewart, Elizabeth J; Szafranski, Jacob; Satorius, Ashley E; Younger, John G; Solomon, Michael J

    2013-05-13

    Biofilms are microbial communities that are characterized by the presence of a viscoelastic extracellular polymeric substance (EPS). Studies have shown that polysaccharides, along with proteins and DNA, are a major constituent of the EPS and play a dominant role in mediating its microstructure and rheological properties. Here, we investigate the possibility of entanglements and associative complexes in solutions of extracellular polysaccharide intercellular adhesin (PIA) extracted from Staphylococcus epidermidis biofilms. We report that the weight average molar mass and radius of gyration of PIA isolates are 2.01×10(5)±1200 g/mol and 29.2±1.2 nm, respectively. The coil overlap concentration, c*, was thus determined to be (32±4)×10(-4) g/mL. Measurements of the in situ concentration of PIA (cPIA,biofilm) was found to be (10±2)×10(-4) g/mL.Thus, cPIA,biofilm

  3. How to measure and predict the molar absorption coefficient of a protein.

    PubMed Central

    Pace, C. N.; Vajdos, F.; Fee, L.; Grimsley, G.; Gray, T.

    1995-01-01

    The molar absorption coefficient, epsilon, of a protein is usually based on concentrations measured by dry weight, nitrogen, or amino acid analysis. The studies reported here suggest that the Edelhoch method is the best method for measuring epsilon for a protein. (This method is described by Gill and von Hippel [1989, Anal Biochem 182:319-326] and is based on data from Edelhoch [1967, Biochemistry 6:1948-1954]). The absorbance of a protein at 280 nm depends on the content of Trp, Tyr, and cystine (disulfide bonds). The average epsilon values for these chromophores in a sample of 18 well-characterized proteins have been estimated, and the epsilon values in water, propanol, 6 M guanidine hydrochloride (GdnHCl), and 8 M urea have been measured. For Trp, the average epsilon values for the proteins are less than the epsilon values measured in any of the solvents. For Tyr, the average epsilon values for the proteins are intermediate between those measured in 6 M GdnHCl and those measured in propanol. Based on a sample of 116 measured epsilon values for 80 proteins, the epsilon at 280 nm of a folded protein in water, epsilon (280), can best be predicted with this equation: epsilon (280) (M-1 cm-1) = (#Trp)(5,500) + (#Tyr)(1,490) + (#cystine)(125) These epsilon (280) values are quite reliable for proteins containing Trp residues, and less reliable for proteins that do not. However, the Edelhoch method is convenient and accurate, and the best approach is to measure rather than predict epsilon. PMID:8563639

  4. Antimicrobial effect of ozonated water, sodium hypochlorite and chlorhexidine gluconate in primary molar root canals

    PubMed Central

    Goztas, Zeynep; Onat, Halenur; Tosun, Gul; Sener, Yagmur; Hadimli, Hasan Huseyin

    2014-01-01

    Objective: The aim was to determine the antimicrobial effect of ozonated water, ozonated water with ultrasonication, sodium hypochloride and chlorhexidine (CHX) in human primary root canals contaminated by Enterococcus faecalis (E. faecalis). Materials and Methods: Fifty-eight extracted human primary molar teeth were used. Crowns were cut off using a diamond saw under water-cooling. One hundred roots were obtained and mechanically prepared. The roots were then sterilized by autoclaving in water for 15 min at 121°C. All samples were contaminated with E. faecalis for 24 h and the root canals were randomly divided into five groups (n = 20). Group I: 25 mg/L of Ozonated water (O3aq), Group II: 25 mg/L of O3aq with ultrasonication, Group III: 2.5% Sodium hypochloride (NaOCl), Group IV: 2% CHX and Group V: Positive control. The canal of each specimen was irrigated for 4 min and positive control was untreated. All root canals were agitated with sterile saline solution. The saline solution was collected from canals with sterile paper points. For each specimen, the paper points were transposed to eppendorf vials containing 2 ml of brain heart infusion. According to bacterial proliferation, the mean values of optical density were achieved by EL?SA (Biotek EL ×800, Absorbance Microplate Reader, ABD) and the data were analyzed. Results: NaOCI, CHX and two types of O3aq were found statistically different than positive control group. NaOCI irrigation was found significantly most effective. Conclusions: NaOCl, CHX and O3aq applications provide antibacterial effect in vitro conditions in primary root canals. PMID:25512726

