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Sample records for age determination by teeth

  1. Root dentine transparency: age determination of human teeth using computerized densitometric analysis.

    Science.gov (United States)

    Drusini, A; Calliari, I; Volpe, A

    1991-05-01

    Root dentine transparency (RDT) was used to estimate the ages of human subjects from 152 intact teeth. Teeth were from 134 subjects, both historical and recent, of known age and sex. The aims of this work are 1) to compare two methods of using RDT to estimate age; 2) to test the applicability of the regression formulae for estimating age obtained from a recent sample on an historical sample; and 3) to estimate the suitability of RDT to determine age at death of 100-year-old skeletons. RDT was measured by two techniques: 1) computerized densitometric analysis and 2) vernier caliper. Age estimations based on computerized densitometric analysis were no more accurate than were those determined by caliper measurement; both give a predictive success of +/- 5 years in about 45-48% of cases for premolars. The television-based digitization system has some disadvantages: It is expensive, not portable, and requires some training to use. However, it furnishes a more standardized method, a rapid graphic illustration of the results, and an immediate storage of statistical information for future use. PMID:1853940

  2. Forensic Medicine: Age Written in Teeth by Nuclear Bomb Tests

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence Livermore National Laboratory

    2005-05-04

    Establishing the age of individuals is an important step in identification and a frequent challenge in forensic medicine. This can be done with high precision up to adolescence by analysis of dentition, but establishing the age of adults has remained difficult. Here we show that measuring {sup 14}C from nuclear bomb tests in tooth enamel provides a sensitive way to establish when a person was born.

  3. Determination of iron, cobalt and zinc in caries teeth by neutron activation analysis

    International Nuclear Information System (INIS)

    The concentration of Fe, Zn and Co in caries teeth was determined by neutron activation analysis to compare with those of complete impacted wisdom teeth. In order to investigate the distribution of three elements, molar teeth were separated not by conventional method like precipitation or UV absorption method but by ashing method. Furthermore, the same elements for dental pulp and softened dentin were determined. The following results were obtained: The concentration of three elements (Fe, Zn and Co) in enamel, dentin and cementum of caries teeth was higher than that in control teeth. Enamel contained more Fe and Co than those in dentin or cementum, whereas Zn was found to be evenly distributed in three parts of the teeth. The concentration of the elements was Zn>Fe>Co in softened dentin, Fe>Zn>Co in dental pulp. (author)

  4. Determination of Lead in Human Teeth by Hydride Generation Atomic Absorption Spectrometry

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    Hassan T. Abdulsahib

    2011-01-01

    Full Text Available Problem statement: The determination of lead in human teeth at concentration levels of ìg/ml is proposed using Hydride Generation Atomic Absorption Spectrometry (HG-AAS. To do this, 2% (wv lanthanum chloride solution is employed as matrix modifying reagent to increase sensitivity and remove matrix interferences. Approach: About 100 µL of sample and 100 µL of 3.0% (m/v NaBH4 are simultaneously injected into carrier streams. The detection of limit of 0.46 µg L-1 for Pb was achieved and the relative standard deviation of 3.0% for 10 µg L-1 lead was obtained. The recovery percentage of the method has been found to be (92.8-100.5% for known quantities of lead added to teeth sample which were completely recovered. A comparison of the proposed method with standard addition method showed nearly results in the same samples of teeth and the results compared with other studies in the world. Results: The method was shown to be satisfactory for determination of traces of lead in teeth samples with excellent accuracy. Teeth analysis reveals that intact teeth contained the highest amounts of lead which provide an evidence that lead may reduce the prevalence of dantal caries. Statistically significant differences (pConclusion: Statistically significant difference between age groups were seen in the mean value of lead concentrations in human teeth, the concentration of lead increased with age. The differences may be due to the exposure of lead and others factors such as differences in diet and drinking water.

  5. Estimation of age from development and eruption of teeth

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    B. S. Manjunatha

    2014-01-01

    Full Text Available The developing dentition is used to assess maturity and estimate the age in many disciplines including anthropology, archeology, forensic science, pediatric dentistry and orthodontics. There is evidence that dental development is less effected than skeletal development by malnutrition and hormonal disorders. There are two methods of dental age assessment, radiographically and by clinically visualization of eruption of teeth. The clinical method to assess dental age is based on the emergence of teeth in the mouth. This method is more suitable since it does not require any special equipment, expertise and is more economical. Tooth formation is the best choice for estimating the age as variations are less as compared to other development factors. Eruption of teeth is one of the changes observed easily among the various dynamic changes that occur from the formation of teeth to the final shedding of teeth. The times of eruption of teeth are fairly constant and this can be made use of in ascertaining the average age of eruption of the tooth. Assessment of age of an individual by examination of teeth is one of the accepted methods of age determination.

  6. Age-Dependent Changes in Pb Concentration in Human Teeth.

    Science.gov (United States)

    Fischer, Agnieszka; Wiechuła, Danuta

    2016-09-01

    The result of exposure to Pb is its accumulation in mineralized tissues. In human body, they constitute a reservoir of approx. 90 % of the Pb reserve. The conducted research aimed at determining the accumulation of Pb in calcified tissues of permanent teeth. The concentration of Pb in 390 samples of teeth taken from a selected group of Polish people was determined using the AAS method. Average concentration of Pb in teeth amounted to 14.3 ± 8.18 μg/g, range of changes: 2.21-54.8 μgPb/g. Accumulation of Pb in human body was determined based on changes in Pb concentration in teeth of subjects aged 13-84 years. It was found that in calcified tissues of teeth, the increase in concentration of Pb that occurs with age is a statistically significant process (p = 0.02, the ANOVA Kruskal-Wallis test). It was determined that the annual increase in concentration of Pb in tissues of teeth is approx. 0.1 μg/g. Moreover, a different course of changes in Pb concentration in tissues of teeth in people born in different years was observed. The level of Pb concentration in teeth of the oldest subjects (>60 years) decreased for those born in the 1930s compared to those in the 1950s. Teeth from younger persons (<60 years) were characterized by an increasing level of Pb concentration. The analysis of changes of Pb indicates that for low exposure, a relatively greater accumulation of Pb concentration in calcified tissues of teeth can occur. PMID:26888348

  7. AGE ESTIMATION BY USING ERUPTION OF PERMANENT TEETH: A COMPARATIVE STUDY IN LOCAL POPULATION TO PROVE/DISPROVE AGES OF ERUPTION USED IN ROUTINE PRACTICE

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    Tamilmani

    2015-10-01

    Full Text Available Estimation of age is one of the important medico legal works where medical knowledge is applied in rendering Justice to the public and to the state. Assessment of age is often required in civil and criminal litigations. Assessment of age of an individual by examination of teeth is one of the universally accepted methods of age estimation. In a developing country like India, a large number of people are illiterate and have no knowledge or records of their date of birth which is required by law enforcing age ncies in matters like, criminal responsibilities, identification, judicial punishment, consent, rape, criminal abortion, employment, attainment of majority, kidnapping and prostitution (Pathak et al, 1999. Age estimation is also required for admission pur poses at the time of schooling, joining services and during retirement. Estimation of age is also required for giving old age benefits. Hence, scientific determination of age is very important. Key words; Eruption of permanent teeth, J udicial punishment , Legal sections , Estimation of age in both sexes.

  8. Gamma irradiation and ESR spectroscopic methods to determine the age of fossil teeth recently excavated in the archaeological site

    International Nuclear Information System (INIS)

    Electron spin resonance (ESR) is one of the modern techniques useful in dating events that are up to 1 million years old and hence very useful in understanding various geological events. A preliminary attempt has been made to date fossil teeth found in Perur, a historical town in Coimbatore district in Tamilnadu. This sample for dating was collected at 1.3m below the surface of the land. The sample was divided into six sets and five of which were given an additive dose (AD) by using γ rays of 405 Gy, 810 Gy, 1620 Gy, 2340 Gy and 3240 Gy respectively. The sample shows similar ESR spectra having g value 2.0045. The absorption lines at this 'g' value has been used to estimate the age, assuming the external dose rate to be 1.12mGy/a. The calculated age of the sample is 2102.67 years old, and the result is good agreement with the reference data. (author)

  9. Accuracy of age estimation of radiographic methods using developing teeth.

    Science.gov (United States)

    Maber, M; Liversidge, H M; Hector, M P

    2006-05-15

    Developing teeth are used to assess maturity and estimate age in a number of disciplines, however the accuracy of different methods has not been systematically investigated. The aim of this study was to determine the accuracy of several methods. Tooth formation was assessed from radiographs of healthy children attending a dental teaching hospital. The sample was 946 children (491 boys, 455 girls, aged 3-16.99 years) with similar number of children from Bangladeshi and British Caucasian ethnic origin. Panoramic radiographs were examined and seven mandibular teeth staged according to Demirjian's dental maturity scale [A. Demirjian, Dental development, CD-ROM, Silver Platter Education, University of Montreal, Montreal, 1993-1994; A. Demirjian, H. Goldstein, J.M. Tanner, A new system of dental age assessment, Hum. Biol. 45 (1973) 211-227; A. Demirjian, H. Goldstein, New systems for dental maturity based on seven and four teeth, Ann. Hum. Biol. 3 (1976) 411-421], Nolla [C.M. Nolla, The development of the permanent teeth, J. Dent. Child. 27 (1960) 254-266] and Haavikko [K. Haavikko, The formation and the alveolar and clinical eruption of the permanent teeth. An orthopantomographic study. Proc. Finn. Dent. Soc. 66 (1970) 103-170]. Dental age was calculated for each method, including an adaptation of Demirjian's method with updated scoring [G. Willems, A. Van Olmen, B. Spiessens, C. Carels, Dental age estimation in Belgian children: Demirjian's technique revisited, J. Forensic Sci. 46 (2001) 893-895]. The mean difference (+/-S.D. in years) between dental and real age was calculated for each method and in the case of Haavikko, each tooth type; and tested using t-test. Mean difference was also calculated for the age group 3-13.99 years for Haavikko (mean and individual teeth). Results show that the most accurate method was by Willems [G. Willems, A. Van Olmen, B. Spiessens, C. Carels, Dental age estimation in Belgian children: Demirjian's technique revisited, J. Forensic Sci

  10. Forensic study of sex determination using PCR on teeth samples.

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    Murakami H

    2000-02-01

    Full Text Available In this study, sex determination using polymerase chain reaction (PCR on tooth material was evaluated from the viewpoint of forensic medicine. The sensitivity of PCR for detection of the Y chromosome-specific alphoid repeat sequence and the X chromosome-specific alphoid repeat sequence was 0.5 pg of genomic DNA. Sex could be determined by PCR of DNA extracted from the pulp of 16 freshly extracted permanent teeth and dentine including the surface of the pulp cavity of 6 freshly extracted milk teeth. Sex could be determined using the pulp in all 20 teeth (10 male and 10 female preserved at room temperature for 22 years. For the pulp of teeth stored in sea water, the sex could be determined in all 8 teeth immersed for 1 week and in 5 of 6 teeth immersed for 4 weeks. In the remaining 1 tooth, in which sex determination based on the pulp failed, the sex could be determined correctly when DNA extracted from the tooth hard tissue was examined. For teeth stored in soil, the sex could be determined accurately in all 8 teeth buried for 1 week, 7 of 8 teeth buried for 4 weeks, and in all 6 teeth buried for 8 weeks. When teeth were heated for 30 min, sex determination from the pulp was possible in all teeth heated to 100, 150, and 200 degrees C, and even in some teeth heated to 250 degrees C. When this method was applied to actual forensic cases, the sex of a mummified body estimated to have been discovered half a year to 1 year after death could be determined readily by examination of the dental pulp. In the skeletons of 2 bodies placed under water for approximately 1 year and approximately 11 years and 7 months, pulp tissues had been dissolved and lost, but sex determination was possible using DNA extracted from hard dental tissues. These results indicate that this method is useful in forensic practices for sex determination based on teeth samples.

  11. Age of an Indonesian Fossil Tooth Determined by Electron Paramagnetic Resonance

    Energy Technology Data Exchange (ETDEWEB)

    Bogard, JS

    2004-04-07

    The first fossil hominid tooth recovered during 1999 excavations from the Cisanca River region in West Java, Indonesia, was associated with a series of bovid teeth from a single individual that was recovered 190 cm beneath the hominid tooth. The age of the fossil bovid teeth was determined using electron paramagnetic resonance (EPR) analysis as part of an effort to bracket the age of the hominid tooth. The EPR-derived age of the bovid teeth is (5.16 {+-} 2.01) x 10{sup 5} years. However, the age estimate reported here is likely an underestimate of the actual age of deposition since evidence of heating was detected in the EPR spectra of the bovid teeth, and the heating may have caused a decrease in the intensity of EPR components on which the age calculation is based.

  12. Weight, height and eruption times of permanent teeth of children aged 4–15 years in Kampala, Uganda

    OpenAIRE

    Kutesa, Annet; Nkamba, Eriab Moses; Muwazi, Louis; Buwembo, William; Rwenyonyi, Charles Mugisha

    2013-01-01

    Background Tooth eruption is a continuous biological process by which developing teeth emerge through the jaws and the overlying mucosa to enter into the oral cavity. Tooth eruption time and sequence are important factors in dental treatment planning, particularly in orthodontics, but also in forensic dentistry to estimate age of a child. Tooth eruption time is influenced by many factors. In this study we set out to determine the timing of eruption of permanent teeth and assess its associatio...

  13. Evaluation of the diffusion of Mn, Fe, Ba and Pb in Middle Ages human teeth by synchrotron microprobe X-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, M.L. [Centro de Fisica Atomica, Universidade de Lisboa, Av. Prof. Gama Pinto 2, 1649-003 Lisboa (Portugal)], E-mail: luisa@cii.fc.ul.pt; Marques, A.F.; Marques, J.P. [Centro de Fisica Atomica, Universidade de Lisboa, Av. Prof. Gama Pinto 2, 1649-003 Lisboa (Portugal); Casaca, C. [Centro de Fisica Atomica, Universidade de Lisboa, Av. Prof. Gama Pinto 2, 1649-003 Lisboa (Portugal); Faculdade de Medicina Dentaria, Universidade de Lisboa, Av. Prof. Gama Pinto, 1700 Lisboa (Portugal)

    2007-07-15

    Human teeth from the Middle Ages have been analysed using a synchrotron microprobe evaluating Mn, Fe, Ba and Pb diffusion from the soil into the tooth structure. It is apparent that post-mortem teeth of ancient populations are influenced by the endogenous environment. The diffusion pattern of some elements can give information both for archaeological purposes and diagenesis processes affecting the apatite ante-mortem elemental content. An X-ray fluorescence set-up with microprobe capabilities, 100 {mu}m of spatial resolution and energy of 18 keV, installed at LURE synchrotron (France) was used. Line scans were performed along the several regions of the teeth, in steps of 100 to 1000 {mu}m. Ba is much enriched in ancient teeth when compared to recent ones, where this element is almost non-existent. Furthermore, the concentration profiles show increased levels of this element close to the external enamel region, reaching values up to 200 {mu}g g{sup -1} decreasing in dentine and achieving a steady level in the inner dentine and root. Pb concentration profiles show strongly increased levels of this element close to the external enamel region (20 {mu}g g{sup -1}), decreasing strongly to the inner part of the dentine (0.5 {mu}g g{sup -1}) contrarily to the normal situation in modern citizens where the highest concentrations for Pb are in the inner root dentine. This behaviour suggests post-mortem uptake from the soil; the presence of elevated levels of Pb can be explained by the fact that this burial place was a car park for more than 20 years. The distribution of Mn and Fe follow very similar patterns and both are very much enriched especially in the outer surfaces in contact with the soil, showing strong contamination from the soil.

  14. The significance of biometric parameters in determining anterior teeth width

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    Strajnić Ljiljana

    2013-01-01

    Full Text Available Background/Aim. An important element of prosthetic treatment of edentulous patients is selecting the size of anterior artificial teeth that will restore the natural harmony of one’s dentolabial structure as well as the whole face. The main objective of this study was to determine the correlation between the inner canthal distance (ICD and interalar width (IAW on one side and the width of both central incisors (CIW, the width of central and lateral incisors (CLIW, the width of anterior teeth (ATW, the width between the canine cusps (CCW, which may be useful in clinical practice. Methods. A total of 89 subjects comprising 23 male and 66 female were studied. Their age ranged from 19 to 34 years with the mean of 25 years. Only the subjects with the preserved natural dentition were included in the sample. All facial and intraoral tooth measurements were made with a Boley Gauge (Buffalo Dental Manufacturing Co., Brooklyn NY, USA having a resolution of 0.1mm. Results. A moderate correlation was established between the interalar width and combined width of anterior teeth and canine cusp width (r = 0.439, r = 0.374. A low correlation was established between the inner canthal distance and the width of anterior teeth and canine cusp width (r = 0.335, r = 0.303. The differences between the two genders were highly significant for all the parameters (p < 0.01. The measured facial distances and width of anterior teeth were higher in men than in women. Conclusion. The results of this study suggest that the examined interalar width and inner canthal distance cannot be considered reliable guidelines in the selection of artificial upper anterior teeth. However, they may be used as a useful additional factor combined with other methods for objective tooth selection. The final decision should be made while working on dentures fitting models with the patient’s consent.

  15. Assessment of structural changes of human teeth by low-field nuclear magnetic resonance (NMR)

    International Nuclear Information System (INIS)

    A technique of low-field pulsed proton nuclear magnetic resonance (NMR) spin relaxation is described for assessment of age-related structural changes (dentin and pulp) of human teeth in vitro. The technique involves spin–spin relaxation measurement and inversion spin–spin spectral analysis methods. The spin–spin relaxation decay curve is converted into a T2 distribution spectrum by a sum of single exponential decays. The NMR spectra from the extracted dentin-portion-only and dental pulp-cells-only were compared with the whole extracted teeth spectra, for the dentin and pulp peak assignments. While dentin and pulp are highly significant parameters in determining tooth quality, variations in these parameters with age can be used as an effective tool for estimating tooth quality. Here we propose an NMR calibration method—the ratio of the amount of dentin to the amount of pulp obtained from NMR T2 distribution spectra can be used for measuring the age-related structural changes in teeth while eliminating any variations in size of teeth. Eight teeth (third molars) extracted from humans, aged among 17–67 years old, were tested in this study. It is found that the intensity ratio of dentin to pulp sensitively changes from 0.48 to 3.2 approaching a linear growth with age. This indicates that age-related structural changes in human teeth can be detected using the low-field NMR technique

  16. Determination of Radius of Curvature for Teeth With Cycloid Profile

    Science.gov (United States)

    Shatalov, E. V.; Efremenkov, E. A.; Shibinskiy, K. G.

    2016-04-01

    In the article the geometric determination of curvature radius is considered for teeth with cycloid profile. The equations are obtained for the determination of a radius of curvature with point coordinates of a cycloid profile. The conditions of convexo-concavity of a teeth profile are defined for transmission with intermediate rollers.

  17. Age estimation from physiological changes of teeth: A reliable age marker?

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    Nishant Singh

    2014-01-01

    Full Text Available Background: Age is an essential factor in establishing the identity of a person. Teeth are one of the most durable and resilient part of skeleton. Gustafson (1950 suggested the use of six retrogressive dental changes that are seen with increasing age. Aim: The aim of the study was to evaluate the results and to check the reliability of modified Gustafson′s method for determining the age of an individual. Materials and Methods: Total 70 patients in the age group of 20-65 years, undergoing extraction were included in this present work. The ground sections of extracted teeth were prepared and examined under the microscope. Modified Gustafson′s criteria were used for the estimation of age. Degree of attrition, root translucency, secondary dentin deposition, cementum apposition, and root resorption were measured. A linear regression formula was obtained using different statistical equations in a sample of 70 patients. Results: The mean age difference of total 70 cases studied was ±2.64 years. Difference of actual and calculated age was significant and was observed at 5% level of significance, that is, t-cal > t-tab (t-cal = 7.72. P < 0.05, indicates that the results were statistically significant. Conclusion: The present study concludes that Gustafson′s method is a reliable method for age estimation with some proposed modifications.

  18. Enamel defect of deciduous teeth in small gestational age children

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    Willyanti S Syarif

    2010-06-01

    Full Text Available Background: Enamel defect could be caused by genetic and environmental factors in prenatal period. Meanwhile, prenatal malnutrition could also cause small gestational age (SGA. Small Gestational Age is the term used for a neonatal baby with birthweight below the -2SD normal value or 10th percentile on the intrauterine Lubchenco curve. This condition is due to intra-uterine growth restriction, and eventually ends up with several developmental defects of organs, including teeth. In fact, deciduous tooth development has a critical phase within this development period. Purpose: The aim of this study is not only to find out the incidence of enamel defect in SGA children, but also to know the percentage of SGA risk factor to develop enamel defect. Method: This was a epidemiology research with consecutive admission technique. It consisted of 153 SGA children aged 9–48 months. Next, the Ponderal index was used to assign SGA types, symmetrical or asymmetrical one-in this study 59 and 94 respectively. On the other hand, three hundred and ninety Appropriate for Gestational Age (AGA children aged 4–48 months were also included in the study as a control group. Enamel defect then was determined by intraoral examination, classified into hypoplasia and hypocalcifications. Chi-square test was finally used to determine the relative risk ratio between the SGA and the control AGA children. Result: The result of this research showed that incidence of enamel defect in SGA children was 86.92%, meanwhile, that in AGA children was 23.08%, 66.00% of which were commonly suffered from hypocalcification. With p<0.05 it is also known that SGA children has the risk of enamel defect with hypocalcification, about 79% higher than AGA children. Conclusion: It could be concluded that 79% of SGA children had the risk of deciduous tooth enamel defect with hypocalcification as the most.Latar belakang: Defek email dapat terjadi karena faktor genetik dan lingkungan sistemik yang

  19. Comparison of digital radiography and apex locator with the conventional method in root length determination of primary teeth

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    I E Neena

    2011-01-01

    Full Text Available Aim: The purpose of this study was to compare the Working length in primary teeth endodontics using intra oral digital radiovisiography and apex locator with conventional method for accuracy. Materials and Methods: This in vivo study was conducted on 30 primary teeth which were indicated for pulpectomy in the patients of the age group of 5-11 years All experimental teeth had adequate remaining tooth structure for rubber dam isolation and radiographicaly visible canals. Endodontic treatment was required due to irreversible pulpitis or pulp necrosis. A standardized intraoral periapical radiograph of the tooth was taken using conventional method by paralleling technique. The distance between the source and the tooth, tooth and the films were standardized using X-ray positioning device. During the pulpectomy procedure, the working length was determined by digital radiograph and apex locator. The measurements were then compared with the conventional method of root canal measurement technique for accuracy Result: From the results obtained we can conclude that Working length determined in primary molars using digital radiography and Apex locator did not show any significant difference in the mean working length measurements when compared with the conventional radiographic method. Conclusions: Apex locator is comparable to conventional radiograph in determining the working length without radiation in the primary teeth. Intraoral digital radiography is the safest method in determining the working length with significant reduction in radiation exposure.Hence, both the techniques can be safely used as alternatives to conventional radiographic methods in determining working length in primary teeth.

  20. The influence of trace elements on fluoride uptake by teeth

    International Nuclear Information System (INIS)

    To investigate the effect of various trace elements on fluoride uptake by teeth, the concentrations of F and other trace elements have been simultaneously determined in different regions of the teeth from children of South Australia. Teeth cross sectioned along the median plane have been used in these investigations, and their inside enamel, dentine and amelodentinal junctions investigated separately for the trace elemental composition. Fluoride has been determined by observing the 6-7 MeV gammas for the 19F(p,αγ)16O reaction, C by activation through the 12C(3He,n)14O reaction, while other trace elements have been measured by the thick target PIXE technique. Linear correlation coefficients have been calculated between the F concentrations in teeth and those of other trace elements observed. Fluoride is found to correlate best with C, Cu and Pb, poorly with Fe, Sr, Ni and Ag, while with Br and Zn it has-ve coefficients. Student's t-test has been applied to the data to examine the significance of the variation of Fand other trace elements amongst different dental tissues from healthy and diseased teeth. (orig.)

  1. Microprobe analysis of teeth by synchrotron radiation: environmental contamination

    International Nuclear Information System (INIS)

    An X-ray fluorescence set-up with microprobe capabilities, installed at the Laboratoire pour l'Utilisation du Rayonnement Electromagnetique (LURE) synchrotron (France) was used for elemental determination in teeth. To evaluate the influence of living habits in dental elemental composition nine teeth collected post-mortem were analysed, five from a miner and four from a fisherman. All teeth from the fisherman were healthy. From the miner some teeth were carious and one of them was filled with metallic amalgam. Teeth were sliced under the vertical plane and each slice was scanned from the root to the enamel for elemental profile determination. The synchrotron microprobe resolution was of 100 μm and incident photons of 18 keV energy were used. The elemental concentration values found suggest heterogeneity of the teeth material. Moreover, the distinct profiles for Mn, Sr, Br and Pb were found when teeth from the miner and from the fisherman are compared which can be associated with dietary habits and environmental influence. Higher concentrations of Mn and Sr were found for the fisherman teeth. In addition, Br was only observed in this group of teeth. Pb levels are higher for the miner teeth in particular for dentine regions. The influence of amalgam, such as, increase of Zn and Hg contents in the teeth material, is only noticed for the immediate surroundings of the treated cavity

  2. Microprobe analysis of teeth by synchrotron radiation: environmental contamination

    Energy Technology Data Exchange (ETDEWEB)

    Pinheiro, T. E-mail: murmur@itn1.itn.pt; Carvalho, M.L.; Casaca, C.; Barreiros, M.A.; Cunha, A.S.; Chevallier, P

    1999-09-02

    An X-ray fluorescence set-up with microprobe capabilities, installed at the Laboratoire pour l'Utilisation du Rayonnement Electromagnetique (LURE) synchrotron (France) was used for elemental determination in teeth. To evaluate the influence of living habits in dental elemental composition nine teeth collected post-mortem were analysed, five from a miner and four from a fisherman. All teeth from the fisherman were healthy. From the miner some teeth were carious and one of them was filled with metallic amalgam. Teeth were sliced under the vertical plane and each slice was scanned from the root to the enamel for elemental profile determination. The synchrotron microprobe resolution was of 100 {mu}m and incident photons of 18 keV energy were used. The elemental concentration values found suggest heterogeneity of the teeth material. Moreover, the distinct profiles for Mn, Sr, Br and Pb were found when teeth from the miner and from the fisherman are compared which can be associated with dietary habits and environmental influence. Higher concentrations of Mn and Sr were found for the fisherman teeth. In addition, Br was only observed in this group of teeth. Pb levels are higher for the miner teeth in particular for dentine regions. The influence of amalgam, such as, increase of Zn and Hg contents in the teeth material, is only noticed for the immediate surroundings of the treated cavity.

  3. Trace Elements in Teeth by ICPMS

    International Nuclear Information System (INIS)

    Teeth are reported to be suitable indicators of trace element exposure from environment and nutritional status. Inductively coupled plasma mass spectrometry (ICP-MS) is used to compare the trace element content of children's primary teeth and adult teeth. Primary teeth are collected from 28 children and 42 adult from non-industrial City. The data are assessed statistically using t-tests. The adult teeth contained significantly greater concentrations of Na, Mg, Al, Fe, Ni, Cu, Sr, Cd, Ba, Pb and U and significantly less Mn, Co, As, Se, Mo and Bi than the children teeth. Additional measurements on adult teeth pulps are performed. Comparison between trace element concentrations in health and caries teeth pulps show that the mean concentrations of Na, Al, K, Cr, Mn, Co, Cu, Zn, Mo, Ag, Bi and U are lower in caries than healthy teeth pulps. On the other hand, the mean concentrations of Mg, Cd and Pb are higher in caries samples than healthy teeth pulps

  4. Volatile constituents of Melissa officinalis leaves determined by plant age.

    Science.gov (United States)

    Nurzyńska-Wierdak, Renata; Bogucka-Kocka, Anna; Szymczak, Grazyna

    2014-05-01

    The present study investigated changes in the content and chemical composition of the essential oil extracted by hydrodistillation from air-dried Melissa officinalis L. (lemon balm) leaves in the first and second year of plant growth. The lemon balm oil was analysed by GC-MS and GC-FID. The presence of 106 compounds, representing 100% of the oil constituents, was determined in the oil. The predominant components were geranial (45.2% and 45.1%) and neral (32.8% and 33.8%); their proportions in the examined samples of the oil obtained from one- and two-year-old plants were comparable. However, the age of lemon balm plants affected the concentration of other constituents and the proportions of the following compounds were subject to especially high fluctuations: citronellal (8.7% and 0.4%), geraniol (trace amounts and 0.6%), and geranyl acetate (0.5% and 3.0%), as well as, among others, isogeranial, E-caryophyllene, caryophyllene oxide, germacrene D, and carvacrol. The essential oil of two-year-old plants was characterized by a richer chemical composition than the oil from younger plants. PMID:25026727

  5. Comparative Evaluation of Electronic Apex Locators and Radiovisiography for Working Length Determination in Primary Teeth in vivo

    Science.gov (United States)

    Singh, Neerja; Rathore, Monika S; Tandon, Shobha; Rajkumar, Balakrishnan

    2016-01-01

    ABSTRACT Aims: The aim of this study was to evaluate the effectiveness of two different varieties of electronic apex locators and radiovisiography (RVG) for working length determination in primary teeth. Materials and methods: A total of 30 primary teeth indicated for pulpectomy in children aged 3 to 8 years were randomly selected and subjected to working length determination using two varieties of electronic apex locators and RVG separately. The data were then subjected to statistical analysis. Results: A very strong correlation between electronic measurement methods and RVG length was observed. Conclusion: Radiovisiography and apex locators are equally effective in determining working length in primary teeth. How to cite this article: Abdullah A, Singh N, Rathore MS, Tandon S, Rajkumar B. Comparative Evaluation of Electronic Apex Locators and Radiovisiography for Working Length Determination in Primary Teeth in vivo. Int J Clin Pediatr Dent 2016;9(2):118-123. PMID:27365931

  6. Accuracy of Demirjian′s 8 teeth method for age prediction in South Indian children: A comparative study

    Directory of Open Access Journals (Sweden)

    Rezwana Begum Mohammed

    2015-01-01

    Full Text Available Introduction: Demirjian′s method of tooth development is most commonly used to assess age in individuals with emerging teeth. However, its application on numerous populations has resulted in wide variations in age estimates and consequent suggestions for the method′s adaptation to the local sample. Original Demirjian′s method utilized seven mandibular teeth, to which recently third molar is added so that the method can be applied on a wider age group. Furthermore, the revised method developed regression formulas for assessing age. In Indians, as these formulas resulted in underestimation, India-specific regression formulas were developed recently. The purpose of this cross-sectional study was to evaluate the accuracy and applicability of original regression formulas (Chaillet and Demirjian 2004 and India-specific regression formulas (Acharya 2010 using Demirjian′s 8 teeth method in South Indian children of age groups 9-20 years. Methods: The present study consisted of 660 randomly selected subjects (330 males and 330 females were in the aged ranging from 9 to 20 years divided into 11 groups according to their age. Demirjian′s 8 teeth method was used for staging of teeth. Results: Demirjian′s method underestimated the dental age (DA by 1.66 years for boys and 1.55 years for girls and 1.61 years in total. Acharya′s method over estimated DA by 0.21 years for boys and 0.85 years for girls and 0.53 years in total. The absolute accuracy was better for Acharya′s method compared with Demirjian method. Conclusion: This study concluded that both the Demirjian and Indian regression formulas were reliable in assessing age making Demirjian′s 8 teeth method applicable for South Indians.

  7. Fluorine determination in human healthy and carious teeth using the PIGE technique

    International Nuclear Information System (INIS)

    The purpose of this study is to determine and compare the fluorine concentration in human teeth from two different populations, living in the Portuguese quite isolated islands of Acores: S. Miguel and Terceira. Both populations have similar dietary habits, similar occupational activities, mostly rural, and the age of both populations is more or less the same, around 40 years. No chronic diseases were registered in any of the donors. The two groups are exposed to different levels of fluorine in drinking water. Terceira island has moderate fluorine concentration levels (1-2 μg g-1) while S. Miguel island is known for the high fluorine concentration levels in its water (>3 μg g-1), especially in one area known as Furnas. Thirty-three teeth, 17 healthy and 16 carious without restoration (14 incisors and canines, 7 premolars and 12 molars), were collected and analyzed for the determination of fluorine concentration in the dentine region, using the nuclear reaction 19F(p,αγ)16O. The teeth were cross-sectioned along the vertical plane and polished, in order to obtain a smooth and plane surface of about 1 mm thickness. In this work an association between caries prevalence and fluorine content of drinking water is discussed and the variation of fluorine concentration among different types of teeth (canines and incisors, premolars, molars) and physical state (carious and non-carious) is examined

  8. Trace element distribution in human teeth by x-ray fluorescence spectrometry and multivariate statistical analysis

    CERN Document Server

    Oprea, Cristiana; Gustova, Marina V; Oprea, Ioan A; Buzguta, Violeta L

    2014-01-01

    X-ray fluorescence spectrometry (XRFS) was used as a multielement method of evaluation of individual whole human tooth or tooth tissues for their amounts of trace elements. Measurements were carried out on human enamel, dentine, and dental cementum, and some differences in tooth matrix composition were noted. In addition, the elemental concentrations determined in teeth from subjects of different ages, nutritional states, professions and gender, living under various environmental conditions and dietary habits, were included in a comparison by multivariate statistical analysis (MVSA) methods. By factor analysis it was established that inorganic components of human teeth varied consistently with their source in the tissue, with more in such tissue from females than in that from males, and more in tooth incisor than in tooth molar.

  9. Holes in teeth - Dental caries in Neolithic and Early Bronze Age populations in Central Germany.

    Science.gov (United States)

    Nicklisch, Nicole; Ganslmeier, Robert; Siebert, Angelina; Friederich, Susanne; Meller, Harald; Alt, Kurt W

    2016-01-01

    This study provides diachronic insight into the epidemiology of carious defects in teeth of Neolithic and Early Bronze Age populations in Central Germany over a period of 4000 years. The data were retrieved from skeletal remains uncovered at 21 sites throughout the Middle Elbe-Saale region (MES), comprising a total of 494 individuals with preserved teeth. The data generated were examined for age- and sex-related differences in order to gain information about the dietary habits and socio-economic structures of the period with the goal of identifying potential diachronic changes. The results indicated that dietary habits changed over the course of the Neolithic period: the prevalence of caries significantly decreased between the Early and Late Neolithic. The adults from the Early Neolithic sample, particularly those from the LBK bore the highest rate of caries. This highlights the essential importance of cereals in the diet of the early farmers in the Middle Elbe-Saale region. As time went on, meat and dairy products became more and more important, which had a positive impact on dental health. The data also show sex-specific differences: women were more often affected by caries than men and female jaws also generally exhibited greater numbers of carious teeth than their male counterparts. Dental health is a reflection of both biological factors and of economic and sociocultural structures. PMID:25765291

  10. Reliability of conventional shade guides in teeth color determination

    Directory of Open Access Journals (Sweden)

    Todorović Ana

    2013-01-01

    Full Text Available Background/Aim. Color matching in prosthodontic therapy is a very important task because it influences the esthetic value of dental restorations. Visual shade matching represents the most frequently applied method in clinical practice. Instrumental measurements provide objective and quantified data in color assessment of natural teeth and restorations. In instrumental shade analysis, the goal is to achieve the smallest ΔE value possible, indicating the most accurate shade match. The aim of this study was to evaluate the reliability of commercially available ceramic shade guides. Methods. VITA Easyshade spectrophotometer (VITA, Germany was used for instrumental color determination. Utilizing this device, color samples of ten VITA Classical and ten VITA 3D - Master shade guides were analyzed. Each color sample from all shade guides was measured three times and the basic parameters of color quality were examined: ΔL, ΔC, ΔH, ΔE, ΔElc. Based on these parameters spectrophotometer marks the shade matching as good, fair or adjust. Results. After performing 1,248 measurements of ceramic color samples, frequency of evaluations adjust, fair and good were statistically significantly different between VITA Classical and VITA 3D Master shade guides (p = 0.002. There were 27.1% cases scored as adjust, 66.3% as fair and 6.7% as good. In VITA 3D - Master shade guides 30.9% cases were evaluated as adjust, 66.4% as fair and 2.7% cases as good. Conclusion. Color samples from different shade guides, produced by the same manufacturer, show variability in basic color parameters, which once again proves the lack of precision and nonuniformity of the conventional method.

  11. Dental radiology: ageing changes in permanent teeth of Beagle dogs

    International Nuclear Information System (INIS)

    Radiographic interpretation of dental or periodontal disease is dependent in part on an understanding of ageing changes, A progressively ageing colony of healthy beagle dogs (120 to 3759 days) was studied by use of high-detail radiographs made following the death of the dog. Morphological features whose radiographic appearance was found to be especially age-dependent were: root canal size, both vertical and horizontal alveolar bone resorption, visualisation of the lamina dura dentis, and detection of hypercementosis. Understanding of these ageing changes is necessary to avoid over-diagnosis of disease

  12. Usia saat inisial akuisisi Streptococcus mutans dan jumlah erupsi gigi sulung pada anak (Initial acquisition age of Mutans Streptococci and number of erupted primary teeth in children)

    OpenAIRE

    Citra Adinda; Udijanto Tedjosasongko; Teguh Budi Wibowo

    2014-01-01

    Background: Mutan Streptococci (MS) are considered as major bacteria in human dental caries. Previous experiments reported that MS needs permanent surface to make stable colonization in human oral mouth. Transmission of MS occured directly or indirectly by salivary contact. The younger the child acquired MS the higher dental caries risk of the child. Purpose: The purposes of this study was to determine the age and number of primary teeth erupted during MS initial acquisition in children. Meth...

  13. Improvement in properties of plastic teeth by electron beam irradiation

    International Nuclear Information System (INIS)

    Improvement of the comfort and esthetics of artificial plastic teeth is desirable for the recently increasing numbers of elderly in society. Plastic teeth made of polycarbonate (PC) were modified by electron beam (EB) irradiation under specific conditions, and the change in the chemical properties of the PC was investigated. The water absorption, glucose attachment, level of bis-phenol-A (BPA) extraction, maltose adhesion, and mucin adhesion on the PC teeth were measured before and after EB irradiation. EB irradiation to a dose of 3.5 kGy at 150 oC in a nitrogen gas atmosphere reduced the water absorption by 20%, glucose absorption by 40%, maltose adhesion by 20%, and the amount of various amino acids, formed as the hydrolysis products of mucin, adhering on the PC teeth were reduced by 60-99%. The BPA content was lower than the detection limit for analysis of both the original and the EB irradiated PC teeth. - Highlights: → Radiation improvement of polycarbonate for plastic teeth by EB irradiation 3.5 kGy at 150 oC in inert gas. → Water and glucose absorption and maltose adhesion on PC teeth were much reduced. → Bis-phenol-A content from PC teeth was lower than the detection limit after irradiation.

  14. HEU age determination

    International Nuclear Information System (INIS)

    A technique has been developed to determine the Highly Enriched Uranium (HEU) Age which is defined as the time since the HEU was produced in an enrichment process. The HEU age is determined from the ratios of relevant uranium parents and their daughters viz 230Th/234U and 231Pa/235U. Uranium isotopes are quantitatively measured by their characteristic gammas and their daughters by alpha spectroscopy. In some of the samples where HEU is enriched more than 99%, the only mode of HEU age determination is by the measurement of 231Pa since there is negligible quantity of 230Th due to very low atom concentrations of 234U in the sample. In this paper we have presented data and methodology of finding the age of two HEU samples

  15. Diagnostic Criteria in Choosing a Method of Deciduous Teeth Periodontitis Treatment

    OpenAIRE

    Sheshukova, O. V.

    2015-01-01

    The study involved 38 children at the age of 5 to 9 years with chronic periodontitis of deciduous teeth. Exctracted teeth on account of chronic periodontitis were evaluated according to the level of resorption using the developed classification of resorption of deciduous teeth roots.According to the analysis of the research data chronic periodontitis of deciduous teeth led to faster resorption of their roots earlier by 2.5-4.5 years. Exctraction of deciduous tooth is advisable in determining ...

  16. Teeth, sex, and testosterone: aging in the world's smallest primate.

    Directory of Open Access Journals (Sweden)

    Sarah Zohdy

    Full Text Available Mouse lemurs (Microcebus spp. are an exciting new primate model for understanding human aging and disease. In captivity, Microcebus murinus develops human-like ailments of old age after five years (e.g., neurodegeneration analogous to Alzheimer's disease but can live beyond 12 years. It is believed that wild Microcebus follow a similar pattern of senescence observed in captive animals, but that predation limits their lifespan to four years, thus preventing observance of these diseases in the wild. Testing whether this assumption is true is informative about both Microcebus natural history and environmental influences on senescence, leading to interpretation of findings for models of human aging. Additionally, the study of Microcebus longevity provides an opportunity to better understand mechanisms of sex-biased longevity. Longevity is often shorter in males of species with high male-male competition, such as Microcebus, but mouse lemurs are sexually monomorphic, suggesting similar lifespans. We collected individual-based observations of wild brown mouse lemurs (Microcebus rufus from 2003-2010 to investigate sex-differences in survival and longevity. Fecal testosterone was measured as a potential mechanism of sex-based differences in survival. We used a combination of high-resolution tooth wear techniques, mark-recapture, and hormone enzyme immunoassays. We found no dental or physical signs of senescence in M. rufus as old as eight years (N = 189, ages 1-8, mean = 2.59 ± 1.63 SE, three years older than captive, senescent congeners (M. murinus. Unlike other polygynandrous vertebrates, we found no sex difference in age-dependent survival, nor sex or age differences in testosterone levels. While elevated male testosterone levels have been implicated in shorter lifespans in several species, this is one of the first studies to show equivalent testosterone levels accompanying equivalent lifespans. Future research on captive aged individuals can

  17. Morphological characterization of the oral cavity of the gilthead seabream (Sparus aurata) with emphasis on the teeth-age adaptation.

    Science.gov (United States)

    Elgendy, Samir A A; Alsafy, Mohamed A M; Tanekhy, Mahmoud

    2016-03-01

    Gilthead sea bream with different age groups that collected from Seawater fisheries, Ismailia Governorate, Egypt, were examined by gross anatomy and scanning electron microscopy to assess the morphological characteristics of the oral cavity. Teeth patterns showed that the gilthead sea bream is adapted to the feeding pattern according to age development, as it modified from spiny form teeth in young fishes to obelisk-like teeth and flat dome-like teeth in growing fishes, with differentiation of teeth into three pairs of canine and conical teeth, that later differentiated to small and large flat teeth. With development, the apical pouch also showed morphological differentiation from curve-like in small fishes to Y-letter shape in medium-sized fishes, which later grow to completely covering the lower jaw in grown adult fishes. Tongue papillae, on the other hand, showed some differentiation being smoother in growing fishes than adult ones. Consistent with development differentiation, the palatine region of young fishes appeared separated from the palate by deep palatine fissure, while that the same palatine region was continuous with the palate with a remnant of palatine fissure as shallow groove was noticed in grown big fishes. Taste buds were characterized in the oral cavity of small and large fishes however in large fishes; the taste buds were more prominent especially at the palate and palatine folds. These and other morphological features of the oral cavity and the feeding habits in small and large gilthead sea bream fishes were recorded. Microsc. Res. Tech. 79:227-236, 2016. © 2016 Wiley Periodicals, Inc. PMID:26791335

  18. ABO blood grouping from hard and soft tissues of teeth by modified absorption-elution technique

    Directory of Open Access Journals (Sweden)

    B K Ramnarayan

    2013-01-01

    Full Text Available Background: Teeth have always been known as stable tissue that can be preserved both physically and chemically for long periods of time. Blood group substances have been known to be present in both the hard and soft tissues of the teeth. Objectives: This study aimed at detection of ABO blood group substances from soft and hard tissues of teeth and also to evaluate the reliability of teeth stored for a relatively long period as a source of blood group substances by absorption-elution technique with some modifications. Results: Blood group obtained from the teeth was compared with those obtained from the blood sample. Pulp showed a very large correlation in both fresh and long-standing teeth though it decreased slightly in the latter. Hard tissue showed a large correlation in both the groups indicating that hard tissue is quite reliable to detect blood group and that there is no much difference in the reliability in both the groups. However, combining pulp and hard tissue, correlation is moderate. Correlation of blood grouping with the age, sex, and jaw distribution was carried out. Conclusion: Blood group identification from hard and soft tissues of teeth aids in the identification of an individual.

  19. Element analysis of teeth from children with and without cystic fibrosis by PIXE-PIGE

    International Nuclear Information System (INIS)

    The objective of this research is to determine whether there is a difference in the Ca, P, Fe, F, Mg, and Sr concentrations in teeth from children with and without cystic fibrosis (CF) as a function of age, sex of the child, maternal smoking habit, maternal drinking habit, and fluoridation of water supply. The nuclear analytical methods used were Proton-Induced X-Ray Emission (PIXE) and Proton-Induced Gamma Emission (PIGE). The findings are: (1) the concentration of Mg is higher in the teeth of children with cystic fibrosis who took antibiotics other than tetracycline (CF+NT) than in non-cystic fibrosis (NCF) teeth for the 'female' category; (2) P concentration is less in (CF+NT) teeth for the 'age greater than ten' group; (3) Fe concentration is greater for females in the NCF group; (4) Ca and Fe concentrations are lower for CF than for NCF in the 'mother smokes' group; (5) F and Sr concentrations for CF+NT are higher for the 'mother drinks' group than for the 'mother does not drink' group; (6) 'mother smokes' shows a depletion of Ca and Fe compared to 'mother does not smoke' for CF+NT. (7) 'fluoridation of water supply' shows an increase in F, except for NCF teeth. (author)

  20. Child lead exposure determined from measurement of x-ray fluorescence of teeth in situ

    International Nuclear Information System (INIS)

    X-ray fluorescence from lead when irradiated by gamma rays from a Co-57 source was utilized to measure the lead concentration in children's teeth in situ. The sensitivity of the method was adequate to detect 15 ppM from a gamma ray exposure to the tooth approximately 1/10 the exposure of a routine dental x-ray examination. The tooth lead levels assayed using x-ray fluorescence correlated well with chemical assay techniques for both extracted permanent and shed primary teeth. Thirty children from the Children's Hospital of Philadelphia suspected of having elevated lead levels had tooth lead levels measured in situ determined using the x-ray fluorescent technique. The tooth lead concentration varied from a low of 16 ppM to a high of 56 ppM

  1. A study of the thickness of cheek teeth subocclusal secondary dentine in horses of different ages

    OpenAIRE

    White, C.; Dixon, P M

    2010-01-01

    P>Reasons for performing study: There is limited knowledge on the thickness of subocclusal secondary dentine in equine cheek teeth (CT). Hypotheses: Subocclusal secondary dentine is of consistent thickness above different pulp horns in individual horses and its thickness increases with age. Methods: 408 permanent CT were extracted post mortem from 17 horses aged 4-30 years, with no history of dental disease. The CT were sectioned longitudinally in the medio-lateral (bucco-palatal/lingual) ...

  2. Reliability of age estimation using Demirjian′s 8 teeth method and India specific formula

    Directory of Open Access Journals (Sweden)

    V Jayanth Kumar

    2011-01-01

    Full Text Available Introduction: The estimation of the age of a person has been an archaic exercise, and since decades even dentists have contributed to this science with several methods through radiography. The tooth with its developmental stages provides us with a non-invasive modality to determine the age of the person. Aim: To evaluate the reliability of age estimation using Demirjian′s 8 teeth method following the French maturity scores and India specific formula. Materials and Methods: The study was conducted on 121 archived digital orthopantamographs which were predominantly pre-treatment orthodontic radiographs from patients without any obvious developmental anomalies. The radiographs were divided into two gender specific groups and further sub-divided into two smaller groups of 7-16 years and 16.1-23 years. The radiographs were evaluated as per Demirjian′s criteria and age was calculated using the formula developed for the Indian population. Results: The results showed that the mean absolute error for the study sample was 1.18 years; in 57.9% of cases the error rate was within ±1 year. The mean absolute error in males (7-16 years was 1.2 years; in males (16.1-23 years was 1.3 years; in females (7-16 years was 0.95 years and in females (16.1-23 years was 1.16 years. Conclusion: The age estimation using this method narrows down the error rate to just over one year making this method reliable. However the inclusion of third molar increases the error rates in the older individuals within the sample.

  3. Mutans Streptococci Colonization in Relation to Feeding Practices, Age and the Number of Teeth in 6 to 30-Month-Old Children: An in vivo Study

    OpenAIRE

    Sharma, Rajesh; Prabhakar, AR; Gaur, Anupama

    2012-01-01

    ABSTRACT Background: Early childhood caries has been characterized as first affecting the primary maxillary anterior teeth, followed by the involvement of the primary molars. Other terms for dental caries in preschool children, which inappropriately may imply cause for the disease, includes baby bottle tooth decay, nursing caries, milk bottle syndrome, baby bottle caries, nursing bottle mouth and nursing mouth. Aim: To explore the relationships of feeding practices, age and number of teeth pr...

  4. Age determination and geological studies

    International Nuclear Information System (INIS)

    Two hundred and eight potassium-argon age determinations carried out on Canadian rocks and minerals are reported. Each age determination is accompanied by a description of the rock and mineral concentrate used; brief interpretative comments regarding the geological significance of each age are also provided where possible. The experimental procedures employed are described in brief outline and the constants used in the calculation of ages are listed. Two geological time-scales are reproduced in tabular form for ready reference and an index of all Geological Survey of Canada K-Ar age determinations published in this format has been prepared using NTS quadrangles as the primary reference

  5. Atmospheric nuclear weapons test history narrated by carbon-14 in human teeth

    International Nuclear Information System (INIS)

    The atmospheric testing of nuclear weapons since 1945 caused a significant increase in the concentration of atmospheric 14C. The 14C concentration in plants that assimilate 14C directly by photosynthesis reflects the atmospheric 14C concentration. Carbon-14 is then transferred into the human body through the food chain. Based on animal experiments, the collagen in human teeth is metabolically inert after its formation. This implies that the collagen of each tooth retains the 14C concentration which reflects the 14C concentration in the blood at the time collagen metabolism ceased. The distribution of the 14C concentration in the collagen of teeth from subjects of various ages would follow a pattern similar to that shown by soft tissues. In this paper the authors elucidate the relationship between the number of nuclear weapon tests and the distribution of 14C concentration in teeth

  6. Determination of age, longevity and age at reproduction of the frog Microhyla ornata by skeletochronology

    Indian Academy of Sciences (India)

    Suresh M Kumbar; Katti Pancharatna

    2001-06-01

    Skeletochronological estimation of age, longevity, age at sexual maturity and breeding of Microhyla ornata was done. Frogs ( = 62) were collected locally in August (rainy season) 1997 and brought to the laboratory. Body mass and snout-vent-length (SVL) of each frog was recorded; the 4th toe of both the hind limbs was clipped under anaesthesia, fixed in 10% formalin, demineralized in 5% nitric acid and processed for histology. Limb bones (femur, humerus, tibiofibula and radioulna) of 6 large sized frogs were also processed for skeletochronology in order to study the rate of resorption. Gonads of 25 frogs (belonging to different body size ranges) were processed for histology in order to ascertain the gametogenic status of individual frogs. One to four growth rings consisting of growth zones and lines of arrested growth (LAGs) were noticed in frogs of different body sizes; the number of LAGs remained identical in all the limb bones and phalanges in 5 out of 6 frogs. Back calculation indicated that the resorption rate is very low in this frog. Male frogs possessed sperm bundles in seminiferous tubules in the 1st year, while females showed yolky follicles in the ovary in the 2nd year. Frogs found in amplexus were 3–5 years old. The results suggest that this frog may live for a maximum of 5 years in the natural population.

  7. Usia saat inisial akuisisi Streptococcus mutans dan jumlah erupsi gigi sulung pada anak (Initial acquisition age of Mutans Streptococci and number of erupted primary teeth in children

    Directory of Open Access Journals (Sweden)

    Citra Adinda

    2014-12-01

    Full Text Available Background: Mutan Streptococci (MS are considered as major bacteria in human dental caries. Previous experiments reported that MS needs permanent surface to make stable colonization in human oral mouth. Transmission of MS occured directly or indirectly by salivary contact. The younger the child acquired MS the higher dental caries risk of the child. Purpose: The purposes of this study was to determine the age and number of primary teeth erupted during MS initial acquisition in children. Methods: The subjects were 30 infants aged 5 months old of Simomulyo region, Surabaya, East Java, Indonesia. Monthly plaque samples were taken using sterile cotton bud and oral examination were done to check number of primary teeth for 6 months period. The MS isolate were isolated using BHI broth and TYC respectively. The MS identification was done by gram staining and colony morphology. Number of erupted primary teeth was determined by counting the erupted teeth in each month. Results: As the result 83% children acquired MS and 17% children remain free from MS. The mean age of initial acquisition was 7,76±0,96 months and the average number of erupted teeth was two teeth. Conclusion: The study revealed that the mean age of MS initial acquisition in children was 7,76±0,96 month and the colonization of MS was found in children with average 2 primary teeth erupted.Latar belakang: Streptococcus Mutans (SM merupakan bakteri utama penyebab karies gigi. Percobaan sebelumnya melaporkan bahwa SM membutuhkan permukaan permanen untuk membuat kolonisasi stabil di rongga mulut. Penularan SM terjadi secara langsung atau tidak langsung melalui kontak saliva. Semakin muda anak mengakuisisi SM semakin tinggi resiko terjadinya karies pada anak tersebut. Tujuan: Penelitian ini bertujuan meneliti umur dan jumlah rata-rata gigi erupsi pada masa inisial akuisisi SM pada anak Metode: Subyek penelitian ini adalah 30 bayi berusia 5 bulan di wilayah Simomulyo, Surabaya, Jawa Timur

  8. Comparison of methods to determine the centre of resistance of teeth.

    Science.gov (United States)

    Schmidt, Falko; Geiger, Martin Eberhard; Jäger, Rudolf; Lapatki, Bernd Georg

    2016-11-01

    In orthodontic treatment, the locations of the centre of resistance (CR) of individual teeth and the applied load system are the major determinants for the type of tooth movement achieved. Currently, CR locations have only been specified for a relatively small number of tooth specimen for research purposes. Analysing cone beam computed tomography data samples from three upper central incisors, this study explores whether the effort to establish accurate CR estimates can be reduced by (i) morphing a pre-existing simplified finite element (FE) mesh to fit to the segmented 3D tooth-bone model, and (ii) individualizing a mean CR location according to a small parameter set characterising the morphology of the tooth and its embedding. The FE morphing approach and the semi-analytical approach led to CR estimates that differ in average only 0.04 and 0.12 mm respectively from those determined by very time-consuming individual FE modelling (standard method). Both approaches may help to estimate the movement of individual teeth during orthodontic treatment and, thus, increase the therapeutic efficacy. PMID:27113861

  9. Age determination of ground-waters by means of carbon 14

    International Nuclear Information System (INIS)

    At present the age determination of ground-waters aged between 1,500 and approximately 40,000 years is only possible by measuring their 14C content. A precise age assignment can be established in slightly mineralised waters, whereas it becomes vague in mineralised waters, particularly in acidulous springs. In general, additional information and data are required about the 13C, D, 18O, 3H, 85Kr and the 39Ar contents, about the ph value, temperature and the principal ions. (DG)

  10. An evaluation of age estimation using teeth from South Asian River dolphins (Platanistidae

    Directory of Open Access Journals (Sweden)

    Christina H Lockyer

    2014-12-01

    Full Text Available The South Asian river dolphins (Platanista gangetica minor and P. g. gangetica are endangered, geographically isolated, freshwater cetaceans. Accurate age estimation of individuals is an important aspect of population biology as it is used for calculating parameters such as age at maturity and reproduction, longevity, and growth and survival rates. However this has never been comprehensively studied for this endangered cetacean family. A sample of 41 teeth from 29 skulls stored in museum collections was available. We compared two different aging methods to select the most appropriate. This involved decalcification and freeze-sectioning of teeth at variable thicknesses (10–25 micron, and staining with 1 Toluidine Blue, or 2 Ehrlichs Acid Haematoxylin. Stains were then compared for readability of Growth Layer Groups (GLG. The optimum section was found at 20 micron using Erhlichs Acid Haematoxylin. Both dentinal and cemental GLG were readable and comparable, but cemental GLG were generally easier to interpret because they were better defined. Ages varied from newborn / young of year (with none or only a neonatal line present to a maximum age of 30 GLG. There is currently no validation available for GLG deposition rate, but it is likely annual because of the extreme seasonal changes in the river habitat. 

  11. Determination of trace amount of lanthanum in animal tissues, special reference to teeth and bone

    International Nuclear Information System (INIS)

    When a lanthanum solution is swabbed on the surface of teeth in vivo or in vitro, lanthanum is substituted for the calcium of enamel surface, and therefore, dental caries formation is inhibited. The study was to determine the amount of lanthanum uptake into teeth and bone, furthermore internal organs, and to provide an aid for estimation on the effect of the element in living bodies. Samples were digested with nitric acid-perchloric acid mixture. After dissolution, lanthanum was precipitated with oxalate using calcium oxalate carrier. The precipitate was decomposed. Lanthanum was extracted into 0.1 M TTA-MIBK, and back-extracted with 1 M nitric acid. ICP emission spectrometry was applied for the determination. Teeth, thighbone, and other organs were drawn out from the rats of which teeth was swabbed with 8 % lanthanum nitrate, 2.5 % lanthanum EDTA, and 10.5 % lanthanum EDTA, once a day for 2 weeks. The maximum content of lanthanum was 54 μg/g in the teeth and 2.7 μg/g in the thighbone. Lanthanum contents for liver, spleen, kidney, and blood were also presented for the samples drawn out within one day and 1, 3, and 5 month later after swabbing. (author)

  12. Comparison of digital radiography and apex locator with the conventional method in root length determination of primary teeth

    OpenAIRE

    I E Neena; A Ananthraj; P. Praveen; Karthik, V.; P. Rani

    2011-01-01

    Aim: The purpose of this study was to compare the Working length in primary teeth endodontics using intra oral digital radiovisiography and apex locator with conventional method for accuracy. Materials and Methods: This in vivo study was conducted on 30 primary teeth which were indicated for pulpectomy in the patients of the age group of 5-11 years All experimental teeth had adequate remaining tooth structure for rubber dam isolation and radiographicaly visible canals. Endodontic treatment wa...

  13. Age Determination of Trace Plutonium by Using ID-MC-ICP-MS

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>In the analysis of the origin of plutonium, the isotopic composition and the age of the material are very important. The age is the first parameter necessary to be determined when deducing the history of the

  14. Determining the relative age of blue ballpoint ink by gas chromatography

    Institute of Scientific and Technical Information of China (English)

    Yao Lijuan; Zhao Pengcheng; Wang Jinghan; Wang Yanji

    2006-01-01

    A method for identifying the writing age of blue ballpoint pen ink has been established due to the imperative demand in forensic laboratories.The content of the volatile components in blue ballpoint pen ink were determined by gas chromatography(GC).The absorbance of dye in blue ballpoint pen ink was measured by UV-Vis spectrometry A writing age curve of the ink was established using the ratio of the content of the volatile components to the dye,based on the identification of 74 kinds of blue ballpoint pen ink of domestic and international origins.The change of benzene alcohol or phenoxetol with the writing age was also tested.Different kinds of blue ballpoint pen ink were detected and the repeatability of the experiment was investigated.The results indicate that the method is reliable,sensitive,systematic and is especially suitable for practical use.

  15. Age determination by back length for African savanna elephants: extending age assessment techniques for aerial-based surveys.

    Directory of Open Access Journals (Sweden)

    Morgan J Trimble

    Full Text Available Determining the age of individuals in a population can lead to a better understanding of population dynamics through age structure analysis and estimation of age-specific fecundity and survival rates. Shoulder height has been used to accurately assign age to free-ranging African savanna elephants. However, back length may provide an analog measurable in aerial-based surveys. We assessed the relationship between back length and age for known-age elephants in Amboseli National Park, Kenya, and Addo Elephant National Park, South Africa. We also compared age- and sex-specific back lengths between these populations and compared adult female back lengths across 11 widely dispersed populations in five African countries. Sex-specific Von Bertalanffy growth curves provided a good fit to the back length data of known-age individuals. Based on back length, accurate ages could be assigned relatively precisely for females up to 23 years of age and males up to 17. The female back length curve allowed more precise age assignment to older females than the curve for shoulder height does, probably because of divergence between the respective growth curves. However, this did not appear to be the case for males, but the sample of known-age males was limited to ≤27 years. Age- and sex-specific back lengths were similar in Amboseli National Park and Addo Elephant National Park. Furthermore, while adult female back lengths in the three Zambian populations were generally shorter than in other populations, back lengths in the remaining eight populations did not differ significantly, in support of claims that growth patterns of African savanna elephants are similar over wide geographic regions. Thus, the growth curves presented here should allow researchers to use aerial-based surveys to assign ages to elephants with greater precision than previously possible and, therefore, to estimate population variables.

  16. Asteroid age distributions determined by space weathering and collisional evolution models

    CERN Document Server

    Willman, Mark; 10.1016/j.icarus.2010.02.017

    2010-01-01

    We provide evidence of consistency between the dynamical evolution of main belt asteroids and their color evolution due to space weathering. The dynamical age of an asteroid's surface \\citep{bib.bot05a,bib.nes05} is the time since its last catastrophic disruption event which is a function of the object's diameter. The age of an S-complex asteroid's surface may also be determined from its color using a space weathering model \\citep[e.g.][]{bib.wil10,bib.jed04,bib.wil08,bib.mar06}. We used a sample of 95 S-complex asteroids from SMASS and obtained their absolute magnitudes and $u,g,r,i,z$ filter magnitudes from SDSS. The absolute magnitudes yield a size-derived age distribution. The $u,g,r,i,z$ filter magnitudes lead to the principal component color which yields a color-derived age distribution by inverting our color-age relationship, an enhanced version of the `dual $\\tau$' space weathering model of \\citet{bib.wil10}. We fit the size-age distribution to the enhanced dual $\\tau$ model and found characteristic w...

  17. NEWER ASPECTS IN THE AGE-DEPENDING ALTERATION OF HORSE TEETHING

    Directory of Open Access Journals (Sweden)

    A. GÁSPÁRDY

    2013-12-01

    Full Text Available The authors give a short orientation about the age related parameters of incisors based on the literature. They tell about their own investigation of two conventional (cup depth and its yearly abrasion and of two first applied (relative abrasion and area of dental table parameters. The previous literature evaluated the parameters in question in two different ways: time period or frequency analysis. The authors introduced a new method: the linearly-corrected row data which is processed by analysis of variance. Their elaboration reaches altogether 107 individuals, three horse types (English Thoroughbred, English Half-breed and pony, and two genders (mare, stallion + gelding. The cup depth at the levelling is the shallowest in the ponies (2 mm, while it is deeper in the Half-breeds (5 mm and in the Thoroughbreds (4.4 mm. This deviation can be explained by body size differences between breeds. The degree of the absolute and the relative abrasion of the cup can be associated with the early utilisation (racing and with the intensive feeding (concentrate. The area of the dental table is the largest in the pony, and the smallest in the Thoroughbred. The reason for the slowest abrasion observed in the ponies can be explained not only by the more traditional feeding but also by the bigger occlusive surface. The authors assume that the selection for the early utilisation of the English Thoroughbred resulted in an automatic change of the well inherited chronology of dentition; more early matured animals producing, in relation to the chronology of dentition. In this breed the general refinement of the whole organism, but especially of the bone system manifests in the narrowing of the teeth also.

  18. New electronic apex locator Romiapex A-15 presented accuracy for working length determination in permanent teeth

    Directory of Open Access Journals (Sweden)

    Etevaldo Matos Maia Filho

    2014-12-01

    Full Text Available Purpose: The present study aims to evaluate, ex vivo, the accuracy of electronic apex locators Root ZX II and Romiapex-15, for working length (WL determination in permanent teeth. Materials and Methods: Fourteen single-rooted teeth (incisors and canines, with their apices fully formed were used. The dental crowns were removed. The anatomic length of the tooth (real measurement was visually determined through the insertion of a size 10 K-file until the tip of the instrument could be observed in the apical foramen under a microscope (20X. Teeth were fixed in a model of resin and adapted into alginate soaked with saline solution, which was used as an  electrical conductor. Using a K-file, root canals were measured electronically using both devices. The results obtained for each apex locator were compared to the real measurements. The accuracy between the devices was statistically analyzed using the Bland-Altman graph, Intraclass Correlation Coefficient (ICC, and Student’s t-test. Results: The mean difference between the measurements using the Root ZX II was 0.277mm greater than the real measurement, while the measurements from the Romiapex-15 were 0.308mm higher on average. The comparison between Root ZX II and Romiapex-15 had no significant difference (p= 0.868. Conclusion: It was concluded that Root ZX II and Romiapex-15 had similar accuracy. Romiapex-15 could be an option for WL determination in permanent teeth.

  19. Female Reproductive Decline Is Determined by Remaining Ovarian Reserve and Age

    OpenAIRE

    Wilkosz, Pawel; Gareth D. Greggains; Tanbo, Tom G.; Fedorcsak, Peter

    2014-01-01

    The early decline and loss of female fertility in humans and other species represents an evolutionary paradox. Despite being born with a vast stock of oocytes, females encounter an exhaustion of ovarian reserve and sterility half way through their natural lives. Female reproductive ageing has been proposed to proceed as an ongoing decline in ovarian reserve, determined by remaining ovarian follicle number. However, despite extensive modelling, the respective contributions of intra-, inter-, a...

  20. In situ analysis of human teeth by external PIXE

    Energy Technology Data Exchange (ETDEWEB)

    Rautray, Tapash R., E-mail: tapash77@hotmail.co [Department of Dental Biomaterials, School of Dentistry, Kyungpook National University, 2-188-1 Samduk-dong, Jung-gu, Daegu (Korea, Republic of); ARASMIN, G. Udayagiri, Kandhamal, Orissa 762100 (India); Das, Saubhagyalaxmi [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005 (India); Rautray, Alekh C. [ARASMIN, G. Udayagiri, Kandhamal, Orissa 762100 (India)

    2010-07-15

    The elemental profiles of the enamel, cementum and caries of human teeth were analysed by the external proton induced X-ray emission studies. Ten elements namely P, Ca, V, Mn, Fe, Cu, Zn, As, Sr and Pb were estimated in the present study. P and Ca were found to be the major elements whereas all other elements were found in trace level. It was observed that the respective concentrations of elements namely P, Ca, Fe, Zn and Pb in enamel are more than those in cementum. Concentration of P ranged between 6.37% and 25% whereas Ca ranged between 12.94% and 43.36%.

  1. Protocol for determining Apparent Young's Modulus of human teeth using laser speckle interferometry

    Science.gov (United States)

    Salvador-Palmer, Rosario; González-Peña, Rolando J.; Martínez-Celorio, René A.; López, Francisco J.; Paredes, Vanessa; Cibrián, Rosa

    2012-10-01

    Digital Speckle Shearing Pattern Interferometry (DSSPI) allows to directly quantify deformations in teeth that are subjected to stress. Eighteen second premolars (2PM) were studied both before and after endodontic treatment made with the ProTaper method in order to evaluate the variation of dental elasticity. We present a protocol for determination tooth Apparent Young's Modulus (AYM). Each tooth underwent different flexion loads from 50 to 300 g. DSSPI technique, makes it possible to show the deformation at each point of a line, selected by the researcher, that goes from the attachment point (Point 0) to the root area where the load is applied (Point 300-350, depending on the tooth size). The deformation of each tooth was characterized by the deformation value of point 150, located around the mid-area of tooth. This value was obtained from a linear regression applied on the deformation values of all the points in the fitted line. The correlation coefficients of these fitted regression lines were always higher than 0.972. The elasticity constant of each tooth was obtained as the slope of a new regression line, corresponding to the different loads applied on the tooth versus the corresponding deformation at point 150. This value, divided by the length of the tooth, is the apparent Young's modulus (AYM), which is expressed in arbitrary units (a.u.). Values of the AYM before (4.16 104 a.u) and after endodontic treatment using the ProTaper method (4.30 104 a.u.) showed no statistically significant difference in the elasticity of teeth (p>0.7).

  2. Evaluation of technical quality and periapical health of root-filled teeth by using cone-beam CT

    Directory of Open Access Journals (Sweden)

    Bilge Gülsüm NUR

    2014-12-01

    Full Text Available Objective This study aimed to assess the quality of root fillings, coronal restorations, complications of all root-filled teeth and their association with apical periodontitis (AP detected by cone-beam computed tomography (CBCT images from an adult Turkish subpopulation. Material and Methods The sample for this study consisted of 242 patients (aging from 15 to 72 years with 522 endodontically treated teeth that were assessed for technical quality of the root canal filling and periapical status of the teeth. Additionally, the apical status of each root-filled tooth was assessed according to the gender, dental arch, tooth type and age classification, undetected canals, instrument fracture, root fracture, apical resorption, apical lesion, furcation lesion and type and quality of the coronal structure. Statistical analysis was performed using percentages and chi-square test. Results The success rate of the root canal treatment was of 54.4%. The success rates of adequate and inadequate root canal treatment were not significantly different (p>0.05. Apical periodontitis was found in 228 (45.6% teeth treated for root canals. Higher prevalence of AP was found in patients aging from 20 to 29 years [64 (27% teeth] and in anterior (canines and incisors teeth [97 (41% teeth]. Conclusions The technical quality of root canal filling performed by dental practitioners in a Turkish subpopulation was consistent with a high prevalence of AP. The probable reasons for this failure are multifactorial, and there may be a need for improved undergraduate education and postgraduate courses to improve the clinical skills of dental practitioners in endodontics.

  3. Elemental comparison in sound and carious human teeth by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Instrumental neutron activation analysis (INAA) was applied to determine Ca, Cl, Mg, Mn, Na, Sr and Zn in human dentin and enamel tissues from carious and sound teeth. Comparisons were made between the results obtained in carious and sound dental tissues for dentin and enamel. The findings obtained were also compared with the published data. Accuracy and precision of the results were evaluated by analyzing certified reference material. (author)

  4. Hg, Bi, Cu and Zn distribution in human teeth treated by dental amalgam measured by synchrotron microprobe

    International Nuclear Information System (INIS)

    Human teeth restored with dental amalgam were analysed by a synchrotron microprobe to evaluate the diffusion of its major constituents, Cu, Zn and Hg, throughout the tooth structures. We measured the elemental distribution inside the tooth from the root to the enamel, specially the region around the amalgam, after its total removal. Hg is present only in restored teeth and concentration profiles show strongly increased levels of this element close to the amalgam region, reaching 500 μg g-1 in one or two cases, decreasing strongly to the inner part of the tooth. Pb concentration profiles do not seem to be affected by metallic amalgam. Very high concentrations of Bi were found in one of the restored teeth, reaching more than 2000 μg g-1, decreasing sharply to the outer regions. The distribution of Mn, Fe, Cu and Zn was also determined in order to evaluate elemental influences by amalgam components. No significant changes in elemental concentrations were detected for Mn and Fe between healthy and restored teeth. However, the levels of Zn and Cu are increased in restored teeth. An X-ray fluorescence set-up with microprobe capabilities, 100 μm of spatial resolution and an energy of 18 keV, installed at LURE synchrotron (France) was used

  5. Hg, Bi, Cu and Zn distribution in human teeth treated by dental amalgam measured by synchrotron microprobe

    Science.gov (United States)

    Carvalho, M. L.; Marques, J. P.; Brito, J.; Casaca, C.; Cunha, A. S.

    2002-11-01

    Human teeth restored with dental amalgam were analysed by a synchrotron microprobe to evaluate the diffusion of its major constituents, Cu, Zn and Hg, throughout the tooth structures. We measured the elemental distribution inside the tooth from the root to the enamel, specially the region around the amalgam, after its total removal. Hg is present only in restored teeth and concentration profiles show strongly increased levels of this element close to the amalgam region, reaching 500 μg g -1 in one or two cases, decreasing strongly to the inner part of the tooth. Pb concentration profiles do not seem to be affected by metallic amalgam. Very high concentrations of Bi were found in one of the restored teeth, reaching more than 2000 μg g -1, decreasing sharply to the outer regions. The distribution of Mn, Fe, Cu and Zn was also determined in order to evaluate elemental influences by amalgam components. No significant changes in elemental concentrations were detected for Mn and Fe between healthy and restored teeth. However, the levels of Zn and Cu are increased in restored teeth. An X-ray fluorescence set-up with microprobe capabilities, 100 μm of spatial resolution and an energy of 18 keV, installed at LURE synchrotron (France) was used.

  6. Hg, Bi, Cu and Zn distribution in human teeth treated by dental amalgam measured by synchrotron microprobe

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, M.L. E-mail: luisa@cii.fc.ul.pt; Marques, J.P.; Brito, J.; Casaca, C.; Cunha, A.S

    2002-11-01

    Human teeth restored with dental amalgam were analysed by a synchrotron microprobe to evaluate the diffusion of its major constituents, Cu, Zn and Hg, throughout the tooth structures. We measured the elemental distribution inside the tooth from the root to the enamel, specially the region around the amalgam, after its total removal. Hg is present only in restored teeth and concentration profiles show strongly increased levels of this element close to the amalgam region, reaching 500 {mu}g g{sup -1} in one or two cases, decreasing strongly to the inner part of the tooth. Pb concentration profiles do not seem to be affected by metallic amalgam. Very high concentrations of Bi were found in one of the restored teeth, reaching more than 2000 {mu}g g{sup -1}, decreasing sharply to the outer regions. The distribution of Mn, Fe, Cu and Zn was also determined in order to evaluate elemental influences by amalgam components. No significant changes in elemental concentrations were detected for Mn and Fe between healthy and restored teeth. However, the levels of Zn and Cu are increased in restored teeth. An X-ray fluorescence set-up with microprobe capabilities, 100 {mu}m of spatial resolution and an energy of 18 keV, installed at LURE synchrotron (France) was used.

  7. Daily physical activity as determined by age, body mass and energy balance

    OpenAIRE

    Klaas R Westerterp

    2015-01-01

    Aim Insight into the determinants of physical activity, including age, body mass and energy balance, facilitates the design of intervention studies with body mass and energy balance as determinants of health and optimal performance. Methods An analysis of physical activity energy expenditure in relation to age and body mass and in relation to energy balance, where activity energy expenditure is derived from daily energy expenditure as measured with doubly labelled water and body movement is m...

  8. Analysis of enamel microbiopsies in shed primary teeth by Scanning Electron Microscopy (SEM) and Polarizing Microscopy (PM)

    Energy Technology Data Exchange (ETDEWEB)

    Costa de Almeida, Glauce Regina; Molina, Gabriela Ferian; Meschiari, Cesar Arruda [Department of Morphology, Stomatology and Physiology, Dental School of Ribeirao Preto, University of Sao Paulo - FORP/USP, Av. do Cafe, S/N, Monte Alegre, CEP 14040-904, Ribeirao Preto, SP (Brazil); Barbosa de Sousa, Frederico [Department of Morphology, Dental School of Joao Pessoa, Federal University of Paraiba - UFPB, Av Castelo Branco - Campus I, CEP 58.059-900, Joao Pessoa, PB (Brazil); Gerlach, Raquel Fernanda, E-mail: rfgerlach@forp.usp.br [Department of Morphology, Stomatology and Physiology, Dental School of Ribeirao Preto, University of Sao Paulo - FORP/USP, Av. do Cafe, S/N, Monte Alegre, CEP 14040-904, Ribeirao Preto, SP (Brazil)

    2009-09-01

    The aims of this study were 1) to verify how close to the theoretically presumed areas are the areas of enamel microbiopsies carried out in vivo or in exfoliated teeth; 2) to test whether the etching solution penetrates beyond the tape borders; 3) to test whether the etching solution demineralizes the enamel in depth. 24 shed upper primary central incisors were randomly divided into two groups: the Rehydrated Teeth Group and the Dry Teeth Group. An enamel microbiopsy was performed, and the enamel microbiopsies were then analyzed by Scanning Electron Microscopy (SEM) and Polarizing Microscopy (PM). Quantitative birefringence measurements were performed. The 'true' etched area was determined by measuring the etched enamel using the NIH Image analysis program. Enamel birefringence was compared using the paired t test. There was a statistically significant difference when the etched areas in the Rehydrated teeth were compared with those of the Dry teeth (p = 0.04). The etched areas varied from - 11.6% to 73.5% of the presumed area in the Rehydrated teeth, and from 6.6% to 61.3% in the Dry teeth. The mean percentage of variation in each group could be used as a correction factor for the etched area. Analysis of PM pictures shows no evidence of in-depth enamel demineralization by the etching solution. No statistically significant differences in enamel birefringence were observed between values underneath and outside the microbiopsy area in the same tooth, showing that no mineral loss occurred below the enamel superficial layer. Our data showed no evidence of in-depth enamel demineralization by the etching solution used in the enamel microbiopsy proposed for primary enamel. This study also showed a variation in the measured diameter of the enamel microbiopsy in nineteen teeth out of twenty four, indicating that in most cases the etching solution penetrated beyond the tape borders.

  9. Analysis of enamel microbiopsies in shed primary teeth by Scanning Electron Microscopy (SEM) and Polarizing Microscopy (PM)

    International Nuclear Information System (INIS)

    The aims of this study were 1) to verify how close to the theoretically presumed areas are the areas of enamel microbiopsies carried out in vivo or in exfoliated teeth; 2) to test whether the etching solution penetrates beyond the tape borders; 3) to test whether the etching solution demineralizes the enamel in depth. 24 shed upper primary central incisors were randomly divided into two groups: the Rehydrated Teeth Group and the Dry Teeth Group. An enamel microbiopsy was performed, and the enamel microbiopsies were then analyzed by Scanning Electron Microscopy (SEM) and Polarizing Microscopy (PM). Quantitative birefringence measurements were performed. The 'true' etched area was determined by measuring the etched enamel using the NIH Image analysis program. Enamel birefringence was compared using the paired t test. There was a statistically significant difference when the etched areas in the Rehydrated teeth were compared with those of the Dry teeth (p = 0.04). The etched areas varied from - 11.6% to 73.5% of the presumed area in the Rehydrated teeth, and from 6.6% to 61.3% in the Dry teeth. The mean percentage of variation in each group could be used as a correction factor for the etched area. Analysis of PM pictures shows no evidence of in-depth enamel demineralization by the etching solution. No statistically significant differences in enamel birefringence were observed between values underneath and outside the microbiopsy area in the same tooth, showing that no mineral loss occurred below the enamel superficial layer. Our data showed no evidence of in-depth enamel demineralization by the etching solution used in the enamel microbiopsy proposed for primary enamel. This study also showed a variation in the measured diameter of the enamel microbiopsy in nineteen teeth out of twenty four, indicating that in most cases the etching solution penetrated beyond the tape borders.

  10. Your Teeth

    Science.gov (United States)

    ... Homework? Here's Help White House Lunch Recipes Your Teeth KidsHealth > For Kids > Your Teeth Print A A ... help you talk. So let's talk teeth! Tiny Teeth Unlike your heart or brain, your teeth weren' ...

  11. Wisdom Teeth Management

    Science.gov (United States)

    Wisdom Teeth Management Wisdom teeth, or third molars, are the last teeth to develop and appear in your mouth. They come in between the ages ... the “Age of Wisdom.” What Is an Impacted Tooth? When a tooth is unable to fully enter ...

  12. Application of PIGE to determine fluorine concentration in human teeth. Contribution to fluorosis study

    International Nuclear Information System (INIS)

    Fluorosis, osteoselerosis, and systemic illness may result when tolerance levels of fluorine intake are exceeded. To avoid these abnormalities, we shall be aware of the mechanisms of their development. For this, quantitative results gathered from different parts of the world are necessary. In this paper, PIGE method is used to determine fluorine concentration in human teeth, collected from different regions of the Algerian Sahara. Both enamel and dentine regions were inspected. The external and internal mappings of the analyzed teeth have shown more variation in the localized fluorine concentration in dentine than in enamel, and the lowest level of fluorine concentration was observed in the frontier crown-root zone. The obtained results reveal relatively high fluorine concentration lying within the limit of fluorosis, according to the standardised grading dental fluorosis. (author)

  13. Quantitative and qualitative analysis of fluoride and multi elements of shark teeth by PIXE

    International Nuclear Information System (INIS)

    Biomineralization has two types, biologically induced mineralization (BIM) and biologically controlled mineralization (BCM). Shark teeth is a typical representative of BCM. We have measured concentrations of fluorine and multi elements in shark teeth collected in the south of Japan. As a result, it was confirmed that the sample preparation method, which was established for the biological samples, is applicable to the shark teeth samples and the elemental concentration was obtained in good accuracy and reproducibility. Moreover, we clarified that the shark teeth is composed of Fluorapatite by the combination with X-ray Diffraction. Fluorine concentration is found to be 5500 μg/g in the shark teeth. We have 100 samples of Shark teeth and are planning on reporting the findings of a study with larger samples in the near future. (author)

  14. Vital Bleaching of Tetracycline-Stained Teeth by Using KTP Laser: A Case Report

    OpenAIRE

    Kinoshita, Jun-Ichiro; Jafarzadeh, Hamid; Forghani, Maryam

    2009-01-01

    Bleaching of discolored teeth is one of the most important topics in aesthetic dentistry. A great challenge in this area is obtaining good results in tetracycline-stained teeth. The wavelength and features of KTP laser, which is a type of Nd:YAG laser, seem to be appropriate for bleaching of these teeth. This case report underlines the importance of knowledge about the photochemical bleaching by using the KTP laser and its side effects on soft tissues.

  15. Determination of the Rubidium Decay Constant by Age Comparison Against the U-Pb System

    Science.gov (United States)

    Nebel, O.; Mezger, K.; Scherer, E. E.; Davies, G. R.

    2006-12-01

    The currently accepted Rb decay constant (λ 87Rb) was suggested by the Subcommission on Geochronology [1] is 1.42 x 10-11yr-1, and has a potential precision at the percent level at best [2]. This value has been used in most Rb-Sr studies in the last three decades. Several attempts to refine λ87Rb by different techniques yielded results that, despite excellent reported precisions, differed from the proposed value and also from each other. In a recent evaluation of published calibrations of the decay constant, Begemann et al. [2] suggested a lower value [~ 1.40 x 10-11yr-1] but also called for a re-determination of λ87Rb to check its accuracy and significantly improve the precision. Subsequent re-determinations [3,4] yielded values that differ significantly from each other and from that proposed by the Subcommission on Geochronology [1], one of which being higher [3], the other one lower [4] than the recommended value. Therefore, at present, there is no consensus on the λ87Rb to be used in Rb-Sr chronology. Here we report three individual determinations of λ87Rb by the method of age comparison. This entails solving for λ87Rb using 1) the measured slopes of high precision Rb-Sr isochrons from igneous rocks and minerals and 2) the emplacement ages of these samples as determined by the precise and presumably accurate U-Pb method. The precision of the measured 87Rb/86Sr has been improved to ~0.2% by measuring Rb concentrations by isotope dilution MC-ICPMS [5] (cf. ~1% for TIMS data). A challenging aspect of Rb-Sr studies is that of spike calibration, which is generally performed using standards prepared from salts of Rb and Sr rather than pure metals. The Rb/Sr values of individual spikes calibrated against two standard solutions made from different salts (iodide and carbonate) agree to within 0.15%, strongly suggesting that the stoichiometry of the salts, after careful dehydration, is sufficiently ideal for accurate spike calibrations. The calibration was checked

  16. The aesthetic treatment for anterior teeth with lost crown by endorestoration

    Directory of Open Access Journals (Sweden)

    Nanik Zubaidah

    2009-06-01

    Full Text Available Background: The aesthetic has an important role in social life, especially the anterior teeth. The aesthetic abnormality of anterior teeth i.e. discoloration, malpotition or the anterior teeth with crown damage for more than one third or all part of crown is lost due to caries or other causes, will influence its appearance especially during smile. Purpose: The aim of this case report, therefore, is to show how teeth with clinical crown lost or only the root left still can be treated by endorestoration treatment in order to reconstruct the shape and function of the teeth similar to the original ones. Case: Female 52 years old with the lost crown of anterior teeth. The patient did not want her teeth to be extracted. Case Management: The abnormality of these teeth are still able to be reconstructed by endorestoration i.e. endodontic treatment with post and core insertion in the root canal will increase its retention and recovery by the porcelain crown fused to metal to recover the original formation and aesthetic and thus has the normal refunction. The treatment, it improve the confidence of the patient, and also can function normally. The patient did not feel pain. Ronsenography showed the periapical lesion diminished, the neighbor gingival was going better in both function and color. Conclusion: Endorestoration treatment on the anterior teeth with lost crown could recover the normal function, dental aesthetic and self confidence.

  17. Age validation of great hammerhead shark (Sphyrna mokarran), determined by bomb radiocarbon analysis

    OpenAIRE

    Passerotti, Michelle S.; John K. Carlson; Piercy, Andrew N.; Campana, Steven E.

    2010-01-01

    Preliminary validation of annual growth band deposition in vertebrae of great hammerhead shark (Sphyrna mokarran) was conducted by using bomb radiocarbon analysis. Adult specimens (n=2) were collected and thin sections of vertebral centra were removed for visual aging and use in radiocarbon assays. Vertebral band counts were used to estimate age, and year of formation was assigned to each growth band by subtracting estimated age from the year of capture. A total of 10 samples were extra...

  18. Cogging Torque and Acoustic Noise Reduction in High Torque BLDC Motors by Teeth Pairings

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Min [Halla Climate Control Co. (Korea, Republic of); Hwang, Sang Moon [Pusan National University (Korea, Republic of)

    1999-03-01

    This paper investigates reduction of acoustic noise and cogging torque in a BLDC motor with larger stator slot open width. Using energy method, cogging torque is analytically determined with airgap MMF function and airgap permeance function and confirmed by FEM analysis. It show that the cogging torque is firstly governed by N{sub L} G{sub NL} B{sub NL} with the fundamental period of N{sub L}, where N{sub L} is the least common multiple of the number of slots and the number of poles, G{sub NL}, airgap permeance function and B{sub NL}, airgap MMF function. It also shows that there exist several tooth width which minimizes the cogging torque, for the motors that smaller slot open width or stator teeth notching is not available. And it proposes a teeth pairing with two different tooth width which can effectively eliminate the cogging torque and thus the acoustic noise. Experimental results show that the proposed teeth pairing reduces the cogging torque by 85% and the acoustic noise by 3.1 dB. (author). 9 refs., 13 figs., 1 tab.

  19. PIXE analysis of trace elements in cetacean teeth

    International Nuclear Information System (INIS)

    PIXE was adopted for analysis of trace elements in teeth of two species of cetaceans, sperm whale (Physeter microcephalus) and pantropical spotted dolphin (Stenella attenuata). The analyses were performed along with the growth layer of the teeth, which is formed annually, suitable for age determination. Mn, Fe, Cu, Zu and Sr were detected in the teeth of sperm whale and pantropical spotted dolphin. Among these trace elements, gradual increase was observed for Zn/Ca ratio in the sperm whale's teeth. (author)

  20. Dentition and age determination of the Warthog Phacochoerus aethiopicus in Zululand, South Africa

    Directory of Open Access Journals (Sweden)

    D.R Mason

    1984-12-01

    Full Text Available Age-specific stages of tooth replacement, eruption and attrition are described for warthogs shot during population control in Zululand. Patterns of tooth replacement and eruption allowed reasonably accurate age determination up to 24 months, whereafter 2-3 year old warthogs could generally be distinguished from older individuals by the relative growth of their third molars. Although stages of wear and loss of the teeth, especially the three molars, were associated with broad age classes, age of adult warthogs may be determined more precisely by counting cementum annuli in sectioned incisor teeth. However, cementum annuli were insufficiently distinctive to permit age estimation in approximately 33 of sections, reflecting particularly variation in intensity and clarity of staining and splitting and merging of rest lines. The use of eye lens dry mass and tusk length: snout width ratios as indices of age was also evaluated. Eye lens dry mass became increasingly unreliable for predicting age beyond 24 months. Considering males and females separately, tusk length: snout width ratios for yearling, 2-3 year old and 3-4 year old warthogs were reasonably distinctive, but subsequent overlap was apparently unfavourable for reliable differentiation of year classes among older warthogs. Body size and tusk * development criteria for distinguishing between three age classes ofwarthogs in the field are presented.

  1. Forensic identification in teeth with caries.

    Science.gov (United States)

    Alia-García, Esther; Parra-Pecharromán, David; Sánchez-Díaz, Ana; Mendez, Susy; Royuela, Ana; Gil-Alberdi, Laura; López-Palafox, Juan; del Campo, Rosa

    2015-12-01

    Human teeth are biological structures that resist extreme conditions thus becoming a useful source of DNA for human forensic identification purposes. When it is possible, forensic prefer only non-damaged teeth whereas those with cavities are usually rejected to avoid both external and internal bacterial contamination. Cavities are one of the most prevalent dental pathology and its incidence increases with ageing. The aim of this study was to validate the use of teeth with cavities for forensic identification. A total of 120 individual teeth from unrelated patients (60 healthy and 60 with cavities, respectively) extracted by a dentist as part of the normal process of treatment, were submitted for further analysis. Dental pulp was obtained after tooth fragmentation, complete DNA was extracted and the corresponding human identification profile was obtained by the AmpFlSTR® NGM SElect™ kit. Cariogenic microbiota was determined by PCR-DGGE with bacterial universal primers and bands were excised, re-amplified and sequenced. From the 120 dental pieces analyzed, a defined genetic profile was obtained in 81 (67.5%) of them, with no statistical differences between the healthy and the cavities-affected teeth. Statistical association between teeth status, DNA content and genetic profiles was not observed. Complex bacterial communities were only detected in the cavities group, being the Streptococcus/Enterococcus, and Lactobacillus genera the most represented. We conclude that teeth with cavities are as valid as healthy dental pieces for forensic human identification. Moreover, the severity of the cariogenic lesion as well as associated bacterial communities seems not to influence the establishment of human dental profiles. PMID:26386340

  2. Experimental and numerical determination of the mechanical response of teeth with reinforced posts.

    Science.gov (United States)

    Papadopoulos, Triantafillos; Papadogiannis, Dimitris; Mouzakis, Dionysios E; Giannadakis, Konstantinos; Papanicolaou, George

    2010-06-01

    The aim of this study was to evaluate the mechanical behavior of endodontically treated teeth restored with fiber reinforced composite posts versus titanium posts, by both experimental testing and numerical simulation (finite element analysis (FEA)). Forty maxillary central incisors were endodontically treated to a size 45 file and then obturated using gutta-percha points and sealer with the lateral condensation technique. The teeth were divided into four groups of ten teeth each. All the posts were of similar dimensions. The first group was restored using carbon fiber reinforced posts (CB), the second and third groups were restored using glass fiber reinforced posts (DP and FW, respectively), and the fourth group (control group) was restored using conventional titanium posts (PP). Half of the specimens of every group were submitted to hydrothermal cycling (2000 cycles, at 5 °C and 55 °C, respectively). All specimens were loaded until failure at a 45° angle with respect to the longitudinal axis at a cross head speed of 0.5 mm min(-1). A two-dimensional finite element model was designed in order to simulate the experimentally obtained results. Mechanical testing revealed that teeth restored with titanium posts exhibited the highest fracture strength. Debonding of the core was the main failure mode observed in glass fiber posts, whereas vertical root fractures were observed in the titanium posts. FEA revealed that the maximum stresses were developed at the interface between the post, dentin and the composite core critical regions in all three cases. Hydrothermal cycling had no significant effect on the fracture behavior of fiber reinforced composite posts. PMID:20505232

  3. Experimental and numerical determination of the mechanical response of teeth with reinforced posts

    Energy Technology Data Exchange (ETDEWEB)

    Papadopoulos, Triantafillos; Papadogiannis, Dimitris [Department of Biomaterials, School of Dentistry, National and Kapodistrian University of Athens (Greece); Mouzakis, Dionysios E [Department of Mechanical Engineering, ATEI of Larisa (Greece); Giannadakis, Konstantinos; Papanicolaou, George, E-mail: trpapad@dent.uoa.g [Composite Materials Group, Department of Mechanical Engineering and Aeronautics, University of Patras (Greece)

    2010-06-01

    The aim of this study was to evaluate the mechanical behavior of endodontically treated teeth restored with fiber reinforced composite posts versus titanium posts, by both experimental testing and numerical simulation (finite element analysis (FEA)). Forty maxillary central incisors were endodontically treated to a size 45 file and then obturated using gutta-percha points and sealer with the lateral condensation technique. The teeth were divided into four groups of ten teeth each. All the posts were of similar dimensions. The first group was restored using carbon fiber reinforced posts (CB), the second and third groups were restored using glass fiber reinforced posts (DP and FW, respectively), and the fourth group (control group) was restored using conventional titanium posts (PP). Half of the specimens of every group were submitted to hydrothermal cycling (2000 cycles, at 5 {sup 0}C and 55 {sup 0}C, respectively). All specimens were loaded until failure at a 45{sup 0} angle with respect to the longitudinal axis at a crosshead speed of 0.5 mm min{sup -1}. A two-dimensional finite element model was designed in order to simulate the experimentally obtained results. Mechanical testing revealed that teeth restored with titanium posts exhibited the highest fracture strength. Debonding of the core was the main failure mode observed in glass fiber posts, whereas vertical root fractures were observed in the titanium posts. FEA revealed that the maximum stresses were developed at the interface between the post, dentin and the composite core critical regions in all three cases. Hydrothermal cycling had no significant effect on the fracture behavior of fiber reinforced composite posts.

  4. Experimental and numerical determination of the mechanical response of teeth with reinforced posts

    International Nuclear Information System (INIS)

    The aim of this study was to evaluate the mechanical behavior of endodontically treated teeth restored with fiber reinforced composite posts versus titanium posts, by both experimental testing and numerical simulation (finite element analysis (FEA)). Forty maxillary central incisors were endodontically treated to a size 45 file and then obturated using gutta-percha points and sealer with the lateral condensation technique. The teeth were divided into four groups of ten teeth each. All the posts were of similar dimensions. The first group was restored using carbon fiber reinforced posts (CB), the second and third groups were restored using glass fiber reinforced posts (DP and FW, respectively), and the fourth group (control group) was restored using conventional titanium posts (PP). Half of the specimens of every group were submitted to hydrothermal cycling (2000 cycles, at 5 0C and 55 0C, respectively). All specimens were loaded until failure at a 450 angle with respect to the longitudinal axis at a crosshead speed of 0.5 mm min-1. A two-dimensional finite element model was designed in order to simulate the experimentally obtained results. Mechanical testing revealed that teeth restored with titanium posts exhibited the highest fracture strength. Debonding of the core was the main failure mode observed in glass fiber posts, whereas vertical root fractures were observed in the titanium posts. FEA revealed that the maximum stresses were developed at the interface between the post, dentin and the composite core critical regions in all three cases. Hydrothermal cycling had no significant effect on the fracture behavior of fiber reinforced composite posts.

  5. Asteroid age distributions determined by space weathering and collisional evolution models

    OpenAIRE

    Willman, Mark; Jedicke, Robert

    2010-01-01

    We provide evidence of consistency between the dynamical evolution of main belt asteroids and their color evolution due to space weathering. The dynamical age of an asteroid's surface \\citep{bib.bot05a,bib.nes05} is the time since its last catastrophic disruption event which is a function of the object's diameter. The age of an S-complex asteroid's surface may also be determined from its color using a space weathering model \\citep[e.g.][]{bib.wil10,bib.jed04,bib.wil08,bib.mar06}. We used a sa...

  6. Pharyngeal teeth of the freshwater drum (Aplodinotus grunniens) a predator of the zebra mussel (Dreissena polymorpha)

    Science.gov (United States)

    French, John R. P., III

    1997-01-01

    The morphology of pharyngeal teeth of freshwater drum (Aplodinotus grunniens) was studied to determine changes that occur during growth of drum that may relate to consumption of zebra mussel (Dreissena polymorpha) by larger fish. Pharyngeal teeth were of three types. Cardiform teeth were replaced by villiform teeth, which were replaced by molariform teeth as the size class of drum increased. Molariform teeth comprised over 85% of total surface area of dentition in fish 265 mm long.

  7. Impacted wisdom teeth

    OpenAIRE

    Dodson, Thomas B.; Susarla, Srinivas M.

    2010-01-01

    Impacted wisdom teeth occur because of a lack of space, obstruction, or abnormal position. They can cause pain, swelling, and infection, and may destroy adjacent teeth and bone.The incidence of impacted wisdom teeth is high, with some 72% of Swedish people aged 20 to 30 years having at least one impacted third molar.

  8. Segmentation of teeth in CT volumetric dataset by panoramic projection and variational level set

    International Nuclear Information System (INIS)

    Quantification of teeth is of clinical importance for various computer assisted procedures such as dental implant, orthodontic planning, face, jaw and cosmetic surgeries. In this regard, segmentation is a major step. In this paper, we propose a method for segmentation of teeth in volumetric computed tomography (CT) data using panoramic re-sampling of the dataset in the coronal view and variational level set. The proposed method consists of five steps as follows: first, we extract a mask in a CT images using Otsu thresholding. Second, the teeth are segmented from other bony tissues by utilizing anatomical knowledge of teeth in the jaws. Third, the proposed method is followed by estimating the arc of the upper and lower jaws and panoramic re-sampling of the dataset. Separation of upper and lower jaws and initial segmentation of teeth are performed by employing the horizontal and vertical projections of the panoramic dataset, respectively. Based the above mentioned procedures an initial mask for each tooth is obtained. Finally, we utilize the initial mask of teeth and apply a Variational level set to refine initial teeth boundaries to final contours. The proposed algorithm was evaluated in the presence of 30 multi-slice CT datasets including 3,600 images. Experimental results reveal the effectiveness of the proposed method. In the proposed algorithm, the variational level set technique was utilized to trace the contour of the teeth. In view of the fact that, this technique is based on the characteristic of the overall region of the teeth image, it is possible to extract a very smooth and accurate tooth contour using this technique. In the presence of the available datasets, the proposed technique was successful in teeth segmentation compared to previous techniques. (orig.)

  9. Segmentation of teeth in CT volumetric dataset by panoramic projection and variational level set

    Energy Technology Data Exchange (ETDEWEB)

    Hosntalab, Mohammad [Islamic Azad University, Faculty of Engineering, Science and Research Branch, Tehran (Iran); Aghaeizadeh Zoroofi, Reza [University of Tehran, Control and Intelligent Processing Center of Excellence, School of Electrical and Computer Engineering, College of Engineering, Tehran (Iran); Abbaspour Tehrani-Fard, Ali [Islamic Azad University, Faculty of Engineering, Science and Research Branch, Tehran (Iran); Sharif University of Technology, Department of Electrical Engineering, Tehran (Iran); Shirani, Gholamreza [Faculty of Dentistry Medical Science of Tehran University, Oral and Maxillofacial Surgery Department, Tehran (Iran)

    2008-09-15

    Quantification of teeth is of clinical importance for various computer assisted procedures such as dental implant, orthodontic planning, face, jaw and cosmetic surgeries. In this regard, segmentation is a major step. In this paper, we propose a method for segmentation of teeth in volumetric computed tomography (CT) data using panoramic re-sampling of the dataset in the coronal view and variational level set. The proposed method consists of five steps as follows: first, we extract a mask in a CT images using Otsu thresholding. Second, the teeth are segmented from other bony tissues by utilizing anatomical knowledge of teeth in the jaws. Third, the proposed method is followed by estimating the arc of the upper and lower jaws and panoramic re-sampling of the dataset. Separation of upper and lower jaws and initial segmentation of teeth are performed by employing the horizontal and vertical projections of the panoramic dataset, respectively. Based the above mentioned procedures an initial mask for each tooth is obtained. Finally, we utilize the initial mask of teeth and apply a Variational level set to refine initial teeth boundaries to final contours. The proposed algorithm was evaluated in the presence of 30 multi-slice CT datasets including 3,600 images. Experimental results reveal the effectiveness of the proposed method. In the proposed algorithm, the variational level set technique was utilized to trace the contour of the teeth. In view of the fact that, this technique is based on the characteristic of the overall region of the teeth image, it is possible to extract a very smooth and accurate tooth contour using this technique. In the presence of the available datasets, the proposed technique was successful in teeth segmentation compared to previous techniques. (orig.)