  5. Silica-alumina molar ratio and some factors effect on the synthesis of zeolites from fly ash

    Microsoft Academic Search

    Yue-zhi Sun; Ke-ming Fu; Hong Zhu; Tian-lin Zhu

    2009-01-01

    In order to improve the activity and eliminate some impurities, pretreatment was used before hydrothermal synthesis. The fly\\u000a ash was mixed with an aqueous NaOH solution, the alkali melted fly ash was also adopted, which is hydrothermally treated at\\u000a about 104 °C, and the liquid\\/solid ratio was controlled at 6:1. In order to control Si\\/Al molar ratio, SiO2 or Al2O3

  6. Comparison of Conventional, Rotary, and Ultrasonic Preparation, Different Final Irrigation Regimens, and 2 Sealers in Primary Molar Root Canal Therapy

    Microsoft Academic Search

    Harun Canoglu; Meryem U. Tekcicek; Zafer C. Cehreli

    2006-01-01

    Purpose: The aim of this study was to compare the shaping effectiveness rotary nickel- titanium (Profi le .04 ISO), ultrasonic (K-Type\\/Satelec), and stainless-steel hand fi le (K-fi le\\/Maillefer) instrumentation and to assess tubular penetration of 2 gutta percha seal- ers (AH Plus and Sealite-Ultra) following 4 different fi nal irrigation regimens in primary molar roots. Methods: Distal roots of extracted

  7. Consecutive condylectomy and molar intrusion using temporary anchorage devices as an alternative for correcting facial asymmetry with condylar hyperplasia.

    PubMed

    Choi, Yoon Jeong; Lee, Sang-Hwy; Baek, Man-Suk; Kim, Jae-Young; Park, Young-Chel

    2015-04-01

    This case report demonstrates the successful treatment of facial asymmetry with condylar hyperplasia with limited surgical and orthodontic treatment. A high condylectomy was performed to shorten the elongated condyle and to remove its active growth site. The maxillary molars on the affected side were then orthodontically intruded using temporary anchorage devices to improve the occlusal cant and posterior open bite of the unaffected side. This combined surgical-orthodontic treatment provided a satisfactory outcome without additional orthognathic surgery. PMID:25836342

  8. Investigation of Adsorption and Inhibitive Effect of Calixarene Derivative Newly Synthesized Towards C38 Steel in Molar HCl

    Microsoft Academic Search

    R. Souane; M. Kaddouri; M. Bouklah; N. Cheriaa; B. Hammouti; J. Vicens

    2009-01-01

    The focus of this study is to synthesize a new calixarene derivative namely calix[6]arene (C21) and to test its performance as corrosion inhibitor of C38 steel in molar HCl at 308 K. Polarization and weight loss measurements were used. Weight loss tests show that C21 retards until to stop corrosion phenomenon at 5 × 10-5 M. C21 is an excellent

  9. Temporal and spatial distribution of Fos protein in the parabrachial nucleus neurons during experimental tooth movement of the rat molar

    Microsoft Academic Search

    Kuniyasu Hiroshima; Takeyasu Maeda; Kooji Hanada; Satoshi Wakisaka

    2001-01-01

    The present study was undertaken to reveal spatio-temporal changes in the distribution of Fos-like immunoreactive (-IR) neurons in the parabrachial nucleus (PBN), one of the important relay nuclei for processing autonomic and somatosensory information from the oro-facial regions, following the induction of experimental tooth movement in rat upper molars. The experimental tooth movement was induced by the insertion of elastic