  10. Supernumerary Teeth in Nepalese Children

    Directory of Open Access Journals (Sweden)

    Varun Pratap Singh

    2014-01-01

    Full Text Available Objective. The objectives of the present study were to investigate the prevalence and characteristics of supernumerary teeth in a patient sample of Nepalese children. Study Design. A survey was performed on 2684 patients (1829 females and 1035 males ranging in age from 6 to 14 for the presence of supernumerary teeth. For each patient with supernumerary teeth the demographic variables (age and sex, number, location, eruption status, and morphology were recorded. Descriptive statistics were performed. Results. Supernumerary teeth were detected in 46 subjects (1.6%, of which 26 were males and 20 were females with a male : female ratio of 1.3 : 1. The most commonly found supernumerary tooth was mesiodens followed by maxillary premolars, maxillary lateral incisor, and mandibular lateral incisor. Of the 55 supernumerary teeth examined, 58.18% (n=32 had conical morphology, followed by tuberculate (30.90%, n=17 and supplemental (10.90%, n=6 forms. The majority of the supernumerary teeth were erupted (56.36%, n=31. Conclusion. The prevalence of supernumerary teeth in Nepalese children was found to be 1.6%, the most frequent type being mesiodens. Conical morphology was found to be the most common form of supernumerary tooth.

  11. Incremental lines in root cementum of human teeth: An approach to their role in age estimation using polarizing microscopy

    Directory of Open Access Journals (Sweden)

    Aggarwal Pooja

    2008-01-01

    Full Text Available Age estimation is an important factor in the identification of an individual in forensic science. The hard tissues of the human dentition are able to resist decay and degradation long after other tissues are lost. This resistance has made teeth useful indicators for age calculation. Recent research indicates that tooth cementum annulations (TCA may be used more reliably than any other morphological or histological traits of the adult skeleton for age estimation. The purpose of this study was to examine the correlation between age and the number of incremental lines in human dental cementum and to ascertain the best method of studying cementum with respect to different forms of microscopy. Thirty nonrestorable teeth were extracted from 20 people, and longitudinal ground section of each tooth was prepared. Photomicrographs of the area at the junction of apical and middle third of the root under light and polarized microscope were taken. The cementum was composed of multiple light and dark bands that were counted on the photomicrograph with the help of image analysis software and added to the average eruption time of individual tooth. The predicted age of the individual was thus obtained. Results showed a significant correlation between the predicted age and actual chronological age of the individual. These data indicate that quantitation of cementum annuli is a moderately reliable means for age estimation in humans and polarizing microscopy is a better means of visualizing incremental lines of cementum compared to light microscopy.

  12. Iron deposition in modern and archaeological teeth

    Energy Technology Data Exchange (ETDEWEB)

    Williams, A.-M.M., E-mail: AnneMarie.Williams@utas.edu.au [School of Medicine, Private Bag 34, University of Tasmania, Hobart 7001 (Australia); Siegele, R. [Australian Nuclear Science and Technology Organisation, PMB 1, Menai, NSW 2234 (Australia)

    2014-09-15

    Iron surface concentrations and profile maps were measured on the enamel of archaeological and modern teeth to determine how iron is deposited in tooth enamel and if it was affected by the post-mortem environment. Teeth from Australian children who died in the second half of the 19th century were compared with contemporary teeth extracted for orthodontic purposes. Surface analysis of the teeth was performed using the 3 MV Van Der Graff Accelerator at The Australian Nuclear Science and Technology Organisation (ANSTO), Sydney, Australia. A small sample of teeth were then cut in the mid sagittal plane and analysed using ANSTO High Energy Heavy Ion Microprobe. Maps and linear profiles were produced showing the distribution of iron across the enamel. Results show that both the levels and distribution of iron in archaeological teeth is quite different to contemporary teeth, raising the suggestion that iron has been significantly altered by the post-mortem environment.

  13. Iron deposition in modern and archaeological teeth

    International Nuclear Information System (INIS)

    Iron surface concentrations and profile maps were measured on the enamel of archaeological and modern teeth to determine how iron is deposited in tooth enamel and if it was affected by the post-mortem environment. Teeth from Australian children who died in the second half of the 19th century were compared with contemporary teeth extracted for orthodontic purposes. Surface analysis of the teeth was performed using the 3 MV Van Der Graff Accelerator at The Australian Nuclear Science and Technology Organisation (ANSTO), Sydney, Australia. A small sample of teeth were then cut in the mid sagittal plane and analysed using ANSTO High Energy Heavy Ion Microprobe. Maps and linear profiles were produced showing the distribution of iron across the enamel. Results show that both the levels and distribution of iron in archaeological teeth is quite different to contemporary teeth, raising the suggestion that iron has been significantly altered by the post-mortem environment

  14. Estimating age of spotted and spinner dolphins (Stenella attenuata and Stenella longirostris) from teeth

    OpenAIRE

    Myrck, Jr., Albert C.; Hohn, Aleta A.; Sloan, Priscilla A.; Kimura, Makoto; Stanley, Drew D.

    1983-01-01

    This paper is an account of preparation and examination techniques and criteria used to estimate age in decalcified and stained tooth thin sections from spinner and spotted dolphins. A dentinal growth layer group (GLG), composed of two thin light and two thicker dark-stained layers, is deposited annually. The GLG component layers are variably visible, but the "ideal" pattern and successive thinning of dentinal GLGs are used as a guide to determine GLG limits. Age-specific thicknesses of de...

  15. Do the levels of selected metals differ significantly between the roots of carious and non-carious teeth?

    International Nuclear Information System (INIS)

    Since the metals deposited in teeth during formation and mineralization processes are to a large extent retained, human teeth receive a considerable attention as the indicators of the heavy metal exposure. The use of permanent teeth is limited because the extraction of healthy permanent teeth just for this purpose is hardly acceptable. As the issue of the loss of elements from a carious lesion in the coronal part of a tooth remains controversial, the valuable material could only be the root of carious and fractured permanent teeth. However, to ensure the validity of the results, it should be ascertained that the levels of certain toxic and essential elements do not differ significantly between the roots of non-carious and carious teeth, and therefore this is the aim of this project. The levels of cadmium, chromium, copper, iron, manganese, lead, zinc, potassium, sodium, calcium and magnesium were determined in the roots of 344 permanent teeth (189 carious and 155 caries-free teeth) from the residents of Ruda Slaska, Poland, aged 18 to 34. No statistically significant difference between the concentration of these metals in the roots of non-carious and carious teeth was found. This finding applies to both the general population and after the grouping by donor's gender and tooth type. The concentration of lead, iron, calcium and manganese in the roots of non-carious and carious teeth exhibited dependence upon tooth type, as well as the concentration of potassium in the roots of carious teeth. Since the mineral composition of the roots of permanent teeth is similar for the non-carious, as well as the carious teeth, they can be indiscriminately selected for the tests required by a research project, as they will produce the comparable results. However, in the case of lead, iron, calcium, potassium and manganese, the comparison should be made after grouping by tooth type

  16. Zinc, lead and copper in human teeth measured by induced coupled argon plasma atomic emission spectroscopy (ICP-AES)

    International Nuclear Information System (INIS)

    Inductively Coupled Argon Plasma Atomic Emission Spectroscopy (ICP-AES) has been used to determine Pb, Zn and Cu levels in 47 exfoliated human teeth (all of which required extraction for orthodontic reasons). Lead concentrations for the group were 1.7 μg (g tooth mass)-1 to 40.5 μg (g tooth mass)-1, with a median of 9.8 (g (g tooth mass)-1. A median lead level in excess of the group value was found for the teeth of six lorry drivers who were included in the study. A more significant enhancement was found for the seven subjects whose age was in excess of 60 years. The median values for Zn and Cu were 123.0 and 0.6 μg (g tooth mass)-1 respectively. Present values for tooth-Zn are lower than published data for other ethnic groups

  17. [Biologico-periodontal considerations in restoration of teeth partially destroyed by caries or traumatism].

    Science.gov (United States)

    Carrillo Martínez, J J; Zermeño Ibarra, J A; Mercado Martínez, E G; Villanueva Neuman, Y; Castellanos Olmedo, R

    1990-01-01

    Since a great number of teeth could be rehabilitated and not extracted, in this paper we analyze the relation Perio-protesis by the point of the biology of marginal periodontal ligament, and the different options to establish this relations when are lost by decay or traumatism. We discuss the contraindications to avoid greater problems than benefits when intend to rehabilitate lost teeth. PMID:1975497

  18. The prediction of fatigue strength for teeth root in gear mechanism by weibull distribution

    International Nuclear Information System (INIS)

    The prediction of fatigue strength for teeth root in gear mechanism, so far, has been calculated by normal distribution with 50% reliability consideration. In this study, the results of teeth root break in evaluated in more realistic sense based on Weibull distribution approach in the region of finite life. By this approach the so called fatigue strength diagrams were obtained with specified reliability level. (author)

  19. Approaches to chronological age assessment based on dental calcification.

    Science.gov (United States)

    Bolanos, M V; Manrique, M C; Bolanos, M J; Briones, M T

    2000-05-15

    The aim of the present study was to find an accurate estimation of chronological age using a small number of selected teeth. For this purpose, the method devised by Nolla [C. Nolla, The development of the permanent teeth, J. Dent. Child. 27 (1960) 254-266.] was used: the development of each of the teeth was determined according to this method on 374 radiographs, 195 of boys (mean age 8.59) and 179 of girls (mean age 8.75). The 28 variables representing the calcification stages were analyzed using cluster analysis followed by multivariate analysis (multiple linear regression model). Patient age was considered to be a dependent variable. Our study showed that antimere teeth are the most homogeneous as regards stages of development. The prediction was more accurate for boys and girls below 10 years of age, using teeth 21, 43 and 46 from boys and teeth 21, 46 and 47 from girls. These teeth accounted for 80% total variance of chronological age for dental calcification. Standard error was +/-1.4 years for boys and +/-1.2 years for girls. When the age of the children remained completely unknown, the best estimates were provided by teeth 43, 47, 46 and 44 from boys and teeth 44, 47 and 43 from girls. PMID:10808098

  20. Determination Of Uranium Concentration In Teeth Female Samples Using Fission Tracks In CR-39 From Different Countries

    International Nuclear Information System (INIS)

    The present study was under taken to measure the uranium concentration in female teeth samples collected from different nationalities.The determination of uranium concentration in these samples has been done by using CR-39 track detector.The nuclear reaction is used as a source of nuclear fission fragments is (n, f) obtained by the bombardment of U-235 with thermal neutrons with flux (5*103 n/cm2 .s) was used from (Am-Be) neutron source.The obtained results show the concentration is ranging from (0.58±0.7ppm) in Oman and Uae to (0.35±0.03ppm)in Iraqi for male, the uranium concentration was the highest in Oman and Uae for female

  1. The use of dental radiography in age determination: Concepts and methods

    Directory of Open Access Journals (Sweden)

    Seyed Amir Hossein Mirhashemi

    2014-06-01

    Full Text Available   The need to identify and determine the age of the unidentified dead person s or accident victims of natural disasters is clear. Also, some remedial measures in the field of orthodontics and pediatric dentistry depend on knowing the patient’s physiological age. Previous studies suggested that dental age have a good correlation with physiological age more than skeletal or o ther common methods of age determination. Among the various methods used to determine dental age , dental radiography provides wide facilities for clinicians. Being noninvasive and the ability of performing the technique on live subjects as well as simplicity and low cost and reliable results , have led researchers to investigate further on that . The formation and calcification process of teeth and changes during aging has been regarded by many, leading to introduce various methods in which the field. In this study, 36 related articles were achieved by searching PUBMED, Science Direct and Google Scholar resources and discussed. Provided what diversified means of determining age using dental radiographs is encouraged , it is recommended to be not restricted to use only one of the methods because the multilateral approach is more reliable.

  2. Apical microleakage of primary teeth root canal filling materials by clearing technique.

    Science.gov (United States)

    Ayhan, H; Alacam, A; Olmez, A

    1996-01-01

    The purpose of this study was to evaluate apical leakage of primary teeth root canals sealed with four different root canal filling materials by clearing technique. Dye penetration ratios of all groups were measured by light microscopy. The mean dye penetration was determined in the group of ZOE to be 0.57 mm. This ratio was 1.05 mm in the group of ZOE + glutaraldehyde (GA). In the groups of Kri I and Ca(OH)2, dye penetrations were 0.47 mm, 0.56 mm respectively. The highest apical leakage value was evaluated in the glutaraldehyde + ZOE group (p<0.05), whereas, no statistical difference was found between the other groups. PMID:8619969

  3. The using of «argenate» application in the treatment of caries of deciduous teeth in children at the age from 2 to 6

    Directory of Open Access Journals (Sweden)

    Veselov D.V.

    2011-03-01

    Full Text Available The efficacy of the drug «Argenat» for the treatment of caries of deciduous teeth in 52 children aged 2-6 years living in areas with low fluoride in drinking water. «Argenat» in practice dentistry in the treatment of childhood caries of deciduous teeth of interest in connection with a pronounced bactericidal effect of silver ions, the main targets of which are bacterial enzymes and membrane structures of cells of the microorganism

  4. Age Determination of Microlepidotus brevipinnis (Steindachner, 1869 (Pisces: Haemulidae in the Coast of Jalisco, Mexico, by Reading Otoliths and Scales

    Directory of Open Access Journals (Sweden)

    E.G. Cabral-Solis

    2010-01-01

    Full Text Available This study deals with age determination of the brassy grunt Microlepidotus brevipinnis by reading otoliths (sagittae and scales which allowed the identification of 13 age groups. Growth of otoliths and scales is proportional to the growth of the fish. The time of formation of fast and slow growth bands in sagittae, as well as the time of ring formation in the scales is one year. The highest growth in length of this species takes place during the first year of life, in which the organism reaches 125.0 mm, this reduces natural mortality of the individuals by decreasing depredation. Growth in weight of this species is isometric. Sexual differentiation of the organisms is apparent after the age of two years and there were differences in the average length for each age in scales and otoliths for males and females. The age of other members of the Haemulidae family were compared with those obtained in the present study and M. brevipinnis reaches its oldest age in 13 years. It occupies a middle point (442.4 mm in relation to the total lengths of other haemulids in the Mexican Pacific coast.

  5. Assessment of endodontically treated teeth by using different radiographic methods: an ex vivo comparison between CBCT and other radiographic techniques

    International Nuclear Information System (INIS)

    To compare different radiographic methods for assessing endodontically treated teeth. Root canal treatments were applied in 120 extracted mandibular teeth, which were divided into four groups: (1) ideal root canal treatment (60 teeth), (2) insufficient lateral condensation (20 teeth), (3) root canals filled short of the apex (20 teeth), (4) overfilled root canal treatment (20 teeth). The teeth were imaged using intraoral film, panoramic film, digital intraoral systems (CCD and PSP), CCD obtained with portable X-ray source, digital panoramic, and CBCT images obtained at 0.3 mm3 and 0.2 mm'3 voxel size. Images were evaluated separately by three observers, twice. Kappa coefficients were calculated. The percentage of correct readings obtained from each modality was calculated and compared using a t-test (p3 voxel images revealed the best results. For insufficient lateral condensation, the best readings were found with periapical film followed by CCD and PSP. The assessment of teeth with root canals filled short of the apex showed the highest percentage of correct readings by CBCT and CCD. For the overfilled canal treatment group, PSP images and conventional periapical film radiographs had the best scores. CBCT was found to be successful in the assessment of teeth with ideal root canal treatment and teeth with canals filled short of the apex.

  6. The determination of age of the fault activities of Shougou Hill, Guangzhou by thermoluminescence dating and nuclear fission track dating

    International Nuclear Information System (INIS)

    The age of the fault activities had been determined by TL dating and nuclear fission track dating. The results show that the fault of Shougou Hill had large and intense activities in mid-cenozoic era, however, intense activities still occurred in early pleistocene and mid-pleistocene. The last activity of the fault occurred 430 000 years ago. The data of TL dating are conformable with data of nuclear fission track dating

  7. Measurement of Ca, Zn and Sr in enamel of human teeth by XRF

    Energy Technology Data Exchange (ETDEWEB)

    Wielopolski, L.; Featherstone, J.D.B.; Cohn, S.H.

    1984-01-01

    Energy dispersive x-ray fluorescence (EDXRF) has been employed to measure Ca, Zn, and Sr in enamel of human teeth. The calibration of the EDXRF system was performed by comparing Sr/Ca ratios with values obtained by atomic absorption analysis of acid etched biopsies of the enamel surface. Two calibration lines were obtained, one line for untreated teeth and the second line for teeth immersed (treated) in solutions containing Sr. A simple analytical model demonstrated that the two calibration lines were the result of the difference in the depth of the enamel sampled by EDXRF and by the acid-etched biopsy. The multi-elemental, non-destructive and quantitative aspects of EDXRF permit the sequential monitoring of the effects of Sr and Zn ions on the mineralization and demineralization processes in human enamel. The portability of the system and adaptability to non-invasive measurements makes it suitable for field studies. 26 references, 4 figures.

  8. Measurement of Ca, Zn and Sr in enamel of human teeth by XRF

    International Nuclear Information System (INIS)

    Energy dispersive x-ray fluorescence (EDXRF) has been employed to measure Ca, Zn, and Sr in enamel of human teeth. The calibration of the EDXRF system was performed by comparing Sr/Ca ratios with values obtained by atomic absorption analysis of acid etched biopsies of the enamel surface. Two calibration lines were obtained, one line for untreated teeth and the second line for teeth immersed (treated) in solutions containing Sr. A simple analytical model demonstrated that the two calibration lines were the result of the difference in the depth of the enamel sampled by EDXRF and by the acid-etched biopsy. The multi-elemental, non-destructive and quantitative aspects of EDXRF permit the sequential monitoring of the effects of Sr and Zn ions on the mineralization and demineralization processes in human enamel. The portability of the system and adaptability to non-invasive measurements makes it suitable for field studies. 26 references, 4 figures

  9. Measurement of Ca, Zn, and Sr in enamel of human teeth by XRF

    International Nuclear Information System (INIS)

    Energy dispersive x-ray fluorescence (EDXRF) has been employed to measure Ca, Zn, and Sr in enamel of human teeth. The calibration of the EDXRF system was performed by comparing Sr/Ca ratios with values obtained by atomic absorption analysis of acid etched biopsies of the enamel surface. Two calibration lines were obtained, one line for untreated teeth and the second line for teeth immersed (treated) in solutions containing Sr. A simple analytical model demonstrated that the two calibration lines were the result of the difference in the depth of the enamel sampled by EDXRF and by the acid-etched biopsy. The multi-elemental, non-destructive and quantitative aspects of EDXRF permit the sequential monitoring of the effects of Sr and Zn ions on the mineralization and demineralization processes in human enamel. The portability of the system and adaptability to non-invasive measurements makes it suitable for field studies. 26 references, 4 figures

  10. [Ancient teeth: research on teeth and jaws from archaeological sites].

    Science.gov (United States)

    Jelsma, J

    2016-05-01

    Archaeology aims to enhance our understanding of the human past. An archaeologist devotes him- or herself to material remains, most often from the earth. The best sources of information about human behaviour and the earlier conditions of life for human beings are gravesites. In addition to being a source of cultural information, well-preserved skeletons offer vast possibilities for biochemical and genetic research. Teeth in particular can provide a treasure trove of information about the lives of our ancestors. With DNA analysis, gender and genetic relationships can be determined, however, the surface of the teeth also provides information about gender, age and genetic relationships and, of course, about the use of the teeth. New discoveries are being made and new (bio-)archaeological analyses are being carried out all the time. PMID:27166454

  11. Cross-Sectional Association between the Number of Missing Teeth and Cardiovascular Disease among Adults Aged 50 or Older: BRFSS 2010

    Directory of Open Access Journals (Sweden)

    R. Constance Wiener

    2014-01-01

    Full Text Available Objective. The relationship between oral health and cardiovascular disease is an emerging area of research. The objective of the current study is to evaluate the association of cardiovascular disease and the number of missing teeth as a risk indicator. Methods. Cross-sectional study design with data on 275,424 respondents aged 50 or older from the 2010 Behavioral Risk Factor Surveillance System survey was used. The dependent variable was self-reported cardiovascular disease. The association between the number of missing teeth and cardiovascular disease was analyzed with multivariable logistic regression. The regression was adjusted for sex, race/ethnicity, age, education, income, dental visits, smoking status, physical activity, and body mass index. Results. In our study sample, 9.9% reported edentulism. Cardiovascular prevalence rates for those with edentulism were 25.4% and for those without any missing teeth were 7.5%. Respondents who reported edentulism teeth were more likely to report cardiovascular disease (AOR = 1.85, 95% CI = 1.71, 2.01. Conclusion. There was an independent association between the number of missing teeth and cardiovascular disease even after controlling for a comprehensive set of risk factors. These findings highlight the need to explore the potential role the number of missing teeth have in the risk of cardiovascular disease among older adults.

  12. Analysis of dose in teeth for estimation of effective dose by the electron spin resonance (ESR) dosimetry using dental enamels

    International Nuclear Information System (INIS)

    Dose in teeth was studied to develop a method that can predict effective dose from results by the Electron Spin Resonance (ESR) dosimetry using dental enamels for external photon exposure. Absorbed dose in teeth and effective dose were calculated by the Electron Gamma Shower Code Version 4 (EGS4). In the Monte Carlo calculations, a region for teeth was newly added to a mathematical human model. Experiments were carried out with a head phantom, which is made of tissue equivalent materials. ESR dosimetry was made with dental enamels irradiated at teeth-part in the head phantom. The absorbed dose in a mouth was also measured with TLDs exposed to gamma rays as the teeth. The Monte Carlo calculation and the experiment gave a quantitative relationship between absorbed dose in teeth and effective dose. The obtained data are considered to be useful for the retrospective individual dose assessment with ESR dosimetry using dental enamels. (author)

  13. Fluoridated drinking water and maturation of permanent teeth at age 12.

    Science.gov (United States)

    Campagna, L; Tsamtsouris, A; Kavadia, K

    1995-01-01

    Dental age was evaluated in 88 children aged 12 years + 6 months in both areas of Boston with fluoridated drinking water and nonfluoridated areas surrounding Athens, Greece. Fluoridation of drinking water in the Boston areas was 1.0 ppm, a level considered 'optimal' in the USA. Girls from the fluoridated Boston area were shown in this study to have a significantly (pdental age when compared to their chronological age according to the tables of Nolla. Boys from the Boston area and boys and girls from the Athens area showed no significant difference when comparing dental age to chronological age. PMID:8611493

  14. An early unknown case of human identification by teeth. William II Villehardouin

    OpenAIRE

    Stavrianos, C.; Petalotis, N; Stavrianos, I

    2009-01-01

    Forensic Dentistry helps to identify living or dead persons by their teeth. There are early records of cases that teeth played such an important role (Popea, Charles the Bold, etc). The aim of this article is to make better known another generally unknown primitive application of Forensic Dentistry in a battle that changed history. The battle of Pelagonia took place in September of 1259 A.D. It was between the Empire of Nicaea (Iznik) and the Despotate of Epirus, Kingdom of Sicily and the Pri...

  15. Validation of dentine deposition rates in beluga whales by interspecies cross dating of temporal δ13C trends in teeth

    Directory of Open Access Journals (Sweden)

    Cory JD Matthews

    2014-11-01

    Full Text Available Isotopic time series from sequentially sampled growth layer groups (GLGs in marine mammal teeth can be combined to build chronologies allowing assessment of isotopic variation in marine ecosystems. Synchronous recording of baseline isotopic variation across dentinal GLGs of species with temporal and spatial overlap in foraging offers a unique opportunity for validation of marine mammal age estimation procedures through calibration of GLG deposition rates in one species against another whose GLG deposition has been independently determined. In this study, we compare trends in stable carbon isotope ratios (d13C across dentinal GLGs of three eastern Canadian Arctic (ECA beluga (Delphinapterus leucas populations through the 1960s-2000s with a d13C time series measured across dentinal GLGs of ECA/Northwest Atlantic killer whales (Orcinus orca from 1944-1999. We use confirmed annual GLG deposition in killer whales as a means to assess beluga GLG deposition, and show linear d13C declines across chronologies of both species were statistically indistinguishable when based on annual GLG deposition in beluga whales, but differed when based on biannual deposition. We suggest d13C declines reflect the oceanic 13C Suess effect, and provide additional support for annual GLG deposition in beluga whales by comparing rates of d13C declines across beluga GLGs with published annual d13C declines attributed to the oceanic 13C Suess effect in the North Atlantic.

  16. Anti-Bacterial effect of Aqueous Garlic Extract (AGE) determined by Disc Diffusion Method against Escherichia coli.

    Science.gov (United States)

    Saha, S; Saha, S K; Hossain, M A; Paul, S K; Gomes, R R; Imtiaz, M; Islam, M M; Nahar, H; Begum, S A; Mirza, T T

    2016-01-01

    The study was performed to determine the antibacterial effect of aqueous extract of garlic (Allium sativum) against standard strain of Escherichia coli ATCC 25922. An interventional study was conducted in Department of Pharmacology and Therapeutics in collaboration with Department of Microbiology, Mymensingh Medical College, Mymensingh. Antibacterial effect of AGE was determined by disc diffusion method. Sensitivity of AGE determined in disc diffusion and the zone of inhibition (ZOI) was 4 mm, 10 mm and 20 mm at 25 μg/10 μl, 50 μg/10 μl and 100 μg/10 μl concentrations respectively. From the findings it is clearly determined the extract has definite antibacterial effect upon Escherichia coli. Further studies are required to detect and isolate the active ingredients present in the Garlic extract as well as detail steps of mechanism responsible for antibacterial effect. Then their effects against the studied organism should be studied in vivo separately and its toxicity profile should also be taken into account. PMID:26931244

  17. Age- and gender-specific differences in left ventricular cardiac function and volumes determined by gated SPET

    International Nuclear Information System (INIS)

    The aim of this study was to determine normative volumetric data and ejection fraction values derived from gated myocardial single-photon emission tomography (SPET) using the commercially available software algorithm QGS (quantitative gated SPET). From a prospective database of 876 consecutive patients who were referred for a 2-day stress-rest technetium-99m tetrofosmin (925 MBq) gated SPET study, 102 patients (43 men, 59 women) with a low (<10%) pre-test likelihood of coronary disease were included (mean age 57.6 years). For stress imaging, a bicycle protocol was used in 79 of the patients and a dipyridamole protocol in 23. Left ventricular ejection fraction (LVEF) and end-diastolic and -systolic volumes (EDV and ESV) were calculated by QGS. EDV and ESV were corrected for body surface area, indicated by EDVi and ESVi. To allow comparison with previous reports using other imaging modalities, men and women were divided into three age groups (<45 years, ≥45 years but <65 years and ≥65 years). Men showed significantly higher EDVi and ESVi values throughout and lower LVEF values when compared with women in the subgroup ≥65 years (P<0.05, ANOVA). Significant negative and positive correlations were found between age and EDVi and ESVi values for both women and men and between LVEF and age in women (Pearson P≤0.01). LVEF values at bicycle stress were significantly higher than at rest (P=0.000, paired t test), which was the result of a significant decrease in ESV (P=0.003), a phenomenon which did not occur following dipyridamole stress (P=0.409). The data presented suggest that LVEF and EDVi and ESVi as assessed by QGS are strongly gender-specific. Although the physiological significance of these results is uncertain and needs further study, these findings demonstrate that the evaluation of cardiac function and volumes of patients by means of QGS should consider age- and gender-matched normative values. (orig.)

  18. Aspartate aminotransferase activity in the pulp of teeth treated for 6 months with fixed orthodontic appliances

    Science.gov (United States)

    Latkauskiene, Dalia; Racinskaite, Vilma; Skucaite, Neringa; Machiulskiene, Vita

    2015-01-01

    Objective To measure aspartate aminotransferase (AST) activity in the pulp of teeth treated with fixed appliances for 6 months, and compare it with AST activity measured in untreated teeth. Methods The study sample consisted of 16 healthy subjects (mean age 25.7 ± 4.3 years) who required the extraction of maxillary premolars for orthodontic reasons. Of these, 6 individuals had a total of 11 sound teeth extracted without any orthodontic treatment (the control group), and 10 individuals had a total of 20 sound teeth extracted after 6 months of orthodontic alignment (the experimental group). Dental pulp samples were extracted from all control and experimental teeth, and the AST activity exhibited by these samples was determined spectrophotometrically at 20℃. Results Mean AST values were 25.29 × 10-5 U/mg (standard deviation [SD] 9.95) in the control group and 27.54 × 10-5 U/mg (SD 31.81) in the experimental group. The difference between these means was not statistically significantly (p = 0.778), and the distribution of the AST values was also similar in both groups. Conclusions No statistically significant increase in AST activity in the pulp of mechanically loaded teeth was detected after 6 months of orthodontic alignment, as compared to that of teeth extracted from individuals who had not undergone orthodontic treatment. This suggests that time-related regenerative processes occur in the dental pulp. PMID:26445721

  19. On the Increasing Fragility of Human Teeth with Age: ADeep-Ultraviolet Resonance Raman Study

    Energy Technology Data Exchange (ETDEWEB)

    Ager III, J.W.; Nalla, R.K.; Balooch, G.; Kim, G.; Pugach, M.; Habelitz, S.; Marshall, G.W.; Kinney, J.H.; Ritchie, R.O.

    2006-07-14

    Ultraviolet resonance Raman spectroscopy (UVRRS) using 244nm excitation was used to investigate the impact of aging on humandentin. The intensity of a spectroscopic feature from the peptide bondsin the collagen increases with tissue age, similar to a finding reportedpreviously for human cortical bone.

  20. Criteria adopted by dentists to indicate the extraction of periodontally involved teeth

    Directory of Open Access Journals (Sweden)

    Carlos Heitor Cunha Moreira

    2007-10-01

    Full Text Available When dealing with patients with periodontal disease of variable severities, dentists must often choose between treating and restoring the involved tooth or indicating its extraction. Different criteria have been adopted in this decision-making process. The purpose of this study was to evaluate the criteria adopted by dentists to indicate the extraction of teeth with periodontitis. Dentists were interviewed at their private practices in three cities of the state of Rio Grande do Sul, Brazil. The evaluated criteria included severity of attachment loss, tooth mobility, furcation involvement, prosthetic planning, periodontal-endodontic lesion, possible systemic involvement due to the presence of periodontitis, referral to a periodontist for evaluation, radiographic bone loss greater than 50%, presence of extensive caries, socio-economic and cultural status of the patient, among others. The most often adopted criteria to indicate the extraction of periodontally affected teeth were the presence of mobility (37.5%, severity of attachment loss (24.3% and radiographic bone loss greater than 50% (21.2%. The results of the present study demonstrated the difficulties faced by dentists to indicate the extraction of teeth with severe attachment loss, in addition to the establishment of an adequate prognosis. Aspects associated with the past disease were still the most often reported to indicate the extraction of teeth for periodontal reasons.

  1. In vitro evaluation of fracture resistance of teeth restored with ceramic inlays by two undercut elimination techniques

    Directory of Open Access Journals (Sweden)

    Mirzayi M.

    2008-12-01

    Full Text Available "nBackground and Aim: Polymerization shrinkage of resin cements during setting leads to stress on teeth receiving indirect esthetic restorations. Some methods like blocking out undercuts during cavity preparation with glass Ionomer can reduce the mass of resin cement and therefore the amount of stress. The aim of this study was to evaluate the fracture resistance of molar teeth, receiving class I ceramic inlays with two different methods of blocking out undercut. "nMaterials and Methods: In this experimental study, thirty intact molar teeth were randomly divided into three groups of 10 each. One group was maintained intact as the control group. Similar class I cavities with identical undercuts were prepared on the other groups. In group 2 the undercut was filled with light cured glass Ionomer (vitremer 3M before making impression, and in group 3 they were blocked out in the lab before preparation of the inlay. All the teeth in test groups were restored with indirect ceramic inlays.(vitadur - Alpha/ single bond / Rely X ARC. After thermocycling load causing fracture was assessed by universal testing machine. All the specimens were examined under a steriomicroscope (X40 to determine type of fracture. The results were analyzed by one way ANOVA and Tukey HSD tests. P< 0.05 was considered as the level of significance. "nResults: The restored groups showed significantly less fracture resistance than the control group. The difference between two test groups was not significant. The fracture in group2 had less destruction. "nConclusion: According to the findings of this study, blocking out the undercut with two different methods (using glass ionomer/ or blocking it out on the die made no diferrence in fracture resistance.

  2. Estimating Gear Teeth Stiffness

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2013-01-01

    The estimation of gear stiffness is important for determining the load distribution between the gear teeth when two sets of teeth are in contact. Two factors have a major influence on the stiffness; firstly the boundary condition through the gear rim size included in the stiffness calculation and...

  3. Analysis of human teeth and bones from the chalcolithic period by X-ray spectrometry

    International Nuclear Information System (INIS)

    Synchrotron microprobe and X-ray fluorescence spectrometry (XRFS) were used to analyse several teeth and pieces of bone, respectively, originating from subjects of the chalcolithic period. A synchrotron microprobe with 100 μm resolution and monochromatic photons of 18 keV were used to scan teeth from the root to the enamel. Bones were analysed by XRFS for their amount of trace elements, using a spectrometer based on a three-axial geometry and an incident beam of 17.4 keV. The detected elements for both analytical procedures were P, K, Ca, Mn, Fe, Cu, Zn, Br, Sr and Pb. The results show high concentrations of Mn, Fe and Cu for different tooth regions when compared with data from contemporary subjects. Moreover, the high levels of Br and Sr can be associated with environment influence and dietary habits rich in protein, especially seafood. It is remarkable that lead is always of the order of magnitude of the detection limit, which is 1-2 μg/g in all analysed teeth. Furthermore, the microprobe analysis of these samples showed that the highest concentration of the heavy metals increases from the outer enamel to the inner dentine root. For the analysed bone samples of women and men, the most important aspects concerning the elemental concentrations are the high levels of Mn and Br and the low concentrations of Pb, as found for teeth

  4. Asteroseismic age determination for dwarfs and giants

    CERN Document Server

    Aguirre, V Silva

    2015-01-01

    Asteroseismology can make a substantial contribution to our understanding of the formation history and evolution of our Galaxy by providing precisely determined stellar properties for thousands of stars in different regions of the Milky Way. We present here the different sets of observables used in determining asteroseismic stellar properties, the typical level of precision obtained, the current status of results for ages of dwarfs and giants and the improvements than can be expected in the near future in the context of Galactic archaeology.

  5. Asteroseismic age determination for dwarfs and giants

    DEFF Research Database (Denmark)

    Silva Aguirre, V.; Serenelli, A. M.

    2015-01-01

    Asteroseismology can make a substantial contribution to our understanding of the formation history and evolution of our Galaxy by providing precisely determined stellar properties for thousands of stars in different regions of the Milky Way. We present here the different sets of observables used ...... determining asteroseismic stellar properties, the typical level of precision obtained, the current status of results for ages of dwarfs and giants and the improvements than can be expected in the near future in the context of Galactic archaeology....

  6. Assessment of endodontically treated teeth by using different radiographic methods: an ex vivo comparison between CBCT and other radiographic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Demiralp, Kemal Oeaguer; Uecok, Oezlem [Dept. of Dentomaxillofacial Radiology, Faculty of Dentistry, Gazi University, Ankara (Turkmenistan); Kamburoglu, Kivanc [Dept. of Dentomaxillofacial Radiology, Faculty of Dentistry, Ankara University, Ankara (Turkmenistan); Selcen Yuesel, Kahraman Guengoer [Dept. of Biostatistics, Faculty of Medicine, Ankara University, Ankara (Turkmenistan); Demiralp, Gokcen [Dept. of Endodontics, Tepebasi Dental Health Center, Ankara (Turkmenistan)

    2012-09-15

    To compare different radiographic methods for assessing endodontically treated teeth. Root canal treatments were applied in 120 extracted mandibular teeth, which were divided into four groups: (1) ideal root canal treatment (60 teeth), (2) insufficient lateral condensation (20 teeth), (3) root canals filled short of the apex (20 teeth), (4) overfilled root canal treatment (20 teeth). The teeth were imaged using intraoral film, panoramic film, digital intraoral systems (CCD and PSP), CCD obtained with portable X-ray source, digital panoramic, and CBCT images obtained at 0.3 mm{sup 3} and 0.2 mm'3 voxel size. Images were evaluated separately by three observers, twice. Kappa coefficients were calculated. The percentage of correct readings obtained from each modality was calculated and compared using a t-test (p<0.05). The intra-observer kappa for each observer ranged between 0.327 and 0.849. The inter-observer kappa for each observer for both readings ranged between 0.312 and 0.749. For the ideal root canal treatment group, CBCT with 0.2 mm{sup 3} voxel images revealed the best results. For insufficient lateral condensation, the best readings were found with periapical film followed by CCD and PSP. The assessment of teeth with root canals filled short of the apex showed the highest percentage of correct readings by CBCT and CCD. For the overfilled canal treatment group, PSP images and conventional periapical film radiographs had the best scores. CBCT was found to be successful in the assessment of teeth with ideal root canal treatment and teeth with canals filled short of the apex.

  7. Aesthetic treatment on anterior teeth crown fracture caused by dental trauma

    Directory of Open Access Journals (Sweden)

    Nanik Zubaidah

    2012-12-01

    Full Text Available Background: Complicated crown fracture is a tooth fracture that involve enamel, dentine and pulp. The incidence of complicated crown fracture ranges from 2% to 13% of all dental injuries and the most commonly involved teeth are the maxillary central incisors. Various treatment modalities are available depending on the clinical, physiological and radiographic examination of the involved teeth. Purpose: The aim of this case report is to present the management of crown fractures with pulpal exposure caused by traumatic injury, through endorestoration approach to reconstruct the shape and function of the teeth. Case: A 17 years old male with complicated crown fractures of anterior teeth #11 #21 and #22. The patient wish for aesthetic dental treatment in both of its form and function. Case management: Crown fractures of anterior teeth with exposed pulp caused by traumatic injury were reconstructed by endorestoration approach. The endodontic treatment with post and core insertion in the root canal which will increase its retention and porcelain fused to metal crown which will aesthetically recover its original form and function. After restoration the patient feel very glad and confident with the result. Conclusion: Endorestoration treatment on anterior teeth with complicated crown fractures and exposed pulp is able to recover the normal form, function and dental aesthetic in accordance with stomatognatic system and self confidence.Latar belakang: Fraktur mahkota kompleks (complicated adalah fraktur pada mahkota gigi yang melibatkan enamel, dentin dan pulpa. Kejadian dari fraktur mahkota kompleks bervariasi antara 2-13% dari semua trauma gigi dan sebagian besar gigi yang terkena adalah gigi insisif pertama rahang atas. Berbagai macam cara perawatan yang dilakukan tergantung pada hasil pemeriksaan klinis, psikologis dan radiografis dari gigi yang terkena. Tujuan: Laporan kasus ini menjelaskan penatalaksanaan fraktur mahkota gigi dengan pulpa terbuka

  8. Malocclusion of teeth

    Science.gov (United States)

    Crowded teeth; Misaligned teeth; Crossbite; Overbite; Underbite; Open bite ... Occlusion refers to the alignment of teeth and the way that the upper and lower teeth fit together (bite). The upper teeth should fit slightly over the lower teeth. ...

  9. Finding 3D Teeth Positions by Using 2D Uncalibrated Dental X-ray Images

    OpenAIRE

    Sridhar, Bitra; Prasad, Dandey Venkata

    2010-01-01

    In Dental Radiology very often several radiographs (uncalibrated in position) are taken from the same person. The radiographs do not provide the depth details, and there is often requirement of three dimensional (3D) data to achieve better diagnosis by radiologist. The purpose of this project is a step forward to solve needs of dentists for evaluating the degree of severity of teeth cavities by 3D reconstruction implementing the uncalibrated radiographs. The 3D information retrieval from two ...

  10. Dental plaque, preventive care, and tooth brushing associated with dental caries in primary teeth in schoolchildren ages 6–9 years of Leon, Nicaragua

    OpenAIRE

    del Socorro Herrera, Miriam; Medina-Solis, Carlo Eduardo; Minaya-Sánchez, Mirna; Pontigo-Loyola, América Patricia; Villalobos-Rodelo, Juan José; Islas-Granillo, Horacio; de la Rosa-Santillana, Rubén; Maupomé, Gerardo

    2013-01-01

    Background Our study aimed to evaluate the effect of various risk indicators for dental caries on primary teeth of Nicaraguan children (from Leon, Nicaragua) ages 6 to 9, using the negative binomial regression model. Material/Methods A cross-sectional study was carried out to collect clinical, demographic, socioeconomic, and behavioral data from 794 schoolchildren ages 6 to 9 years, randomly selected from 25 schools in the city of León, Nicaragua. Clinical examinations for dental caries (dmft...

  11. Effects of human aging on patterns of local cerebral glucose utilization determined by the [18F]fluorodeoxyglucose method

    International Nuclear Information System (INIS)

    The [18F]fluorodeoxyglucose (FDG) scan method with positron emission computed tomography was used to determine patterns of local cerebral glucose utilization (LCMRglu) in 40 normal volunteer subjects aged 18 to 78 years. Throughout all the studies, each subject was quiet, without movement, with eyes open and ears unplugged, exposed only to ambient room light and sound. For the entire group, whole brain mean CMRglu was 26.1 +/- 6.1 mumol 100 g-1 min-1 (mean +/- SD, n . 40). At age 78, mean CMRglu was, on the average, 26% less than at age 18, an alteration of the same order as the variance among subjects at any age. The gradual decline of mean CMRglu with advancing age occurred at a faster rate than was reported for mean cerebral oxygen utilization, possibly due to increasingly altered pathways for glucose utilization, or to increasing oxidation of ketone bodies or other alternative substrates. Glucose utilization in the hemispheres was symmetrical and mean CMRglu of overall cortex, caudate, and thalamus was equal in individuals at all ages. The slopes of decline with age were similar when LCMRglu was averaged over zones corresponding to centrum semiovale, caudate, putamen, and frontal, temporal, parietal, occipital, and primary visual cortex. However, the metabolic ratio of superior frontal cortex to superior parietal cortex declined with age, possibly due to selective degeneration of superior frontal cortex or to differences between age groups in the sensory and cognitive response to the study. These results should be useful in distinguishing age from disease effects when the FDG scan method is used

  12. Isotopic age determination in Bergslagen, Sweden. 1

    International Nuclear Information System (INIS)

    This paper is an introduction to a series of short communications 'Isotopic age determinations in Bergslagen, Sweden', which will be submitted to this journal. An earlier paper on K-Ar ages of hornblendes in skarns and metabasites in the Hjulsjoe area has been published elsewhere (Moorman et al., 1982). This joint research project of the ZWO-Laboratory of Isotope Geology and the Geological Institute University of Amsterdam forms part of the research program of the 'Stichting voor Isotopen-Geologisch Onderzoek', supported by the Netherlands Organization for the Advancement of Pure Research (Z.W.O.). (Auth.)

  13. [Palatogram including lingual and occlusal surface of teeth analyzed by image processor].

    Science.gov (United States)

    Taniguchi, H

    1989-06-01

    (palatogram). The subjects were 30 dentulous adults (21 men, 9 women). The artificial palates made of black vinyl seat covering the palate and occlusal surfaces of maxillary teeth were coated with white alginate powder and inserted into the mouths of the subjects. After pronunciation of the test sound, the tongue contact areas on artificial palate were demonstrated by wetting of powder and changing in color from white to black. Thus photographs of the palatograms were Measurements have been made on the tongue contact area of the palate and maxillary teeth during pronunciation of /sa, fi, çi, ka, ki, ta, na, ra, ja/ (palatogram). The subjects were 30 dentulous adults (21 men, 9 women). The artificial palates made of black vinyl seat covering the palate and occlusal surfaces of maxillary teeth wer coated with white alginate powder and inserted into the mouths of the subjects. After pronunciation of the test sound, the tongue contact areas on artificial palate were demonstrated by wetting of powder and changing in color from white to black. Thus photographs of the palatograms were taken. An image processor system was employed for averaging each subject's 5 samples of same sound. The averaged outline of each subject's palatograms were converted to the standardized dental arch form and added and stored into frame memory. The 60-90% of subject's common parts were extracted from the added palatograms of same sound and illustrated in different gray levels. The results indicate that the tongue-to-teeth contact area of each sound differ from the others, however, it's range is confined within cervical half of lingual surface of incisors and lingual cusps of molars. PMID:2489723

  14. Monitoring of Environmental Contamination and Addressing Health Risks Through the Analysis of Teeth by Means of Nuclear Techniques

    International Nuclear Information System (INIS)

    Radionuclides (mostly uranium and thorium) and heavy metals (lead and cadmium) are environmental contaminants produced by agricultural and industrial activities, or are simply the result of soil and water pollution by non regular human activities (e.g. disposal of garbage in rivers and water ponds). Humans incorporate these contaminants via the food chain, where bones are the most important target-organ. The incidence of health risk and hazards would depend, obviously, on the time length and intensity of such incorporation. However, while in vivo monitoring of human bones is difficult, the analysis of teeth is a promising possibility, particularly for the quantification of lead and cadmium in deciduous tooth (milk tooth), and uranium in adult tooth. This study will be focused, initially, on the Guarapiranga dam and on the human settlements located in its surroundings. Their teeth will be collected and classified by age and social-economical status, with the collaboration of the Dentistry School from UNISA, which is developing several social tasks in the Guarapiranga region. Water, plants and fishes will be collected and analyzed too, aiming at biokinetic al study of contaminants, particularly the transfer dynamics among the species of the dam. (Author)

  15. Study to determination the age and extension rate of corals in related to climate change by X-ray

    International Nuclear Information System (INIS)

    The research has been conducted to determine the age and growing rate of corals using x-ray and its correlation with El-nino events and climate change in Kepulauan Seribu. Massive corals Porites Lutea were drilled vertically using pneumatic drilling with 5 cm in diameter. Samples were prepared, x-rayed and analyzed using software Image-J to determine age, linear growth direction and rate. The result shows that average of growth rate of coral in three locations in Kepulauan Seribu is about the same, however the growing rate toward onshore is higher than other locations. Based on the analysis of growing rate, there are two-largest El-Nino events that can be determined related to the period of 1997-1998 and 1982-1983. (author)

  16. The teeth, jaws, and salivary glands

    International Nuclear Information System (INIS)

    Roentgenographic examination of the teeth is used by the medical profession largely to determine the presence or absence of infection involving the teeth and jaws. Certain changes in the alveolus result from generalized disease, and examination of the teeth is helpful in assessing these conditions as well. Tumors arising on the alveolar ridge, tongue, or other intraoral sites may involve the bony alveolus. Roentgenographic examination is used to look for and follow the progress of such tumors. Specific techniques for dental radiography include intraoral dental roentgenographic study and the panoramic type of extraoral examinations. Three general intraoral methods of examination are used - the intraoral dental, bite-wing, and occlusal

  17. Age determination methods in harbour seals (Phoca vitulina with a review of methods applicable to carnivores

    Directory of Open Access Journals (Sweden)

    Christina Lockyer

    2010-09-01

    Full Text Available The development of age determination methods in marine mammals is reviewed with particular reference to the use of teeth Growth Layer Groups (GLGs formed in the dentine and cement of carnivores. Using this background, practices for sampling, tooth extraction and collection, storage and different methods of preparation of teeth as well as reading and counting GLGs are discussed and evaluated for the harbour seal (Phoca vitulina. The paper includes comments on best practices for counting GLGs with new examples from known-age seals, and also a detailed examination of confounding factors in interpreting GLGs such as mineralization anomalies and the phenomena of accessory lines, “false annuli” and “paired laminae” which have not been discussed previously. The paper concludes with recommendations for undertaking age estimation in harbour seals from sampling through final GLG interpretation with special emphasis on standardization of methods with other researchers.

  18. The mean visible labial length of maxillary and mandibular anterior teeth at rest

    International Nuclear Information System (INIS)

    To determine the mean visible labial length of maxillary and mandibular anterior teeth at rest. Study Design: Cross-sectional study. Place and Duration of Study: Department of Prosthodontics, Dr. Ishrat-ul-Ebad Khan Institute of Oral Health Sciences, Karachi, from October 2012 to March 2013. Methodology: A total of 200 subjects were included. Measurements were carried out using digital caliper from the border of the lip to the incisal edges of incisor and to the cusp tip for the canines. The length of the upper lip was measured from subnasale to stomion. Statistical analyses were performed by Mann Whitney-U test and Kruskal Walli's test. Results: The age of the participant ranged between 20 and 65 years. At rest, females significantly displayed more of the maxillary central incisor (2.93 +- 1.57 mm; p=0.003), lateral incisor (1.87 +- 1.12 mm; p=0.005) and canine (0.59 +- 0.62 mm; p=0.031). With increasing age, the amount of maxillary anterior teeth visible at rest significantly decreased (p < 0.001), and increased for the mandibular teeth (p < 0.001). Subjects with shorter upper lips significantly displayed more maxillary anterior incisor structure than subjects with longer upper lip (p < 0.001). Conclusion: Females displayed significantly more labial length of the maxillary anterior teeth. The mean visible labial length of maxillary anterior teeth significantly decreased with increasing age and increased for the mandibular teeth. As the upper lip length increased, the mean visible labial length of maxillary anterior teeth significantly decreased. (author)

  19. Cross-Sectional Association between the Number of Missing Teeth and Cardiovascular Disease among Adults Aged 50 or Older: BRFSS 2010

    OpenAIRE

    R. Constance Wiener; Usha Sambamoorthi

    2014-01-01

    Objective. The relationship between oral health and cardiovascular disease is an emerging area of research. The objective of the current study is to evaluate the association of cardiovascular disease and the number of missing teeth as a risk indicator. Methods. Cross-sectional study design with data on 275,424 respondents aged 50 or older from the 2010 Behavioral Risk Factor Surveillance System survey was used. The dependent variable was self-reported cardiovascular disease. The association...

  20. Age dynamics of zinc and iron contents in human hair determined by INAA and ICP-ES

    International Nuclear Information System (INIS)

    Full text: In last decades, the determination of chemical element levels in human hair has been a subject of continual interest in the forensic, clinical, occupational and environmental medicine. Hair has been increasingly used as a monitor for many elements and has been proposed for assessing environmental exposure, nutritional status, and for diagnosis of disease. It has many advantages for assessment over the more traditional kinds of medical objects such as blood and urine because of ease of collection, transport and storage. Also, trace element concentrations in hair samples represent an integrated response over time compared with blood and urine levels, which can rapidly fluctuate in response to variations of nutritional and environmental conditions. The fact that contents of many chemical elements in hair are relatively high also facilitates the analysis. It is known that the result of the hair analysis may not directly relate to the intake amount, nor does it always reflect the amount actually absorbed. Despite these limitations, the analysis of human hair can still provide a basis for estimating ambient exposure to certain elements. The first step in construction of such basis is investigations the national population normal levels of chemical element contents in hair related to sex, age and some other factors under quality control of results. The objectives of this analytical work were to evaluate the reference range of Zn and Fe in adult scalp hair and to evaluate the effect of age and sex on elemental contents. In this study, head hair samples from adult health persons living in or near Obninsk (the small city in rural region 105 km south-west Moscow), were analysed by two methods in three analytical laboratories: instrumental neutron activation analysis (INAA - one laboratory) and atomic emission spectrometry with inductively coupled plasma (ISP-AES - two laboratories). Scalp hair samples were obtained at necropsy from eighty-three cadavers (38 women

  1. Teething Tots

    Science.gov (United States)

    ... the first set of teeth will fall out, tooth decay makes them fall out more quickly, leaving gaps ... brush and floss. Another important tip for preventing tooth decay: Don't let your baby fall asleep with ...

  2. Determination of the metal distribution in tooth fillings in real teeth based on element sensitive X-ray tomography

    International Nuclear Information System (INIS)

    Since a couple of centuries people are using metal tooth-fillings in order to protect their teeth. In the beginning of the 19th century the amalgam or silver fillings were introduced for to first time. Nowadays, dentists mostly use amalgam. These fillings are a mixture of silver, tin and mercury. The mercury which is abundant, about 50%, is dangerous for any living organism. Mercury has a particular affinity for the brain tissue but is also accumulated in the liver, kidneys, lungs, gastrointestinal track and jawbone. Mercury Basely crosses the placenta and is gathered in the heart, pituitary gland and liver of the fetus. It is been proven that the mercury vaporises and enter enters the body via the lungs. Since a couple of years we apply the element sensitive X-ray tomography technique on heavy elements like uranium or lead. By scanning teeth using photons having two different energies, one just below and one just above the K-edge of the element under investigation, the tomography becomes element sensitive. The experiment has been done at the ESRF, beam line ID15A, with a very intense tunable monochromatic high energy X-ray beam. We made tomographies of different teeth with 20 μm image resolution. The slices were 20 μm apart. The results after reconstruction are three dimensional mercury maps which can tell us something about the possibility of mercury diffusion into the roots of the tooth. From there the mercury could enter the blood stream and end up in the organs. (author)

  3. Teeth as biomonitors of selenium concentrations in tissues of beluga whales (Delphinapterus leucas)

    Energy Technology Data Exchange (ETDEWEB)

    Kinghorn, April [Centre for Indigenous Peoples Nutrition and Environment, Macdonald Campus, McGill University, 21-111 Lakeshore Road, Ste. Anne-de-Bellevue, Quebec, H9X 3V9 (Canada); Humphries, Murray M. [Centre for Indigenous Peoples Nutrition and Environment, Macdonald Campus, McGill University, 21-111 Lakeshore Road, Ste. Anne-de-Bellevue, Quebec, H9X 3V9 (Canada); Department of Natural Resource Science, Macdonald Campus, McGill University, 21-111 Lakeshore Road, Ste. Anne-de-Bellevue, Quebec, H9X 3V9 (Canada); Outridge, Peter [Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario, K1A 0E8 (Canada); Chan, Hing Man [Community Health Sciences Program, University of Northern British Columbia, 3333 University Way, Prince George, British Columbia, V2N 4Z9 (Canada)], E-mail: lchan@unbc.ca

    2008-08-25

    Selenium (Se) is an essential element which has been shown to play an important role in protecting marine mammals against the toxic effects of mercury (Hg) and other metals. It has been suggested that metal concentration in marine mammal teeth can potentially be used as bioindicators for body burden. The objective of this study was to investigate the relationship between Se concentrations in beluga (Delphinapterus leucas) teeth and those previously measured in soft tissues (liver, kidney, muscle and muktuk). Tooth Hg concentrations are also measured, and the relationships between Se and Hg in teeth and soft tissues are examined. Se in the teeth of beluga was measured using hydride generation atomic fluorescence spectrometry (HG-AFS) and Hg in beluga teeth was measured by cold-vapour atomic absorption. Tooth Se concentrations ranged from 108 ng/g to 245 ng/g dry weight, and tooth Hg concentrations ranged from 10 to 189 ng/g dry weight. In the soft tissues, Se concentrations were highest in the liver, followed by kidney, muktuk, and muscle. There were significant correlations between tooth Se concentrations and animal age, tooth Se and liver and muscle Se, and between liver Se and animal age. The molar ratio of Hg:Se in the liver was found to be 0.70. This study is the first to measure Se in the teeth of a marine mammal species, and HG-AFS is found to be an effective technique for determining Se in beluga teeth. Tooth Se can be used as predictor for liver and muscle Se, although these relationships may be strongly influenced by the association of Se with Hg in marine mammal tissues. This study contributes to an increased understanding of the storage and metabolism of Se in marine mammals.

  4. Teeth as biomonitors of selenium concentrations in tissues of beluga whales (Delphinapterus leucas)

    International Nuclear Information System (INIS)

    Selenium (Se) is an essential element which has been shown to play an important role in protecting marine mammals against the toxic effects of mercury (Hg) and other metals. It has been suggested that metal concentration in marine mammal teeth can potentially be used as bioindicators for body burden. The objective of this study was to investigate the relationship between Se concentrations in beluga (Delphinapterus leucas) teeth and those previously measured in soft tissues (liver, kidney, muscle and muktuk). Tooth Hg concentrations are also measured, and the relationships between Se and Hg in teeth and soft tissues are examined. Se in the teeth of beluga was measured using hydride generation atomic fluorescence spectrometry (HG-AFS) and Hg in beluga teeth was measured by cold-vapour atomic absorption. Tooth Se concentrations ranged from 108 ng/g to 245 ng/g dry weight, and tooth Hg concentrations ranged from 10 to 189 ng/g dry weight. In the soft tissues, Se concentrations were highest in the liver, followed by kidney, muktuk, and muscle. There were significant correlations between tooth Se concentrations and animal age, tooth Se and liver and muscle Se, and between liver Se and animal age. The molar ratio of Hg:Se in the liver was found to be 0.70. This study is the first to measure Se in the teeth of a marine mammal species, and HG-AFS is found to be an effective technique for determining Se in beluga teeth. Tooth Se can be used as predictor for liver and muscle Se, although these relationships may be strongly influenced by the association of Se with Hg in marine mammal tissues. This study contributes to an increased understanding of the storage and metabolism of Se in marine mammals

  5. Wear of primary teeth caused by opposed all-ceramic or stainless steel crowns

    Science.gov (United States)

    Bae, Ik-Hyun; Noh, Tae-Hwan; Ju, Sung-Won; Lee, Tae-Kyoung; Ahn, Jin-Soo; Jeong, Tae-Sung

    2016-01-01

    PURPOSE This study was conducted to evaluate the effects of full-coverage all-ceramic zirconia, lithium disilicate glass-ceramic, leucite glass-ceramic, or stainless steel crowns on antagonistic primary tooth wear. MATERIALS AND METHODS There were four study groups: the stainless steel (Steel) group, the leucite glass-ceramic (Leucite) group, the lithium disilicate glass-ceramic (Lithium) group, and the monolithic zirconia (Zirconia) group. Ten flat crown specimens were prepared per group; opposing teeth were prepared using primary canines. A wear test was conducted over 100,000 chewing cycles using a dual-axis chewing simulator and a 50 N masticating force, and wear losses of antagonistic teeth and restorative materials were calculated using a three-dimensional profiling system and an electronic scale, respectively. Statistical significance was determined using One-way ANOVA and Tukey's test (P.05). CONCLUSION Leucite glass-ceramic and lithium disilicate glass-ceramic cause more primary tooth wear than stainless steel or zirconia. PMID:26949487

  6. Enhancement of two-photon transition rate by selectively removing certain frequency comb teeth

    CERN Document Server

    Zhang, Shuangyou; Zhao, Jianye

    2015-01-01

    We present experiments demonstrating an enhancement of resonant two-photon transition rate in 87Rb utilizing spectral phase manipulation of the excitation frequency comb. By selectively removing certain comb teeth, the resonant two-photon transition rate can be improved, and reach a factor of more than 1.8. The femtosecond pulse-train excitation of two-photon transition is investigated theoretically based on general multiphoton transitions and the results are compared with the experiments. The theory presented here gives a clear insight of physical mechanism of this quantum coherent control and indicates that it is simple, effective and universal for nonlinear interactions between frequency combs and matters.

  7. Brushing Your Child’s Teeth

    Science.gov (United States)

    ... age. Taking care of your child's gums and teeth every day helps prevent tooth decay and gum disease. It also helps make ... child. Learn how to care for your children's teeth and gums starting when they are newborn. When ...

  8. The autoradiographic pattern of the in vitro uptake of proline by the coronal areas of intact and carious human teeth

    International Nuclear Information System (INIS)

    The biosynthesis of collagen in teeth was studied by following the uptake of proline in vitro. Whole crowns of human teeth were incubated for 6 h with (14C)- or (3H)-proline. Autoradiographs were prepared from sections of intact teeth and teeth with carious lesions of varying depths and location. The number of silver grains per cm2 in the predentine, odontoblast layer and pulp were counted in selected fields magnified x 430 representing the deepest parts of the carious lesions. No differences in the labelling pattern were observed between the intact teeth incubated freshly after extraction and those preserved in liquid nitrogen. The densest labelling of intact teeth was seen in the predentine and odontoblast layer. The alterations under initial dentine caries appeared as increased labelling of the predentine and decreased labelling of the odontoblast layer; no alterations were observed in the underlying pulp. In advanced lesions, the predentine labelling decreased and that in the odontoblast layer and pulp increased. In the initial stages, caries seem to activate collagen synthesis in a relatively restricted area of the underlying structures, but in advanced stages, caries seem to increase the odontoblastic cellular polypeptide chain formation but prevent further maturation of the collagen. (author)

  9. Volume of sealer in the apical region of teeth filled by different techniques: a micro-CT analysis

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Vanessa Lessa; Souza-Gabriel, Aline Evangelista; Cruz Filho, Antonio Miranda da; Pecora, Jesus Djalma; Silva, Ricardo Gariba, E-mail: vanessalessa@usp.br [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Escola de Odontologia. Departamento de Odontologia Restauradora

    2016-05-01

    The volume of sealer in the apical 1 mm of teeth filled using different techniques was evaluated by micro-commuted tomography (micro-CT). Sixty-four maxillary central incisors were prepared using NiTi rotary instruments. Teeth were randomly distributed into four groups according to root canal sealers (AH Plus, Endofill, Sealapex, and Sealer 26) and subdivided into two subgroups according to the filling techniques (active and passive lateral condensation; n = 8 each). Subsequently, teeth were examined using the 1174 SkyScan micro-CT device. Images were reconstructed using the NRecon software, and the sealer volume (mm{sup 3}) in the apical region was analyzed using the two-way ANOVA and post-hoc Student-Newman-Keuls test (α = 0.05). The lowest volume of sealer was observed in teeth filled with Sealapex (0.100 ± 0.009) and Endofill (0.103 ± 0.010). The highest volume was observed in teeth filled with AH Plus (0.112 ± 0.008) and Sealer 26 (0.109 ± 0.018) (p > 0.05). Regarding the filling technique, a lower sealer volume was observed using the active lateral condensation technique compared with that using the passive lateral condensation technique (0.100 ± 0.010 vs. 0.111 ± 0.012) (p < 0.05). Therefore, the lowest volume of sealer was observed in teeth filled with Sealapex and Endofill using the active lateral condensation technique. (author)

  10. Volume of sealer in the apical region of teeth filled by different techniques: a micro-CT analysis

    International Nuclear Information System (INIS)

    The volume of sealer in the apical 1 mm of teeth filled using different techniques was evaluated by micro-commuted tomography (micro-CT). Sixty-four maxillary central incisors were prepared using NiTi rotary instruments. Teeth were randomly distributed into four groups according to root canal sealers (AH Plus, Endofill, Sealapex, and Sealer 26) and subdivided into two subgroups according to the filling techniques (active and passive lateral condensation; n = 8 each). Subsequently, teeth were examined using the 1174 SkyScan micro-CT device. Images were reconstructed using the NRecon software, and the sealer volume (mm3) in the apical region was analyzed using the two-way ANOVA and post-hoc Student-Newman-Keuls test (α = 0.05). The lowest volume of sealer was observed in teeth filled with Sealapex (0.100 ± 0.009) and Endofill (0.103 ± 0.010). The highest volume was observed in teeth filled with AH Plus (0.112 ± 0.008) and Sealer 26 (0.109 ± 0.018) (p > 0.05). Regarding the filling technique, a lower sealer volume was observed using the active lateral condensation technique compared with that using the passive lateral condensation technique (0.100 ± 0.010 vs. 0.111 ± 0.012) (p < 0.05). Therefore, the lowest volume of sealer was observed in teeth filled with Sealapex and Endofill using the active lateral condensation technique. (author)

  11. Strontium 90 and cesium 137 content in man's teeth and hair

    International Nuclear Information System (INIS)

    In 1972, samples from teeth and hair were collected from the following age groups: 1-10 years of age, 10-20 years of age, over 20 years of age. The data show highest concentration of strontium 90 in children's teeth, followed by the second group (10-20 years of age) and the lowest concentration in the age group over 20 years. No reliable age related differences in the hair concentrations of strontium 90 and cesium 137 are found. The data for strontium 90 and cesium 137 content in teeth and hair are in good agreement with the literature data for other European countries. (author)

  12. Analyzer of Spectra for Age Determination (ASAD) - Algorithm and Applications

    OpenAIRE

    Asa'd, Randa

    2014-01-01

    Analyzer of Spectra for Age Determination (ASAD) is a new package that can easily predict the age and reddening of stellar clusters from their observed optical integrated spectra by comparing them to synthesis model spectra. The ages obtained with ASAD are consistent with ages obtained from previous cluster age methods requiring a more rigorous and time-consuming analysis. This package not only provides fast results, but also allows the user to comprehend the accuracy of these results by prov...

  13. The study of impacted and supernumerary teeth in young man by the full mouth roentgenograms

    International Nuclear Information System (INIS)

    The author has observed 906 full mouth roentgenograms in Korean young man who had the impacted and supernumerary teeth. Impacted and supernumerary teeth were analysed upon several items, such as incidences and positions in the dental arch . The results were as follows; 1. The incidences of impacted teeth were 59.05%, and the ratio of upper jaw to lower one was 1:3. 2. The frequency of the supernumerary teeth were 5.52%, and the ratio of maxilla to mandible was 49:1. 3. No significant differences between right and left side in both jaws, but incidence rate of the supernumerary teeth was 74% in the maxillary central incisor area. 4. The positions of impacted and supernumerary teeth were vertical and inverted shapes in maxilla, whereas horizontal a nd mesio-angular forms in mandible.

  14. Influence of voluntary teeth clenching on the stabilization of postural stance disturbed by electrical stimulation of unilateral lower limb.

    Science.gov (United States)

    Fujino, Sachiko; Takahashi, Toshiyuki; Ueno, Toshiaki

    2010-01-01

    Studies on the relationship between dental occlusion and body balance have suggested that occlusion status contributes to the maintenance of postural balance. However, little has been reported about the effects of voluntary teeth clenching on the stabilization of postural stance in novel environments. In the present study we investigated whether teeth clenching influenced adaptation to the perturbation introduced by electrical stimulation of a unilateral lower limb. Subjects (12 adults) stood on a force plate, from which motion data were obtained in the horizontal plane with and without voluntary teeth clenching and were instructed to maintain the position throughout the experiment. We evoked a novel environment by supramaximal percutaneous electrical stimulation of the common peroneal nerve. Electromyograms (EMG) were recorded from the masseter and the peroneus longus (PL) muscles with bipolar surface cup electrodes. When the disturbed postural stance was generated by electrical stimulation, the maximum reaction force in the anterior-posterior (A/P) direction with teeth clenching (CL) was significantly smaller than that without voluntary teeth clenching (control; CO) (p<0.05) and the peak time of the ground reaction force/body mass (GRF/BM) in the A/P direction occurred earlier in the CL condition than CO (p<0.05). There were no significant differences in the peak-to-peak amplitude of GRF/BM and the peak time of GRF/BM, in the M/L direction under both CL and CO conditions. Thus, the present study showed that voluntary teeth clenching contributed to stabilization of the postural stance perturbed transiently by electrical stimulation. We concluded that voluntary teeth clenching plays an important role in rapid postural adaptation to the anterior-posterior perturbation in the upright position. PMID:19879763

  15. Isotopic age determinations in Bergslagen, Sweden: VII

    International Nuclear Information System (INIS)

    Rb-Sr whole-rock analysis of seven samples of the Fellingsbro-type Younger Granite east of Kopparberg gives an age of 1715 +- 50 Ma and an initial 87Sr/86Sr ratio of 0.7046+-0.0026 (errors 95% confidence level). This age falls in the age range determined for the Younger Granites of the Vaermland-Smaaland, Dala and Fellingsbro Groups, 1.74-1.64 Ga. Reliable age data from the Malingsbo-type granites in the Kopparberg area are still lacking, however, so it is uncertain whether they can be included in the Fellingsbro Group of Younger Granites. (orig.)

  16. Personal Factors Determining Patient Satisfaction with All-Ceramic Crown Treatment for Single Anterior Teeth.

    Science.gov (United States)

    Zou, Yun; Zhan, DeSong

    2016-01-01

    The Eysenck Personality Questionnaire's (EPQ) N value (neuroticism) was used to evaluate information from 158 patients before ceramic crown treatment. Patient satisfaction was also evaluated using a satisfaction questionnaire 2 weeks post treatment. Patient expectations were not correlated with sex, age, or N value, and sex was not correlated with patient satisfaction other than in relation to crown shape. Total esthetic satisfaction and feature improvement were positively correlated with age, while satisfaction for five specific criteria was negatively correlated with N value and overall expectation. These observations underscore the importance of considering the physical and psychologic aspects of patient care when planning dental treatment. PMID:27611752

  17. Analysis of Torque Ripple Caused by Three-Phase Unbalance in Claw Teeth Motors

    Science.gov (United States)

    Koyama, Takayuki; Nakatsugawa, Junnosuke; Enomoto, Yuji

    A soft magnetic composite (SMC) has some advantages, namely, three-dimensional magnetic isotropy and low eddy current loss. Thus, it can be used to build a new type of motor with a three-dimensional structure, improved space factor of winding improved the power density. A claw teeth motor is one of the motors that have three-dimensional structure, and it is made of an SMC. Due to its structure, the claw teeth motor has an unbalanced three-phase magnetic circuit, which leads to low-order harmonic components in the torque waveform. For reducing the torque ripple, it is important to estimate the magnetic torque and the cogging torque because the total torque is the sum of these torques. In this study a method for decomposing the total torque under the load condition into the magnetic torque and cogging torque is presented. The proposed method can quantitatively estimate low-order harmonic components of the magnetic torque and cogging torque caused by an unbalanced three-phase magnetic circuit for each phase.

  18. Determination of the Thermal Expansion Coefficient of Concrete at Early Ages by Using Temperature-stress Testing Machine

    Institute of Scientific and Technical Information of China (English)

    HUO Kaicheng; SHUI Zhonghe; LI Yue

    2006-01-01

    By using the uptodate temperatuer-stress testing machine, the thermal expansion coefficient of concrete at early ages was studied and indicative conclusions were achieved: temperature rising due to hydration heat is not directly correlated with cracking, but the temperature and stress evolution process should be taken into consideration in the same time. Proper chemical admixtures and mineral compositions can improve the mechanical properties of concrete such as thermal expansion coefficient, which is very indicative in practice.

  19. Anterior Teeth Mutilation and The Occurrence of Posterior Teeth Atrition in Siberut Island

    OpenAIRE

    Isnindiah Koerniati

    2013-01-01

    The Mentawai ethnic group is accustomed to the practice of anterior teeth mutilation on males and females prior to reaching puberty age at Siberut Island, Mentawai Islands Regency, West Sumatra Province. Objective: of this research was to analyze the effects of anterior teeth mutilation on the teeth of the Mentawai ethnic, and prove that there is a correlation between anterior teeth mutilation and posterior teeth attritions. Material & method: There were 179 respondents who contributed to...

  20. Age determination enhanced by embryonic foot bud and foot plate measurements in relation to Carnegie stages, and the influence of maternal cigarette smoking

    DEFF Research Database (Denmark)

    Lutterodt, M C; Rosendahl, M; Yding Andersen, C;

    2009-01-01

    habits, and delivered a urine sample for cotinine analysis. Embryonic age was evaluated by vaginal ultrasound measurements and by post-termination foot length and compared with the Carnegie stages. RESULTS: Foot bud and foot plate were defined and measured as foot length in embryos aged 35-47 days p......BACKGROUND: Reliable age determination of first-trimester human embryos and fetuses is an important parameter for clinical use and basic science. Age determination by ultrasound or morphometric parameters of embryos 4-6 weeks post conception (p.c.) have been questioned, and more accurate methods.......c. (range 0.8-2.1 mm). In embryos and fetuses aged 41-69 days p.c., heel-toe length was measured (range 2.5-7.5 mm). We found a significant linear correlation between foot length and age. Morphology of the feet was compared visually with the Carnegie collection, and we found that the mean ages of the two...

  1. Determination of hydrogen concentration in a-Si and a-Ge layers by elastic recoil detection analysis

    International Nuclear Information System (INIS)

    Compete text of publication follows. Hydrogenated amorphous Si and Ge films are of current interest in academic and industrial research due to their unique physical properties and important applications. The incorporation of hydrogen in the amorphous network is an accepted means for reducing the density of defect states in the midgap. The passivation of dangling-bonds leads to a significant improvement in the electronic and optical properties of these layers. However, hydrogen is also suspected to degrade the performance of amorphous Si and Ge material and devices. Several studies related to hydrogen motion have been proposed to explain the light and thermal degradation effect in these layers. Thus to improve the performance and reliability of these devices, it is crucially important to understand the role of hydrogen in amorphous layers. In our previous works the structural changes of hydrogenated a-Si/Ge multilayers as a function of annealing condition was investigated. It was shown that during annealing the samples underwent significant structural changes. Due to the fast out-diffusion of hydrogen from the layers prepared with high (6 ml/min) H2 flow rate, bubbles and craters were created on the surface. However, in the multilayer samples prepared with hydrogen flow rate lower than 6 ml/min the macroscopic degradation by formation bubbles and craters was more moderated. The diffusion measurement shows that in these samples the structural degradation and intermixing of layers was slower than in the non-hydrogenated samples. As it was suggested the hydrogen can inactivate the dangling bonds of amorphous layers and, as a result of this, the intermixing slows down. It was also predicted that the hydrogen first released from the Ge layers because of the lower binding energy. In this work, we have studied the individual a-Si and a-Ge hydrogenated layers prepared by RF sputtering on Si (100) substrates. The absolute value of atomic content of the H was determined by

  2. Study of the grasping spines and teeth of 6 chaetognath species observed by scanning electron microscopy.

    Science.gov (United States)

    Moreno, I

    1979-01-01

    The grasping spines and teeth of 6 species of Chaetognatha have been studied with the scanning electron microscope, describing in the grasping spines: curvature, surface, ridge and insertion and in the teeth, its characters and their arrangement on the head. PMID:507374

  3. Determination of sexual dimorphism via maxillary first molar teeth in Himachali population

    OpenAIRE

    Swati Singla; Rakhi Gupta; Abhiney Puri; Sucheta Bansal; Smita Singla; Rajat Nangia

    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...

  4. Streptococci biofilm decontamination on teeth by low-temperature air plasma of dc corona discharges

    International Nuclear Information System (INIS)

    Non-thermal plasmas of atmospheric pressure air direct current corona discharges were investigated for potential applications in dental medicine. The objective of this ex vivo study was to apply cold plasmas for the decontamination of Streptococci biofilm grown on extracted human teeth, and to estimate their antimicrobial efficiency and the plasma's impact on the enamel and dentine of the treated tooth surfaces. The results show that both positive streamer and negative Trichel pulse coronas can reduce bacterial population in the biofilm by up to 3 logs in a 10 min exposure time. This bactericidal effect can be reached faster (within 5 min) by electrostatic spraying of water through the discharge onto the treated tooth surface. Examination of the tooth surface after plasma exposure by infrared spectroscopy and scanning electron microscopy did not show any significant alteration in the tooth material composition or the tooth surface structures. (paper)

  5. Streptococci biofilm decontamination on teeth by low-temperature air plasma of dc corona discharges

    Science.gov (United States)

    Kovalóvá, Z.; Zahoran, M.; Zahoranová, A.; Machala, Z.

    2014-06-01

    Non-thermal plasmas of atmospheric pressure air direct current corona discharges were investigated for potential applications in dental medicine. The objective of this ex vivo study was to apply cold plasmas for the decontamination of Streptococci biofilm grown on extracted human teeth, and to estimate their antimicrobial efficiency and the plasma's impact on the enamel and dentine of the treated tooth surfaces. The results show that both positive streamer and negative Trichel pulse coronas can reduce bacterial population in the biofilm by up to 3 logs in a 10 min exposure time. This bactericidal effect can be reached faster (within 5 min) by electrostatic spraying of water through the discharge onto the treated tooth surface. Examination of the tooth surface after plasma exposure by infrared spectroscopy and scanning electron microscopy did not show any significant alteration in the tooth material composition or the tooth surface structures.

  6. A study about teeth extraction of irradiated patients by head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong Kack; Park, Hyung Kook [Korea Cancer Center Hospital, Seoul (Korea, Republic of)

    1996-12-01

    Radiation therapy, in addition to its therapeutic effects, cause several complications in oral region. As a result of radiation, the blood supply to bone is decreased, and large areas of hypocellular, hypovascular, hypoxic tissue are created that are devoid of functioning fibroblasts and osteobasts. Therefore, the extraction of teeth after irradiation to the jaws has generally been regarded as a potentially hazardous procedure because of the possible initiation of osteradionecrosis. Hyperbaric oxygen therapy appears to assist in salvaging irradiated tissue by tissue angioneogenesis in marginally viable tissue induced by high oxygen tissue level. Hyperbaric oxygen therapy is beneficial for patients at risk for the development of osteoradionecrosis, such as irradiated patients requiring tooth extraction. We obtained good results when extraction is performed with hyperbaric oxygen therapy in 17 cases with head and neck malignancy and present results with review of literatures. (author). 35 refs., 2 tabs.

  7. A study about teeth extraction of irradiated patients by head and neck cancer

    International Nuclear Information System (INIS)

    Radiation therapy, in addition to its therapeutic effects, cause several complications in oral region. As a result of radiation, the blood supply to bone is decreased, and large areas of hypocellular, hypovascular, hypoxic tissue are created that are devoid of functioning fibroblasts and osteobasts. Therefore, the extraction of teeth after irradiation to the jaws has generally been regarded as a potentially hazardous procedure because of the possible initiation of osteradionecrosis. Hyperbaric oxygen therapy appears to assist in salvaging irradiated tissue by tissue angioneogenesis in marginally viable tissue induced by high oxygen tissue level. Hyperbaric oxygen therapy is beneficial for patients at risk for the development of osteoradionecrosis, such as irradiated patients requiring tooth extraction. We obtained good results when extraction is performed with hyperbaric oxygen therapy in 17 cases with head and neck malignancy and present results with review of literatures. (author). 35 refs., 2 tabs

  8. Forensic quest for age determination of bloodstains.

    Science.gov (United States)

    Bremmer, Rolf H; de Bruin, Karla G; van Gemert, Martin J C; van Leeuwen, Ton G; Aalders, Maurice C G

    2012-03-10

    Bloodstains at crime scenes are among the most important types of evidence for forensic investigators. They can be used for DNA-profiling for verifying the suspect's identity or for pattern analysis in order to reconstruct the crime. However, until now, using bloodstains to determine the time elapsed since the crime was committed is still not possible. From a criminalistic point of view, an accurate estimation of when the crime was committed enables to verify witnesses' statements, limits the number of suspects and assesses alibis. Despite several attempts and exploration of many technologies during a century, no method has been materialized into forensic practice. This review gives an overview of an extensive search in scientific literature of techniques that address the quest for age determination of bloodstains. We found that most techniques are complementary to each other, in short as well as long term age determination. Techniques are compared concerning their sensitivity for short and long term ageing of bloodstains and concerning their possible applicability to be used on a crime scene. In addition, experimental challenges like substrate variation, interdonor variation and environmental influences are addressed. Comparison of these techniques contributes to our knowledge of the physics and biochemistry in an ageing bloodstain. Further improvement and incorporation of environmental factors are necessary to enable age determination of bloodstains to be acceptable in court. PMID:21868178

  9. Sensitivity of whole human teeth to fast neutrons and gamma-rays estimated by L-band EPR spectroscopy

    International Nuclear Information System (INIS)

    This paper reports the first attempt to use L-band spectroscopy for estimating the sensitivity of whole teeth to fast neutrons and gamma-rays. Three teeth were successively irradiated first with fast neutrons with a wide energy spectrum (mean energy around 30 MeV) up to ∼160 Gy and then with gamma-rays up to ∼14 Gy. After each irradiation, L-band (∼1 GHz) EPR spectra of each whole tooth surrounded by the surface-coil resonator were recorded, yielding a single composite line principally due to CO2- and native radicals. The sensitivities are estimated by the slopes of the linear dose response curves of the dosimetric CO2- radicals. The ratios of the gamma/neutron sensitivities were found to be in the range 8-9 (±2) for the three teeth

  10. Root and canal symmetry in the mandibular anterior teeth of patients attending a dental clinic: CBCT study

    Directory of Open Access Journals (Sweden)

    Guven KAYAOGLU

    2015-01-01

    Full Text Available The aims of this study were to evaluate the number of roots/root canals in the mandibular anterior teeth of a Turkish population, to assess the relationship between gender or age and the frequency of two canals in a single root, and to determine the symmetry in root/root canal numbers between contralateral sides among patients. Cone-beam computed tomography images (n = 1128; 6253 teeth taken at the Department of Dentomaxillofacial Radiology of the Faculty of Dentistry of Gazi University were examined by three observers and a supervisor, all of whom were blinded to patient gender and age. Axial, sagittal, and cross-sectional slices with a thickness of 1 mm were used. Numbers of roots and canals for each type of tooth were recorded. Most teeth had a single root and single root canal. Roots with two canals were more frequent in the incisors (14.9%, 17.2%, and 6.1% of the central incisors, lateral incisors, and canines, respectively. Teeth with two roots were more frequent in the canines (3.1%vs. 0% or 0.1%. Females more often had canines with double root canals (p < 0.001. When at least one tooth had two root canals, bilateral symmetry between contralateral teeth was found in 45.0%, 29.0%, and 28.0% of cases for central incisors, lateral incisors, and canines, respectively. Patients older than 56 years had fewer teeth with double root canals (p ≤ 0.001. A small proportion of the mandibular anterior teeth had two roots or root canals. Double root canals were mostly unilateral. Age and gender were associated with the number of root canals.

  11. Radiation load in determining bone age

    International Nuclear Information System (INIS)

    The determination of the bone age in children is based on X-ray of the left wrist. By means of the dosimetric device 'Robotron 2300' it is shown that the average surface dose for single X-ray is about 49.105 Gy. The execution of single X-ray is well-grounded and the conditions for it are specified: blending of the object and shielding of the gonads and the whole body with a lead rubber as well as immobilizing of the hand with a specially made appliance. The risk of radiation injury during the study is practically negligible. Having in mind the significance of the problems which could be solved using the results of such a study, the benefit/harm relationship is in favour of broader use of the method. 12 refs., 1tab. described

  12. The role of inducible Nitric Oxide Synthase in teeth periapical lesions immunopathogenesis caused by Enterococcus faecalis

    Directory of Open Access Journals (Sweden)

    Tamara Yuanita

    2013-03-01

    Full Text Available Background: Periapical lesions, are characterized by an immune response to the invading bacteria consequences periapical bone destruction. In root canal treatment failure was found Enterococcus faecalis (E. faecalis as most species. iNOS found an important role in protection against infection, plays vital roles in fighting pathogens and contributing to disease pathology. Purpose: This study was to observed the role of iNOS in teeth periapical lessions immunopathogenesis caused by E. faecalis. Methods: The randomized post-only control group design used in this study, This study used 24 Wistar rats, were divided into three groups (each group consisted of 8 rats, as negative controls group is a normal teeth, in the positive controls group was made by drilling the upper right first molar to penetrate the dental pulp and was induced with 10µl BHI-b then filled with Glass Ionomer Cement (GIC and the treatment group, after drilling the teeth, then inoculated with E. faecalis ATCC 29212 106 CFU into 10µl BHI-b then filled with GIC to prevent contamination. It takes 21 days to get periapical lesions and rat were sacrificed, and then the expression of iNOS was measured. Results: Statistical analysis using ANOVA found a significant differenced between control and treatment groups (p<0.05. Conclusion: This study concluded that iNOS role in teeth periapical lesions immunopathogenesis caused by E. faecalis.Latar belakang: Lesi periapikal merupakan hasil suatu respon imun untuk melawan invasi bakteri yang mengakibatkan destruksi tulang periapikal. Pada perawatan saluran akar yang mengalami kegagalan ditemukan Enterococcus faecalis sebagai spesies terbanyak. iNOS berperan penting untuk proteksi terhadap bakteri, mempunyai peran yang vital untuk melawan patogen dan berkonstribusi secara patologik untuk menyebabkan suatu penyakit. Tujuan: Penelitian ini bertujuan untuk mengobservasi peran iNOS secara imunohistokimia pada lesi periapikal tikus Wistar. Metode

  13. Comparison of Microleakage of Glass Ionomer Restoration in Primary Teeth Prepared by Er: YAG Laser and the Conventional Method

    OpenAIRE

    M. Ghandehari; G. Mighani; Shahabi, S.; Chiniforush, N.; Z. Shirmohammadi

    2012-01-01

    Objective: One of the main criteria in evaluating the restorative materials is the degree of microleakage. The aim of this study was to compare the microleakage of glass ionomer restored cavities prepared by Er:YAG laser or turbine and bur.Materials and Methods: Twenty extracted caries-free deciduous posterior teeth were selected for this study. The teeth were randomly divided into two groups for cavity preparation. Cavities in group one were prepared by high speed turbine and bur. In the sec...

  14. [Epidemiology of teeth hypersensitivity].

    Science.gov (United States)

    Lutskaia, I K; Zinovenko, O G; Kovalenko, I P

    2015-01-01

    A clinical examination of 98 patients aged 20 to 75 years was carried out to identifyclinical and epidemiological features of hard tooth tissueshypersensitivity. The survey found out what stimuli (cold, hot, sour, mechanical, chemical) cause the appearance of dental hyperesthesia. The detailed survey of the affected area aimed to determine the presence of dental caries, gingival recession, wedge-shaped defects, erosions, microcracks and chipped enamel, as well as wear of the tooth crown. Forty-threepatients of 98 (43.88%) had tooth sensitivity. Most affected age group was 25-34 years (33%). Among patients studied with hyperesthesia 86% complained of pain. It was establishedthat dental hyperesthesia most often causes an intense, but quickly passing pain response, wherein upon exposure of several types of stimuli. Teeth with high sensitivity showed signs of abrasion (74.1%), most often--on the vestibular surface (44.4%). Patients under 45 years had notable cracks and wedge-shaped defects. In patients 45 years and older cracks and increased abrasion of hard dental tissues was seen. PMID:26271696

  15. Development of a SPME-GC-MS method for the determination of volatile compounds in Shanxi aged vinegar and its analytical characterization by aroma wheel.

    Science.gov (United States)

    Zhu, Hong; Zhu, Jie; Wang, Lili; Li, Zaigui

    2016-01-01

    A solid-phase microextraction followed by gas chromatography-mass spectrometry method was developed to determine the volatile compounds in Shanxi aged vinegar. The optimal extraction conditions were: 50 °C for 20 min with a PDMS/DVB fiber. This analytical method was validated and showed satisfactory repeatability (0.5 %volatile compounds. According to the calculation of odor activity value, 19 volatile compounds were identified as aroma-active compounds. Among them, propanoic acid, acetic acid, trimethyl-oxazole, butanoic acid, acetoin, 3-methylbutanoic acid and furfural were the most powerful odorants. The aroma wheel of Shanxi aged vinegar showed that the classes of sensory descriptors are first fatty and roasty, next woody and nutty and minor fruity and floral. Principal component analysis enabled us to investigate dissimilarity/similarity of Shanxi aged vinegar sample of different raw material and ageing time. PMID:26787940

  16. Sterilization of Extracted Human Teeth.

    Science.gov (United States)

    Pantera, Eugene A., Jr.; Schuster, George S.

    1990-01-01

    At present, there is no specific recommendation for sterilization of extracted human teeth used in dental technique courses. The purpose of this study was to determine whether autoclaving would be effective in the sterilization of extracted teeth without compromising the characteristics that make their use in clinical simulations desirable. (MLW)

  17. Use of monoclonal antibodies in local passive immunization to prevent colonization of human teeth by Streptococcus mutans.

    OpenAIRE

    Ma, J K; Smith, R; Lehner, T.

    1987-01-01

    Local passive immunization with monoclonal antibodies (MAbs) raised against streptococcal antigen (SA) I/II protects monkeys against colonization of teeth by Streptococcus mutans and the subsequent development of dental caries. In this study we extended the preclinical experiments to human subjects. In the first study of eight healthy subjects, four had anti-SA I/II MAb (immunoglobulin G2a [IgG2a]) and four had saline applied to their teeth on three occasions. A streptomycin-resistant S. muta...

  18. Estimating Gear Teeth Stiffness

    OpenAIRE

    Pedersen, Niels Leergaard

    2013-01-01

    The estimation of gear stiffness is important for determining the load distribution between the gear teeth when two sets of teeth are in contact. Two factors have a major influence on the stiffness; firstly the boundary condition through the gear rim size included in the stiffness calculation and secondly the size of the contact. In the FE calculation the true gear tooth root profile is applied. The meshing stiffness’s of gears are highly non-linear, it is however found that the stiffness of ...

  19. Aesthetic treatment on anterior teeth crown fracture caused by dental trauma

    OpenAIRE

    Nanik Zubaidah

    2012-01-01

    Background: Complicated crown fracture is a tooth fracture that involve enamel, dentine and pulp. The incidence of complicated crown fracture ranges from 2% to 13% of all dental injuries and the most commonly involved teeth are the maxillary central incisors. Various treatment modalities are available depending on the clinical, physiological and radiographic examination of the involved teeth. Purpose: The aim of this case report is to present the management of crown fractures with pulpal expo...

  20. Periapical and endodontic status of permanent teeth in patients with hypophosphatemic rickets

    DEFF Research Database (Denmark)

    Andersen, Mette Guldbæk; Beck-Nielsen, Signe; Haubek, Dorte;

    2012-01-01

    genetically. The aim of the present study was to describe the periapical and endodontic status of permanent teeth in patients with genetically and/or biochemically confirmed HR. The patients were recruited from a medical study on HR patients. The patients underwent a dental examination including a digital...... panoramic radiograph, which was scored for endodontically affected teeth (i.e. teeth with periapical radiolucencies and/or endodontically treated teeth). A total of 52 patients (age range: 5·7-74·5 years; 17 males and 35 females) were included. HR patients were characterised by a high number of...... endodontically affected teeth (mean: 4·2; s.d.: 5·0). The number of affected teeth rose significantly with age (P ...

  1. Analyzer of Spectra for Age Determination (ASAD) - Algorithm and Applications

    CERN Document Server

    Asa'd, Randa

    2014-01-01

    Analyzer of Spectra for Age Determination (ASAD) is a new package that can easily predict the age and reddening of stellar clusters from their observed optical integrated spectra by comparing them to synthesis model spectra. The ages obtained with ASAD are consistent with ages obtained from previous cluster age methods requiring a more rigorous and time-consuming analysis. This package not only provides fast results, but also allows the user to comprehend the accuracy of these results by providing surface plots and spectral plots for all combinations of observations and models. ASAD is available for download on the Web and can be immediately used on both Mac and Windows.

  2. Simultaneous in-situ determination of U-Pb age and trace elements in zircon by LA-ICP-MS in 20 μm spot size

    Institute of Scientific and Technical Information of China (English)

    LIU XiaoMing; GAO Shan; DIWU ChunRong; YUAN HongLin; HU ZhaoChu

    2007-01-01

    Simultaneous in-situ determination of U-Pb agea and 20 trace elements of three international zircon standards (91500, GJ1 and TEMORA 1) and one laboratory zircon standard (SK10-2) separated from Cenozoic fine-grained gabbro was carried out on quadrupole ICP-MS equipped with 193 nm excimer laser in 20 μm spot size. The weighted mean 208Pb/238U ages of g1500, GJ1 and TEMORA 1 are 1064.4±4.8 Ma (2σ), 603.2±2.4 Ma (2σ) and 418.2±2.4 Ma (2σ), respectively. The relative standard deviations (RSDs) of 206Pb/238U ages (2σ) are less than 2.2% for single measurements and 0.6% for weighted means. The obtained weighted mean 206Pb/238U ages of three atandard zircons agree with the recommended values within 2σσerror. The weighted mean 206Pb/238U age of SK10-2 is 31.42±0.25 Ma (2σ)and the RSDs of 206Pb/238U ages (2σ) are between 2.4% and 5.7% for single measurements and less than 0.8% for weighted mean. The obtained weighted mean 206Pb/238U age is in good agreement with the age obtained by Yuan (2004). Trace element concentrations of NIST612 and NIST614 obtained under the same LA-ICP-MS operating conditions agree with the recommended values within analytical error. The results indicate that it is possible to measure U-Pb age and trace elements aimultaneously by LA-ICP-MS in a small spot size of 20 μm.

  3. Lead and cadmium in human teeth from Jordan by atomic absorption spectrometry: Some factors influencing their concentrations

    International Nuclear Information System (INIS)

    The aim of this study was to measure the concentrations of lead (Pb) and cadmium (Cd) in human teeth and to investigate the affecting factors. Teeth samples (n = 268) were collected from people living in different cities in Jordan including Amman, Zarqa, Al-Mafraq and Irbid and analyzed for Pb and Cd using atomic absorption spectrometry (AAS). A questionnaire was used to gather information on each person, such as age, sex, place where the patient lives, smoking, presence of amalgam fillings inside the mouth, and whether the patient uses toothpaste or not. The mean concentrations of Pb and Cd were 28.91 μg/g and 0.44 μg/g, respectively. The results indicate that there is a clear relation between Pb and Cd concentrations and the presence of amalgam fillings, smoking, and place of living. Pb was sex-dependent, whereas Cd was not. Our results show that Pb and Cd concentrations in samples obtained from Al-Mafraq and Irbid are higher than those obtained from Amman and Zarqa. Pb was highest in Mafraq, whereas Cd was highest in Irbid. The Pb and Cd concentrations in teeth from smokers (means: Pb = 31.89 μg/g, Cd = 0.49 μg/g) were significantly higher than those from nonsmokers (means: Pb = 24.07 μg/g, Cd = 0.37 μg/g). Pb and Cd concentrations in teeth of patients with amalgam fillings (means: Pb = 31.02 μg/g and Cd = 0.52 μg/g) were significantly higher than those from patients without amalgam fillings (means: Pb = 26.87 μg/g and Cd = 0.41 μg/g). Our results show that brushing the teeth daily with toothpaste does not significantly decrease the concentration of both Pb and Cd. The mean concentrations of Pb and Cd do not vary significantly between the ages 20-30, 31-40, and 41-50, but both increased rapidly at age 51-60

  4. [The elemental composition of teeth hard tissues depending on the state of the environment].

    Science.gov (United States)

    Suladze, N; Shishniashvili, T; Margvelashvili, V; Kobakhidze, K

    2014-01-01

    At present, great attention is paid to the origin of man-made micro elemental anomalies. To monitor the state of the environment and its effects on the human body, of great importance is the determination of the amount and distribution of various chemical elements in the dentin and enamel of the teeth. To determine the essential (Ca, Zn, Mn, Ni), conditionally essential (Rb, Ni, Sr) and toxic (Pb, Hg) trace elements in the mineralized tissues of the teeth and to identify the relationship between the elemental composition of the tooth structure and the state of the general and dental health depending on the state of the environment, we have examined 29 children aged 3-4 years who have carried out analysis of hard tissue of teeth (teeth used for remote medical reasons) for the maintenance of nine chemical elements. Children living in a relatively environmentally favorable conditions essential value and conditionally essential elements in the mineralized tissues of the teeth were within normal limits, and toxic elements slightly increased limits that differ from those of children living in environmentally disadvantaged areas. In particular, these essential elements were significantly reduced (except for zinc), as indicators of toxic elements - mercury and lead, increased by 12.5% and 44.5%, respectively, which is clearly reflected on the state of dental health because noted decompensated form of tooth decay. Thus, deviations in a state of general and dental health of children associated with an imbalance of macro-and microelements in the mineralized tissues of the teeth. PMID:24523324

  5. The Correlation between Different Facial Measurements and the Width of Maxillary Anterior Teeth

    Directory of Open Access Journals (Sweden)

    Hassan Ahangari A.

    2011-08-01

    Full Text Available Statement of Problem: One of the most important procedures in the rehabilitation of an edentulous space in the anterior segment is the selection of an appropriate size of the anterior teeth in order to achieve the perfect esthetic results.Purpose: The purpose of this study was to examine the correlation between horizontal measurements of the face and width of the maxillary anterior teeth.Material and methods: In this descriptive-analytical and cross-sectional study, the face and teeth of the 77 subjects (39 women and 38 men aged between 20-30 with no facial and dental deformities were examined. Some horizontal dimensions of the face including IC (intercanthal, IP (interpupillary, BZW (bizygomatic width, IA (interalar, and ICm (Intercomussural width and perceived width of the teeth were calculated with AutoCAD software with 0.1 mm accuracy on the photos. The actual width of the teeth was calculated with a digital caliper by 0.1 mm accuracy on the maxillary casts. The data were analyzed in SPSS software using the Pearson correlation coefficient and t-test.Results: Except for the IC and the sum of the actual width of the six maxillary anterior teeth on the cast, the rest of the measurements were significantly different by gender ( p < 0.05. All the correlations between facial measurements and width of the teeth were bigger than when they were separated by gender. In women, the correlation between IC and the six anterior teeth in the front view (SANTF was the highest one ( r = 0.436, p = 0.005. However, the highest correlation was related to the ICm and SANTF in men. (r = 0.0501, p =0.001Conclusion: Within the limitation of this study, the results suggest that except for the BZW, the rest of the facial measurements including IC, IP, IA and ICm can be used as a preliminary criterion for determining the width of the maxillary anterior teeth of the edentulous patients.

  6. Age determination using ultrasonography in young football players

    Directory of Open Access Journals (Sweden)

    Mehdi Karami

    2014-01-01

    Full Text Available Background: Increasing of age cheating in sports makes problems to athletes comparable to taking illegal substances. Current method used by AFC and FIFA is applying MRI of growth plate of distal of radius to determine the bone age. This study was designed to evaluate the diagnostic accuracy of ultrasonography in bone age determination by measuring the width of growth plate in distal of radius, and comparing it with identity documents. Materials and Methods: The study was conducted from September to December 2009 in the Department of Radiology at Al-Zahra University Hospital, Isfahan, Iran. Ultrasonography was done for 82 (15-20 years old young professional football players and results were compared with identity documents (such as National ID card. Young football players were divided into three age categories: 16 years old, 17 years old, and 18 years old. Receiver Operator Characteristics (ROC curves for discriminant values and sensitivity and specificity were analyzed. Results: Cut-off point was set for each group, based on the width of the growth plate, and negative test was defined as subjects < cut-off point, showing subjects over the defined age in each group. ROC curve analysis demonstrates consistently acceptable diagnostic sensitivity and specificity values in age determination of each group. Conclusions: The overall predictive accuracy of ultrasonography, as described by the area under the ROC curve, was high for determination of bone age. It has an acceptable sensitivity and specificity to use for determination of age in sport competitions, and has the capability to become the screening test for age determination, especially because it is inexpensive and without any risk of radiation. It seems to be comparable with MRI in age determination.

  7. Evaluation of Endodontic Treatment Failure of Teeth With Periapical Radiolucent Areas and Factors Affecting It

    Directory of Open Access Journals (Sweden)

    S. Khedmat

    2004-06-01

    Full Text Available Statement of Problem: Failure of endodontic treatment is determined on the basis of radiographic findings and clinical signs and/ or symptoms of the treated teeth.Purpose: The purpose of this study was to determine endodontic treatment failure in relation to various factors influencing it in teeth with periapical lesions (clinically and radiographically.Materials and Methods: Teeth which had periapical lesions before treatment were selected from a series of teeth treated by endodontics’ postgraduate students over 5-year period (1997-2001 in Faculty of Dentistry Tehran university of Medical Science.post operative follow up in 50 patients was possible .The patient’s ages ranged between 16 to 62 years old. 40 of patients were female and 10 were male. At the recall appointment,first the clinical information (pain, swelling, tenderness to palpation, percussion, … were recorded in a questionnaire form, then two radiographies were obtained from each tooth.The radiographies were assessed separately by three to five endodontists. Strindberg's criteria were used to Judge the failure of endodontic treatment. The observation periodranged from 1 to 5 years. The Data were analyzed statistically by using chi-square, Fisher’s exact test and MC Nemar test.Results: Among different factors considered in this study, Fistula and sensation to percussion were reduced significantly (MC Nemar test, P=0.004. There were no significant difference between the extention of root canal filling, age and type of coronal restorationand endodontic failure which may be due to the small sample size of this study.Conclusion: The rate of endodontic failure was 16%, which means 84% success rate,which is similar to results obtained from previous studies. The high success rate of endodontic treatment in teeth with periapical lesion may be explained by the fact that obturation has a definitive effect on reducing inflammation in periradicular area.