  10. Evolution of the Tribosphenic Molar Pattern in Early Mammals, with Comments on the “Dual-Origin” Hypothesis

    Microsoft Academic Search

    Brian M. Davis

    Development of the tribosphenic molar was a fundamental event that likely influenced the rise of modern mammals. This multi-functional\\u000a complex combined shearing and grinding in a single chewing stroke, and provided the base morphology for the later evolution\\u000a of the myriad dental morphologies employed by mammals today. Here a series of morphotypes are presented that represent stepwise\\u000a acquisition of characters

  11. Stability of silver clusters in mordenites with different SiO 2\\/Al 2O 3 molar ratio

    Microsoft Academic Search

    Nina E Bogdanchikova; Vitalii P. Petranovskii; Roberto Machorro M; Yoshihiro Sugi; Victor M Soto G; Sergio Fuentes M

    1999-01-01

    The stability and decay of silver clusters characterized by absorption bands 320 and 285 nm incorporated in mordenites with different SiO2\\/Al2O3 molar ratios were studied under ambient conditions. Significantly different rates of disappearance of these two bands were the basis for assigning them to different silver species. Oxidation converts the clusters peaking at 320 and 285 nm into other silver

  12. Evaluation of isthmus prevalence, location, and types in mesial roots of mandibular molars in the Iranian Population

    PubMed Central

    Mehrvarzfar, Payman; Akhlagi, Nahid Mohammadzade; Khodaei, Fatemeh; Shojaee, Golnaz; Shirazi, Sara

    2014-01-01

    Background: Management of canal isthmus is considered as an important factor for successful endodontic treatment. Accordingly, this study was designed to determine the prevalence, location, and types of isthmus in mesial root canals of extracted mandibular molars in a sample of Iranian population. Materials and Methods: In this cross-sectional descriptive study, 60 extracted molars with two mesial canals were included. The samples were initially decoronated and then, roots were sectioned horizontally at 2, 4, and 6 mm levels from the apex via a low-speed handpiece with a thin metallic disk and finally prepared and stained with Indian ink. All sections were examined using a stereomicroscope at a magnification of ×30. Prevalence, location, and types of isthmus were evaluated based on the classifications by Kim and Teixeira and all data were statistically analyzed by the chi-squared test. The statistical significance level was established at 0.05. Results: Eighty-three percent of extracted mandibular molars had an isthmus at the mesial root. This prevalence increased with distance from the apex, that is, 92% at 6 mm from the apex and 70% at 2 mm from the apex. A statistically significant difference was found between the sections at 2 and 6 mm from the apex (P < 0.05), but no other significant differences between other levels (P > 0.05). Conclusion: Isthmus is very common in the mesial roots of the mandibular permanent molars in the Iranian population, with the highest prevalence in the 6 mm distance from the root apex. Therefore, detection, cleaning, and filling of these apical 6 mm isthmuses are of great benefit in modern endodontics. PMID:24932198

  13. Influence of the molar concentration and substrate temperature on fluorine-doped zinc oxide thin films chemically sprayed

    Microsoft Academic Search

    J. Rodríguez-Báez; A. Maldonado; G. Torres-Delgado; R. Castanedo-Pérez; M. de la L. Olvera

    2006-01-01

    The effect of both the molar concentration of the starting solution and the substrate temperature on the electrical, morphological, structural and optical properties of chemically sprayed fluorine-doped zinc oxide (ZnO:F) thin films deposited on glass substrates is analyzed in this work. All the starting solutions employed were aged for 10 days before the deposition. The results show that as the

  14. Influence of extended operation time and of occlusal force on determination of pulpal healing pattern in replanted mouse molars

    Microsoft Academic Search

    Tomoko Hasegawa; Hironobu Suzuki; Hiromasa Yoshie; Hayato Ohshima

    2007-01-01

    The mechanism regulating the divergent healing processes following tooth replantation is unclear. This study clarifies the\\u000a relationship between the healing pattern, the time taken for tooth replantation, and the influence of occlusal force. We investigated\\u000a the pulpal healing process after tooth replantation by immunohistochemistry for 5-bromo-2?-deoxyuridine and nestin and by\\u000a histochemistry for tartrate-resistant acid phosphatase. The upper right first molar