  8. Removal of black stains from teeth by photodynamic therapy: clinical and microbiological analysis.

    Science.gov (United States)

    Pessoa, Larissa; Galvão, Virgilio; Damante, Carla; Sant'Ana, Adriana Campos Passanezi

    2015-01-01

    Black-pigmented bacteria (BPB) are Gram-negative anaerobic, non-motile, proteolytic rods strongly implicated in the pathogenesis of periodontal disease. Although pigments are produced in vitro, black pigmentation is rarely found clinically. However, it may compromise aesthetics and contribute to gingival inflammation. The aim of this report is to describe a clinical case of a 10-year-old boy showing black pigmentation covering all teeth and to propose an alternative therapy for removal of black pigmentation, based on photodynamic therapy (PDT). In order to perform microbiological analysis, plaque samples were collected before and after PDT, and analysed by real-time-PCR (RT-PCR). The results showed a significant reduction in BPB levels after therapy, along with clinical evidence of absence of black pigmentation and reduction in gingival bleeding, although the plaque index remained unaltered. This case showed that PDT is effective for eliminating black pigmentation caused by BPB, without recurrence during a follow-up period of 7 months. PMID:26701991

  9. [Treatment of ankylosed teeth by segmental corticotomy: the Orthodontic Bone Stretching technique. Preliminary study].

    Science.gov (United States)

    Bousquet, Philippe; Artz, Christèle; Canal, Pierre

    2013-12-01

    Ankylosed anterior teeth are associated with infraclusion and can lead to a concomitant significant esthetic defect. After a review of the techniques used move these teeth into the arch, this article describes a new technique to restore occlusion and improve esthetics, or to prepare the case for either a prosthetic or implant treatment, Orthodontic Bone Stretching (OBS). This technic combines partial corticotomy and orthodontic treatment and produces bone stretching. After 8 to 12 weeks of force application, the ankylosed teeth are repositioned into occlusion or, if extraction is necessary, the bone crest is at a level consistent with a prosthetic or implant treatment. OBS technique can be adapted to implant infraclusion, or the vertical regeneration of atrophied ridge. PMID:24280548

  10. DNA isolation from teeth by organic extraction and identification of sex of the individual by analyzing the AMEL gene marker using PCR

    Directory of Open Access Journals (Sweden)

    Subramanian Thangaraj Praveen Kumar

    2016-01-01

    Full Text Available Background: To identify the sex of the deceased individual from dental hard tissue such as enamel and dentine. Objective: To isolate the DNA from dental hard tissue (enamel and dentin from teeth extracted for prophylactic purpose, to assess the quality and purity of DNA and to identify the sex using polymerized chain reactor (PCR. Materials and Methods: DNA was extracted following phenol/chloroform (organic extraction from 20 male and 20 female teeth. The samples that contain the amelogenin gene (amel were amplified by PCR. The products of the PCR were run on agarose gel with ethidium bromide staining on gel documentation system. Results: The results on the gel showed the presence of X-specific bands at 212 bp and Y-specific bands at 218 bp. Males were distinguished from females by the presence of two bands whereas female samples showed only one, that is, X-specific band on the gel. The gender from the known samples was determined with complete accuracy, and the results were analyzed statistically by the Chi-square test. Conclusion: In our study, the PCR-based method showed 100% specificity and sensitivity.

  11. In vitro evaluation of microleakage in restored teeth with synthetic resins by neutrongraphy

    International Nuclear Information System (INIS)

    The goal of the present study was to evaluate, using neutron graphic images, microleakage in teeth that were treated with resins. Teeth samples were drilled, producing wells with similar dimensions in each tooth. Afterwards, they were thoroughly filled with different resins to avoid voids. In preliminary tests, four different resins were used, and after submitted to neutron radiography their images were analyzed. The results of this trial showed good adherent for all the resins used, and since no micro leakage were seen on the images, the restoration procedure was successfully. (author)

  12. In vitro evaluation of microleakage in restored teeth with synthetic resins by neutrongraphy

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, A.L.N.; Crispim, V.R., E-mail: abarbosa@ien.gov.b, E-mail: verginia@con.ufrj.b [Universidade Federal do Rio de Janeiro (PEN/COPPE/UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia. Programa de Engenharia Nuclear

    2011-07-01

    The goal of the present study was to evaluate, using neutron graphic images, microleakage in teeth that were treated with resins. Teeth samples were drilled, producing wells with similar dimensions in each tooth. Afterwards, they were thoroughly filled with different resins to avoid voids. In preliminary tests, four different resins were used, and after submitted to neutron radiography their images were analyzed. The results of this trial showed good adherent for all the resins used, and since no micro leakage were seen on the images, the restoration procedure was successfully. (author)

  13. Foetal age determination and development in elephants.

    Science.gov (United States)

    Hildebrandt, Thomas; Drews, Barbara; Gaeth, Ann P; Goeritz, Frank; Hermes, Robert; Schmitt, Dennis; Gray, Charlie; Rich, Peter; Streich, Wolf Juergen; Short, Roger V; Renfree, Marilyn B

    2007-02-01

    Elephants have the longest pregnancy of all mammals, with an average gestation of around 660 days, so their embryonic and foetal development have always been of special interest. Hitherto, it has only been possible to estimate foetal ages from theoretical calculations based on foetal mass. The recent development of sophisticated ultrasound procedures for elephants has now made it possible to monitor the growth and development of foetuses of known gestational age conceived in captivity from natural matings or artificial insemination. We have studied the early stages of pregnancy in 10 captive Asian and 9 African elephants by transrectal ultrasound. Measurements of foetal crown-rump lengths have provided the first accurate growth curves, which differ significantly from the previous theoretical estimates based on the cube root of foetal mass. We have used these to age 22 African elephant foetuses collected during culling operations. Pregnancy can be first recognized ultrasonographically by day 50, the presumptive yolk sac by about day 75 and the zonary placenta by about day 85. The trunk is first recognizable by days 85-90 and is distinct by day 104, while the first heartbeats are evident from around day 80. By combining ultrasonography and morphology, we have been able to produce the first reliable criteria for estimating gestational age and ontological development of Asian and African elephant foetuses during the first third of gestation. PMID:17164195

  14. Teeth Injuries (For Parents)

    Science.gov (United States)

    ... Things to Know About Zika & Pregnancy First Aid: Teeth Injuries KidsHealth > For Parents > First Aid: Teeth Injuries ... or young child injures the gums or baby teeth: Apply pressure to the area (if it's bleeding) ...

  15. Fracture resistance of endodontically treated teeth restored by different FRC posts: An in vitro study

    Directory of Open Access Journals (Sweden)

    Torabi Kianoosh

    2009-01-01

    Full Text Available Background: Posts and cores are often required for restoration of pulpless teeth and to provide retention and resistance for a complete crown, but conventional posts may increase the root fracture. Objective: This study was performed to compare the root fracture resistance of extracted teeth treated with different fibers reinforced with composite posts and treated teeth with conventional post and core systems. Materials and Methods: Root canal therapy was performed for 50 mandibular first premolars. The coronal portion of each tooth was amputated, and five post and core systems (cast, polyethylene woven, glass, carbon, and quartz fiber posts were compared. Acrylic resin blocks were used for mounting, using a layer of elastomeric impression material covering the roots. The load was applied axially and measured with a universal testing machine. Results and Conclusion: Significantly, cast posts and cores had a higher failure threshold including teeth fracture; whereas, fiber posts failure was due to core fracture, with or without fractures in coronal portion of posts. Difference in FRC posts did not provide any significant difference in the load failure and the mode of fracture.

  16. Biological psychological and social determinants of old age: Bio-psycho-social aspects of human aging

    Directory of Open Access Journals (Sweden)

    Małgorzata Dziechciaż

    2014-11-01

    Full Text Available Biological psychological and social determinants of old age: Bio-psycho-social aspects of human aging. The aging of humans is a physiological and dynamic process ongoing with time. In accordance with most gerontologists’ assertions it starts in the fourth decade of life and leads to death. The process of human aging is complex and individualized, occurs in the biological, psychological and social sphere. Biological aging is characterized by progressive age-changes in metabolism and physicochemical properties of cells, leading to impaired self-regulation, regeneration, and to structural changes and functional tissues and organs. It is a natural and irreversible process which can run as successful aging, typical or pathological. Biological changes that occur with age in the human body affect mood, attitude to the environment, physical condition and social activity, and designate the place of seniors in the family and society. Psychical ageing refers to human awareness and his adaptability to the ageing process. Among adaptation attitudes we can differentiate: constructive, dependence, hostile towards others and towards self attitudes. With progressed age, difficulties with adjustment to the new situation are increasing, adverse changes in the cognitive and intellectual sphere take place, perception process involutes, perceived sensations and information received is lowered, and thinking processes change. Social ageing is limited to the role of an old person is culturally conditioned and may change as customs change. Social ageing refers to how a human being perceives the ageing process and how society sees it.

  17. Contemporary methods for determining root canal working length in primary teeth: digital radiography and electronic apex locators

    OpenAIRE

    Zeren, Ali Emre; Sarı, Şaziye

    2014-01-01

    With developing technology, in endodontics, like in other fields of dentistry, different approaches are introduced as means for improving success, efficacy and comfort of treatment. In pedodontics, a branch of dentistry where patient compliance and treatment periods are crucial, the new treatment approaches help dentists perform more efficient and faster. Currently, digital radiography and apex locators are widely used in the root canal treatment of permanent teeth. The aim of this review was...

  18. Determining optimum aging time using novel core flooding equipment

    DEFF Research Database (Denmark)

    Ahkami, Mehrdad; Chakravarty, Krishna Hara; Xiarchos, Ioannis;

    2016-01-01

    New methods for enhanced oil recovery are typically developed using core flooding techniques. Establishing reservoir conditions is essential before the experimental campaign commences. The realistic oil-rock wettability can be obtained through optimum aging of the core. Aging time is affected by...... optimum aging time regardless of variations in crude oil, rock, and brine properties. State of the art core flooding equipment has been developed that can be used for consistently determining the resistivity of the coreplug during aging and waterflooding using advanced data acquisition software. In the...

  19. Immunohistological Evaluation of Revascularized Immature Permanent Necrotic Teeth Treated by Platelet-Rich Plasma: An Animal Investigation

    Directory of Open Access Journals (Sweden)

    Saeed Moradi

    2016-09-01

    Full Text Available Objective: Pulp regeneration within the root canal of necrotic teeth is considered an ideal treatment to allow for continued root development and recover teeth vitality. This study aims to evaluate the inductive effect of platelet-rich plasma (PRP on expression of angiogenesis factors and pulpal revascularization of immature necrotic teeth. Materials and Methods: In this experimental animal study, we randomly divided 28 immature premolars from two mixed breed dogs into four groups, two experimental, negative and a positive control. Premolars in negative control group were left intact to develop normally. In the positive control and experimental groups, we removed the pulps and induced pulp necrosis, after which the chambers were sealed. Then, we applied the revascularization protocol in the experimental teeth located in the right quadrant. Two months later, the same protocol was applied to the left quadrant. The root canals were disinfected by irrigation with sodium hypochlorite (NaOCl solution and application a triple antibiotic past. Following the induction of a blood clot (BC inside the canal space, the coronal portion of the canals was assigned to either of two experimental groups: group 1 [BC+PRP+ mineral trioxide aggregate (MTA], group 2 (BC+MTA. Access cavities were sealed with a Glass Ionomer. The jaws that held the teeth were processed for histologic analysis of newly formed tissue and immunohistochemical evaluation according to vascular endothelial growth factor (VEGF and factor VIII expressions in the canals. Results: Histological analysis demonstrated no significant difference in the formation of new vital tissue inside the root canals between groups1 (42.8% and 2 (43.5%, P>0.05. Based on immunohistochemical evaluation, micro-vessel density (MVD of the granulation tissues in both groups were similar and were higher compared with the normal pulp. We observed strongly positive expressions of VEGF and factor VIII in the stromal and

  20. Determination of the seric levels of follicle-stimulating hormone, lutein hormone and testosterone in Nellore bovine at different ages, by means of radioimmunoanalysis

    International Nuclear Information System (INIS)

    One hundred male bovines, Nellore breed, coming from the region of Botucatu, State of Sao Paulo, Brazil, were in this research. The animals were distributed into five groups, according to their average age, as follows: 6.25, 9.50, 20.3, 29.7 and 61.1 months, and raised under range conditions. Blood samples were collected from the jugular vein, two and half to three hours after semen collection. Harmone concentrations were determined by radioimmunoassay (RIA). The mean values for the biochemical tests carried out with the serum samples were: 4.70+-1.15 mUI/ml, CV= 24.4% for FSH; 4.98+-0.99 mUI/ml, CV= 19.86% for LH, and 2.78+-3.68ng/ml, CV= 132.48% for testosterone. The analysis of variance showed significant effect (P<0.05) of the age grade on the traits studied. (author)

  1. In vitro inhibition of bacteria from root canals of primary teeth by various dental materials.

    Science.gov (United States)

    Tchaou, W S; Turng, B F; Minah, G E; Coll, J A

    1995-01-01

    The primary tooth pulpectomy is a common clinical procedure. The choice of filling material is important to the success rate, but antibacterial properties of such materials against organisms known to inhabit infected primary root canals have not been well documented. This study compared the antibacterial effectiveness of 10 materials: 1. Calcium hydroxide mixed with camphorated parachlorophenol (Ca(OH)2+CPC) 2. Calcium hydroxide mixed with sterile water (Ca(OH)2+H2O) 3. Zinc oxide mixed with CPC (ZnO+CPC) 4. Zinc oxide mixed with eugenol (ZOE) 5. ZOE mixed with formocresol (ZOE+FC) 6. Zinc oxide mixed with sterile water (ZnO+H2O) 7. ZOE mixed with chlorhexidine dihydrochloride (ZOE+CHX) 8. Kri paste 9. Vitapex paste 10. Vaseline (control) These materials were compared against microbial specimens obtained from 13 infected primary teeth by using an agar diffusion assay. The results suggest that the materials could be divided into three categories. Category I, with the strongest antibacterial effect included ZnO+CPC, Ca(OH)2+CPC, and ZOE+FC. Category II, with a medium antibacterial effect included ZOE+CHX, Kri, ZOE, and ZnO+H2O. Category III, with no or minimal antibacterial effect included Vitapex, Ca(OH)2+H2O, and Vaseline. There were no significant differences within each category, but there were significant differences between the categories. The one exception was the antibacterial effect of ZOE+FC which was not significantly different from ZOE+CHX, Kri, or ZOE. PMID:8524684

  2. Discrimination of human bodies from bones and teeth remains by Laser Induced Breakdown Spectroscopy and Neural Networks

    Energy Technology Data Exchange (ETDEWEB)

    Moncayo, S.; Manzoor, S.; Ugidos, T.; Navarro-Villoslada, F.; Caceres, J.O., E-mail: jcaceres@ucm.es

    2014-11-01

    A fast and minimally destructive method based on Laser Induced Breakdown Spectroscopy (LIBS) and Neural Networks (NN) has been developed and applied to the classification and discrimination of human bones and teeth fragments. The methodology can be useful in Disaster Victim Identification (DVI) tasks. The elemental compositions of bone and teeth samples provided enough information to achieve a correct discrimination and reassembling of different human remains. Individuals were classified with spectral correlation higher than 95%, regardless of the type of bone or tooth sample analyzed. No false positive or false negative was observed, demonstrating the high robustness and accuracy of the proposed methodology. - Highlights: • Classification and discrimination of human remains have been studied. • Remains were analyzed by Laser Induced Breakdown Spectroscopy (LIBS). • Neural Networks models (NN) were used. • Individuals were classified with spectral correlation higher than 95 %. • LIBS-NN showed the potential for rapid and cost-effective analysis.

  3. Discrimination of human bodies from bones and teeth remains by Laser Induced Breakdown Spectroscopy and Neural Networks

    International Nuclear Information System (INIS)

    A fast and minimally destructive method based on Laser Induced Breakdown Spectroscopy (LIBS) and Neural Networks (NN) has been developed and applied to the classification and discrimination of human bones and teeth fragments. The methodology can be useful in Disaster Victim Identification (DVI) tasks. The elemental compositions of bone and teeth samples provided enough information to achieve a correct discrimination and reassembling of different human remains. Individuals were classified with spectral correlation higher than 95%, regardless of the type of bone or tooth sample analyzed. No false positive or false negative was observed, demonstrating the high robustness and accuracy of the proposed methodology. - Highlights: • Classification and discrimination of human remains have been studied. • Remains were analyzed by Laser Induced Breakdown Spectroscopy (LIBS). • Neural Networks models (NN) were used. • Individuals were classified with spectral correlation higher than 95 %. • LIBS-NN showed the potential for rapid and cost-effective analysis

  4. Automated Determination of Bone Age in a Modern Chinese Population

    International Nuclear Information System (INIS)

    Rationale and Objective. Large studies have previously been performed to set up a Chinese bone age reference, but it has been difficult to compare the maturation of Chinese children with populations elsewhere due to the potential variability between raters in different parts of the world. We re-analysed the radiographs from a large study of normal Chinese children using an automated bone age rating method to establish a Chinese bone age reference, and to compare the tempo of maturation in the Chinese with other populations. Materials and Methods. X-rays from 2883 boys and 3143 girls aged 2–20 years from five Chinese cities, taken in 2005, were evaluated using the BoneXpert automated method. Results. Chinese children reached full maturity at the same age as previously studied Asian children from Los Angeles, but 0.6 years earlier than Caucasian children in Los Angeles. The Greulich-Pyle bone age method was adapted to the Chinese population creating a new bone age scale BX-China05. The standard deviation between BX-China05 and chronologic age was 1.01 years in boys aged 8–14, and 1.08 years in girls aged 7–12. Conclusion. By eliminating rater variability, the automated method provides a reliable and efficient standard for bone age determination in China

  5. Age of Cu-Au mineralisation, Cloncurry district, eastern Mt Isa Inlier, Queensland, as determined by 40Ar/39Ar dating

    International Nuclear Information System (INIS)

    The 40Ar/39Ar dating of alteration biotite. muscovite and amphibole from a number of post-peak metamorphic Cu-Au deposits and alteration systems in the Cloncurry district. north Queensland has determined the timing of mineralisation and hydrothermal activity. Alteration biotite from the Ernest Henry Cu-Au, Starra Au-Cu, and Mt Elliott Cu-Au deposits, sericite associated with hematite breccias in the Wimberu Granite, muscovite from an albitite pipe that intrudes the Gilded Rose Breccia. And sericite from a granitoid near the Osborne Cu-Au deposit. yield ages which are broadly contemporaneous with the late ca 1510-1485 Ma phases of the Williams and Naraku Batholiths. Hornblende and biotite alteration, which pre-date Cu-Au mineralisation at Osborne. give a maximum age of ca 1540 Ma for the deposit. which is also a probable minimum age for peak metamorphism. Metamorphic minerals from the vicinity of Osborne yield dates which are significantly older (ca 1590-1570 Ma) than those from the hydrothermal phases. Dating by the K-Ar method of red. Hematitic K-feldspars which are regionally common in the Cloncurry district was not effective as the mineral yields ages up to 300 million years younger than coexisting alteration sericite. The 40Ar/39Ar age spectra obtained from most hydrothermal phases in the Eastern Fold Belt. Mt Isa Inlier commonly contain flat parts which comprise a large proportion of the released gas and are indicative of rapid cooling through the temperature of partial closure to Ar diffusion for the respective minerals. Copyright (1998) Blackwell Science Asia

  6. Isotopic age determinations in Bergslagen, Sweden. IV

    International Nuclear Information System (INIS)

    Rb-Sr whole-rock isotope analyses of ten samples of Graengen granite yield a best-fit line corresponding to an age of 1663 +- 51 Ma with an initial 87Sr/86Sr ratio of 0.70844 +- 0.00578. Four samples of Tallaasberget granite give a best-fit line corresponding to an age of 1639 +- 185 Ma with an initial 87Sr/86Sr ratio of 0.70191 +- 0.04241. Isochron relationships appear disturbed by the low-grade retrograde metamorphism which has affected the granites. Taking account of the limits of error it is suggested that the Graengen and Tallaasberget granites in the Hjulsjoe region, Bergslagen, Central Sweden, are coeval with the 1.7-1.6 Ga granites of the Smaaland and Vaermland Groups in S and SW Sweden. (Auth.)

  7. A computer aided design procedure for generating gear teeth

    Science.gov (United States)

    Chang, S. H.; Huston, R. L.; Coy, J. J.

    1984-01-01

    A procedure for computer aided design (CAD) of gear teeth is presented. It is developed for generated teeth fabricated by a hob cutter or a shaper. It provides a means for analytically and numerically determining the tooth profile, given the cutter profile. An illustrative example with involute tooth profiles is given. Application with non-standard profiles and with bevel, spiral bevel, and hypoid gears is discussed.

  8. Teething and nutritional condition in children between 5 and 13 years.

    Directory of Open Access Journals (Sweden)

    Clotilde de la Caridad Mora Pérez

    2009-04-01

    Full Text Available Background: During last decades it has become increasingly evident the importance of nutritional factors in the development and renovation of buccal tissues, particularly of teeth. Objective: To characterize permanent teething and its relation with nutritional factors in children between 5 and 13 years. Methods: Cross-sectional descriptive, observational study developed in a universe formed by 1003 children of Health Area II in Cienfuegos, out of which a sample of 330 children was selected. Data was collected from schools, regarding the teething age and nutritional status. Ponder and measurements were carried out. Results: The average teething age was lower for girls in both maxillary bones; teething sequence was 6,1,2,4,5,3,7 for the maxilla and 6,1,2,3,4,5,7 for the inferior maxillary bone. There was a prevalence of normal weight among girls, followed by thin and undernourished values. Among boy, there was a prevalence of obesity, overweight and normal weight in that order. Nutritional statuses of thin and undernourished were related with a delayed teething, mainly in the inferior maxillary bone. Permanent teething was delayed with regard to the national media. Conclusion: A clear relation was established between teething age and nutrition, mainly among thin and undernourished children.

  9. Multiple Impacted Teeth: Report of 3 Cases

    OpenAIRE

    Bayar, Gürkan Raşit; Ortakoḡlu, Kerim; Sencimen, Metin

    2008-01-01

    While impaction of tooth is widespread, multiple impacted teeth by itself is a rare condition and often found in association with syndromes such as cleidocranial dysplasia or Gardner’s syndrome. A light of radiographic examination, we describe three Turkish young males with multiple impacted teeth who didn’t possess any systemic conditions or syndromes involving both jaws. The first patient, a 21-year-old young male, had 16 unerupted teeth and 5 unerupted supernumerary teeth. The second patie...

  10. What determines hatchling weight: breeder age or incubated egg weight?

    OpenAIRE

    AB Traldi; Menten JFM; CS Silva; PV Rizzo; PWZ Pereira; J Santarosa

    2011-01-01

    Two experiments were carried out to determine which factor influences weight at hatch of broiler chicks: breeder age or incubated egg weight. In Experiment 1, 2340 eggs produced by 29- and 55-week-old Ross® broiler breeders were incubated. The eggs selected for incubation weighed one standard deviation below and above average egg weight. In Experiment 2, 2160 eggs weighing 62 g produced by breeders of both ages were incubated. In both experiments, 50 additional eggs within the weight interval...

  11. Determination of hydrogen concentration in a-Si and a-Ge layers by elastic recoil detection analysis

    OpenAIRE

    Kh?nh, Nguyen Quoc; Csik, Attila; Serenyi, Miklos; Erd?lyi, Zolt?n; Beke, Dezső L?szl?; Frigeri, Cesare

    2010-01-01

    Hydrogenated amorphous Si and Ge films are of current interest in academic and industrial research due to their unique physical properties and important applications. The passivation of dangling-bonds leads to a significant improvement in the electronic properties by adding hydrogen into these layers. The hydrogen content in these layers is also an important factor deciding the density and the optical band gap. However, hydrogen is also suspected to degrade the performance of amorphous Si and...

  12. Combination esthetic treatment of anterior teeth affected by idiopathic enamel hypoplasia: a case report.

    Science.gov (United States)

    Roberts, Donald L; Warner, Ben F; Bentley, Dan A; Quock, Ryan L

    2016-01-01

    The esthetic management of enamel dysplasia presents an opportunity for the practitioner to integrate expertise in diagnosis, biomaterials, and technique. In addition to considerations of appearance, careful attention must be paid to occlusal function and restorative material properties. This case report highlights a combined approach of conservative lithium disilicate indirect restorations and composite resin direct veneers to electively restore the anterior teeth of a patient diagnosed with idiopathic enamel hypoplasia. PMID:27148656

  13. Teeth white and fair.

    Science.gov (United States)

    Reed, R V

    1998-03-01

    Most dentists practicing today, in fact most dentists living today, accept porcelain, in one form or another, as a fundamental determinant of dental armamentarium. It must be remembered, however, that porcelain, in spite of some admonishments by the Chicken Littles, has not and is not about to fall like the sky. A great amount of purpose, intellect, and dedication proffered by porcelain's protagonists was the springboard that eventually led to near total acceptance of that product by dentists and the public they treated. Porcelain's introduction, however, was not accompanied by a professional unity that orchestrated its arrival with a blare of bugles and a ruffle of drums. Rather, the early proponents and opponents churned and swiped at each other for some decades. Teeth White and Fair recounts the origin, struggle, and growth of an early porcelain manufacturing company; the diversity of the men involved in the production of porcelain; the profession's dichotomy regarding the acceptance of porcelain; and the details of manufacture of that then embryonic dental product. Finally, the reader is given a peek at evolving cosmetic oriented materials that desire to garner ascension as valued players on the stages of cosmetic dental restorative materials. PMID:9709660

  14. Determination of the age of research-reactor fuel rods

    International Nuclear Information System (INIS)

    It is demonstrated that a previously developed method for non-destructive, gamma-spectrometric age determination of uranium can be successfully used to determine the age of research-reactor fuel rods. It relies on measuring the daughter/parent activity ratio 214Bi/234U by low-background, high-resolution gamma-spectrometry using intrinsic efficiency calibration. The method does not require the use of any reference materials nor the use of an efficiency-calibrated geometry, and in many cases it could be applied by safeguards inspectors even on the site of the inspection. (author)

  15. Lead in teeth from lead-dosed goats: Microdistribution and relationship to the cumulative lead dose

    OpenAIRE

    Bellis, David J.; Hetter, Katherine M.; Jones, Joseph; Amarasiriwardena, Dula; Parsons, Patrick J.

    2007-01-01

    Teeth are commonly used as a biomarker of long-term lead exposure. There appear to be few data, however, on the content or distribution of lead in teeth where data on specific lead intake (dose) are also available. This study describes the analysis of a convenience sample of teeth from animals that were dosed with lead for other purposes, i.e., a proficiency testing program for blood lead. Lead concentration of whole teeth obtained from 23 animals, as determined by atomic absorption spectrome...

  16. Relationship of deciduous teeth emergence with physical growth

    Directory of Open Access Journals (Sweden)

    Nadia L Soliman

    2012-01-01

    Full Text Available Introduction: Tooth eruption, recognized as an aspect of human growth and development, could possibly be influenced by a number of factors. It may reflect the general body development. Aim: The aim of the present research is to investigate the relationship of deciduous teeth emergence with physical growth (weight/height indices. Materials and Methods: A study was conducted among a sample of 1132 Egyptian infants whose ages range from 4 to 36 months. The sample was collected from some randomly selected health centers affiliated to the ministry of health where various socioeconomic strata from different geographic localities were recruited. The children visit there regularly for vaccination at definite ages. Weight and height were evaluated as factors that might have influence on the time of deciduous teeth emergence. Results: The results showed a certain degree of correlation between the number of deciduous teeth emerged and the studied anthropometric measurements which differed by sex and age. Conclusion: All anthropometric parameters showed relationship with the number of teeth at different levels. Although weight showed influence on the number of teeth emerged, it was less significant than height.

  17. Age determination of subdural hematomas: survey among radiologists.

    Science.gov (United States)

    Postema, F A M; Sieswerda-Hoogendoorn, Tessa; Majoie, C B L M; van Rijn, R R

    2014-08-01

    Abusive head trauma is a severe form of child abuse. One important diagnostic finding is the presence of a subdural hematoma. Age determination of subdural hematomas is important to relate radiological findings to the clinical history presented by the caregivers. In court this topic is relevant as dating subdural hematomas can lead to identification of a suspect. The aim of our study is to describe the current practice among radiologists in the Netherlands regarding the age determination of subdural hematomas in children. This is a cross-sectional study, describing the results of an online questionnaire regarding dating subdural hematomas among pediatric and neuro-radiologists in the Netherlands. The questionnaire consisted of sociodemographic questions, theoretical questions and eight pediatric cases in which the participants were asked to date subdural hematomas based on imaging findings. Fifty-one out of 172 radiologists (30 %) filled out the questionnaire. The percentage of participants that reported it was possible to date the subdural hematoma varied between 58 and 90 % for the eight different cases. In four of eight cases (50 %), the age of the subdural hematoma as known from clinical history fell within the range reported by the participants. None of the participants was "very certain" of their age determination. The results demonstrate that there is a considerable practice variation among Dutch radiologists regarding the age determination of subdural hematomas. This implicates that dating of subdural hematomas is not suitable to use in court, as no uniformity among experts exists. PMID:24553773

  18. What are the longevities of teeth and oral implants?

    DEFF Research Database (Denmark)

    Holm-Pedersen, Poul; Lang, Niklaus P; Müller, Frauke

    2007-01-01

    To analyse tooth loss and to evaluate the longevity of healthy teeth and teeth compromised by diseases and influenced by therapy as well as that of oral implants.......To analyse tooth loss and to evaluate the longevity of healthy teeth and teeth compromised by diseases and influenced by therapy as well as that of oral implants....

  19. Positioning of anterior teeth in removable dentures

    Directory of Open Access Journals (Sweden)

    Strajnić Ljiljana

    2002-01-01

    Full Text Available Introduction The aim of this paper was to present methods of placement of artificial anterior teeth in edentulous individuals. The following review takes account of the majority of papers published during the last 100 years. The review has been divided into sections regarding the method used to determine the position of artificial anterior teeth. Geometric aspect Gysi (1895-1920 produced the first scientific theory about the position of artificial anterior teeth. Physiognomic theory The aim of this theory is to find the most natural position for artificial anterior teeth for each individual. Camper's "face angle" as a physiognomic criterion, has been introduced in papers of Wehrli (1961, Marxhors (1966, Tanzer (1968, Lombardi (1973. Esthetic aspect Important names in the field of dental esthetics are: Schön and Singer (1961, Arnheim (1965, Krajiček (1969, Tanzer (1968, Lombardi (1973, Goldstein (1976. They have introduced principles of visual aspects for selection of contours, dimension and position of artificial anterior teeth. Constitution aspect Flagg (1880, Williams (1913 and Hrauf (1957, 1958, have considered body constitution and individual characteristics regarding position of artificial anterior teeth. Physiological theory In 1971, Marxhors pointed to the fact that the position of artificial teeth corresponds with the function of the surrounding soft tissue and from the aspect of physiognomy as well. Phonetic aspect According to Silverman (1962 artificial anterior teeth are nearest when we pronounce the sound "S". Cephalometrical research Rayson (1970, Watson (1989, Strajnić Lj. (1999, Bassi F. (2001 have presented cephalometric radiographic analyses of natural anterior teeth compared with cephalometric radiographic analyses of artificial anterior teeth. A review of dental literature shows several factors suggesting modalities which should determine the position of artificial anterior teeth. Numerous methods have been designed for

  20. Application of the nuclear microprobe to the study of organic and inorganic composition of teeth irradiated by a laser beam

    International Nuclear Information System (INIS)

    The nuclear microprobe uses both direct observation of nuclear reactions induced by deuterons and X ray emission induced by protons or deuterons. Thanks to these techniques, concentration profiles of the main elements (C, N, P, Ca...) contained in different parts of healthy teeth (enamel, dentine and cementum) are drawn in control zones and laser irradiated zones. The results obtained show that important perturbations appear during the irradiation by the laser beam; we observe successively, depleted zones in carbon and nitrogen which contain calcium and phosphorus and hypomineralized zones which contain organic material. 10 refs

  1. The innervation of the zebrafish pharyngeal jaws and teeth.

    Science.gov (United States)

    Crucke, Jeroen; Van de Kelft, Annelore; Huysseune, Ann

    2015-07-01

    Zebrafish (Danio rerio) teeth are increasingly used as a model to study odontogenesis in non-mammalians. Using serial semi-thin section histology and immunohistochemistry, the nerves innervating the pharyngeal jaws and teeth have been identified. The last pair of branchial arches, which are non-gill bearing but which carry the teeth, are innervated by an internal branch of a post-trematic ramus of the vagal nerve. Another, external, branch is probably responsible for the motor innervation of the branchiomeric musculature. Nerve fibres appear in the pulp cavity of the teeth only late during cytodifferentiation, and are therefore likely not involved in early steps of tooth formation. The precise role of the nervous system during continuous tooth replacement remains to be determined. Nonetheless, this study provides the necessary morphological background information to address this question. PMID:26018453

  2. Evaluation of quality of permanent teeth restorations in children of areas contaminated by heavy metal salts

    Directory of Open Access Journals (Sweden)

    V. V. Avakov

    2014-04-01

    Full Text Available The influence of the environment on the child health is one of priority issues of the present time and it is of great social importance. Increased dental diseases associated with climatic and geographical characteristics of the area are widely discussed in the literature. The leading among them are environmentally determined dental diseases in children associated with geochemical and technogenic pollution of the area where they live. Increasing amounts of hard metal salts is the urgent hygienic problem, due to severity of their multi-element analysis in microsubjects, and negative influence on health of the children population, due to tropism, ability to cumulation, long biological life in the body and antagonism of heavy metal salts to the number of microelements. Influence of hard metal salts on dental diseases development is undeniable. Particular attention is paid to their influence on caries process and treatment peculiarities. Despite the fact that modern аdhesive dentistry in recent years has made a significant breakthrough in improving adhesive systems, correct choice of adhesive system depending on changes in the structure of hard tissue under geochemical contaminants (like heavy metal salts is the most important step. It is the decisive factor for adaptation and connection of restoration with the restoration base. We should remember that on the way of adhesive system there is an altered structure preventing from deep penetration of such system and, consequently, leading to violation of restoration tightness. Therefore, early detection of complications by clinical evaluation of quality of the restorations is of great interest. Multi-vector approach to treatment of dental caries in children living in conditions of technogenic pollution by heavy metal salts is extremely urgent and important issue. Significant niche in this approach is given to adhesive preparation methods combined with local fluoridation, using fluoride medication of the

  3. Study on the simultaneous measurement of fluorine and calcium in human teeth by neutron activation analysis

    International Nuclear Information System (INIS)

    This study was undertaken to examine the potential of neutron activation analysis in the simultaneous measurement of F and Ca concentrations responsible for the occurence of dental caries. The contents of F and Ca were found to be 556±43.6 ppm and 26.3±1.5%, respectively, in the dental powder samples. These results were in good accordance with those with other routine chemical analysis. The neutron activation method allowed F and Ca contents to be measured simultaneously; F and Ca contents in the upper central incisor was 298±38 ppm and 23.0±3.5%, respectively, on the left side and 261±40 ppm and 24.9±4.7%, respectively, on the right side. For the upper cuspid , F and Ca contents were 312±34 ppm and 24.4±1.1%, respectively; the corresponding figures were 276±52 ppm and 21.8±1.8% for the upper first molar. Regarding F and Ca contents, there was no significant difference between these teeth. In conclusion, neutron activation analysis is very useful for measuring F and Ca contents in teeth because of its high sensitivity, non-destructivivity and simultaneous measurement of multiple elements. (N.K.)

  4. Minimization of cogging torque in permanent magnet motors by teeth pairing and magnet arc design using genetic algorithm

    International Nuclear Information System (INIS)

    Cogging torque is often a principal source of vibration and acoustic noise in high precision spindle motor applications. In this paper, cogging torque is analytically calculated using energy method with Fourier series expansion. It shows that cogging torque is effectively minimized by controlling airgap permeance function with teeth pairing design, and by controlling flux density function with magnet arc design. For an optimization technique, genetic algorithm is applied to handle trade-off effects of design parameters. Results show that the proposed method can reduce the cogging torque effectively

  5. Correlation of plaque nitric oxide levels with plaque Streptococcus mutans, plaque pH and decayed, missing and filled teeth index of children of different age groups

    Directory of Open Access Journals (Sweden)

    Sawinderjit Saini

    2016-01-01

    Full Text Available Context: Dental plaque is considered one of the most important etiological factors for dental caries. Nitrate and Nitrite levels in saliva are considered protective against oral and gastrointestinal disease. Plaque nitric oxide (NO levels and its role in dental caries has not be explored in the literature. Aim: Determine the correlation of the plaque nitric oxide (NO with dental caries in vivo. Materials and Method: 75 healthy children between ages of 3-15 years were selected. The age, state of dentition and the level of caries in all individuals were determined by the same examiner, using DMFT/deft index. The plaque samples collected were subjected to nitric oxide estimation, streptococcus mutans count and pH for correlation. Statistical Analysis Used: SPSS computer based software was used for descriptive data analysis. ANOVA one way analysis and Karl pearson′s correlation was carried out. Results and Conclusion: Statistically significant relationship was observed between plaque nitric oxide and dental caries in all age groups. Similarly, significant correlation of nitric oxide was found in relation to plaque streptococcus mutans and plaque pH. Thus concluded, plaque nitric oxide can be considered as a risk assessment tool for prediction of dental caries.

  6. A SURVEY OF DECAYED, MISSING OF FILLED TEETH AND PROSTHETIC STATUS IN MIDDLE AND OLD AGED PEOPLE IN QINGDAO%青岛市中老年人牙齿龋失补及修复状况的调查

    Institute of Scientific and Technical Information of China (English)

    景倩; 张倩; 李婷婷; 许家森

    2013-01-01

    Objective To understand the dental health and prosthetic status of middle-and-old aged people at nursing homes in Qingdao and their socioeconomic status (SES).Methods Six nursing homes were randomly selected from Qingdao to survey 522 residents aged ≥55 years for their decayed teeth,filling up,missing teeth and prosthetic status-by way of a questionnaire and oral examination.Results The probability of full dentition caries (FDC) was associated with SES,the higher SES,the higher chance for FDC.The chance of loss of teeth in anterior and premolar region increased as the age grew.The tooth-filling rate was correlated with age,sex and SES,higher rate was seen in female.In premolars and molars,high filling rate was noted in those of high-SES individuals,the rate decreased with the increase of age.The repair rate in each dentition area related only with age.Conclusion The oral health status of population at nursing homes in Qingdao is relatively poor,age,sex and SES affect the dental status,but in different areas of dentition,the manifestations are various.%目的 了解青岛市区老年公寓人群的牙齿健康状况及修复状况,并评估其与年龄、性别和社会经济状况(SES)的相关性.方法 随机选取青岛市区6所老年公寓,采用捷径方法获得55岁以上人群522名,通过问卷及口腔检查的方式获得其牙齿龋损、充填、缺失及修复等口腔健康状况数据.结果 仅全牙列的患龋概率与SES相关,高等级SES者的患龋概率较高.随着年龄的增长,前牙区和前磨牙区的牙齿缺失概率增加.牙齿充填概率与年龄、性别和SES均相关,在牙列各区域,女性的牙齿充填概率高于男性;在前磨牙区和磨牙区,高等级SES者的牙齿充填概率较高;但随着年龄的增长,牙齿充填概率降低;牙列各区域的修复概率仅与年龄相关.结论 青岛市老年公寓中老年人的口腔健康状况较差,年龄、性别和SES影响牙齿状况,但在牙列不同区域的表现不同.

  7. Isotopic age determinations in Bergslagen, Sweden. 3

    International Nuclear Information System (INIS)

    Rb-Sr whole-rock isotope analyses of five granite and two diorite samples of the Hyttsjoe Suite of intrusions in the Filipstad region, Central Sweden, yield an isochron age of 1841 +- 55 Ma with an initial 87Sr/86Sr ratio of 0.70217 +- 0.00098. This age is regarded as the emplacement age of the Hyttsjoe Suite of gabbros-diorites-tonalites-granites, which thus represents an intrusive subdivision of the 1.9-1.8 Ga Bergslagen Supracrustal Series. (Auth.)

  8. Clinical comparison of various esthetic restorative options for coronal build-up of primary anterior teeth

    Directory of Open Access Journals (Sweden)

    Himanshu Duhan

    2015-01-01

    Full Text Available Background: This study was designed to compare the clinical performance of composite, strip crowns, biological restoration, and composite with stainless steel band when used for the coronal build-up of anterior teeth. Materials and Methods: A total of 20 patients aged 3-6 years presenting with mutilated primary anterior teeth due to caries or trauma were selected for the study using randomized simple sampling. A total of 52 primary anterior teeth were randomly divided into four equal groups having 13 teeth in each group. Teeth in Group I were restored with composite, in Group II with strip crowns, in Group III with biologic restoration and with stainless steel band reinforced composite in group IV. The restorations were evaluated for color match, retention, surface texture, and anatomic form according to Ryge′s Direct (US Public Health Service evaluation criteria at baseline (immediate postoperative, after 48 h, 3, 6, and 9 months. The data obtained were statistically analyzed using Chi-square test, and level of significance, that is, P value was determined. Results: At baseline, none of the groups showed any color changes. Other than Group III all other groups showed highly significant changes (P 0.05. Deterioration in surface texture was exhibited maximum by restorations in Group IV followed by Group I at 3 months. Whereas, no surface changes were seen in Group II and III. Only Group I and IV showed discontinuity in anatomic form after 3 months. After 6 months, except in Group II, discontinuity in anatomic form was observed in all the groups. Discontinuity in anatomic form was seen in all the 4 groups after 9 months although the difference was not significant (P > 0.05. Conclusion: Biological restoration was found to be most satisfying esthetically owing to color compatibility with the patient′s tooth. Thus, it has a great potential to be used as esthetic restorative option in primary anteriors.

  9. Electric spin resonance and instrumental neutron activation element analyses of Chernobyl nuclear power plant accident clean-up worker teeth

    International Nuclear Information System (INIS)

    Instrumental neutron activation analysis was used to determine the concentrations of macro-, micro-, and trace elements (Ca, Ba, Sr, Mn, Se, Zn, Co) in teeth of Chernobyl's NPP accident clean-up workers examined in the Centre of Occupational and Radiological medicine of P.Stradins Clinical Hospital, Medicine Academy of Latvia. The strontium concentration was high in teeth of clean-up that in control teeth. Electron spin resonance was used to determine the absorption dose. The absorbed dose reconstruction was achieved by additive dose method. The absorbed dose measured by ESR in teeth was always higher than the documented exposure doses. (author)

  10. Genetic background of supernumerary teeth

    OpenAIRE

    Subasioglu, Asli; Savas, Selcuk; Kucukyilmaz, Ebru; Kesim, Servet; Yagci, Ahmet; Dundar, Munis

    2015-01-01

    Supernumerary teeth (ST) are odontostomatologic anomaly characterized by as the existence excessive number of teeth in relation to the normal dental formula. This condition is commonly seen with several congenital genetic disorders such as Gardner's syndrome, cleidocranial dysostosis and cleft lip and palate. Less common syndromes that are associated with ST are; Fabry Disease, Ellis-van Creveld syndrome, Nance-Horan syndrome, Rubinstein-Taybi Syndrome and Trico–Rhino–Phalangeal syndrome. ST ...

  11. Isotopic age determinations in Bergslagen, Sweden. 2

    International Nuclear Information System (INIS)

    This paper reports the isotopic dating of a Filipstad-type granite with rapakivi facies, exposed around the village of Rockesholm, about 20 km S of Grythyttan. Ten samples were taken from the river bed at Rockesholm dam site and two from nearby exposures. The Rb and Sr concentrations and Rb/Sr ratios of the whole-rocks were determined by X-ray fluorescence spectrometry. All samples were measured as pressed-powder pellets; the mass-absorption corrections for both sample and external standard are based upon the Compton scattering of the Mo-Kα primary beam. The biotite was analysed for Rb and Sr by mass-spectrometric isotope dilution. Sr isotopic compositions were determined directly on unspiked Sr for whole-rocks and calculated from the isotope dilution runs for the biotite. From the Rb-Sr whole-rock data it is concluded that the Filipstad-type granite at Rockesholm has been emplaced about 1700 Ma ago. (Auth.)

  12. Impact of asteroseismology on improving stellar ages determination

    CERN Document Server

    Lebreton, Yveline

    2013-01-01

    High precision photometry as performed by the CoRoT and Kepler satellites on-board instruments has allowed to detect stellar oscillations over the whole HR diagram. Oscillation frequencies are closely related to stellar interior properties via the density and sound speed profiles, themselves tightly linked with the mass and evolutionary state of stars. Seismic diagnostics performed on stellar internal structure models allow to infer the age and mass of oscillating stars. The accuracy and precision of the age determination depend both on the goodness of the observational parameters (seismic and classical) and on our ability to model a given star properly. They therefore suffer from any misunderstanding of the physical processes at work inside stars (as microscopic physics, transport processes...). In this paper, we recall some seismic diagnostics of stellar age and we illustrate their efficiency in age-dating the CoRoT target HD 52265.

  13. Modelling laser speckle photographs of decayed teeth by applying a digital image information technique

    Science.gov (United States)

    Ansari, M. Z.; da Silva, L. C.; da Silva, J. V. P.; Deana, A. M.

    2016-09-01

    We report on the application of a digital image model to assess early carious lesions on teeth. When decay is in its early stages, the lesions were illuminated with a laser and the laser speckle images were obtained. Due to the differences in the optical properties between healthy and carious tissue, both regions produced different scatter patterns. The digital image information technique allowed us to produce colour-coded 3D surface plots of the intensity information in the speckle images, where the height (on the z-axis) and the colour in the rendering correlate with the intensity of a pixel in the image. The quantitative changes in colour component density enhance the contrast between the decayed and sound tissue, and visualization of the carious lesions become significantly evident. Therefore, the proposed technique may be adopted in the early diagnosis of carious lesions.

  14. Brushing your infant's teeth

    Science.gov (United States)

    ... gov/ency/patientinstructions/000769.htm Brushing Your Child’s Teeth To use the sharing features on this page, ... how to brush their teeth on their own. Tooth and Gum Care for Young Children You should ...

  15. Malocclusion (Misaligned Teeth)

    Science.gov (United States)

    ... 2 Diabetes, Heart Disease a Dangerous Combo Are 'Workaholics' Prone to OCD, Anxiety? ALL NEWS > Resources First ... crown may fracture, and teeth may eventually loosen. Causes There are several causes of misaligned teeth: Size ...

  16. Deaths by ZIP Code by Age, 2013

    Data.gov (United States)

    U.S. Department of Health & Human Services — This dataset is for death of California residents, by Zip Code, by age group by place of residence. The death counts per age group, represents the deaths to...

  17. Analysis on the features of tooth wear of anterior teeth in 832 adults with the age of 35~54 years old%832名35~54岁成年人前牙磨损特征分析

    Institute of Scientific and Technical Information of China (English)

    王珺; 吉凯

    2013-01-01

    目的:分析当代成年人的前牙磨损特征.方法:以832名35 ~ 54岁成年人为研究对象,评价其前牙磨损指数,并对年龄、性别、有无磨牙症史及饮食习惯等情况进行问卷调查.结果:①前牙重度磨损发生率34.67%;②45 ~54岁年龄组前牙平均磨损指数高于35 ~44岁年龄组(P<0.05);③男性前牙平均磨损指数高于女性(P<0.05);④前牙磨损指数与磨牙症、酗酒关系密切(P<0.05).结论:①前牙磨损具有明显的增龄性效应;②磨牙症、酗酒是本样本人群前牙磨损的重要危险因素.%Objective To investigate the clinical features of tooth wear of anterior teeth in adults.Methods 832 adults with the age of 35~54 years old were involved.The tooth wear index of anterior teeth was analyzed,and data about their age,sex,bruxism and the dietary pattern were collected.Results ①The incidence of severe tooth wear in anterior teeth was 34.67%.②The tooth wear index in 45~54 age group was higher than that in 35~44 age group (P<0.05).③The tooth wear index in male was higher than that in female(P<0.05).④The tooth index of anterior teeth has close relationship with bruxism and excessive drinking.Conclusion ①The tooth wear index of anterior teeth in adults is age-dependent.②Bruxism and excessive drinking are important risk factors for tooth wear of anterior teeth in the present sample.

  18. Absolute age determination of quaternary faults

    International Nuclear Information System (INIS)

    To constrain the age of neotectonic fault movement, Rb-Sr, K-Ar, U-series disequilibrium, C-14 and Be-10 methods were applied to the fault gouges, fracture infillings and sediments from the Malbang, Ipsil, Wonwonsa faults faults in the Ulsan fault zone, Yangsan fault in the Yeongdeog area and southeastern coastal area. Rb-Sr and K-Ar data imply that the fault movement of the Ulan fault zone initiated at around 30 Ma and preliminary dating result for the Yang san fault is around 70 Ma in the Yeongdeog area. K-Ar and U-series disequilibrium dating results for fracture infillings in the Ipsil fault are consistent with reported ESR ages. Radiocarbon ages of quaternary sediments from the Jeongjari area are discordant with stratigraphic sequence. Carbon isotope data indicate a difference of sedimentry environment for those samples. Be-10 dating results for the Suryum fault area are consistent with reported OSL results

  19. Absolute age determination of quaternary faults

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, Chang Sik; Lee, Seok Hoon; Choi, Man Sik [Korea Basic Science Institute, Seoul (Korea, Republic of)] (and others)

    2000-03-15

    To constrain the age of neotectonic fault movement, Rb-Sr, K-Ar, U-series disequilibrium, C-14 and Be-10 methods were applied to the fault gouges, fracture infillings and sediments from the Malbang, Ipsil, Wonwonsa faults faults in the Ulsan fault zone, Yangsan fault in the Yeongdeog area and southeastern coastal area. Rb-Sr and K-Ar data imply that the fault movement of the Ulan fault zone initiated at around 30 Ma and preliminary dating result for the Yang san fault is around 70 Ma in the Yeongdeog area. K-Ar and U-series disequilibrium dating results for fracture infillings in the Ipsil fault are consistent with reported ESR ages. Radiocarbon ages of quaternary sediments from the Jeongjari area are discordant with stratigraphic sequence. Carbon isotope data indicate a difference of sedimentry environment for those samples. Be-10 dating results for the Suryum fault area are consistent with reported OSL results.

  20. Subluxation injuries of maxillary primary anterior teeth: epidemiology and prognosis of 207 traumatized teeth.

    Science.gov (United States)

    Fried, I; Erickson, P; Schwartz, S; Keenan, K

    1996-01-01

    This study investigated the epidemiology, sequelae, and prognosis of subluxation injuries to the maxillary primary anterior dentition. Data were collected from dental records at the Montreal Children's Hospital, Montreal, Canada, of patients sustaining trauma between 1982 and 1993. The study group consisted of 207 teeth in 134 patients, 81 males and 53 females. The age of the patients ranged from 0.8 years to 7.5 years, with a mean of 3.5 years. The highest incidence of trauma was in males between the ages of 3 and 4 years, and in females between 1 and 3 years. The highest incidence of trauma (66.2%) involved the primary central incisors. The most common cause of trauma (52%) was simple falls indoors. Occlusal or periapical radiographs were the radiographic view of choice unless an anterior nasal spine fracture was suspected, in which case a lateral projection was exposed. Approximately 64% of the study teeth had a mobility ranging from 0.6 to 1.5 mm. Treatment varied from no treatment (80% of teeth) to extraction. Post-traumatic evaluations were distributed into six common time intervals used by dentists for follow up. The results indicated that patient discomfort and occlusal interference were not common. Discoloration and pulpal calcification increased with time. Mobility decreased with time, with the majority of teeth returning to a normal physiologic range. External resorption may have been present, but was rare. Treatment or antibiotics were rarely needed at follow-up visits. Overall, these teeth responded positively, and there was a low morbidity associated with subluxation injuries. PMID:8710718

  1. Relationship between premature loss of primary teeth with oral hygiene, consumption of soft drinks, dental care, and previous caries experience

    OpenAIRE

    Sandra Aremy López-Gómez; Juan José Villalobos-Rodelo; Leticia Ávila-Burgos; Juan Fernando Casanova-Rosado; Ana Alicia Vallejos-Sánchez; Salvador Eduardo Lucas-Rincón; Nuria Patiño-Marín; Carlo Eduardo Medina-Solís

    2016-01-01

    We determine the relationship between premature loss of primary teeth and oral hygiene, consumption of soft drinks, dental care and previous caries experience. This study focused on 833 Mexican schoolchildren aged 6–7. We performed an oral examination to determine caries experience and the simplified oral hygiene index. The dependent variable was the prevalence of at least one missing tooth (or indicated for extraction) of the primary dentition; this variable was coded as 0 = no loss of teeth...

  2. Age as a Determinant of Interpersonal Evaluations.

    Science.gov (United States)

    Scheier, Michael F.; Schulz, Richard

    This study focuses on the impact of age on interpersonal evaluation of persons, particularly the elderly as individuals and not as a group. Using a 75-year-old target and a 23-year-old target, the experimenter predicted and found support for the idea that personal information contained in a transcript would evoke sympathy, and thereby lead…

  3. Comparison of Microleakage of Glass Ionomer Restoration in Primary Teeth Prepared by Er: YAG Laser and the Conventional Method

    Directory of Open Access Journals (Sweden)

    M. Ghandehari

    2012-01-01

    Full Text Available Objective: One of the main criteria in evaluating the restorative materials is the degree of microleakage. The aim of this study was to compare the microleakage of glass ionomer restored cavities prepared by Er:YAG laser or turbine and bur.Materials and Methods: Twenty extracted caries-free deciduous posterior teeth were selected for this study. The teeth were randomly divided into two groups for cavity preparation. Cavities in group one were prepared by high speed turbine and bur. In the second group, Er:YAG laser with a 3W output power, 300 mJ energy and 10 Hz frequency was used. Cavities were restored with GC Fuji II LC. After thermocycling, the samples were immersed into 0.5% methylene blue solution. They were sectioned for examination under optic microscope.Results: The Wilcoxon signed ranks test showed no significant difference between microleakage of the laser group and the conventional group (P>0.05.Conclusion: Er:YAG laser with its advantages in pediatric dentistry may be suggested as an alternative device for cavity preparation.Key Words: Er:YAG laser, Glass ionomer, Microleakage

  4. Evaluation by biphotonic absorbtiometry of the bony mineral content and determination of the fracture threshold in a population of patients between the ages of 60 and 75 years

    International Nuclear Information System (INIS)

    A measurement of the bony density of vertebrae and femur was carried out, in the course of a prospective study, in 99 patients between the ages of 60 and 75 years, living in northern France. 76 patients had no recognized problem of demineralization and 23 others were consulting for an evaluation of vertebral compression. The measurement of the bony density was done by biphotonic absorbtiometry with a source of labelled Gadolinium. In women, a significant difference in the values obtained by absorbtiometry in terms of the existence of vertebral compressions, symptomatic or not, is noted. A statistical study using the ROC curves method (Receiver Operating System) has enabled us to determine a threshold of high risk of vertebral fracture measured at 31 g or 0.85 g/cm2 in women, and 35 g or 0.85 g/cm2 in men. In addition, there is a significant correlation with the vertebral radiographical index as defined by Meunier. Among the various factors of influence which were studied, only the size and the morphotype seem to play an essential role in our study group. The comparative study of the densities measured in the femoral neck and the lumbar spine enabled us to find a very significant correlation in patients with as well as without compression (r = 0.714, p < 0.001). Biphotonic absorbtiometry proves therefore to be a method which may be used to define a group with a high fracture risk permitting to determine, as early as possible, therapeutic, curative and preventive measures

  5. Isotopic age determination in Bergslagen, Sweden. 1. Introduction

    Energy Technology Data Exchange (ETDEWEB)

    Oen, I.S. (Amsterdam Univ. (Netherlands). Geologisch Inst.); Verschure, R.H. (Laboratorium voor Isotopen-Geologie, Amsterdam (Netherlands))

    1982-09-01

    This paper is an introduction to a series of short communications 'Isotopic age determinations in Bergslagen, Sweden', which will be submitted to this journal. An earlier paper on K-Ar ages of hornblendes in skarns and metabasites in the Hjulsjoe area has been published elsewhere (Moorman et al., 1982). This joint research project of the ZWO-Laboratory of Isotope Geology and the Geological Institute University of Amsterdam forms part of the research program of the 'Stichting voor Isotopen-Geologisch Onderzoek', supported by the Netherlands Organization for the Advancement of Pure Research (Z.W.O.).

  6. The new age determination of Polar Ural eclogites

    International Nuclear Information System (INIS)

    By the method of Sm-Nd dating the age of minerals within eclogites of the Polar Urals was determined. Essential difference in mineral age of barruazite eclogite (366 ± 8.5 mln. years) and kyanite eclogite (339 ± 16 mln. years) was ascertained. Discrete stages of the eclogites formation can be among the reasons for the difference observed. It is pointed out that variations in Sm/Nd ratios of the eclogites can be related either to differentiation at magmatic stage or to metamorphism

  7. Determinants of differences in the activity budgets of Rhinopithecus bieti by age/sex class at Xiangguqing in the Baimaxueshan nature reserve, China

    Directory of Open Access Journals (Sweden)

    Li Yanhong

    2015-01-01

    Full Text Available Ecological factors are known to influence the activity budgets of Yunnan snub-nosed monkeys (Rhinopithecus bieti. However, little is known about how activity budgets vary between age/sex classes, because the species is difficult to observe in the wild. This study provides the first detailed activity budgets subdivided by age/sex classes based on observations of the largest habituated group at Xiangguqing in Baimaxueshan Nature Reserve. This study was conducted from June 2008 to May 2009. We found that adult females spent more time feeding (44.8% than adult males (39.5%, juveniles (39.1%, and infants (14.2%. Adult males allocated more time to miscellaneous activities (12.5% than did adult females (3.8%. Infants were being groomed 6.9% of the time, which was the highest proportion among all age/sex classes. Adults spent more time feeding, while immature individuals allocated more time to moving and other activities. There are several reasons activity budgets may vary by age/sex class: 1 differential reproductive investment between males and females; 2 developmental differences among the age categories; 3 social relationships between members of different age/sex classes, particularly dominance. In addition, group size and adult sex ratio may also impact activity budgets. These variations in activity budgets among the different age/sex classes may become a selective pressure that shapes the development and growth pattern in this species.

  8. Element sensitive X-ray micro tomography for determination of the metal diffusion in teeth with amalgam fillings

    International Nuclear Information System (INIS)

    Element sensitive X-ray tomography has been applied to detect the metal diffusion from the amalgam tooth filling into the tooth. By performing tomographies with energies above and below the K-edges of the various metals of the amalgam, it is possible to determine their distribution. Here presented are the results of measurements at ID15 and ID19 of the ESRF. To improve the sensitivity of our measurements a method for contrast enhancement for projections was developed.

  9. Two age populations of zircons from the Timber Creek kimberlites, Northern Territory, as determined by laser-ablation ICP-MS analysis

    International Nuclear Information System (INIS)

    Two populations of kimberlitic zircon are present in the Timber Creek kimberlites, Northern Territory. Laser-ablation ICP-MS U-Pb dating yields an age of 1483 ± 15 (2σ) Ma for the main group and an age of 179 ± 2 Ma for the other group. This distinction of two age groups is strongly supported by Hf isotope data on the same zircons. Although the trace-element patterns of both populations are typical of mantle-derived zircons, the 'young' population has slightly higher concentrations of most trace elements, but has lower Hf, Nb, Ta and Pb contents. The distinct differences in trace-element contents and Hf isotopic composition of the two zircon populations indicate that they were derived from different magma sources. The dating results indicate that the emplacement age of the Timber Creek kimberlites cannot be older than the age of the 'young' zircon population (i.e. 179 ± 2 Ma). This clarifies the inconsistency between the previously reported SHRIMP age of the Timber Creek zircons (1462 ± 53 Ma) and the much younger age (1200Ma) of the sediments of the Victoria River Basin into which these kimberlites have intruded. The Timber Creek kimberlites are a newly recognised extension of the widespread Jurassic kimberlite activity known in Western Australia and South Australia. Copyright (2001) Geological Society of Australia

  10. Stepwise excavation may enhance pulp preservation in permanent teeth affected by dental caries

    DEFF Research Database (Denmark)

    Bjørndal, Lars

    2011-01-01

    ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Ways of enhancing pulp preservation by stepwise excavation-a systematic review. Hayashi M, Fujitani M, Yamaki C, Momoi Y. J Dent 2011;39(2):95-107. Epub 2010 Dec 3. REVIEWER: Lars Bjørndal, DDS, PhD, Dr Odont PURPOSE/QUESTION: To determine the clinical...

  11. Age- and gender-specific differences in left and right ventricular cardiac function and mass determined by cine magnetic resonance imaging

    International Nuclear Information System (INIS)

    We examined possible age- and gender-specific differences in the function and mass of left (LV) and right (RV) ventricles in 36 healthy volunteers using cine gradient-recalled echo magnetic resonance imaging. Subjects were divided into four groups (nine men and nine women in each): men aged under 45 years (32 ± 7), women aged under 45 (27 ± 6), men aged over 45 (59 ± 8), and women aged over 45 (57 ± 9). Functional analysis of cardiac volume and mass and of LV wall motion was performed by manual segmentation of the endocardial and epicardial borders of the end-diastolic and end-systolic frame; both absolute and normalized (per square meter body surface area) values were evaluated. With age there was a significant decrease in both absolute and normalized LV and RV chamber volumes (EDV, ESV), while LV and RV masses remained unchanged. Gender-specific differences were found in cardiac mass and volume (for men and women, respectively: LV mass, 155 ± 18 and 110 ± 16 g; LV EDV, 118 ± 27 and 96 ± 21 ml; LV ESV, 40 ± 13 and 29 ± 9 ml; RV mass, 52 ± 10 and 39 ± 5 g; RV EDV, 131 ± 28 and 100 ± 23 ml; RV ESV, 53 ± 17 and 33 ± 15 ml). Normalization to body surface area eliminated differences in LV volumes but not those in LV mass, RV mass, or RV function. Functional parameters such as cardiac output and LV ejection fraction showed nonsignificant or only slight differences and were thus largely independent of age and gender. Intra- and interobserver variability ranged between 1.4 % and 5.9 % for all parameters. Cine magnetic resonance imaging thus shows age- and gender-specific differences in cardiac function, and therefore the evaluation of cardiac function in patients should consider age- and gender-matched normative values. (orig.)

  12. Pteridine fluorescence for age determination of Anopheles mosquitoes.

    Science.gov (United States)

    Wu, D; Lehane, M J

    1999-02-01

    The age structure of mosquito populations is of great relevance to understanding the dynamics of disease transmission and in monitoring the success of control operations. Unfortunately, the ovarian dissection methods currently available for determining the age of adult mosquitoes are technically difficult, slow and may be of limited value, because the proportion of diagnostic ovarioles in the ovary declines with age. By means of reversed-phase HPLC this study investigated the malaria vectors Anopheles gambiae and An. stephensi to see if changes in fluorescent pteridine pigments, which have been used in other insects to determine the age of field-caught individuals, may be useful for age determination in mosquitoes. Whole body fluorescence was inversely proportional to age (P 91%) up to 30 days postemergence, with the regression values: y = 40580-706x for An. gambiae, and y = 52896-681x for An. stephensi. In both species the main pteridines were 6-biopterin, pterin-6-carboxylic acid and an unidentified fluorescent compound. An. gambiae had only 50-70% as much fluorescence as An. stephensi, and fluorescent compounds were relatively more concentrated in the head than in the thorax (ratios 1:0.8 An. gambiae; 1:0.5 An. stephensi). The results of this laboratory study are encouraging. It seems feasible that this simpler and faster technique of fluorescence quantification could yield results of equivalent accuracy to the interpretation of ovarian dissection. A double-blind field trial comparing the accuracy of this technique to marked, released and recaptured mosquitoes is required to test the usefulness of the pteridine method in the field. PMID:10194749

  13. Characterization of ancient teeth and bones from animal and pre-historic human by nuclear methods

    International Nuclear Information System (INIS)

    The search for the evidence of the oldest homonid in Thailand was carried out in the upper northern part of the country consisting of Lampang, Chiang Mai, Phayao, Phrae, Nan, Chiang Rai and Mae Hong Son and Lampang was set up as a center. Three nuclear analytical techniques, i.e. X-ray fluorescence using X-ray tube and isotopic sources, neutron activation analysis and low-background gamma spectroscopy were employed to investigate the samples. The results of elemental composition in fossilised teeth can be used to classify the type of human and animal as it is related to the dietary behaviour. The relationship between elements in fossils and soil or rock can be used to identify the location where the fossils came from. The level of natural radioactivity in soil samples from different locations will be helpful in defining the surveyed region. All of the knowledge will support the development of nuclear analytical technique in archeological study. Besides, the research team found four pieces of fossils which assembled the right frontal region of a calvaria. It appears to be the first indication of a Homo Erectus partial cranial vault ever discovered in Thailand. This discovery is very important in human evolution study

  14. The challenge of dating Early Pleistocene fossil teeth by the combined uranium series-electron spin resonance method: the Venta Micena palaeontological site (Orce, Spain)

    International Nuclear Information System (INIS)

    The palaeontological site of Venta Micena (Orce, Andalusia, Spain) lies in the eastern sector of the Guadix-Baza basin, one of the best documented areas in Europe for Plio-Pleistocene bio-stratigraphy. The combination of bio-chronological and palaeo-magnetic results, combined with the radiometric data obtained for Atapuerca Sima del Elefante, indicated that the Venta Micena stratum was formed between the Jaramillo and Olduvai palaeo-magnetic events, most likely between 1.22 and 1.77 Ma. Five fossil teeth from two outcrops (sites A and B) were selected to assess the potential of combined uranium series-electron spin resonance (US-ESR) dating of Early Pleistocene sites. Although the US-ESR results of the first outcrop showed a large scatter between the three teeth, the mean age of 1.37 ± 0.24 Ma can be considered a reasonable age estimate for Venta Micena. The mean ESR age of 0.62 ± 0.03 Ma obtained for site B seems to be a severe underestimation when compared with the independent age control. This underestimation is attributed to a relative recent U-mobilization event that led to some U-leaching. The results show that any ESR age calculations of old samples are extremely sensitive to variations in the measured 230Th/234U ratios in dental tissues. Although the results demonstrate that ESR can in principle be applied to Early Pleistocene sites, they also reveal the complexity of dating such old teeth. It is necessary to continue research in several directions, such as study of the behaviour of ESR signals in old teeth and understanding recent U-mobilization processes, to improve the reliability of the combined US-ESR dating method applied to Early Pleistocene times, a period for which the number of available numerical dating techniques is very limited. (authors)

  15. Correlation of plaque nitric oxide levels with plaque Streptococcus mutans, plaque pH and decayed, missing and filled teeth index of children of different age groups

    OpenAIRE

    Sawinderjit Saini; Hina Noorani; P K Shivaprakash

    2016-01-01

    Context: Dental plaque is considered one of the most important etiological factors for dental caries. Nitrate and Nitrite levels in saliva are considered protective against oral and gastrointestinal disease. Plaque nitric oxide (NO) levels and its role in dental caries has not be explored in the literature. Aim: Determine the correlation of the plaque nitric oxide (NO) with dental caries in vivo. Materials and Method: 75 healthy children between ages of 3-15 years were selected. The age, stat...

  16. Restoring primary anterior teeth.

    Science.gov (United States)

    Waggoner, William F

    2002-01-01

    A variety of esthetic restorative materials are available for restoring primary incisors. Knowledge of the specific strengths, weakness, and properties of each material will enhance the clinician's ability to make the best choice of selection for each individual situation. Intracoronal restorations of primary teeth may utilize resin composites, glass ionomer cements, resin-modified ionomers, or polyacid-modified resins. Each has distinct advantages and disadvantages and the clinical conditions of placement may be a strong determining factor as to which material is utilized. Full coronal restoration of primary incisors may be indicated for a number of reasons. Crowns available for restoration of primary incisors include those that are directly bonded onto the tooth, which generally are a resin material, and those crowns that are luted onto the tooth and are some type of stainless steel crown. However, due to lack of supporting clinical data, none of the crowns can be said to be superior to the others under all circumstances. Though caries in the mandibular region is rare, restorative solutions for mandibular incisors are needed. Neither stainless steel crowns nor celluloid crown forms are made specifically for mandibular incisors. Many options exist to repair carious primary incisors, but there is insufficient controlled, clinical data to suggest that one type of restoration is superior to another. This does not discount the fact that dentists have been using many of these crowns for years with much success. Operator preferences, esthetic demands by parents, the child's behavior, and moisture and hemorrhage control are all variables which affect the decision and ultimate outcome of whatever restorative treatment is chosen. PMID:12412967

  17. Effect of acupuncture on the pain perception thresholds of human teeth

    DEFF Research Database (Denmark)

    Bakke, Merete

    1976-01-01

    The effect of acumpuncture on the pain perception threshold of maxillary incisors and canines as determined by a Bofors Pulp Tester was studied in 33 dental students 19-30 years of age. Test teeth were cleaned with pumice and 10% alcohol, air-dried, and insulated at the approximal surfaces......), or S44 (foot). Compared with control threshold (8.44 muA) acupuncture was accompanied by a small increase, most pronounced after 45 min (1.51 muA, P less than 0.0005). However, the hypalgesia observed was insufficient to justify acupuncture as a means of pain control in conservative dentistry....

  18. Effect of CPP-ACP Paste on Enamel Carious Lesion of Primary Upper Anterior Teeth Assessed by Quantitative Light-Induced Fluorescence: A One-Year Clinical Trial.

    Science.gov (United States)

    Sitthisettapong, Thanya; Doi, Takashi; Nishida, Yuhei; Kambara, Masaki; Phantumvanit, Prathip

    2015-01-01

    The purpose of this clinical trial was to evaluate the effect of 1 year of daily application of 10% w/v CPP-ACP (casein phosphopeptide-amorphous calcium phosphate) paste in addition to regular toothbrushing with fluoridated toothpaste on the remineralization of enamel carious lesions in preschool children using quantitative light-induced fluorescence (QLF). A total of 103 Thai children (aged 2(1)/2-3(1)/2 years) with high caries risk who had at least 1 enamel carious lesion (ICDAS 1-3) on the labial surface of the upper anterior teeth were assigned to receive either CPP-ACP paste (n = 53) or placebo control (n = 50) following toothbrushing with fluoridated toothpaste after lunch at school. QLF measurement was performed at baseline, 6 months and 1 year. At 1 year, a significant reduction in fluorescence loss (ΔF), lesion area and lesion volume (ΔQ; p ≤ 0.001) of the lesions were found over time in both groups. However, no significant difference was observed between the groups (p = 0.79, 0.98 and 0.88, respectively). There was no statistically significant difference between the odds of ΔQ transition to a stage of regression or arrest compared with progression from baseline to 1 year between the two groups (OR = 1.03, 95% CI 0.31-3.39). The daily application of 10% w/v CPP-ACP paste on a school day for 1 year resulted in no improvement of enamel carious lesion remineralization in the primary upper anterior teeth as assessed by QLF. The lesion improvement was not superior to remineralization from regular toothbrushing with fluoridated toothpaste alone in these children. PMID:26228178

  19. Bomb dating, age validation and quality control of age determinations of monodontids and other marine mammals

    Directory of Open Access Journals (Sweden)

    Steven E Campana

    2014-05-01

    Full Text Available Methods for confirming the accuracy of age determination methods are reasonably well established in fishes, but the millions of routine age determinations which take place every year require their own quality control protocols. In contrast, methods for ensuring accuracy in age determination of monodontids and other marine mammals are still being developed. Here we review the basis and application of bomb radiocarbon to marine mammal age validation, highlighting its value for providing unambiguous estimates of age for belugas and other long-lived animals which form growth bands. Bomb radiocarbon is particularly useful for marine mammals, given that the age of an individual animal can be determined to within ±1-3 years, as long as it was alive during the 1960s. However, ongoing age determinations require careful monitoring to ensure that age interpretations remain consistent across ages and through time. Quality control protocols using reference collections of ageing material, in conjunction with age bias plots and measures of precision, are capable of detecting virtually all of the systematic ageing errors that often occur once age determinations of an animal become routine.

  20. DNA Damage: A Main Determinant of Vascular Aging.

    Science.gov (United States)

    Bautista-Niño, Paula K; Portilla-Fernandez, Eliana; Vaughan, Douglas E; Danser, A H Jan; Roks, Anton J M

    2016-01-01

    Vascular aging plays a central role in health problems and mortality in older people. Apart from the impact of several classical cardiovascular risk factors on the vasculature, chronological aging remains the single most important determinant of cardiovascular problems. The causative mechanisms by which chronological aging mediates its impact, independently from classical risk factors, remain to be elucidated. In recent years evidence has accumulated that unrepaired DNA damage may play an important role. Observations in animal models and in humans indicate that under conditions during which DNA damage accumulates in an accelerated rate, functional decline of the vasculature takes place in a similar but more rapid or more exaggerated way than occurs in the absence of such conditions. Also epidemiological studies suggest a relationship between DNA maintenance and age-related cardiovascular disease. Accordingly, mouse models of defective DNA repair are means to study the mechanisms involved in biological aging of the vasculature. We here review the evidence of the role of DNA damage in vascular aging, and present mechanisms by which genomic instability interferes with regulation of the vascular tone. In addition, we present potential remedies against vascular aging induced by genomic instability. Central to this review is the role of diverse types of DNA damage (telomeric, non-telomeric and mitochondrial), of cellular changes (apoptosis, senescence, autophagy), mediators of senescence and cell growth (plasminogen activator inhibitor-1 (PAI-1), cyclin-dependent kinase inhibitors, senescence-associated secretory phenotype (SASP)/senescence-messaging secretome (SMS), insulin and insulin-like growth factor 1 (IGF-1) signaling), the adenosine monophosphate-activated protein kinase (AMPK)-mammalian target of rapamycin (mTOR)-nuclear factor kappa B (NFκB) axis, reactive oxygen species (ROS) vs. endothelial nitric oxide synthase (eNOS)-cyclic guanosine monophosphate (c

  1. K/C age determination in potassium fieldspars

    International Nuclear Information System (INIS)

    A method for the potassium/calcium age determination of geological material is described. The calcium isotope intensities are measured with a mass spectrometer by the thermal ionization technique. The 42Ca/44Ca isotope ratio is used as an internal standard to correct the measured 40Ca/42Ca ratio for mass discrimination. The radiogenic 40Ca portion and the calcium content of the minerals are determined in different analytical steps. Two feldspars are dated with relative standard deviations of 1.8 and 4 per cent, respectively. (orig.)

  2. The deglaciation of Iztaccíhuatl volcano (Mexico) from the Little Ice Age maximum to the present, determined by photogrametry and lichenometry

    Science.gov (United States)

    Palacios, D.; García-Sancho, L.; Zamorano, J. J.; Andrés, N.; Pintado, A.

    2012-04-01

    Iztaccíhualt Volcano (19°10'20''N, 98°38'30''W, 5230 m asl) preserves an important moraine complex from the Little Ice Age (LIA), which stretches to 4300 m asl. These moraines are different from former ones because they are not covered by ash fall from the last plinian explosive phases of the nearby Popocatépetl volcano. In fact, the last emission of those pyroclasts took place during the XI century (Vázquez-Selem, 2000). The summit area of the Iztaccíhualt volcano still has glaciers whose terminus are located around 5000 m asl. From the end of the LIA until present the glacier terminus have ascended 700 m. To study the deglaciation process in Iztaccíhualt volcano from the LIA maximum to present, the Ayoloco valley was selected as it is the most important valley of the western slope of the volcano. Taking this valley as a reference, we determined the limits of glaciers in different dates by georeferencing the aerial and panoramic photographs (from 1897 to 2000) and analysing the 1958 field cartography of the glacial limits (Lorenzo, 1964). On the one hand, we carried out a statistical analysis of the size of the Rhizocarpon geographicum thallus and, on the other hand, we undertook a statistical study of the biodiversity of the lichen species through a number of cross-sections from the lowest LIA moraines to the current glacier snouts. This methodology allowed dating the exact moment in which the glacier retreated over certain points of the analysed cross-sections and determining the ecesis and the growth curve of the Rhizocarpon geographicum specie. In the Ayoloco valley the average growth rate is of 0.23 mm per year. From this information, we could deduce the evolution of the glacier from the LIA maximum to present. The results indicate that two main advances took place during the XVII and the XIX centuries. At the beginning of the XX century the glacier terminus were very close to the moraines of the maximum advance. An intense glacial retreat took place

  3. The Success Rate in a Complicated Spatial Memory Test Is Determined by Age, Sex, Life History and Search Strategies in Cynomolgus Monkeys

    DEFF Research Database (Denmark)

    Darusman, Huda S; Kalliokoski, Otto; Sajuthi, Dondin;

    2014-01-01

    to failure and chronological memory recall. These strategies appeared to be shared by most subjects, however, the overall success rate appeared to also depend on individual characteristics including age, gender and whether the subject had been born in caged captivity or not. By elucidating some of...

  4. A Spectrophotometric Color Evaluation of Natural Teeth and Gingival

    DEFF Research Database (Denmark)

    Peng, Min; Hosseini, Mandana; Gotfredsen, Klaus

    2012-01-01

    Objectives: The aim of the present study was to evaluate the color of natural teeth and gingival in anterior maxillary using a new spectrophotometer. Materials and Methods: Thirty four patients with 52 healthy natural teeth and gingival in anterior maxillary were recruited. The color at four...... positions of each tooth (incisal 1/3, body1/3, cervical 1/3 and gingival) were assessed using a spectrophotometer (SpectroShadeTM, Micro Dental, Seria No. HDL3214, MHT, S.p.A, Italy) in CIELab coordinates. Descriptive statistics of Spss17.0 was used to analyze the distribution of color coordinates. Pearson...... correlation was used to test the relationship between the coordinates and age. Independent t test was used to test the difference between gender groups. Results: All the color coordinates for teeth and gingival were in right-left symmetric distribution by the central incisors and the distribution was in same...

  5. Human teeth biobank for research in odontology

    OpenAIRE

    Lina C Gonzáles Pita; Úsuga Vacca, Margarita Viviana; Torres Rodríguez, Carolina; Delgado Mejía, Edgar

    2014-01-01

    Human teeth biobank (HTB) is a higher education linked non-profit entity that collects, stores and administers donated teeth. Such an entity is supported by sanitary, biosafety, ethical and legal regulations. The purpose of this article is to describe the creation and development of an HTB comprising the biological, ethical, legal and biosafety aspects and the importance of keeping extracted teeth under controlled, reproducible and standardized conditions that do not affect their structure an...

  6. In Vitro Evaluation of the Enamel Surface Hardness Reduction in Primary and Permanent Teeth Caused by Two Most Common Acidic Soft Drinks

    Directory of Open Access Journals (Sweden)

    Nozari A.

    2011-05-01

    Full Text Available Statement of Problem: Dental erosion is defined as the loss of tooth substance by chemical processes not involving bacteria. Dental erosion has been found to be a common cause of tooth wear. Clinically apparent erosion has been found to be related to dietary factors such as the acid content of the beverages.Purpose: Evaluation of enamel erosion in the primary and permanent teeth as the result of two most common acidic drinks produced in Iranian factories, Mirinda and Pepsi.Materials and Method: The outermost surfaces of 20 primary and 20 permanent teeth were polished flat by using the finest grade sandpaper and water in order to facilitate the proper measurement. The specimens were then prepared by cutting 3-4 mm of the buccal surface of teeth by diamond burs. The specimens were then rinsed with distilled water and stored in 100˚10 humidity before testing. The surface micro-hardness of each specimen was measured by micro vickers Hardness tester before, after 5 minutes, and 10 minutes exposure to fresh solution of each drink (10 teeth per test group. Mann-Whitney and Wilcoxon signed rank tests were used for the estatistical analysis.Results: The results showed that both drinks, Mirinda and Pepsi, produced significant surface hardness loss at 5 and 10 minutes of exposure time ( p =0.05. The amount of erosive effect was changed as the exposure time increased (change from 5 to 10 minutes. There was no statistically significant difference between the amounts of surface hardness loss in the primary and permanent enamel ( p >0.05. Conclusion: Both drinks may have almost similar but significant erosive effect on the primary and permanent enamel surfaces. Although there wasn’t any difference between erosive effect of the two beverages, this effect was increased with increase in time. The primary teeth enamel was not found to be more susceptibe to acidic beverage-induced erosion than the permanent teeth.

  7. 'In vitro' assessment to instrumented indentation hardness tests in enamel of bovine teeth, before and after dental bleaching by laser

    International Nuclear Information System (INIS)

    The laser enamel bleaching is a common used procedure due to its satisfactory esthetic results. The possible changes on the dental structures caused by the bleaching technique are of great importance. The enamel superficial microhardness changes through instrumented indentation hardness on bovine teeth were analyzed in this present study. The samples were divided in two halves, one being the control and the other irradiated with a diode laser (808 nm) or with a Nd:YAG laser (1064 nm) to activate the Whiteness HP bleaching gel (hydrogen peroxide at 35%). It was possible to conclude that there was a statistical significant increase on the enamel superficial microhardness (Group I, sample 1 and Group II, sample 1) despite this increase did not seem to indicate a concern regarding the enamel surface resistance change. There was not a significant statistical change on the enamel microhardness on the other samples. The final conclusion is that there was no superficial enamel morphological change after these treatments. (author)

  8. Determining the Type, Redshift, and Age of a Supernova Spectrum

    CERN Document Server

    Blondin, Stéphane

    2007-01-01

    We present an algorithm to identify the type of an SN spectrum and to determine its redshift and age. This algorithm, based on the correlation techniques of Tonry & Davis, is implemented in the Supernova Identification (SNID) code. It is used by members of ongoing high-redshift SN searches to distinguish between type Ia and type Ib/c SNe, and to identify "peculiar" SNe Ia. We develop a diagnostic to quantify the quality of a correlation between the input and template spectra, which enables a formal evaluation of the associated redshift error. Furthermore, by comparing the correlation redshifts obtained using SNID with those determined from narrow lines in the SN host galaxy spectrum, we show that accurate redshifts (with a typical error less than 0.01) can be determined for SNe Ia without a spectrum of the host galaxy. Last, the age of an input spectrum is determined with a typical 3-day accuracy, shown here by using high-redshift SNe Ia with well-sampled light curves. The success of the correlation techn...

  9. Age assessment of ivory by analysis of 14C and 90Sr to determine whether there is an antique on hand.

    Science.gov (United States)

    Schmied, Stefanie A K; Brunnermeier, Matthias J; Schupfner, Robert; Wolfbeis, Otto S

    2011-04-15

    A method is described to determine whether an elephant has died before 1955 or not. This is accomplished by determination of the radionuclides (14)C and (90)Sr in artifacts made of ivory. The reliability of this method is considerably increased by double nuclide analysis and therefore is applicable for judicial expert opinions. PMID:21371831

  10. Platelet size and age determine platelet function independently

    International Nuclear Information System (INIS)

    A study was undertaken to examine the interaction of platelet size and age in determining in vitro platelet function. Baboon megakaryocytes were labeled in vivo by the injection of 75Se-methionine. Blood was collected when the label was predominantly associated with younger platelets (day 2) and with older platelets (day 9). Size-dependent platelet subpopulations were prepared on both days by counterflow centrifugation. The reactivity of each platelet subpopulation was determined on both days by measuring thrombin-induced aggregation. Platelets were fixed after partial aggregation had occurred by the addition of EDTA/formalin. After removal of the aggregated platelets by differential centrifugation, the supernatant medium was assayed for remaining platelets and 75Se radioactivity. Comparing day 2 and day 9, no significant difference was seen in the rate of aggregation of a given subpopulation. However, aggregation was more rapid in the larger platelet fractions than in the smaller ones on both days. A greater percentage of the 75Se radioactivity appeared in the platelet aggregates on day 2 than on day 9. This effect was independent of platelet size, as it occurred to a similar extent in the unfractionated platelets and in each of the size-dependent platelet subpopulations. The data indicate that young platelets are more active than older platelets. This study demonstrates that size and age are both determinants of platelet function, but by independent mechanisms

  11. Sterilisation of extracted human teeth for educational use

    Directory of Open Access Journals (Sweden)

    Kumar M

    2005-01-01

    Full Text Available Sixty intact, non-carious and unrestored teeth extracted due to periodontal disease were used to determine the most effective method of sterilisation. The teeth were divided into six groups, each containing 10 teeth. Group 1 teeth were immersed in 10% formalin for seven days, group 2 teeth were immersed in 3% hydrogen peroxide for seven days, group 3 teeth were immersed in 2.6% sodium hypochlorite for seven days, group 4 teeth were boiled in water at 100°C for 20 minutes, group 5 teeth were autoclaved at 121°C at 15 lbs psi for 30 minutes, and group 6 teeth were immersed in normal saline for seven days. After the treatment, the teeth were individually inoculated into trypticase soy broth and incubated for 48 hours. A questionnaire survey was also conducted to determine the awareness of dental students regarding infection due to extracted human teeth and the common disinfection/sterilisation methods used. Autoclaving at 121°C, 15 lbs psi for 30 minutes and immersion in 10% formalin for seven days were effective in disinfecting/sterilising extracted human teeth. Chemicals such as 2.6% sodium hypochlorite, 3% hydrogen peroxide and boiling in water were not effective. The results indicate that autoclaving for 30 minutes or immersion in 10% formalin for seven days could be effectively used for disinfection/sterilisation of extracted human teeth.

  12. Determination of Diastolic Dysfunction Cut-Off Value by Tissue Doppler Imaging in Adults 70 Years of Age or Older: A Comparative Analysis of Pulsed-Wave and Color-Coded Tissue Doppler Imaging

    OpenAIRE

    Baek, Hee-Kyung; Park, Tae-Ho; Park, Sun-Yi; Kim, Jung-Hwan; Seo, Jeong-Min; Kim, Woo-Jae; Nam, Young-Hee; Kim, Moo-Hyun; Kim, Young-Dae

    2011-01-01

    Background and Objectives The cut-off value of diastolic dysfunction by tissue Doppler imaging (TDI) is affected by aging and modalities used (pulsed-wave vs. color-coded). The purpose of this study was to investigate the diastolic function of healthy elderly people and to determine the appropriate cut-off value of diastolic dysfunction in elderly individuals. Subjects and Methods Healthy volunteers (n=76) and patients with hypertension (n=51) aged ≥70 years underwent 2-dimensional and Dopple...

  13. A survey of root canal treatment of molar teeth by general dental practitioners in private practice in Saudi Arabia

    Science.gov (United States)

    Al-Fouzan, Khalid S.

    2010-01-01

    The purpose of this study was to evaluate the practice and depth of knowledge of root canal treatment by general dental practitioners working in private dental centers in different cities within the Kingdom of Saudi Arabia. A questionnaire was distributed to 400 general dental practitioners. Completed questionnaires were analyzed in term of simple summary statistics. A total of 252 (63%) practitioners responded. The majority of the respondents were Syrians (59%) and Egyptians (32%). Ninety-one per cent of the respondents indicated that they performed root canal treatment. Amongst those who carried out root canal treatment, only seven practitioners (3%) used rubber dam for isolation. More than half of the respondents (55%) used saline to irrigate canals during treatment. Forty-six per cent of practitioners used formocresol as an inter appointment medicament. The standardized and step-back preparation techniques were the method of choice for the majority of the respondents (91%). Ninety-seven per cent of the practitioners used stainless steel hand instruments to prepare root canals and the majority (92%) used gutta-percha for obturation. Seventy-four per cent of the respondent used cold lateral condensation. The average number of radiographs routinely taken for root canal treatment was four. Ninety-three per cent indicated that they usually completed a root canal treatment of molar teeth in three or more visits. Eighty-eight per cent of the practitioners preferred waiting for 1 or 2 weeks to restore the teeth permanently. Results of this study confirm that many general dental practitioners are not following quality guidelines for endodontic treatment. PMID:23960485

  14. Problems associated with reworked teeth in electron spin resonance (ESR) dating

    Science.gov (United States)

    Blackwell, Bonnie A.

    A single radiation-sensitive ESR signal at g = 2.0018 occurs in well crystallized fossil tooth enamel, but not in modern teeth. In dating fossil teeth, the equivalent radiation dose (A Σ needed to produce the observed ESR signal is the integral, with respect to time, of the natural, environmental dose rate experienced by the tooth after its deposition. Regardless of the uranium (U) uptake history assumed, a reliable age estimate requires a good estimate for the external dose rate during the tooth's history. If teeth in a stratigraphic unit have been reworked from older units or are post-depositional intrusions, external dose rates measured in situ do not accurately reflect those experienced by the tooth. For teeth from a single unit, significant variations in the calculated ages, A Σs, enamel or dentine U concentrations all indicate mixed sample collections. Where enough subsamples can be collected from single teeth, isochron analyses negate the need for a separate external dose measurement, while calculating the sample age and the external dose rate experienced by the tooth. Failing that, modelling the sedimentary dose rates using time-averaged total external dose calculations becomes necessary. These principles are illustrated using teeth from the australopithecine sites Sterkfontein and Swartkrans, South Africa.

  15. 77 FR 4858 - Culturally Significant Objects Imported for Exhibition Determinations: “Byzantium and Islam: Age...

    Science.gov (United States)

    2012-01-31

    ... Culturally Significant Objects Imported for Exhibition Determinations: ``Byzantium and Islam: Age of... determinations made by ] the Department of State pertaining to the exhibition ``Byzantium and Islam: Age of... Islam: Age of Transition (7th-9th Century),'' imported from abroad for temporary exhibition within...

  16. Significance of proper oral hygiene for health condition of mouth and teeth

    Directory of Open Access Journals (Sweden)

    Ljaljević Agima

    2012-01-01

    Full Text Available Background/Aim. Proper mouth and teeth hygiene has influence on the prevention of a great number of diseases and very often some of them are not related only to oral cavity. Most frequent diseases of mouth and teeth such as caries and periodontal diseases are caused, among other factors, by poor oral hygiene. They are also more frequent in young population. The aim of this study was to estimate the influence of sociodemographic characteristics and hygienic habit on oral health in children aged 11-15 years. Methods. This crosssectional study was conducted by the dental teams in dentist surgeries in Tivat Health Center between May and September 2009. The sample consisted of patients 11 to 15 years of age. A questionnaire and dental examination of mouth and teeth were used as research instruments. The examinations were conducted in accordance with the World Health Organization methodology and criteria. The data obtained from the interviews were correlated with those obtained from the clinical examinations. Results. The results show that the majority of respondents brush their teeth twice a day and visit the dentist once in every six months. The research also shows that 57% respondents have caries of deciduous teeth and over 63% respondents of permanent teeth. Gingivitis was found in 14% and orthodontic anomalies in 44.7% respondents. A half of respondents who brush their teeth rarely have problems with gingivitis. There is a highly statistically significant difference between the occurrence of gingivitis and the frequency of teeth brushing. Conclusion. There is a significant difference between mouth and oral hygiene and sex as well as other sociodemographic characteristics of respondents. The study showed the correlation between occurrence of caries and the gingivitis and frequency of teeth brushing and dental visits.

  17. Effect of two kinds of iron drops on the discoloration, atomic absorption and structural changes of primary teeth enamel

    Directory of Open Access Journals (Sweden)

    Mehran M.

    2009-03-01

    Full Text Available "nBackground and Aim: Black staining after taking iron drops on the primary teeth is always concern of parents. There is not an exact explanation for the mechanism of iron black staining. The purpose of this study was to compare tooth discolorations, atomic absorption and structural changes of primary teeth enamel caused by two kinds of iron drops[ Kharazmi(Iran and Fer-in-sol(USA]. "nMaterials and Methods: In this ex-vivo study, 93 sound primary teeth in normal color range were divided into five groups. Two groups of samples were immersed into the Artificial Caries Challenge(ACC for two weeks before getting exposured to iron drops: Group 1 Control(NS: sound enamel teeth which were kept in Normal Saline environment(NS(13teeth. Group 2 (NS-KH: NS, kharazmi iron drop (20 teeth. Group 3 (ACC-KH: ACC, Kharazmi iron drop (20teeth. Group 4 (NS-F-in-S: NS, Fer-in-Sol iron drop (20teeth. Group 5 (ACC-F-in-S: ACC, Fer-in-Sol iron drop. Visual tooth discolorations were determined by a specialist in operative dentistry who was not aware of experimental groups. The iron concentration was measured by ICP system (Vista-pro, Australia and the structural changes were studied by SEM (Philips, Netherland. The data of discoloration were studied with Kruskal-Wallis test and multiple comparison using Bonferroni type test, and with the data of atomic absorption were studied with oneway ANOVA test and Tukey HSD test. "nResults: The discoloration in the teeth immersed into the ACC (ACC-KH, ACC-F-in-S was more severe than the sound enamel surface (NS-KH, NS-F-IN-S (p<0.001 and Kharazmi iron drop caused more discoloration in the teeth immersed into the ACC (p=0.018. The teeth immersed into the ACC, absorbed more iron than the sound enamel surface (p<0.001 and also the teeth immersed into the ACC absorbed more Kharazmi iron drop (p<0.001. In the Scanning Electron Microscopy study, at low magnification in the sound teeth the perikymata was arranged regular. At low

  18. Non-syndromic supernumerary teeth: report of a case with 6 supernumerary teeth

    Directory of Open Access Journals (Sweden)

    Taghibakhsh M

    2011-02-01

    Full Text Available "nBackground and Aims: Multiple supernumerary teeth are rare and often found in association with syndromes such as Gardner, Cleidocranial dysplasia and cleft lip and palate, with a much less chance for isolated"nnon-syndromic cases. The aim of this study was to report a case with 6 supernumerary teeth without syndromic association."nCase Report: The patient was a 33 year-old female, referred to oral diseases and diagnosis department with chief complaint of sensitivity to cold and hot food in right upper premolar region. Oral examination revealed 5 erupted lingually supernumerary teeth (four in mandibular and one in maxillary premolar region, respectively. Further panoramic radiography clarified an extra impacted tooth in the palatal region of left premolar maxillary area. All extra teeth had been appeared since the age of 17 during one year, as the patient claimed. Medical history and thorough clinical and paraclinical examinations were not significant except for the hypothyroidism, since 5 years ago. No other family member noticed to be the case. Based on our findings, a diagnosis of non-syndromic multiple supernumerary teeth was established."nConclusion: A thorough examination of each patient presented with supernumerary teeth, including panoramic and intraoral radiographic images may provide valuable information regarding accompanying syndromes and unerupted teeth. Early diagnosis is an essential step for orthodontic or surgical decisions making, preventing or avoiding worsening complications such as malocclusion, adjacent normal teeth delayed eruption or rotation, diasthema, cystic lesions and resorption of contiguous teeth.

  19. Pulp/tooth ratio of mandibular first and second molars on panoramic radiographs: An aid for forensic age estimation

    Science.gov (United States)

    Shah, Palak H.; Venkatesh, Rashmi

    2016-01-01

    Objective: To determine and compare the accuracy of pulp/tooth ratio method in mandibular first and second molar teeth in forensic age estimation. Materials and Methods: A total 300 panoramic radiographs of the Gujarati population (187 males and 113 females) were studied. The measurements of Pulp Chamber Height (PCH) and Crown Root Trunk Height (CRTH) were performed on the mandibular first and second molar teeth. The acquired data was subjected to correlation and regression. Results: The pulp chamber crown root trunk height ratios (PCTHR) of both the first (r = −0.609) and second molars (r = −0.422) were significantly correlated with the age of the individual. Individual regression formulae were derived for both the teeth which were then used separately to calculate the age. The standard errors estimate (SEE) for the first and second molars were 8.84 years and 10.11 years, respectively. There was no statistically significant difference between chronological and calculated age by both the teeth (P = 1.000). Conclusion: The mandibular first and second molar is a potential tool for age estimation in forensic dentistry. The pulp/tooth ratio of both the teeth is a useful method for forensic age prediction with reasonable accuracy in the Gujarati population.

  20. The age of second language acquisition determines the variability in activation elicited by narration in three languages in Broca's and Wernicke's area.