  15. Pulp-capping with Recombinant Human Insulin like Growth Factor I (rhIGF-I) in Rat Molars

    Microsoft Academic Search

    H. Lovschall; O. Fejerskov; A. Flyvbjerg

    2001-01-01

    The aim of this study was to explore pulp healing and reparative dentinogenesis following pulp-capping by using recombinant human insulin-like growth factor I (rhIGF-I). Exposures were made through the mesial pulp horn in first upper molars in two-month-old Wistar rats. The pulp was covered with one dose of sterile 4% methylcellulose gel containing either 400 ng rhIGF-I or saline in

  16. Responses of immunocompetent cells in the dental pulp to replantation during the regeneration process in rat molars

    Microsoft Academic Search

    Aya Shimizu; Kuniko Nakakura-Ohshima; Tadashi Noda; Takeyasu Maeda; Hayato Ohshima

    2000-01-01

    Responses of immunocompetent cells to tooth replantation during the regeneration process of the dental pulp in rat molars were investigated by immunocytochemistry using antibodies to class II major histocompatibility complex (MHC) molecules (OX6 antibody), monocyte\\/macrophage lineage cells (ED1 antibody) and protein gene product 9.5 (PGP 9.5), as well as by histochemical reaction for periodic acid-Schiff (PAS). Tooth replantation caused an

  17. Responses of macrophage-associated antigen-expressing cells in the dental pulp of rat molars to experimental tooth replantation

    Microsoft Academic Search

    Seree Rungvechvuttivittaya; Takashi Okiji; Hideaki Suda

    1998-01-01

    Bacterial infection of the dental pulp is a major hindrance to successful pulp regeneration after tooth replantation. This study examined how macrophages and class II molecule-expressing cells of the pulp respond to tooth replantation, on the hypothesis that they contribute to the defence and repair of the traumatized pulp. Upper right first molars of 5-week-old male Wistar rats were replanted

  18. Aqueous leachability of metakaolin-based geopolymers with molar ratios of Si\\/Al = 1.5–4

    Microsoft Academic Search

    Z. Aly; E. R. Vance; D. S. Perera; J. V. Hanna; C. S. Griffith; J. Davis; D. Durce

    2008-01-01

    The leachability in water of metakaolin based geopolymers with molar ratios of Na\\/Al=1 and Si\\/Al=1.5–4.0 has been investigated in order to optimise the composition for the immobilisation of nuclear waste. Formulations with Si\\/Al of around 2 are the most suitable using the ASTM\\/PCT leach test method. The variability of the leach results is discussed with reference to the microstructure, compressive

  19. Partially molten magma ocean model

    SciTech Connect

    Shirley, D.N.

    1983-02-15

    The properties of the lunar crust and upper mantle can be explained if the outer 300-400 km of the moon was initially only partially molten rather than fully molten. The top of the partially molten region contained about 20% melt and decreased to 0% at 300-400 km depth. Nuclei of anorthositic crust formed over localized bodies of magma segregated from the partial melt, then grew peripherally until they coverd the moon. Throughout most of its growth period the anorthosite crust floated on a layer of magma a few km thick. The thickness of this layer is regulated by the opposing forces of loss of material by fractional crystallization and addition of magma from the partial melt below. Concentrations of Sr, Eu, and Sm in pristine ferroan anorthosites are found to be consistent with this model, as are trends for the ferroan anorthosites and Mg-rich suites on a diagram of An in plagioclase vs. mg in mafics. Clustering of Eu, Sr, and mg values found among pristine ferroan anorthosites are predicted by this model.

  20. Leadership in Partially Distributed Teams

    ERIC Educational Resources Information Center

    Plotnick, Linda

    2009-01-01

    Inter-organizational collaboration is becoming more common. When organizations collaborate they often do so in partially distributed teams (PDTs). A PDT is a hybrid team that has at least one collocated subteam and at least two subteams that are geographically distributed and communicate primarily through electronic media. While PDTs share many…