    Science.gov (United States)

    Bloch, Constantine; Kaiser, Anelis; Kuenzli, Esther; Zappatore, Daniela; Haller, Sven; Franceschini, Rita; Luedi, Georges; Radue, Ernst-Wilhelm; Nitsch, Cordula

    2009-02-01

    It is generally accepted that the presence of a second language (L2) has an impact on the neuronal substrates build up and used for language processing; the influence of the age of L2 exposure, however, is not established. We tested the hypothesis that the age of L2 acquisition has an effect on the cortical representation of a multilingual repertoire in 44 multilinguals with different age of exposure to a L2 (simultaneous or covert simultaneous exposure to L1 and L2, sequential acquisition of L1 and L2 between 1 and 5 years, late learning of L2 after 9 years of age) and all fluent in a late learned L3. Regional activation in a language production task showed a high in-between-subject variability, which was higher than within-subject variability between L1, L2, and L3. We, therefore, performed a single subject analysis and calculated the within-subject variance in the numbers of activated voxels in Broca's and Wernicke's area. Subjects with early exposure to L2 showed low variability in brain activation in all three languages, in the two early as well as the late learned language. In contrast, late multilinguals exhibited higher variability. Thus, cerebral representation of languages is linked to the age of L2 acquisition: early exposure to more than one language gives rise to a language processing network that is activated homogeneously by early and late learned languages, while the inhomogeneous activation in late multilinguals indicates more independent access to the multilingual repertoire. Early passive exposure to L2 results in the same low variance as active bilingual upbringing. Variability in local brain activity increases progressively from the simultaneous to late L2 exposure, indicating a gradual transition from the mode of early bilingual language representation to that of late ones. PMID:19061905

  1. Radiographic studies on the development of cheek teeth in donkeys

    International Nuclear Information System (INIS)

    The current study was carried out on 60 head specimens of donkeys in addition to five living animals. Specimens and animal's heads were radiographed. Radiographs were grouped from 1 day up to 15 years of age. Recorded data included the following points: 1) Time of radiographic appearance and different developmental stages of deciduous and permanent cheek teeth. 2) Length of deciduous cheek teeth from birth to shedding. 3) Length of permanent cheek teeth from birth to senility. 4) Body and root length from age 5 up to 15 years of age. 5) Wolf teeth: occurrence, time of eruption and shedding. All results were documented and illustrated in tables and photographs

  2. Estimation of age based on tooth cementum annulations: A comparative study using light, polarized, and phase contrast microscopy

    Science.gov (United States)

    Kaur, Prabhpreet; Astekar, Madhusudan; Singh, Jappreet; Arora, Karandeep Singh; Bhalla, Gagandeep

    2015-01-01

    Context: The identification of living or deceased persons using unique traits and characteristics of the teeth and jaws is a cornerstone of forensic science. Teeth have been used to estimate age both in the young and old, as well as in the living and dead. Gradual structural changes in teeth throughout life are the basis for age estimation. Tooth cementum annulation (TCA) is a microscopic method for the determination of an individual's age based on the analysis of incremental lines of cementum. Aim: To compare ages estimated using incremental lines of cementum as visualized by bright field microscopy, polarized microscopy, and phase contrast microscopy with the actual age of subject and to determine accuracy and feasibility of the method used. Materials and Methods: Cementum annulations of 60 permanent teeth were analyzed after longitudinal ground sections were made in the mesiodistal plane. The incremental lines were counted manually using a light, polarized and phase contrast microscopy. Ages were estimated and then compared with the actual age of individual. Statistical Analysis: Analysis of variance (ANOVA), Student's t-test, the Pearson product-moment corre (PPMCC) and regression analysis were performed. Results: PPMCC value r = 0.347, 0.542 and 0.989 were obtained using light, polarized and phase contrast microscopy methods respectively. Conclusion: It was concluded that incremental lines of cementum were most clearly visible under a phase contrast microscope, followed by a polarized microscope, and then a light microscope when used for age estimation. PMID:26816462

  3. Osteoblastic differentiation of stem cells from human exfoliated deciduous teeth induced by thermosensitive hydrogels with strontium phosphate

    International Nuclear Information System (INIS)

    Stem cells from human exfoliated deciduous teeth (SHEDs) are a novel source of multi-potential stem cells for tissue engineering because of their potential to differentiate into multiple cell lineages. Strontium exhibits an important function in bone remodeling because it can simulate bone formation and decrease bone resorption. Hydrogels can mimic the natural cellular environment. The association of hydrogels with cell viability is determined using biological tests, including rheological experiments. In this study, osteogenic differentiation was investigated through SHED encapsulation in hydrogels containing strontium phosphate. Results of 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) and proliferating cell nuclear antigen (PCNA) immunofluorescence staining indicated that the cells grew well and SHEDs proliferated in the hydrogels. Strontium-loaded chitosan-based hydrogels induced the biomineralization and high expression of alkaline phosphatase. Moreover, the expression levels of bone-related genes, including type-I collagen, Runx2, osteopontin (OP), and osteonectin (ON), were up-regulated during the osteogenic differentiation of SHEDs. This study demonstrated that strontium can be an effective inducer of osteogenesis for SHEDs. Elucidating the function of bioceramics (such as strontium) is useful in designing and developing strategies for bone tissue engineering. - Highlights: • SHEDs have been considered as alternative sources of adult stem cells in tissue engineering. • Strontium phosphate can enhance the osteogenic differentiation of SHEDs. • Hydrogels can mimic the natural cellular environment. • Bioceramics (such as strontium) is useful in designing and developing strategies for bone tissue engineering

  4. Osteoblastic differentiation of stem cells from human exfoliated deciduous teeth induced by thermosensitive hydrogels with strontium phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Su, Wen-Ta, E-mail: f10549@ntut.edu.tw [Department of Chemical Engineering and Biotechnology National Taipei University of Technology, Taipei, Taiwan (China); Chou, Wei-Ling [Department of Chemical Engineering and Biotechnology National Taipei University of Technology, Taipei, Taiwan (China); Chou, Chih-Ming [Department of Biochemistry, Taipei Medical University, Taipei, Taiwan (China)

    2015-07-01

    Stem cells from human exfoliated deciduous teeth (SHEDs) are a novel source of multi-potential stem cells for tissue engineering because of their potential to differentiate into multiple cell lineages. Strontium exhibits an important function in bone remodeling because it can simulate bone formation and decrease bone resorption. Hydrogels can mimic the natural cellular environment. The association of hydrogels with cell viability is determined using biological tests, including rheological experiments. In this study, osteogenic differentiation was investigated through SHED encapsulation in hydrogels containing strontium phosphate. Results of 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) and proliferating cell nuclear antigen (PCNA) immunofluorescence staining indicated that the cells grew well and SHEDs proliferated in the hydrogels. Strontium-loaded chitosan-based hydrogels induced the biomineralization and high expression of alkaline phosphatase. Moreover, the expression levels of bone-related genes, including type-I collagen, Runx2, osteopontin (OP), and osteonectin (ON), were up-regulated during the osteogenic differentiation of SHEDs. This study demonstrated that strontium can be an effective inducer of osteogenesis for SHEDs. Elucidating the function of bioceramics (such as strontium) is useful in designing and developing strategies for bone tissue engineering. - Highlights: • SHEDs have been considered as alternative sources of adult stem cells in tissue engineering. • Strontium phosphate can enhance the osteogenic differentiation of SHEDs. • Hydrogels can mimic the natural cellular environment. • Bioceramics (such as strontium) is useful in designing and developing strategies for bone tissue engineering.

  5. BARIUM IN TEETH AS INDICATOR OF BODY BURDEN

    Science.gov (United States)

    A study was conducted to determine the biological availability of naturally occurring barium in a municipal drinking water by the analysis of barium in deciduous teeth of children. The grade school children of two Illinois towns were chosen for the study. The towns were chosen ba...

  6. Age determination of bottom sediments from Lake Hovsgol, Mongolia

    International Nuclear Information System (INIS)

    Dating plays a key role in determining past environmental changes in lake sediments cores. The feldspar post-IR infrared stimulated luminescence (IRSL) procedure is one of the IRSL procedures and has a great potential to date older samples compared to quartz optically stimulated luminescence (OSL). In this study, the post-IR IRSL (pIRIR) procedure was applied to the polymineral fine grained sediments from Lake Khuvsgul (Hovsgol), Mongolia, and these ages were compared to 14C ages of bulk samples from the certain depths. The pIRIR ages are always younger than 14C ages from bulk samples, however, it was possible to construct the suitable age model based on luminescence and 14C ages. Therefore, pIRIR225 protocol can be contributed to estimate the sedimentation age of lake sediments as well as 14C dating. (author)

  7. Tables for determining lead, uranium, and thorium isotope ages

    Science.gov (United States)

    Schonfeld, E.

    1974-01-01

    Tables for determining lead, uranium, and thorium isotope ages are presented in the form of computer printouts. Decay constants, analytical expressions for the functions evaluated, and the precision of the calculations are briefly discussed.

  8. Evaluation of Laser Ablation Inductively Coupled Plasma Mass Spectrometry for the Quantitative Determination of Lead in Different Parts of Archeological Human Teeth

    OpenAIRE

    Bellis, David J.; Parsons, Patrick J.; Jones, Joseph; Amarasiriwardena, Dula

    2009-01-01

    The lead content of teeth or tooth-parts has been used as a biomarker of cumulative lead exposure in clinical, epidemiological, environmental, and archaeological studies. Through the application of laser ablation inductively coupled plasma mass spectrometry, a pilot study of the micrometer-scale distribution and quantification of lead was conducted for two human teeth obtained from an archeological burial site in Manhattan, New York, USA. Lead was highly localized within each tooth, with accu...

  9. Development of an epidemiological index for primary anterior teeth affected by erosion and prevalence of dental erosion in pre-school Saudi children

    OpenAIRE

    Al-Malik, M.

    2000-01-01

    Erosion affects both dentitions but has proved difficult to measure. It has been thought to affect children who are less susceptible to caries but previous studies have been confined to countries where caries prevalence is low. The aims of this study were first, to develop and then investigate the validity of an index to measure erosion in primary teeth. Secondly, to determine the prevalence of erosion in primary incisors amongst kindergarten children in Jeddah and its relat...

  10. [Cryopreservation of teeth].

    Science.gov (United States)

    Zimmerli, Melanie; Filippi, Andreas

    2010-01-01

    After tooth loss dental implants or fixed prosthetic restorations are not indicated in children and adolescents due to incomplete maxillary and mandibular development. Cryopreservation is a method for long-term storage of healthy teeth which were removed for orthodontic reasons or due to traumatic origin. These preserved teeth can be used as autogenous replants or transplants after tooth loss. During transport to and from the freezing facilities prior to freezing the teeth are stored in a cell culture medium. The tooth is transferred into a freezing tube containing cell culture medium and cryoprotectant DMSO. Teeth autotransplanted after cryopreservation show vitality of the PDL cells. Usually no enamel and/or dentinal cracks can be observed. After tooth loss transplantation of cryopreserved teeth could be an effective and biological therapy for tooth replacement. PMID:21545030

  11. 21 CFR 872.5550 - Teething ring.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Teething ring. 872.5550 Section 872.5550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES... divice intended for use by infants for medical purposes to soothe gums during the teething process....

  12. Mouth and Teeth (For Parents)

    Science.gov (United States)

    ... Things to Know About Zika & Pregnancy Mouth and Teeth KidsHealth > For Parents > Mouth and Teeth Print A ... lives. continue Basic Anatomy of the Mouth and Teeth The entrance to the digestive tract, the mouth ...

  13. Supernumerary teeth in clinical practice

    OpenAIRE

    Szkaradkiewicz, Anna K; Karpiński, Tomasz M.

    2011-01-01

    Introduction: Hyperdontia is the condition of having supernumerary teeth, or teeth which appear in addition to the regular number of teeth. The prevalence rates of supernumerary teeth in the permanent dentition amounts 0.1-6.9%, and in deciduous dentition 0.4-0.8%. The presence of supernumerary teeth can be found in everyday dental practice. Case presentation: We describe 3 cases of patients with supernumerary teeth. First patient had supernumerary lateral incisor 12s, second - premolar fu...

  14. Case report of the radiation damage to the developing teeth

    International Nuclear Information System (INIS)

    In the treatment of malignant diseases about the head and neck, radium, x-rays and other radioactive materials are used as therapeutic agents. When irradiation is heavy, deleterious effects may be seen later in jaws, the teeh, or in both teeth and jaws. Young patients with undeveloped and developing teeth, despite lower dosages, are more subject to radiation damage to the teeth. After heavy exposure, grossly stunted teeth may appear. The crown is sometimes smoller than normal and deformed, and the root may be grossly underdeveloped. Sometimes the crown is formed normally but the roots are absent. This case is presented in which the mandibular jaw was irradiated at 3 years old and it was possible to examine some of the abnormal teeth in detail by using clinical, radiographic, and histologic technicques. The patient was first seen on June 21, 1982, at the age of 6 years old and one month. His medical history revealed that when he was 3 years old a malignant fibrous histiocytoma of the left mandibula. Radiation therapy (Linac) began at 3 years old and three months and extended over a period of one month. The total dose was 4750 rads. The crown of other teeth were formed normally but when the patient was 7 years old, the upper left lateral incisor was appeared to have short clinical crown. Radiographs revealed that roots of lower incisors were short and roots of molars were absent. The extracted lower molar was cut undecalcified to produce planoparallel section. The section showed that the dysplastic dentin was formed and it was continuous with the alveolar bone at the base of the tooth. (author)

  15. Prevalence of congenitally missing permanent teeth in Iran

    Directory of Open Access Journals (Sweden)

    Mahnaz Sheikhi

    2012-01-01

    Conclusion: The prevalence of congenitally missing teeth (CMT in Iranian permanent dentition was 10.9%. The most common congenitally missing teeth were mandibular second premolar fallowed by maxillary second premolars.

  16. EVALUATION OF QUALITY OF PERMANENT TEETH RESTORATIONS IN CHILDREN OF AREAS CONTAMINATED BY HEAVY METAL SALTS

    OpenAIRE

    V. V. Avakov; N. N. Rozhko

    2014-01-01

    The influence of the environment on the child health is one of priority issues of the present time and it is of great social importance. Increased dental diseases associated with climatic and geographical characteristics of the area are widely discussed in the literature. The leading among them are environmentally determined dental diseases in children associated with geochemical and technogenic pollution of the area where they live. Increasing amounts of hard metal salts is the urgent hygien...

  17. Survival of Root-filled Teeth in the Swedish Adult Population

    DEFF Research Database (Denmark)

    Fransson, Helena; Dawson, Victoria S; Frisk, Fredrik;

    2016-01-01

    INTRODUCTION: The aim was to assess survival in the Swedish population of teeth treated by nonsurgical root canal treatment during 2009. METHODS: Data from the Swedish Social Insurance Agency were analyzed by Kaplan-Meier analysis to assess cumulative tooth survival during a period of 5-6 years of...... all teeth that were root-filled during 2009. RESULTS: In 2009, 248,299 teeth were reported as root-filled. The average age of the patients at the time of the root filling was 55 years (range, 20-102 years). The teeth most frequently root-filled were the maxillary and mandibular first molars. During...... the 5- to 6-year period 25,228 of the root-filled teeth (10.2%) were reported to have been extracted; thus 223,071 teeth (89.8%) survived. Tooth survival was highest in the youngest age group (93.2%). The highest survival (93.0%) was for the mandibular premolars, and the lowest (87.5%) was for the...

  18. Consequences of dental trauma to the primary teeth on the permanent dentition

    Directory of Open Access Journals (Sweden)

    Mabel Mariela Rodriguez Cordeiro

    2012-12-01

    Full Text Available Introduction: Dental trauma to primary teeth or to the jaws may cause disorders on the development of permanent successor teeth. The alterations may either occur at the time of accident or be caused by post-traumatic consequences. Objective: The aim of this paper is to present cases of alterations on permanent dentition following dental trauma to primary teeth. Case reports: Three cases are presented in this paper. The severity of the post-traumatic sequels shown by the permanent teeth kept a direct relationship with the extent of the impact and patient’s age at the accident. These sequels resulted in whitish or brownish opacities, enamel hypoplasia, root dilacerations, and total arrest of root development. Conclusion: It can be concluded that the protocols for patients who had experienced dental trauma must observe a systematic clinical and radiographic follow-up as well as alternatives of treatment for the primary and permanent teeth involved. Prognostics and treatments related to the sequels in permanent teeth may be obtained from a close analysis of clinical and radiographic aspects, avoiding more damages to the stomatognathic system. The severity of the sequels is directly related to the degree of permanent tooth formation (child’s age, type of dental trauma and extent of the impact.

  19. Electron spin resonance dating of teeth from Western Brazilian megafauna - preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, Angela, E-mail: angela.kinoshita@usc.br [Departamento de Fisica, FFCLRP, Universidade de Sao Paulo, 14040-901 Ribeirao Preto-SP (Brazil); Universidade Sagrado Coracao, Rua Irma Arminda 10-50, 17011-160 Bauru - Sao Paulo (Brazil); Jose, Flavio A. [Departamento de Fisica, FFCLRP, Universidade de Sao Paulo, 14040-901 Ribeirao Preto-SP (Brazil); Sundaram, Dharani; Paixao, Jesus da S.; Soares, Isabella R.M. [Universidade Federal de Mato Grosso, Departamento de Geologia Geral, 78090-000 Cuiaba-MT (Brazil); Figueiredo, Ana Maria [Instituto de Pesquisas Energeticas e Nucleares (IPEN), 05422-970 Sao Paulo-SP (Brazil); Baffa, Oswaldo [Departamento de Fisica, FFCLRP, Universidade de Sao Paulo, 14040-901 Ribeirao Preto-SP (Brazil)

    2011-09-15

    Electron Spin Resonance (ESR) was applied to determine ages of Haplomastodon teeth from Western Brazilian Megafauna. The Equivalent Doses (D{sub e}) of (1.3 {+-} 0.2)kGy, (800 {+-} 100)Gy and (140 {+-} 20)Gy were found and the software ROSY ESR dating was employed to convert D{sub e} in age, using isotope concentrations determined by neutron activation analysis (NAA) and other information, resulting in (500 {+-} 100)ka, (320 {+-} 50) and (90 {+-} 10)ka considering the Combination Uptake (CU) model for Uranium uptake, set as an Early Uptake (EU) for dentine and Linear Uptake (LU) for enamel. There are scarce reports about Pleistocene Megafauna in this area. This paper presents the first dating of megafauna tooth and this study could contribute to improve the knowledge about the paleoclimate and paleoenvironment of this region and prompt more investigations in this area.

  20. Electron spin resonance dating of teeth from Western Brazilian megafauna - preliminary results

    International Nuclear Information System (INIS)

    Electron Spin Resonance (ESR) was applied to determine ages of Haplomastodon teeth from Western Brazilian Megafauna. The Equivalent Doses (De) of (1.3 ± 0.2)kGy, (800 ± 100)Gy and (140 ± 20)Gy were found and the software ROSY ESR dating was employed to convert De in age, using isotope concentrations determined by neutron activation analysis (NAA) and other information, resulting in (500 ± 100)ka, (320 ± 50) and (90 ± 10)ka considering the Combination Uptake (CU) model for Uranium uptake, set as an Early Uptake (EU) for dentine and Linear Uptake (LU) for enamel. There are scarce reports about Pleistocene Megafauna in this area. This paper presents the first dating of megafauna tooth and this study could contribute to improve the knowledge about the paleoclimate and paleoenvironment of this region and prompt more investigations in this area.

  1. Comparative Evaluation of Impact Strength of Fragment Bonded Teeth and Intact Teeth: An In Vitro Study

    OpenAIRE

    Venugopal, L.; Lakshmi, M Narasimha; Babu, Devatha Ashok; Kiran, V Ravi

    2014-01-01

    Background: To test and compare the impact strength of fragment bonded teeth with that of intact teeth by using impact testing machine (pendulum type) as a mode of load. Materials and Methods: Forty extracted, maxillary, central incisors selected for this study (20 control group and 20 experimental group). In experimental group, teeth crowns were fractured with a microtome at 2.5 mm from mesioincisal angle cervically, fractured portion is attached to original crown ...

  2. The dental cavities of equine cheek teeth: three-dimensional reconstructions based on high resolution micro-computed tomography

    Directory of Open Access Journals (Sweden)

    Kopke Susan

    2012-09-01

    Full Text Available Abstract Background Recent studies reported on the very complex morphology of the pulp system in equine cheek teeth. The continuous production of secondary dentine leads to distinct age-related changes of the endodontic cavity. Detailed anatomical knowledge of the dental cavities in all ages is required to explain the aetiopathology of typical equine endodontic diseases. Furthermore, data on mandibular and maxillary pulp systems is in high demand to provide a basis for the development of endodontic therapies. However, until now examination of the pulp cavity has been based on either sectioned teeth or clinical computed tomography. More precise results were expected by using micro-computed tomography with a resolution of about 0.1 mm and three-dimensional reconstructions based on previous greyscale analyses and histological verification. The aim of the present study was to describe the physiological configurations of the pulp system within a wide spectrum of tooth ages. Results Maxillary teeth: All morphological constituents of the endodontic cavity were present in teeth between 4 and 16 years: Triadan 06s displayed six pulp horns and five root canals, Triadan 07-10s five pulp horns and four root canals and Triadan 11s seven pulp horns and four to six root canals. A common pulp chamber was most frequent in teeth ≤5 years, but was found even in a tooth of 9 years. A large variety of pulp configurations was observed within 2.5 and 16 years post eruption, but most commonly a separation into mesial and distal pulp compartments was seen. Maxillary cheek teeth showed up to four separate pulp compartments but the frequency of two, three and four pulp compartments was not related to tooth age (P > 0.05. In Triadan 06s, pulp horn 6 was always connected to pulp horns 1 and 3 and root canal I. In Triadan 11s, pulp horns 7 and 8 were present in variable constitutions. Mandibular teeth: A common pulp chamber was present in teeth up to 15 years, but most

  3. Fluorescence properties of human teeth and dental calculus for clinical applications

    Science.gov (United States)

    Lee, Yong-Keun

    2015-04-01

    Fluorescent emission of human teeth and dental calculus is important for the esthetic rehabilitation of teeth, diagnosis of dental caries, and detection of dental calculus. The purposes of this review were to summarize the fluorescence and phosphorescence of human teeth by ambient ultraviolet (UV) light, to investigate the clinically relevant fluorescence measurement methods in dentistry, and to review the fluorescence of teeth and dental calculus by specific wavelength light. Dentine was three times more phosphorescent than enamel. When exposed to light sources containing UV components, the fluorescence of human teeth gives them the quality of vitality, and fluorescent emission with a peak of 440 nm is observed. Esthetic restorative materials should have fluorescence properties similar to those of natural teeth. Based on the fluorescence of teeth and restorative materials as determined with a spectrophotometer, a fluorescence parameter was defined. As to the fluorescence spectra by a specific wavelength, varied wavelengths were investigated for clinical applications, and several methods for the diagnosis of dental caries and the detection of dental calculus were developed. Since fluorescent properties of dental hard tissues have been used and would be expanded in diverse fields of clinical practice, these properties should be investigated further, embracing newly developed optical techniques.

  4. Evaluation of Reasons of Permanent Teeth Extraction in Iranian People (2009

    Directory of Open Access Journals (Sweden)

    Kakoei S.

    2012-02-01

    Full Text Available Statement of Problem: Everyday, many people lose their teeth because of various reasons. Knowing the reasons of tooth extraction would help officials to make decisions for helping patients saving their teeth.Purpose: The aim of this study was to investigate the reasons of teeth extraction in dental clinics and some private offices in the city of Kerman in November 2009- February 2010.Materials and Method: In this cross-sectional study, the reasons of teeth extraction in 2076 teeth from 1500 patients selected by simple sampling from Kerman dental clinics were evaluated. Personal data such as gender, age, educational level, occupation, and family size as well as the main reason of tooth extraction (decay, periodontal diseases, prosthesis, tooth impaction, orthodontic reasons, and patient’s request and the type of tooth were collected by a checklist. Data were analyzed in SPSS, version 11.5 using χ² test.Results: The two main reasons of tooth extraction were dental caries (43.6% and patient request (30.6%, respectively. Overall, the first and third molars of the lower jaw were the most commonly extracted teeth. There was a significant relationship between gender and tooth extraction because of caries and orthodontic reasons ( p <0.0001. Meanwhile, the patients’ age had a significant relationship with most teeth extraction reasons ( p <0.0001. Except for patient’s request, educational level had a significant impact on other teeth extraction reasons ( p <0.0001. Conclusion: According to the results of this study, the most common reasons of tooth extraction were dental caries and patient request despite their restorability. Preventive programs and routine dental examination are recommended.

  5. Magnesium content in jaws and teeth of rats with experimental caries

    Energy Technology Data Exchange (ETDEWEB)

    Djulgerova, E.; Bakyrdshiev, P. (Meditsinska Akademiya, Sofia (Bulgaria)); Kuleff, I. (Sofia Univ. (Bulgaria). Khimicheski Fakultet); Apostolov, D. (Bylgarska Akademiya na Naukite, Sofia. Inst. za Yadrena Izsledvaniya i Yadrena Energetika)

    1983-09-26

    The content of Mg is determined in the teeth and maxillary bones of rats by instrumental neutron activation analysis (INAA). The rats are fed with carbohydrate diet to which MgCl/sub 2/, NaF and methylene blue are added. An opposite influence of F ions and methylene blue on magnesium content in bones and teeth is found, while both additives reduce the caries.

  6. The magnesium content in jaws and teeth of rats with experimental caries

    International Nuclear Information System (INIS)

    The content of Mg is determined in the teeth and maxillary bones of rats by instrumental neutron activation analysis (INAA). The rats are fed with carbohydrate diet to which MgCl2, NaF and methylene blue are added. An opposite influence of F ions and methylene blue on magnesium content in bones and teeth is found, while both additives reduce the caries. (author)

  7. METHODS FOR AGE AND GROWTH DETERMINATION IN CEPHALOPODS

    OpenAIRE

    Svjetlana Krstulović Šifner

    2008-01-01

    Different methods used in age determination of cephalopods and their importance for assessment and management purposes for this group of marine organisms are described in the paper. Scientific investigations have proved that indirect methods (length frequency data) are not reliable enough and should always be accompanied with one direct method, although these methods are very demanding and time consuming. Today, statoliths are the most frequently used direct method for age estimation. These h...

  8. Non-financial determinants of the retirement age

    OpenAIRE

    Vermeer, C.A.F.

    2015-01-01

    This dissertation examines the importance of non-financial determinants for the individual retirement age. Recent increases in statutory retirement ages around the world point to the relevance of this issue. Financial incentives alone cannot fully explain observed retirement behavior. Chapter 2 examines the possible relevance of insights from behavioral economics and social norms for retirement and concludes that defaults, reference points and social norms are likely explanations for observed...

  9. Premating isolation is determined by larval rearing substrates in cactophilic Drosophila mojavensis. X. Age-specific dynamics of adult epicuticular hydrocarbon expression in response to different host plants.

    Science.gov (United States)

    Etges, William J; de Oliveira, Cassia C

    2014-06-01

    Analysis of sexual selection and sexual isolation in Drosophila mojavensis and its relatives has revealed a pervasive role of rearing substrates on adult courtship behavior when flies were reared on fermenting cactus in preadult stages. Here, we assessed expression of contact pheromones comprised of epicuticular hydrocarbons (CHCs) from eclosion to 28 days of age in adults from two populations reared on fermenting tissues of two host cacti over the entire life cycle. Flies were never exposed to laboratory food and showed significant reductions in average CHC amounts consistent with CHCs of wild-caught flies. Overall, total hydrocarbon amounts increased from eclosion to 14-18 days, well past age at sexual maturity, and then declined in older flies. Most flies did not survive past 4 weeks. Baja California and mainland populations showed significantly different age-specific CHC profiles where Baja adults showed far less age-specific changes in CHC expression. Adults from populations reared on the host cactus typically used in nature expressed more CHCs than on the alternate host. MANCOVA with age as the covariate for the first six CHC principal components showed extensive differences in CHC composition due to age, population, cactus, sex, and age × population, age × sex, and age × cactus interactions. Thus, understanding variation in CHC composition as adult D. mojavensis age requires information about population and host plant differences, with potential influences on patterns of mate choice, sexual selection, and sexual isolation, and ultimately how these pheromones are expressed in natural populations. Studies of drosophilid aging in the wild are badly needed. PMID:25360246

  10. About Kids' Teeth

    Science.gov (United States)

    ... for tooth decay and gum disease. Good oral hygiene is especially important for people wearing braces. And ... bottle pool around the teeth while the child sleeps. Bacteria in the mouth use these sugars as ...

  11. Malocclusion of teeth

    Science.gov (United States)

    ... are easier to clean and decrease risk of tooth decay and periodontal diseases ( gingivitis or periodontitis ). Eliminate strain ... braces and may permanently mark teeth or cause tooth decay if not properly cared for. You will need ...

  12. Supragingival Microbial Profiles of Permanent and Deciduous Teeth in Children with Mixed Dentition.

    Directory of Open Access Journals (Sweden)

    Weihua Shi

    Full Text Available The present study was designed to investigate the microbial profiles of teeth in different locations in mixed-dentition-stage children, and to compare the microbiomes of permanent and deciduous teeth in the same healthy oral cavity.Supragingival plaque samples of teeth in various locations-the first permanent molars, deciduous molars, deciduous canines and incisors and permanent incisors-were collected from 20 healthy mixed-dentition-stage children with 10-12 permanent teeth erupted. Plaque DNA was extracted, and the V3-V4 hypervariable region of the bacterial 16S rRNA gene was amplified and subjected to sequencing.On average, 18,051 high-quality sequences per sample were generated. Permanent tooth sites tended to host more diverse bacterial communities than those of deciduous tooth sites. A total of 12 phyla, 21 classes, 38 orders, 66 families, 74 genera were detected ultimately. Five predominant phyla (Proteobacteria, Firmicutes, Bacteroidetes, Fusobacteria and Actinobacteria were highly variable among sites. Of 26 genera with a mean relative abundance of >0.1%, 16 showed significant differences in relative abundance among the groups. More than 20% of the total operational taxonomical units were detected only in permanent or deciduous teeth. The variation in the microbial community composition was due mainly to permanent teeth being enriched in Actinomyces and deciduous teeth in Treponema. The core microbiome of supragingival plaque in mixed dentition comprised 19 genera with complex correlationships.Our results suggest differences in microbial diversity and composition between permanent and deciduous teeth sites in mixed dentition. Moreover, the core microbiome of these sites was determined. These findings enhance our understanding of the development of the native oral microbiota with age.

  13. Supragingival Microbial Profiles of Permanent and Deciduous Teeth in Children with Mixed Dentition

    Science.gov (United States)

    Shi, Weihua; Qin, Man; Chen, Feng; Xia, Bin

    2016-01-01

    Objectives The present study was designed to investigate the microbial profiles of teeth in different locations in mixed-dentition-stage children, and to compare the microbiomes of permanent and deciduous teeth in the same healthy oral cavity. Methods Supragingival plaque samples of teeth in various locations—the first permanent molars, deciduous molars, deciduous canines and incisors and permanent incisors—were collected from 20 healthy mixed-dentition-stage children with 10–12 permanent teeth erupted. Plaque DNA was extracted, and the V3–V4 hypervariable region of the bacterial 16S rRNA gene was amplified and subjected to sequencing. Results On average, 18,051 high-quality sequences per sample were generated. Permanent tooth sites tended to host more diverse bacterial communities than those of deciduous tooth sites. A total of 12 phyla, 21 classes, 38 orders, 66 families, 74 genera were detected ultimately. Five predominant phyla (Proteobacteria, Firmicutes, Bacteroidetes, Fusobacteria and Actinobacteria) were highly variable among sites. Of 26 genera with a mean relative abundance of >0.1%, 16 showed significant differences in relative abundance among the groups. More than 20% of the total operational taxonomical units were detected only in permanent or deciduous teeth. The variation in the microbial community composition was due mainly to permanent teeth being enriched in Actinomyces and deciduous teeth in Treponema. The core microbiome of supragingival plaque in mixed dentition comprised 19 genera with complex correlationships. Conclusion Our results suggest differences in microbial diversity and composition between permanent and deciduous teeth sites in mixed dentition. Moreover, the core microbiome of these sites was determined. These findings enhance our understanding of the development of the native oral microbiota with age. PMID:26752284

  14. Orthodontic forces released by low-friction versus conventional systems during alignment of apically or buccally malposed teeth.

    Science.gov (United States)

    Baccetti, Tiziano; Franchi, Lorenzo; Camporesi, Matteo; Defraia, Efisio

    2011-02-01

    The aim of the present study was to analyse the forces released by passive stainless steel self-ligating brackets (SLBs) and by a non-conventional elastomeric ligature-bracket system on conventional brackets ([slide ligatures on conventional brackets (SLCB)]) when compared with conventional elastomeric ligatures on conventional brackets (CLCB) during the alignment of apically or buccally malposed teeth in the maxillary arch. An experimental model consisting of five brackets was used to assess the forces released by the three different bracket-ligature systems with 0.012-inch super-elastic (SE) nickel-titanium (NiTi) wires in the presence of different amounts of apical or buccal canine misalignment of the canine (ranging from 1.5 to 6 mm). The forces released by each wire/bracket/ligature combination with the three different amounts of apical or buccal canine misalignment were tested 20 times. Comparisons between the different types of wire/bracket/ligature systems were carried out by means of analysis of variance on ranks with Dunnett's post hoc test (P systems. At 3 mm of apical misalignment a significantly greater amount of orthodontic force was released by SLB or SLCB when compared with CLCB, while no significant differences were found among the three systems at 3 mm of buccal canine displacement. When correction of a large amount of misalignment (6 mm) was attempted, a noticeable amount of force for alignment was still generated by the passive SLB and SLCB systems while no force was released in presence of CLCB. PMID:20631083

  15. The dynamic relationship between pathological migrating teeth and periodontal disease

    OpenAIRE

    Rathod, Surekha R; Kolte, Abhay P; Snehal Chintawar

    2013-01-01

    Background: Pathologic migration is defined as change in tooth position resulting from disruption of the forces that maintain teeth in normal position in relation to their arch. The disruption of equilibrium in tooth position may be caused by several etiologic factors. So, the aim of the study was to evaluate the pathologic tooth migration (PTM) in the upper anterior sextant and its relationship with predisposing and external factors such as bone loss, tooth loss, gingival inflammation, age, ...

  16. Relationship of deciduous teeth emergence with physical growth

    OpenAIRE

    Nadia L Soliman; Medhat A El-Zainy; Rania Mossad Hassan; Riham Mohamed Aly

    2012-01-01

    Introduction: Tooth eruption, recognized as an aspect of human growth and development, could possibly be influenced by a number of factors. It may reflect the general body development. Aim: The aim of the present research is to investigate the relationship of deciduous teeth emergence with physical growth (weight/height indices). Materials and Methods: A study was conducted among a sample of 1132 Egyptian infants whose ages range from 4 to 36 months. The sample was collected from so...

  17. ESR measurements of background doses in teeth of Japanese residents

    International Nuclear Information System (INIS)

    The background doses for the teeth of Japanese residents were obtained by electron spin resonance (ESR) method. The doses obtained from 77 of 92 samples are less than 100 mGy while the doses of the other samples are high up to 250 mGy. The doses for buccal part of the teeth are higher than lingual part possibly due to contributions from dental X ray examination. A positive correlation was found between the ages of the donors and the obtained doses. The averaged annual ESR dose was calculated to be 0.87 mGy/y. These doses have to be considered in actual retrospective dosimetry studies for possible radiation accidents. The statistically significant critical level for Japanese residents would be about 200 mGy for individual doses and about 100 mGy for averaged group doses for α = 5% for those with ages older than 50.

  18. Taking Care of Your Teeth

    Science.gov (United States)

    ... teeth are important in many ways. If you take care of them, they'll help take care of you. Strong, healthy teeth help you chew ... have some baby teeth? If you don't take care of your teeth, cavities and unhealthy gums will ...

  19. Spectroscopic Determination of Masses (and Implied Ages) for Red Giants

    Science.gov (United States)

    Ness, M.; Hogg, David W.; Rix, H.-W.; Martig, M.; Pinsonneault, Marc H.; Ho, A. Y. Q.

    2016-06-01

    The mass of a star is arguably its most fundamental parameter. For red giant stars, tracers luminous enough to be observed across the Galaxy, mass implies a stellar evolution age. It has proven to be extremely difficult to infer ages and masses directly from red giant spectra using existing methods. From the Kepler and apogee surveys, samples of several thousand stars exist with high-quality spectra and asteroseismic masses. Here we show that from these data we can build a data-driven spectral model using The Cannon, which can determine stellar masses to ∼0.07 dex from apogee dr12 spectra of red giants; these imply age estimates accurate to ∼0.2 dex (40%). We show that The Cannon constrains these ages foremost from spectral regions with CN absorption lines, elements whose surface abundances reflect mass-dependent dredge-up. We deliver an unprecedented catalog of 70,000 giants (including 20,000 red clump stars) with mass and age estimates, spanning the entire disk (from the Galactic center to R∼ 20 kpc). We show that the age information in the spectra is not simply a corollary of the birth-material abundances {{[Fe/H]}} and [α /{Fe}], and that, even within a monoabundance population of stars, there are age variations that vary sensibly with Galactic position. Such stellar age constraints across the Milky Way open up new avenues in Galactic archeology.

  20. Spectroscopic Determination of Masses (and Implied Ages) for Red Giants

    Science.gov (United States)

    Ness, M.; Hogg, David W.; Rix, H.-W.; Martig, M.; Pinsonneault, Marc H.; Ho, A. Y. Q.

    2016-06-01

    The mass of a star is arguably its most fundamental parameter. For red giant stars, tracers luminous enough to be observed across the Galaxy, mass implies a stellar evolution age. It has proven to be extremely difficult to infer ages and masses directly from red giant spectra using existing methods. From the Kepler and apogee surveys, samples of several thousand stars exist with high-quality spectra and asteroseismic masses. Here we show that from these data we can build a data-driven spectral model using The Cannon, which can determine stellar masses to ˜0.07 dex from apogee dr12 spectra of red giants; these imply age estimates accurate to ˜0.2 dex (40%). We show that The Cannon constrains these ages foremost from spectral regions with CN absorption lines, elements whose surface abundances reflect mass-dependent dredge-up. We deliver an unprecedented catalog of 70,000 giants (including 20,000 red clump stars) with mass and age estimates, spanning the entire disk (from the Galactic center to R˜ 20 kpc). We show that the age information in the spectra is not simply a corollary of the birth-material abundances {{[Fe/H]}} and [α /{Fe}], and that, even within a monoabundance population of stars, there are age variations that vary sensibly with Galactic position. Such stellar age constraints across the Milky Way open up new avenues in Galactic archeology.

  1. Visualization of in vitro evaluation of restored teeth with synthetic resins by neutron radiography

    International Nuclear Information System (INIS)

    The goal of the present study was to evaluate whether the technique of neutron radiography can provide information on strength and adherence in dental restoration with synthetic polymeric materials, particularly as a tool for the analysis of micro leakage and voids. Thus, tooth samples were drilled, producing cavities with similar dimensions in each tooth, and then carefully filled with eight types of resins that are the most commonly used by dentists. After exposing the tooth samples to a neutron beam, their radiographic images were analyzed. This technique gave good results showing that all the tooth samples were suitably restored. (author)

  2. High resolution neutron tomography applied to tooth fillings on real teeth by use of neutron lens

    International Nuclear Information System (INIS)

    Today tomography is a well known technique for nondestructive analysis of samples. By taking several X-ray pictures from an object, it is possible to make a 3D reconstruction. The same thing can be done with neutrons. Since very recent it is possible to produce a high-flux neutron beam. By looking at the attenuation of the neutron beam in the sample from different angles, it is possible to make a neutron tomography. The properties of neutrons are so much different from X-rays that a new era in tomography has started. Where X-rays have a hard time penetrating samples containing heavy elements (Pb, Bi, U, Hg, Au), neutrons just seem to walk through. But when the neutrons encounter samples containing light compounds like water, oil, paper, B, Li,... they are easily absorbed. This makes the use of neutrons for imaging complementary to the well known X-ray imaging. The most used tooth filling material nowadays is amalgam. Amalgam is a mixture of different metals, like silver, tin, copper, mercury. Mercury is dangerous for the human body when it enters the blood stream. These fillings are very dense and X-rays have a very hard time penetrating it. Neutrons are the ideal probe for investigation of these high density regions. The result of the tomography reveals information on the long term stability of amalgam fillings and could help the still ongoing debate on the safety of the fillings. (author)

  3. Electrical Aging Phenomena of Power Cables Aged by Switching Impulses

    Institute of Scientific and Technical Information of China (English)

    L.Cao; A.Zanwar; S.Grzybowski

    2013-01-01

    Due to the insufficient information regarding the aging phenomenon of cables caused by switching impulses,we aged 15 kV XLPE and EPR cable samples by 10000 switching impulses in experiments and tested them.Plus in order to compare the aging phenomenon under multi-stress conditions,additional EPR cable samples were aged by rated AC voltage and current with switching impulses superimposed.We used measurements of partial discharge parameters to monitor the cables' conditions during their aging process,and the AC breakdown voltages measurement to evaluate the cables after aging.Moreover,the Fourier transform infrared (FTIR) spectroscopy measurements revealed the changes of insulation materials after aging.The measurement results confirm that the accelerated aging of cable samples had taken place.The impacts of each individual aging factor are shown through the selected measurements and comparison.The study also helps to assess the reliability of the XLPE and EPR cables under similar condition while serving in power systems.

  4. Microscopic age determination of human skeletons including an unknown but calculable variable

    DEFF Research Database (Denmark)

    Wallin, Johan Albert; Tkocz, Izabella; Kristensen, Gustav

    1994-01-01

    Histomorphometric semi-automatic image analysis of cross-sections of 101 femoral diaphyseal bone sections were performed to reconsider to what degree osteon remodelling in the outer cortex is affected by age. The data were analysed statistically using the generalized least squares method. The mod...... impression of higher precision of age determination. The present study demonstrates that determination of age at death through microscopic bone morphometry is considerably less precise than generally stated in the literature....

  5. Fracture resistance exhibited by endodontically treated and retreated teeth shaped by ProTaper NEXT versus WaveOne: An in vitro study

    Directory of Open Access Journals (Sweden)

    Neha Deepak Khalap

    2015-01-01

    Full Text Available Aim: To compare the fracture resistance exhibited by teeth after primary endodontic treatment and retreatment. Materials and Methods: One hundred freshly extracted human teeth were selected. 20 samples served as control (untreated. Eighty experimental samples were divided into two groups (n = 40 for instrumentation using rotary Protaper NEXT (PTN or reciprocating WaveOne (WO files and obturated using warm lateral compaction. Half of the samples (n = 20 from each group were subjected to a load. The remaining half were subjected to retreatment using Protaper universal retreatment files (RFs followed by a file larger than the master apical file used in groups 1 and 2 and reobturated. Group A: Control, Group B: PTN + obturation, Group C: WO + obturation, Group D: RF + PTN + obturation and Group E: RF + WO + obturation. The retreatment specimens were also subjected to load and the readings acquired were statistically analyzed. Result: When compared between the groups, control group exhibited the highest fracture resistance (P < 0.01. When multiple tests were performed, Group E exhibited significantly less fracture resistance (P < 0.01. Conclusion: Endodontic treatment and retreatment both results in lowering the fracture resistance of a tooth.

  6. Spectroscopic determination of masses (and implied ages) for red giants

    Science.gov (United States)

    Ness, Melissa; Hogg, David W.; Rix, Hans-Walter; Martig, Marie; Ho, Anna

    2016-01-01

    The mass of a star is arguably its most fundamental parameter and for red giant stars it implies a stellar evolution age. Stellar masses and ages have never been derived directly from spectra of red giants. However, using the APOGEE Kepler sample of stars, (the APOKASC sample), with high-quality spectra and astroseismic masses, we can build a data-driven spectral model using THE CANNON (arXiv:1501.07604) to infer stellar mass and therefore age from stellar spectra. We determine stellar masses to 0.07 dex from APOGEE DR12 spectra of red giants; these imply age estimates accurate to 0.2 dex (40 percent). THE CANNON constrains the ages foremost from spectral regions with particular absorption lines, elements whose surface abundances reflect mass-dependent dredge-up. We deliver an unprecedented catalog of 85,000 giants (including 20,000 red-clump stars) with mass and age estimates, spanning the entire disk (from the Galactic center to R ˜ 20 kpc). Such stellar age constraints across the Milky Way open up new avenues in Galactic archeology.

  7. Determinants of active aging among the elderly Portuguese population

    OpenAIRE

    Calha, António

    2014-01-01

    Our aim in this communication is to contribute to the characterization of motor skills of the Portuguese elderly population, determining their relationship with age and with the subjective health status. We characterized the capabilities of gross motor skills (GMS) and fine motor skills (FMS) based on two indices that aggregate various indicators.

  8. Biological psychological and social determinants of old age: bio-psycho-social aspects of human aging.

    Science.gov (United States)

    Dziechciaż, Małgorzata; Filip, Rafał

    2014-01-01

    The aging of humans is a physiological and dynamic process ongoing with time. In accordance with most gerontologists' assertions it starts in the fourth decade of life and leads to death. The process of human aging is complex and individualized, occurs in the biological, psychological and social sphere. Biological aging is characterized by progressive age-changes in metabolism and physicochemical properties of cells, leading to impaired self-regulation, regeneration, and to structural changes and functional tissues and organs. It is a natural and irreversible process which can run as successful aging, typical or pathological. Biological changes that occur with age in the human body affect mood, attitude to the environment, physical condition and social activity, and designate the place of seniors in the family and society. Psychical ageing refers to human awareness and his adaptability to the ageing process. Among adaptation attitudes we can differentiate: constructive, dependence, hostile towards others and towards self attitudes. With progressed age, difficulties with adjustment to the new situation are increasing, adverse changes in the cognitive and intellectual sphere take place, perception process involutes, perceived sensations and information received is lowered, and thinking processes change. Social ageing is limited to the role of an old person is culturally conditioned and may change as customs change. Social ageing refers to how a human being perceives the ageing process and how society sees it. PMID:25528930

  9. Reliability of Third Molar Development for Age Estimation by Radiographic Examination (Demirjian’s Method)

    OpenAIRE

    Naik, Sushil B; Swapnil N Patil; Kamble, Seema D; Mowade, Tushar; Motghare, Pavan

    2014-01-01

    Introduction: Dental age estimation methods are of particular value because teeth are highly resistant to mechanical, chemical, or physical impacts and time. Teeth are the strongest parts in the human body and are therefore very resistant to external influences, such as extreme temperatures, explosions, and other extreme conditions, which make them available for extensive postmortem periods.

  10. Survival of Composite Resin Restorations of severely Decayed Primary Anterior Teeth retained by Glass Fiber Posts or Reversed-orientated Metal Posts

    Science.gov (United States)

    Ranjkesh, Bahram; Lovschall, Henrik; Erfanparast, Leila; Jafarabadi, Mohammad A; Oskouei, Sina Ghertasi; Isidor, Flemming

    2016-01-01

    ABSTRACT Aim: The aim of this study was to compare the survival of composite resin restorations retained by glass fiber posts or reversed-orientated (upside-down) metal posts in severely decayed primary anterior teeth after 6, 12, and 18 months. Materials and methods: A total of forty-four 3- to 5-year-old children with bilateral severely decayed primary maxillary canines were included. Patients were treated under general anesthesia. After pulpectomy, an intracanal post was seated in the primary maxillary canine on each side: either a glass fiber post or a metallic post in reversed orientation and teeth restored with light-cured composite. Survival rate of each technique was evaluated at predetermined follow-ups and data were analyzed with McNemar’s test (α = 0.05). Results: The difference in survival of restorations retained by two types of posts was not statistically significant in clinical and radiographical evaluations after 6, 12, and 18 months. The survival rate of reversed-orientated metal and glass fiber posts after 18 months was 81.1 and 67.6% respectively (p = 0.14). Conclusion: Reversed-orientated metal post did not show lower clinical survival compared with glass fiber posts in 18-month follow-up. Hence, reversed-orientated metal post can be considered as a potential method to obtain retention for composite restorations in severely decayed primary anterior teeth. How to cite this article: Vafaei A, Ranjkesh B, L0vschall H, Erfanparast L, Jafarabadi MA, Oskouei SG, Isidor F. Survival of Composite Resin Restorations of severely Decayed Primary Anterior Teeth retained by Glass Fiber Posts or Reversed-orientated Metal Posts. Int J Clin Pediatr Dent 2016;9(2):109-113. PMID:27365929

  11. Determination of U-Pb age and rare earth element concentrations of zircons from Cenozoic intrusions in northeastern China by laser ablation ICP-MS

    Institute of Scientific and Technical Information of China (English)

    YUAN Honglin; WU Fuyuan; GAO Shan; LIU Xiaoming; XU Ping; SUN Deyou

    2003-01-01

    Using the in situ zircon U-Pb dating method of LA-ICPMS, we analyzed the 31 Ma old SHRIMP U-Pb age of the Yongsheng nepheline syenite from southern Jilin Province under different spot sizes. The obtained ages are comparable with that of SHRIMP in both accuracy and precision. The age is also identical to that of the Yinmawanshan gabbro from the Liaodong Peninsula within error. Both the Yongsheng nepheline syenite and the Yinmawanshan gabbro represent the youngest known exposed intrusions in northeastern and even eastern China. The results indicate the Eocene mantle-derived magmatic underplating, and the rapid crustal uplifting of this region since 30 Ma. The analyses also document extremely high LREE concentrations and relatively flat REE patterns for the zircons from the Yongsheng nepheline syenite, which represent a new type of zircon REE pattern.

  12. Estimation of dental age by Nolla’s method using orthopantomographs among rural free residential school children

    OpenAIRE

    Nandlal B, Karthikeya Patil, Ravi S

    2014-01-01

    Introduction: Teeth and dental restorations are resistant to destruction by fire and the elements are therefore useful in identification. This permits accurate identification of a missing child or remains. The Rural Residential free school at Suttur houses a large number of inmates and hence dental records are kept for their identification. Objective: Estimation of Age of children. Methods: Orthopantomographs were used to study for estimation of age of children, using a Nolla’s method of den...

  13. Results after replantation of avulsed permanent teeth. II. Periodontal healing and the role of physiologic storage and antiresorptive-regenerative therapy.

    Science.gov (United States)

    Pohl, Yango; Filippi, Andreas; Kirschner, Horst

    2005-04-01

    The status of the periodontal ligament (PDL) and of the pulp are decisive for the healing of avulsed and replanted teeth. A tooth rescue box was developed and distributed to offer optimal storage conditions for avulsed teeth. The therapy comprised extraoral endodontic treatment and applications of medicaments to enhance periodontal healing. In this long-term clinical study the healing results following avulsion and replantation were investigated. Twenty-eight permanent teeth in 24 patients were evaluated. The extraoral storage media and periods varied considerably. Soon after avulsion six teeth were stored in a cell culture medium (tooth rescue box Dentosafe) for 1-53 h; the PDL was defined as not compromised. Sixteen teeth were stored in a non-physiologic situation temporarily, the PDL was considered as compromised. Six teeth were stored in non-physiologic conditions for longer periods; the condition of the PDL was defined as hopeless. On 14 teeth antiresorptive-regenerative therapy (ART) with the local application of glucocorticoids and enamel matrix derivative and the systemic administration of doxycyclin was used. In all teeth extraoral endodontic treatment by retrograde insertion of posts was performed. The mean observation period was 31.2 months (+/-24.1; 5.1-100.2; median: 23.8). All six teeth rescued physiologically healed with a functional PDL (functional healing, FH) irrespective of the storage period. Of eight teeth with a compromised PDL on which ART was used, three teeth healed with a functional PDL. All other teeth showed replacement resorption, in three teeth additionally infection-related resorption was recorded. The predominant influence on the healing results was the immediate physiologic rescue of avulsed teeth (chi-square, P = 0.0001). The use of ART seemed to support FH (chi-square, P = 0.0547) in teeth with a compromised PDL. No other factors (maturity of roots, crown fractures, gender, age, antibiotics) were related to healing. In a linear

  14. SU-E-J-58: Dosimetric Verification of Metal Artifact Effects: Comparison of Dose Distributions Affected by Patient Teeth and Implants

    Energy Technology Data Exchange (ETDEWEB)

    Lee, M; Kang, S; Lee, S; Suh, T [Department of Biomedical Engineering, College of Medicine, The Catholic University of Korea, Seoul (Korea, Republic of); Research Institute of Biomedical Engineering, College of Medicine, The Catholic University of Korea (Korea, Republic of); Lee, J [Konkuk University Medical Center, Seoul (Korea, Republic of); Research Institute of Health Science, Korea University, Seoul (Korea, Republic of); Park, J [Research Institute of Biomedical Engineering, College of Medicine, The Catholic University of Korea (Korea, Republic of); Dept. of Pediatrics and Molecular Imaging Program at Stanford, Stanford University, Stanford (United States); Park, H [Department of Radiation Oncology, Ajou University School of Medicine, Suwon (Korea, Republic of); Lee, B [Research Institute of Health Science, Korea University, Seoul (Korea, Republic of); Daejeon Sun Hospital, Daejeon (Korea, Republic of)

    2014-06-01

    Purpose: Implant-supported dentures seem particularly appropriate for the predicament of becoming edentulous and cancer patients are no exceptions. As the number of people having dental implants increased in different ages, critical dosimetric verification of metal artifact effects are required for the more accurate head and neck radiation therapy. The purpose of this study is to verify the theoretical analysis of the metal(streak and dark) artifact, and to evaluate dosimetric effect which cause by dental implants in CT images of patients with the patient teeth and implants inserted humanoid phantom. Methods: The phantom comprises cylinder which is shaped to simulate the anatomical structures of a human head and neck. Through applying various clinical cases, made phantom which is closely allied to human. Developed phantom can verify two classes: (i)closed mouth (ii)opened mouth. RapidArc plans of 4 cases were created in the Eclipse planning system. Total dose of 2000 cGy in 10 fractions is prescribed to the whole planning target volume (PTV) using 6MV photon beams. Acuros XB (AXB) advanced dose calculation algorithm, Analytical Anisotropic Algorithm (AAA) and progressive resolution optimizer were used in dose optimization and calculation. Results: In closed and opened mouth phantom, because dark artifacts formed extensively around the metal implants, dose variation was relatively higher than that of streak artifacts. As the PTV was delineated on the dark regions or large streak artifact regions, maximum 7.8% dose error and average 3.2% difference was observed. The averaged minimum dose to the PTV predicted by AAA was about 5.6% higher and OARs doses are also 5.2% higher compared to AXB. Conclusion: The results of this study showed that AXB dose calculation involving high-density materials is more accurate than AAA calculation, and AXB was superior to AAA in dose predictions beyond dark artifact/air cavity portion when compared against the measurements.

  15. SU-E-J-58: Dosimetric Verification of Metal Artifact Effects: Comparison of Dose Distributions Affected by Patient Teeth and Implants

    International Nuclear Information System (INIS)

    Purpose: Implant-supported dentures seem particularly appropriate for the predicament of becoming edentulous and cancer patients are no exceptions. As the number of people having dental implants increased in different ages, critical dosimetric verification of metal artifact effects are required for the more accurate head and neck radiation therapy. The purpose of this study is to verify the theoretical analysis of the metal(streak and dark) artifact, and to evaluate dosimetric effect which cause by dental implants in CT images of patients with the patient teeth and implants inserted humanoid phantom. Methods: The phantom comprises cylinder which is shaped to simulate the anatomical structures of a human head and neck. Through applying various clinical cases, made phantom which is closely allied to human. Developed phantom can verify two classes: (i)closed mouth (ii)opened mouth. RapidArc plans of 4 cases were created in the Eclipse planning system. Total dose of 2000 cGy in 10 fractions is prescribed to the whole planning target volume (PTV) using 6MV photon beams. Acuros XB (AXB) advanced dose calculation algorithm, Analytical Anisotropic Algorithm (AAA) and progressive resolution optimizer were used in dose optimization and calculation. Results: In closed and opened mouth phantom, because dark artifacts formed extensively around the metal implants, dose variation was relatively higher than that of streak artifacts. As the PTV was delineated on the dark regions or large streak artifact regions, maximum 7.8% dose error and average 3.2% difference was observed. The averaged minimum dose to the PTV predicted by AAA was about 5.6% higher and OARs doses are also 5.2% higher compared to AXB. Conclusion: The results of this study showed that AXB dose calculation involving high-density materials is more accurate than AAA calculation, and AXB was superior to AAA in dose predictions beyond dark artifact/air cavity portion when compared against the measurements

  16. Age determination in roe deer - a new approach to tooth wear evaluated on known age individuals

    DEFF Research Database (Denmark)

    Høye, Toke Thomas

    2006-01-01

    A novel, simple, and objective method is presented for ageing roe deer Capreolus capreolus (Linnaeus, 1758) evaluated on 471 lower jaws from roe deer of known age (351 with permanent premolars). It is based on tooth eruption patterns and presence/absence of wear characters in jaws from roe deer...... originate from two separated Danish roe deer populations exposed to contrasting habitats, but no difference in wear rate is found between populations. Thus, previous concern about the validity of age determination methods based on tooth wear may have been overstated. The findings demonstrate that objective...

  17. Radiographic Assessment of the Technical Quality and Periapical Health of Root-Filled Teeth Performed by General Practitioners in a Turkish Subpopulation

    Directory of Open Access Journals (Sweden)

    E. Tarim Ertas

    2013-01-01

    Full Text Available Aim. The aim of this study was to evaluate by means of radiographs the technical quality of root fillings performed by dental practitioners. Methods and Material. Standardized periapical radiographs were made on 484 patients who received endodontic treatment in private practice. A total of 831 endodontically treated teeth with 1448 roots were evaluated for technical quality of the root canal filling and the periapical status of the teeth. Also, the apical status of each root-filled tooth was assessed according to the length, density, and taper of root fillings, and the presence of apical transportation, broken root instruments, and overfilled sealer or gutta-percha material was recorded for each root canal. Results. Of the endodontically treated teeth 26.6% had healthy periapical tissues, while technically good endodontic treatment constituted 12.8%. Based on the treatment success, there was no significant difference between the tooth groups. Statistical analysis of the data did not demonstrate statistically significant differences between the various parameters that were evaluated (. Conclusions. Technical quality of root fillings in a population who received treatment in private practice was poor and was consistent with a low prevalence of apical health. The probable reasons for this failure are multifactorial and may be improved if the operators improve their skills with continuing postgraduate education programs.

  18. Delayed replantation of avulsed teeth

    Directory of Open Access Journals (Sweden)

    Adil N

    2007-05-01

    Full Text Available Dental injuries are very common and their extent has been classified by Ellis. Avulsion of tooth is a grievous injury and ranges from 1-16% among the traumatic injuries, of which maxillary anterior are commonest. Reimplantation of avulsed teeth is a standard procedure. However, it has certain limitations. Most often their management is very challenging. In this case report we are presenting the management of maxillary incisors by replantation after 36 hrs in a 12 year old girl.

  19. Delayed replantation of avulsed teeth

    OpenAIRE

    Adil N; Ahmed S; Jindal M; Arshad S

    2007-01-01

    Dental injuries are very common and their extent has been classified by Ellis. Avulsion of tooth is a grievous injury and ranges from 1-16% among the traumatic injuries, of which maxillary anterior are commonest. Reimplantation of avulsed teeth is a standard procedure. However, it has certain limitations. Most often their management is very challenging. In this case report we are presenting the management of maxillary incisors by replantation after 36 hrs in a 12 year old girl.

  20. Dental maturity of Saudi children: Role of ethnicity in age determination

    International Nuclear Information System (INIS)

    Demirjian's dental maturity scores and curves have been widely used for human age determination. Several authors have reported considerable differences between the true and estimated age based on the Demirjian curves, which have been accounted for by ethnicity. The purpose of the current study was to assess the role of ethnicity-specific dental maturation curves in age estimation of Saudi children. A sample of 452 healthy Saudi children aged 4 to 14 years were aged based on the original French-Canadian Demirjian curves and several modified Demirjian curves specified for certain ethnic groups: Saudi, Kuwaiti, Polish, Dutch, Pakistani, and Belgian. One-way ANOVA and a post hoc Scheffe's test were used to assess the differences between chronological age and dental age estimated by the different curves (P<0.05). The curves designed for Dutch, Polish, Saudi, and Belgian (5th percentile) populations had a significantly lower error in estimating age than the original French-Canadian and Belgian (50th percentile) curves. The optimal curve for males was the Saudi one, with a mean absolute difference between estimated age and chronological age of 8.6 months. For females, the optimal curve was the Polish one, with a mean absolute difference of 7.4 months. It was revealed that accurate age determination was not related to certain ethnicity-specific curves. We conclude that ethnicity might play a role in age determination, but not a principal one.

  1. Dental maturity of Saudi children: Role of ethnicity in age determination

    Energy Technology Data Exchange (ETDEWEB)

    Baghdadi, Ziad D. [Dept. of Preventive Dentistry, Riyadh Colleges of Dentistry and Pharmacy, Riyadh (Saudi Arabia)

    2013-12-15

    Demirjian's dental maturity scores and curves have been widely used for human age determination. Several authors have reported considerable differences between the true and estimated age based on the Demirjian curves, which have been accounted for by ethnicity. The purpose of the current study was to assess the role of ethnicity-specific dental maturation curves in age estimation of Saudi children. A sample of 452 healthy Saudi children aged 4 to 14 years were aged based on the original French-Canadian Demirjian curves and several modified Demirjian curves specified for certain ethnic groups: Saudi, Kuwaiti, Polish, Dutch, Pakistani, and Belgian. One-way ANOVA and a post hoc Scheffe's test were used to assess the differences between chronological age and dental age estimated by the different curves (P<0.05). The curves designed for Dutch, Polish, Saudi, and Belgian (5th percentile) populations had a significantly lower error in estimating age than the original French-Canadian and Belgian (50th percentile) curves. The optimal curve for males was the Saudi one, with a mean absolute difference between estimated age and chronological age of 8.6 months. For females, the optimal curve was the Polish one, with a mean absolute difference of 7.4 months. It was revealed that accurate age determination was not related to certain ethnicity-specific curves. We conclude that ethnicity might play a role in age determination, but not a principal one.

  2. Determinants of iron accumulation in the normal aging brain.

    Science.gov (United States)

    Pirpamer, Lukas; Hofer, Edith; Gesierich, Benno; De Guio, François; Freudenberger, Paul; Seiler, Stephan; Duering, Marco; Jouvent, Eric; Duchesnay, Edouard; Dichgans, Martin; Ropele, Stefan; Schmidt, Reinhold

    2016-07-01

    In a recent postmortem study, R2* relaxometry in gray matter (GM) of the brain has been validated as a noninvasive measure for iron content in brain tissue. Iron accumulation in the normal aging brain is a common finding and relates to brain maturation and degeneration. The goal of this study was to assess the determinants of iron accumulation during brain aging. The study cohort consisted of 314 healthy community-dwelling participants of the Austrian Stroke Prevention Study. Their age ranged from 38-82 years. Quantitative magnetic resonance imaging was performed on 3T and included R2* mapping, based on a 3D multi-echo gradient echo sequence. The median of R2* values was measured in all GM regions, which were segmented automatically using FreeSurfer. We investigated 25 possible determinants for cerebral iron deposition. These included demographics, brain volume, lifestyle factors, cerebrovascular risk factors, serum levels of iron, and single nucleotide polymorphisms related to iron regulating genes (rs1800562, rs3811647, rs1799945, and rs1049296). The body mass index (BMI) was significantly related to R2* in 15/32 analyzed brain regions with the strongest correlations found in the amygdala (p = 0.0091), medial temporal lobe (p = 0.0002), and hippocampus (p ≤ 0.0001). Further associations to R2* values were found in deep GM for age and smoking. No significant associations were found for gender, GM volume, serum levels of iron, or iron-associated genetic polymorphisms. In conclusion, besides age, the BMI and smoking are the only significant determinants of brain iron accumulation in normally aging subjects. Smoking relates to iron deposition in the basal ganglia, whereas higher BMI is associated with iron content in the neocortex following an Alzheimer-like distribution. PMID:27255824

  3. Supernumerary teeth in clinical practice

    Directory of Open Access Journals (Sweden)

    Anna K. Szkaradkiewicz

    2011-07-01

    Full Text Available Introduction: Hyperdontia is the condition of having supernumerary teeth, or teeth which appear in addition to the regular number of teeth. The prevalence rates of supernumerary teeth in the permanent dentition amounts 0.1-6.9%, and in deciduous dentition 0.4-0.8%. The presence of supernumerary teeth can be found in everyday dental practice.Case presentation: We describe 3 cases of patients with supernumerary teeth. First patient had supernumerary lateral incisor 12s, second - premolar fused, multicuspid, supernumerary deciduous tooth 64s of having several interconnected roots, and third - erupted odontoma between teeth 13 and 14. In all cases treatment involved the removal of the supernumerary tooth.Conclusions: The decision on proceeding with the supernumerary teeth should be based on the full clinical picture and interview. Early diagnosis and removal of supernumerary teeth allow to avoid or reduce possible complications.

  4. Differences by Age Groups in Health Care Spending

    OpenAIRE

    Fisher, Charles R.

    1980-01-01

    This paper presents differences by age in health care spending by type of expenditure and by source of funds through 1978. Use of health care services generally increases with age. The average health bill reached $2,026 for the aged in 1978, $764 for the intermediate age group, and $286 for the young. Biological, demographic, and policy factors determine each age group's share of health spending. Public funds financed over three-fifths of the health expenses of the aged, with Medicare and Med...

  5. Levels of lead, cadmium, copper, iron, and zinc in deciduous teeth of children living in Irbid, Jordan by ICP-OES: some factors affecting their concentrations.

    Science.gov (United States)

    Alomary, A; Al-Momani, I F; Obeidat, S M; Massadeh, A M

    2013-04-01

    The aim of this study was to measure the concentrations of lead (Pb), cadmium (Cd), copper (Cu), iron (Fe), and zinc (Zn) in deciduous teeth from children living in Jordan and to investigate the affecting factors. Deciduous teeth samples (n = 320, without fillings) were collected from 5- to 12-year-old children and analyzed for Pb, Cd, Cu, Fe, and Zn using inductively coupled plasma-optical emission spectrometry. A questionnaire was used to gather information on each child, such as sex, age, tooth type (incisors, canines, and molars), tooth position within the mouth (upper or lower jaw), caries status, presence of amalgam fillings inside the mouth, type of drinking water (tap water, home purified water, and plant purified water), and zone of residence (close to or far from heavy traffic roads). The mean concentrations of Pb, Cd, Cu, Fe, and Zn were 30.26, 0.55, 6.23, 34.72, and 128.21 μg/g, respectively. Our results indicate that there is a clear relation between the concentrations of the metals analyzed in this study and tooth type, tooth position within the mouth, caries status, presence of amalgam fillings inside the mouth, and type of drinking water. No significant differences in the concentrations of the five metals analyzed were observed due to sex. Our results also show that no significant difference among Pb, Cd, Cu, Fe, and Zn concentrations and age among the ages of 5-6, 7-8, 9-10, and 11-12, except for Pb, which decreases at age 11-12. PMID:22851195

  6. The Replacement of Missing Teeth

    OpenAIRE

    Zarb, George A.

    1988-01-01

    Dentists have used a great deal of ingenuity in replacing lost teeth. Until recently, however, it was not possible to duplicate the natural situation and attach tooth-root analogues to the host bone. Osseointegration allows such an attachment, in which threaded unalloyed titanium implants are placed in the bone by means of a meticulous surgical procedure. The documented successful use of this process has already altered profoundly the predicament of the edentulous patient. The application of ...

  7. Influence of marine sources on 14C ages : isotopic data from Watom Island, Papua New Guinea inhumations and pig teeth in light of new dietary standards

    International Nuclear Information System (INIS)

    Gauging the effect of 14C-depleted marine foods on radiocarbon ages requires an accurate assessment of the likely proportion of marine foods in the diet. Several factors must be considered, including region-specific δ13C, δ15N and δ34S data values (regional stable isotope values can differ from global averages), temporal variations in δ13C which offset values in modern dietary standards by up to 1.5 permille, and that modelling which considers only 13C may overestimate the contribution of various dietary sources. Here, we compare previous calculations by linear interpolation of δ13C and a complex computer simulation of marine contribution to the diet of inhumations from the SAC archaeological site Watom Island, Papua New Guinea, with the ISOSOURCE mixing model and a revised database of regional dietary sources and their isotopic values, to estimate marine diet contributions and radiocarbon offsets for burials from the SAC site. Though different estimates of marine contribution to diet do not significantly alter previous calibrations of radiocarbon ages for the inhumations, the new ISOSOURCE calculations challenge the idea of excessive exploitation of marine resources and support evidence for arboriculture and horticulture being a major component in Lapita diet. (author). 87 refs., 3 figs., 8 tabs

  8. ESTHETICS IN PRIMARY TEETH

    Directory of Open Access Journals (Sweden)

    Mathew Renu Ann

    2013-08-01

    Full Text Available Dental esthetics is an integral part of facial esthetics. Esthetic problems in childhood and adolescence can have a significant effect on psychosocial development and interaction with peers. Esthetic restoration of primary anterior teeth can be especially challenging due to the small size of the teeth, close proximity of pulp to tooth surface, relatively thin enamel and surface area for bonding, issues related to child behavior and finally cost of the treatment. The advent of different techniques, devices, and materials helps in creating beautiful restorations which help children and adolescents improve their self-image.

  9. Genetic background of supernumerary teeth.

    Science.gov (United States)

    Subasioglu, Asli; Savas, Selcuk; Kucukyilmaz, Ebru; Kesim, Servet; Yagci, Ahmet; Dundar, Munis

    2015-01-01

    Supernumerary teeth (ST) are odontostomatologic anomaly characterized by as the existence excessive number of teeth in relation to the normal dental formula. This condition is commonly seen with several congenital genetic disorders such as Gardner's syndrome, cleidocranial dysostosis and cleft lip and palate. Less common syndromes that are associated with ST are; Fabry Disease, Ellis-van Creveld syndrome, Nance-Horan syndrome, Rubinstein-Taybi Syndrome and Trico-Rhino-Phalangeal syndrome. ST can be an important component of a distinctive disorder and an important clue for early diagnosis. Certainly early detecting the abnormalities gives us to make correct management of the patient and also it is important for making well-informed decisions about long-term medical care and treatment. In this review, the genetic syndromes that are related with ST were discussed. PMID:25713500

  10. Age determination of 15 old to intermediate-age small Magellanic cloud star clusters

    International Nuclear Information System (INIS)

    We present color-magnitude diagrams in the V and I bands for 15 star clusters in the Small Magellanic Cloud (SMC) based on data taken with the Very Large Telescope (VLT, Chile). We selected these clusters from our previous work, wherein we derived cluster radial velocities and metallicities from calcium II infrared triplet (CaT) spectra also taken with the VLT. We discovered that the ages of six of our clusters have been appreciably underestimated by previous studies, which used comparatively small telescopes, graphically illustrating the need for large apertures to obtain reliable ages of old and intermediate-age SMC star clusters. In particular, three of these clusters, L4, L6, and L110, turn out to be among the oldest SMC clusters known, with ages of 7.9 ± 1.1, 8.7 ± 1.2, and 7.6 ± 1.0 Gyr, respectively, helping to fill a possible 'SMC cluster age gap'. Using the current ages and metallicities from Parisi et al., we analyze the age distribution, age gradient, and age-metallicity relation (AMR) of a sample of SMC clusters measured homogeneously. There is a suggestion of bimodality in the age distribution but it does not show a constant slope for the first 4 Gyr, and we find no evidence for an age gradient. Due to the improved ages of our cluster sample, we find that our AMR is now better represented in the intermediate/old period than we had derived in Parisi et al., where we simply took ages available in the literature. Additionally, clusters younger than ∼4 Gyr now show better agreement with the bursting model of Pagel and Tautvaišienė, but we confirm that this model is not a good representation of the AMR during the intermediate/old period. A more complicated model is needed to explain the SMC chemical evolution in that period.

  11. Age determination of 15 old to intermediate-age small Magellanic cloud star clusters

    Energy Technology Data Exchange (ETDEWEB)

    Parisi, M. C.; Clariá, J. J.; Piatti, A. E. [Observatorio Astronómico, Universidad Nacional de Córdoba, Laprida 854, Córdoba, CP 5000 (Argentina); Geisler, D.; Leiton, R. [Departamento de Astronomía, Universidad de Concepción, Casilla 160-C, Concepción (Chile); Carraro, G. [European Southern Observatory, Casilla 19001, Santiago de Chile (Chile); Costa, E. [Universidad de Chile, Casilla 36-D, Santiago de Chile (Chile); Grocholski, A. J. [Department of Physics and Astronomy, Louisiana State University, 202 Nicholson Hall, Tower Drive, Baton Rouge, LA 70803-4001 (United States); Sarajedini, A., E-mail: celeste@oac.uncor.edu, E-mail: claria@oac.uncor.edu, E-mail: andres@oac.uncor.edu, E-mail: dgeisler@astro-udec.cl, E-mail: roger.leiton@astro-udec.cl, E-mail: gcarraro@eso.org, E-mail: costa@das.uchile.cl, E-mail: grocholski@phys.lsu.edu, E-mail: ata@astro.ufl.edu [Department of Astronomy, University of Florida, P.O. Box 112055, Gainesville, FL 32611 (United States)

    2014-04-01

    We present color-magnitude diagrams in the V and I bands for 15 star clusters in the Small Magellanic Cloud (SMC) based on data taken with the Very Large Telescope (VLT, Chile). We selected these clusters from our previous work, wherein we derived cluster radial velocities and metallicities from calcium II infrared triplet (CaT) spectra also taken with the VLT. We discovered that the ages of six of our clusters have been appreciably underestimated by previous studies, which used comparatively small telescopes, graphically illustrating the need for large apertures to obtain reliable ages of old and intermediate-age SMC star clusters. In particular, three of these clusters, L4, L6, and L110, turn out to be among the oldest SMC clusters known, with ages of 7.9 ± 1.1, 8.7 ± 1.2, and 7.6 ± 1.0 Gyr, respectively, helping to fill a possible 'SMC cluster age gap'. Using the current ages and metallicities from Parisi et al., we analyze the age distribution, age gradient, and age-metallicity relation (AMR) of a sample of SMC clusters measured homogeneously. There is a suggestion of bimodality in the age distribution but it does not show a constant slope for the first 4 Gyr, and we find no evidence for an age gradient. Due to the improved ages of our cluster sample, we find that our AMR is now better represented in the intermediate/old period than we had derived in Parisi et al., where we simply took ages available in the literature. Additionally, clusters younger than ∼4 Gyr now show better agreement with the bursting model of Pagel and Tautvaišienė, but we confirm that this model is not a good representation of the AMR during the intermediate/old period. A more complicated model is needed to explain the SMC chemical evolution in that period.

  12. Determination of uranium and thorium by neutron activation analysis applied to fossil samples dating

    Energy Technology Data Exchange (ETDEWEB)

    Ticianelli, Regina B.; Figueiredo, Ana Maria Graciano; Zahn, Guilherme S. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Kinoshita, Angela; Baffa, Oswaldo [Universidade de Sao Paulo (FFCRLP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto. Dept. de Fisica

    2011-07-01

    Electron Spin Resonance (ESR) dating is based on the fact that ionizing radiation can create stable free radicals in insulating materials, like tooth enamel and bones. The concentration of these radicals - determined by ESR - is a function of the dose deposed in the sample along the years. The accumulated dose of radiation, called Archaeological Dose, is produced by the exposition to environmental radiation provided by U, Th, K and cosmic rays. If the environmental dose rate in the site where the fossil sample is found is known, it is possible to convert this dose into the age of the sample. The annual dose rate coming from the radioactive elements present in the soil and in the sample itself can be calculated by determining the U, Th and K concentration. Therefore, the determination of the dose rate depends on the concentration of these main radioactive elements. Neutron Activation Analysis has the sensitivity and the accuracy necessary to determine U, Th and K with this objective. Depending on the composition of the sample, the determination of U and Th can be improved irradiating the sample inside a Cd capsule, reducing the thermal neutron incidence on the sample and, therefore, diminishing the activation of possible interfering nuclides. In this study the optimal irradiation and counting conditions were established for U and Th determination in fossil teeth and soil. (author)

  13. Spectroscopic determination of masses (and implied ages) for red giants

    CERN Document Server

    Ness, M; Rix, H-W; Martig, M; Pinsonneault, Marc H; Ho, A Y Q

    2015-01-01

    The mass of a star is arguably its most fundamental parameter. For red giant stars, tracers luminous enough to be observed across the Galaxy, mass implies a stellar evolution age. It has proven to be extremely difficult to infer ages and masses directly from red giant spectra using existing methods. From the KEPLER and APOGEE surveys, samples of several thousand stars exist with high-quality spectra and asteroseismic masses. Here we show that from these data we can build a data-driven spectral model using The Cannon, which can determine stellar masses to $\\sim$ 0.07 dex from APOGEE DR12 spectra of red giants; these imply age estimates accurate to $\\sim$ 0.2 dex (40 percent). We show that The Cannon constrains these ages foremost from spectral regions with CN absorption lines, elements whose surface abundances reflect mass-dependent dredge-up. We deliver an unprecedented catalog of 80,000 giants (including 20,000 red-clump stars) with mass and age estimates, spanning the entire disk (from the Galactic center t...

  14. Evaluation of anatomy and morphology of human mandibular premolar teeth by cone-beam computed tomography in Iranian population

    Directory of Open Access Journals (Sweden)

    Amin Sobhani Mohhsen

    2013-08-01

    Full Text Available   Background and Aims: Successful root canal therapy requires knowledge of tooth anatomy and root canal morphology. For permanent mandibular premolars, great variety in size, shape and number of roots and root fusion expression has been reported in the literature. There is a wide variety of methods used in studies for evaluating the root canal morphology. One of these methods is Cone-beam Computed tomography (CBCT that reduces the limitations of two-dimensional X-ray imaging, with less exposure in comparison with other 3D radiographies. Thus, this study was designed to evaluate the differences in the root and canal morphology of permanent mandibular premolars in an Iranian population by means of CBCT images.   Materials and Methods: We searched a database of CBCT scans and evaluated 400 (20-60 years old patients who met the inclusion criteria and teeth in this images (CBCT were evaluated in three dimensions (Axial, Coronal and Sagital. Tooth length, number of roots, number of canals, canal type, root curvature and the effect of gender on any of the items mentioned were evaluated. Data were analyzed using T-test.   Results: The average length of the first premolar of mandibular was 22.27 mm and second premolar was 22.28 mm. 98.4% of the first premolar and 98.2% of the second premolar were single root., and 87.3% and 93.1% were single channel. The incidence of number of canals based on vertochy divisions were:type 1: 90.7% and 90.8%, type 0: 2.2% and 2.8%, type 4: 3.3% and 3.1%, type 6: 1.4% and 2.1% and type 3: 2.5% and 1.5% respectively. In any case, there was no significant difference between males and females (P<0.001.   Conclusion: Results indicate that dentists can obtain valuable information about the anatomy and morphology of the root canals using CBCT.

  15. Absolute age determination of quaternary fault and formation

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, Chang Sik; Lee, Kwang Sik; Choi, Man Sik [Korea Basic Science Institute, Taejon (Korea, Republic of)] (and others)

    2003-03-15

    Rb-Sr and K-Ar dating results for the fault rocks suggest the occurrence of recurrent fault activity around 80-95 Ma, 70 Ma, 50 Ma, 30 Ma and 23 Ma along the Yangsan fault zone. The apparent K-Ar ages tend to be older than Rb-Sr ages, probably indicating the effect of excess radiogenic Ar, which will be furthur investigated by Ar-Ar method. The OSL SAR protocol using 220 .deg. C cut-heat yields reproducible and stratigraphically consistent OSL ages ranging from 71 ka to 48 ka for beach deposits of the marine terrace No 2. The apparent OSL ages for the marine terrace No 3 range from 92 ka to 61 ka. These ages constrain the minimum age of the platform considering the underestimation effect resulted from deposition underwater. Therefore we regard the formation age of the terrace No 3 as MIS(Marine Isotopic Stage) 5c or 5e. Rb-Sr and K-Ar dating results for the fault rocks suggest the occurrence of recurrent fault activity around 40 Ma, 30 Ma and 23 Ma along the Ulsan fault zone. Relatively young (< 10 Ma) fault activities are recognized in the Oesa, Janghangri and Wonwonsa sites.

  16. Bayes reconstruction of missing teeth

    DEFF Research Database (Denmark)

    Sporring, Jon; Jensen, Katrine Hommelhoff

    2008-01-01

     We propose a method for restoring the surface of tooth crowns in a 3D model of a human denture, so that the pose and anatomical features of the tooth will work well for chewing. This is achieved by including information about the position and anatomy of the other teeth in the mouth. Our system...... contains two major parts: A statistical model of a selection of tooth shapes and a reconstruction of missing data. We use a training set consisting of 3D scans of dental cast models obtained with a laser scanner, and we have build a model of the shape variability of the teeth, their neighbors, and their...... regularization of the log-likelihood estimate based on differential geometrical properties of teeth surfaces, and we show general conditions under which this may be considered a Bayes prior.Finally we use Bayes method to propose the reconstruction of missing data, for e.g. finding the most probable shape of a...

  17. Right to Left Ventricular Diameter Ratio ≥0.42 is the Warning Flag for Suspecting Atrial Septal Defect in Preschool Children: Age- and Body Surface Area-Related Reference Values Determined by M-Mode Echocardiography.

    Science.gov (United States)

    Hashimoto, Ikuo; Watanabe, Kazuhiro; Ichida, Fukiko

    2016-04-01

    It is not always easy to observe and screen atrial septal defects (ASD) using echocardiography. In addition, there are no established echocardiographic reference indices for screening patients with ASDs. We retrospectively reviewed our database and recruited 151 isolated ASD patients and 2769 healthy subjects. In total, 307 echocardiographic studies were performed for ASD patients. Surgical repairs were done in 75 of the ASD patients. The ratio of right to left ventricular end-diastolic dimensions (RVD/LVD), which was determined by M-mode echocardiography, was used as an index of RV dilatation. After obtaining age- and body surface area (BSA)-related RVD/LVD nomograms in healthy subjects, we calculated the z-scores of RVD/LVD for all subjects and obtained the optimal cut-off values to differentiate patients with ASD from healthy subjects. The optimal cut-off values were high in neonates and gradually decreased with an increase in the age and BSA, but were almost constant in children aged >4 years or whose BSA was >0.65 m(2). The cut-off values of RVD/LVD for suspected ASD were ≥0.42 in children aged >4 years or those whose BSA was >0.65 m(2). Those for an ASD operation were ≥0.46 in those whose BSA > 0.65 m(2). The RVD/LVD determined by M-mode echocardiography is a useful index to evaluate RV dilatation in patients with ASDs. The RVD/LVD ≥ 0.42 is the warning flag for suspecting ASD in preschool children and that ≥0.46 may be a clinical important sign to determine ASD operation. PMID:26700967

  18. Transposition of teeth: A forensic perspective

    Directory of Open Access Journals (Sweden)

    Supriya Nambiar

    2014-01-01

    Full Text Available Dental identification plays a key role in mass casualties and is usually based on disturbances of tooth eruption, malocclusions and/or previous dental treatments, changes brought about by age, pathological conditions and developmental disturbances. Tooth transposition is a disturbance of tooth eruption and is defined as change in the position of two adjacent teeth within the same quadrant. This review aims to discuss the prevalence and the etiology of transposition through a literature survey and to discuss its importance and implications as pertaining to the field of forensics. In summary, transposition is a rare and severe positional anomaly that represents a challenge for a dentist. It requires a keen eye on the part of the forensic pathologist to identify the condition.

  19. Age determinations of the Zoetlief Group: a Ventersdorp Supergroup correlative

    International Nuclear Information System (INIS)

    Rb-Sr, Pb-Pb and single zircon dating of the Kareefontein Quartz Phorphyry, northeastern Cape Province, South Africa, confirm the correlation proposed by SACS (1980) between the Zoetlief Group and the Ventersdorp Supergroup. Rb-Sr and Pb-Pb whole-rock ages of ca. 2 350 to 1 900 Ma for the Kareefontein permit no definitive interpretation but are nevertheless similar to the age patterns for the Ventersdorp and support the correlation. The clearest evidence is the almost perfect match between the Kareefontein single zircon Pb evaporation date of 2 714 ± 3 Ma and zircon SHRIMP dates for the Makwassie Quartz Porphyry and Klipriviersberg Formation of the Ventersdorp. Nd model ages of 3.05 to 3.22 Ga are interpreted as the minimum age of formation of the crustal protolith parental to the Kareefontein Quartz Porphyry melt. 5 figs., 4 tabs., 31 refs

  20. Quality evaluation of aged concrete by ultrasound

    Science.gov (United States)

    Tavossi, H. M.; Tittmann, Bernhard R.; Cohen-Tenoudji, Frederic

    1999-02-01

    The velocity, attenuation and scattering of ultrasonic waves measured in concrete, mortar and cement structures can be used to evaluate their quality with weathering and aging. In this investigation the hardening of concrete mixture with time is monitored by ultrasonic waves under different conditions of temperature and water to cement ratio. The measured ultrasonic parameters can then be utilized to determine the final quality of the completely cured concrete structure from initial measurement. The quality of a concrete structure is determined by its resistance to compression and its rigidity, which should be within the acceptable values required by the design specifications. The internal and external flaws that could lower its strength can also be detected by ultrasonic technique. Aging process of concrete by weathering can be simulated in the laboratory by subjecting the concrete to extremes of cold and hot cycles in the range of temperatures normally encountered in summer and winter. In this research ultrasonic sensors in low frequency range of 40 to 100 kHz are used to monitor the quality of concrete. Ultrasonic pulses transmitted through the concrete sample are recorded for analysis in time and frequency domains. ULtrasonic waves penetration in concrete of the order of few feet has been achieved in laboratory. Data analyses on ultrasonic signal velocity, spectral content, phase and attenuation, can be utilized to evaluate, in situ, the quality and mechanical strength of concrete.

  1. Radiographic evaluation of dental age of adults using Kvaal′s method

    Directory of Open Access Journals (Sweden)

    Ridhima Sharma

    2010-01-01

    Full Text Available Introduction: It is a well-known fact that the assessment of the dental development can be related to an individual′s age, but after the age of 21 years when the wisdom teeth also complete their development, there arises a need for an optimal age estimation procedure. With advancing age, there is a reduction in the size of the pulp due to secondary dentin deposition and a measurement of this reduction can also be used as a parameter to assess the age of the individuals, both in the living and dead. Aims and Objectives: The purpose of the present study was to evaluate the feasibility of this approach in the estimation of age of adults, using Kvaal′s method in the set sample. Materials and Methods: The material consisted of the digital long-cone intraoral periapical radiographs from 50 subjects of either sex in the age group of 15-60 years, who were selected after evaluation for the set inclusion and exclusion criteria. The pulp width and length from radiographs of 6 selected teeth, namely, maxillary central incisor, lateral incisor, and second premolar and mandibular lateral incisor, canine, and first premolar of either right or left side were measured using the RVG trophy software [Trophy® Windows is a software program supplied by Trophy Radiologie (Trophy Windows Version 5.03, Copyright 1993-2002,Trophy RVG patented by Trophy, Chicago]. In order to compensate for the differences in magnification and angulation, various ratios were calculated and the mean of all ratios (M was taken as the first predictor, while the difference between the mean of 2 width ratios and the mean of 2 length ratios (W − L was taken as the second predictor. Different regression formulae for all 6 teeth, 3 maxillary teeth, 3 mandibular teeth, and each of the individual teeth were derived and the age was assessed. The assessed age was then co-related with the actual age of the patient using the Student′s t test. Results: The results showed that the coefficient of

  2. Determination of oligoelements in dental enamel by neutron irradiation

    International Nuclear Information System (INIS)

    In order to determine oligoelements in the enamel of the teeth by using neutron activation analysis, we have perfected a rapid and simple method to separate these oligoelements from scandium, sodium, calcium and phosphorus. The method is based on the formation of pyrollidine-dithiocarbamate complexes. We have shown that the complexes of these elements (Cr, Mo, W, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Ag, Cd, In, Sn, Sb, Te, Pt, Au, Hg) are extractable up to 99% by ethyle acetate in a single extraction. Some results are presented. (author)

  3. Impacted Teeth and Mandibular Fracture

    OpenAIRE

    Metin, Murat; Şener, İsmail; Tek, Mustafa

    2007-01-01

    Objectives In this retrospective study, we measured the relationship between the presences of impacted or unerupted teeth in the mandible and mandibular fractures. Methods The records and radiographs of 41 patients with mandibular fracture associated with impacted or unerupted teeth were examined. The presence of impacted or unerupted teeth were assessed for each patient and related to the occurrence of fractures of mandible. Results Patients with fracture in the impacted or unerupted teeth a...

  4. Bone density of the arm and forearm as an age indicator in specimens of stranded striped dolphins (Stenella coeruleoalba).

    Science.gov (United States)

    Guglielmini, Carlo; Zotti, Alessandro; Bernardini, Daniele; Pietra, Marco; Podestá, Michela; Cozzi, Bruno

    2002-07-01

    The age of odontocetes living in the wild is determined mainly by analysis of dentine layers in sections of the teeth. We examined a series of specimens from striped dolphins (Stenella coeruleoalba, Meyen, 1833) that had stranded along the Italian coast of the Mediterranean sea. The present study analyzes and describes bone density in the arm and forearm of the stranded specimens, and correlates the data with total body length of the animal and age as determined by the number of dentine layers in sections of the teeth. According to our model, age can be predicted on the basis of bone density and total body length of the stranded animal. This is the first study to use bone density as a biological parameter to understand the wear and tear of life in the sea. The results suggest that bone density is a new tool for recording age in wild odontocetes. PMID:12115272

  5. Pulp vitality preservation after traumatic dental injuries to permanent teeth

    Directory of Open Access Journals (Sweden)

    Blagojević Duška

    2013-01-01

    Full Text Available Introduction. The pulp vitality preservation after a trauma to permanent teeth is of great importance since dental injuries are common. The aim of our study was to investigate the pulp vitality preservation after tooth injuries. Material and Methods. A retrospective analysis of records of patients with a trauma was performed. The sample consisted of all patients who had been referred to the Department of Dentistry of Vojvodina for a trauma to permanent teeth during the period 2005-2010. We recorded the type of injury, treatment, state of vitality during the first visit and subsequent check-ups. Results. The study included 162 children and adolescents aged 6-18 years having a trauma to 314 permanent teeth. The most frequent type of injuries in permanent teeth was fractures (54.5%, whereas luxation was a less common trauma (45.5%. Though different kinds of traumas have different optimal time for treatment, a period of 24 hours was taken as optimal; hence, 189 teeth were treated in optimal time and 55 complications occurred in them; while 105 complications occurred in 114 teeth which were treated 24 hours after the trauma. A year after the trauma the pulp vitality was preserved in 88 teeth (32%, pulp necrosis and other complications developed in 160 teeth (68%. Conclusion. The therapy of pulp vitality preservation in injured teeth was found successful in 32% and unsuccessful in 68% of cases at check-ups over one year.

  6. Work characteristics and determinants of job satisfaction in four age groups: university employees' point of view.

    NARCIS (Netherlands)

    Bos, J.T.; Donders, N.C.G.M.; Bouwman-Brouwer, K.M.; Gulden, J.W.J. van der

    2009-01-01

    PURPOSE: To investigate (a) differences in work characteristics and (b) determinants of job satisfaction among employees in different age groups. METHODS: A cross-sectional questionnaire was filled in by 1,112 university employees, classified into four age groups. (a) Work characteristics were analy

  7. Physical Attractiveness, Age, and Sex as Determinants of Reactions to Resumes.

    Science.gov (United States)

    Quereshi, M. Y.; Kay, Janet P.

    1986-01-01

    Physical attractiveness, age, and sex were manipulated to determine their effect on the evaluation of 54 hypothetical applicants' resumes for three different jobs by 60 Master's in Business Administration students. Physical attractiveness favorably influenced the suitability ratings for all jobs; raters' sex and age were not significant but…

  8. Reconstructing the life-time lead exposure in children using dentine in deciduous teeth

    International Nuclear Information System (INIS)

    Data are presented to demonstrate that the circumpulpal dentine of deciduous teeth can be used to reconstruct a detailed record of childhood exposure to lead. By combining high spatial resolution laser ablation ICP-MS with dental histology, information was acquired on the concentration of lead in dentine from in utero to several years after birth, using a true time template of dentine growth. Time corrected lead analyses for pairs of deciduous molars confirmed that between-tooth variation for the same child was negligible and that meaningful exposure histories can be obtained from a single, multi-point ablation transect on longitudinal sections of individual teeth. For a laser beam of 100 μm diameter, the lead signal for each ablation point represented a time span of 42 days. Simultaneous analyses for Sr, Zn and Mg suggest that the incorporation of Pb into dentine (carbonated apatite) is most likely controlled by nanocrystal growth mechanisms. The study also highlights the importance of discriminating between primary and secondary dentine and the dangers of translating lead analyses into blood lead estimates without determining the age or duration of dentine sampled. Further work is in progress to validate deciduous teeth as blood lead biomarkers. - Highlights: ► Reconstruction of childhood exposure history to Pb using deciduous tooth dentine. ► Pb analyses acquired for dentine growth increments of 42 days. ► Highly correlated Pb concentration profiles for pairs of deciduous molars. ► Data for Sr, Zn and Mg provide a model for the incorporation of Pb into dentine.

  9. Reconstructing the life-time lead exposure in children using dentine in deciduous teeth

    Energy Technology Data Exchange (ETDEWEB)

    Shepherd, Thomas J., E-mail: shepherdtj@aol.com [School of Earth and Environment, University of Leeds, Leeds LS2 9JT (United Kingdom); Dirks, Wendy [Centre for Oral Health Research, School of Dental Sciences, Newcastle University, Newcastle upon Tyne NE2 4BW (United Kingdom); Manmee, Charuwan; Hodgson, Susan [Institute of Health and Society, Newcastle University, Newcastle upon Tyne NE2 4AX (United Kingdom); Banks, David A. [School of Earth and Environment, University of Leeds, Leeds LS2 9JT (United Kingdom); Averley, Paul [Centre for Oral Health Research, School of Dental Sciences, Newcastle University, Newcastle upon Tyne NE2 4BW (United Kingdom); Queensway Dental Practice, 170 Queensway, Billingham, Teesside TS23 2NT (United Kingdom); Pless-Mulloli, Tanja [Institute of Health and Society, Newcastle University, Newcastle upon Tyne NE2 4AX (United Kingdom); Newcastle Institute for Research on Sustainability, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom)

    2012-05-15

    Data are presented to demonstrate that the circumpulpal dentine of deciduous teeth can be used to reconstruct a detailed record of childhood exposure to lead. By combining high spatial resolution laser ablation ICP-MS with dental histology, information was acquired on the concentration of lead in dentine from in utero to several years after birth, using a true time template of dentine growth. Time corrected lead analyses for pairs of deciduous molars confirmed that between-tooth variation for the same child was negligible and that meaningful exposure histories can be obtained from a single, multi-point ablation transect on longitudinal sections of individual teeth. For a laser beam of 100 {mu}m diameter, the lead signal for each ablation point represented a time span of 42 days. Simultaneous analyses for Sr, Zn and Mg suggest that the incorporation of Pb into dentine (carbonated apatite) is most likely controlled by nanocrystal growth mechanisms. The study also highlights the importance of discriminating between primary and secondary dentine and the dangers of translating lead analyses into blood lead estimates without determining the age or duration of dentine sampled. Further work is in progress to validate deciduous teeth as blood lead biomarkers. - Highlights: Black-Right-Pointing-Pointer Reconstruction of childhood exposure history to Pb using deciduous tooth dentine. Black-Right-Pointing-Pointer Pb analyses acquired for dentine growth increments of 42 days. Black-Right-Pointing-Pointer Highly correlated Pb concentration profiles for pairs of deciduous molars. Black-Right-Pointing-Pointer Data for Sr, Zn and Mg provide a model for the incorporation of Pb into dentine.

  10. AGE DETERMINATION FOR 346 NEARBY STARS IN THE HERSCHEL DEBRIS SURVEY

    International Nuclear Information System (INIS)

    DEBRIS is a flux-limited survey of nearby stars (spectral types A-M) for evidence of debris disks with the Herschel Space Observatory. One goal of the survey is to determine disk incidence as a function of various stellar parameters. Understanding debris disk evolution depends on knowledge of the precise age of stars around which these debris disks are found. However, finding ages for field stars is notoriously difficult. Furthermore, in an unbiased sample like DEBRIS, one is working with stars across many spectral types. This requires a multi-method approach to age determination. In this paper, we outline several methods of age determination broken down by spectral type, including some strengths and limitations of each method. In total, we were able to calculate ages for 263 of 274 F-, G-, and K-type stars, and all 83 A-type stars in the DEBRIS sample.

  11. DNA isolation from teeth by organic extraction and identification of sex of the individual by analyzing the AMEL gene marker using PCR

    OpenAIRE

    Subramanian Thangaraj Praveen Kumar; Nalini Aswath

    2016-01-01

    Background: To identify the sex of the deceased individual from dental hard tissue such as enamel and dentine. Objective: To isolate the DNA from dental hard tissue (enamel and dentin) from teeth extracted for prophylactic purpose, to assess the quality and purity of DNA and to identify the sex using polymerized chain reactor (PCR). Materials and Methods: DNA was extracted following phenol/chloroform (organic) extraction from 20 male and 20 female teeth. The samples that contain the amelogeni...

  12. NON - OPERATIVE TREATMENT OF NON - CAVITATED APPROXIMAL CARIOUS LESIONS OF PERMANENT CHIDREN’S TEETH.

    Directory of Open Access Journals (Sweden)

    Rossiza I. Kabakchieva

    2014-10-01

    Full Text Available Aim: To apply and follow up in clinical conditions the success rate of microinvasive technique of infiltration with low viscosity resin ICON® (DMG of non cavitated approximal caries lesions of permanent children's teeth for a period of one year. Material and methods: The study included 18 children aged 7-16 years. They were divided into two groups - children with medium and high caries risk. The survey include 20 teeth with approximal non-cavitated enamel lesions up to the outer third of dentin (E1, E2, D1 – according to the manufacturer’s instructions of ICON®. The size of the lesions was determined using bitewing radiographs and the activity - by Papilla Bleeding Index. The clinical application of the infiltr+ant (ICON® Caries Infiltrant Proximal, DMG was conducted according to the manufacturer's instructions. Bitewing radiographs were made at 6 and 12 months after infiltration in order to evaluate the success of the method. A test of the difference between two relative proportions and alternative test for analysis of the results were used. Results: Our study confirm the hypothesis that this method of infiltration is equally successful for permanent teeth in patients with moderate caries risk as well as those at high caries risk. Conclusion: This study is the first survey regarding the success of the application of ICON® for treatment of non-cavitated approximal carious lesions in permanent dentition of children in the country. Research in this direction should continue in order to increase the conviction that caries can be controlled and arrested in its earliest stages.

  13. Test Plan to Update SRS High Level Waste Tank Material Properties Database by Determining Synergistic Effects of Dynamic Strain Aging and Stress Corrosion Cracking

    International Nuclear Information System (INIS)

    The structural integrity of High Level Waste tanks is defined by the demonstrated confinement of the waste by the tank structure under design basis conditions. a comprehensive test plan is presented here to develop a mechanical and corrosion properties database to develop a fundamental understanding of the synergistic effects of DSA and SCC due to high temperature service of the HLW tanks

  14. Test Plan to Update SRS High Level Waste Tank Material Properties Database by Determining Synergistic Effects of Dynamic Strain Aging and Stress Corrosion Cracking; TOPICAL

    International Nuclear Information System (INIS)

    The structural integrity of High Level Waste tanks is defined by the demonstrated confinement of the waste by the tank structure under design basis conditions. a comprehensive test plan is presented here to develop a mechanical and corrosion properties database to develop a fundamental understanding of the synergistic effects of DSA and SCC due to high temperature service of the HLW tanks

  15. Effect of dietary, social, and lifestyle determinants of accelerated aging and its common clinical presentation: A survey study

    OpenAIRE

    Samarakoon, S. M. S.; Chandola, H. M.; Ravishankar, B.

    2011-01-01

    Aging is unavoidable and natural phenomenon of life. Modern gerontologists are realizing the fact that aging is a disease, which Ayurveda had accepted as natural disease since long. Rate of aging is determined by one's biological, social, lifestyle, and psychological conditions and adversity of which leads to accelerated form of aging (Akalaja jara or premature aging). The aim of this study is to identify potential factors that may accelerate aging in the context of dietry factors, lifestyle ...

  16. Sports-Related Eye Injuries by Age

    Science.gov (United States)

    Sports-Related Eye Injuries by Age Activity Estimated Injuries* Ages 0–14 Ages 15+ Basketball 5,237 ... Exercise, Weightlifting) 1,697 401 1,297 Racquet Sports 1,241 233 1,008 Ball Sports, Unspecified ...

  17. Immunocytochemical Detection of Dentin Matrix Proteins in Primary Teeth from Patients with Dentinogenesis Imperfecta Associated with Osteogenesis Imperfecta

    OpenAIRE

    G Orsini; Majorana, A; Mazzoni, A.; Putignano, A; Falconi, M; Polimeni, A.; Breschi, L.

    2014-01-01

    Dentinogenesis imperfecta determines structural alterations of the collagen structure still not completely elucidated. Immunohistochemical analysis was used to assay Type I and VI collagen, various non-collagenous proteins distribution in human primary teeth from healthy patients or from patients affected by type I dentinogenesis imperfecta (DGI-I) associated with osteogenesis imperfecta (OI). In sound primary teeth, an organized well-known ordered pattern of the type I collagen fibrils was f...

  18. Accuracy of Root ZX in teeth with simulated root perforation in the presence of gel or liquid type endodontic irrigant

    OpenAIRE

    Shin, Hyeong-Soon; Yang, Won-Kyung; Kim, Mi-Ri; Ko, Hyun-Jung; Cho, Kyung-Mo; Park, Se-Hee; Kim, Jin-Woo

    2012-01-01

    Objectives To evaluate the accuracy of the Root ZX in teeth with simulated root perforation in the presence of gel or liquid type endodontic irrigants, such as saline, 5.25% sodium hypochlorite (NaOCl), 2% chlorhexidine liquid, 2% chlorhexidine gel, and RC-Prep, and also to determine the electrical conductivities of these endodontic irrigants. Materials and Methods A root perforation was simulated on twenty freshly extracted teeth by means of a small perforation made on the proximal surface o...

  19. Multielemental analysis of prehistoric animal teeth by laser-induced breakdown spectroscopy and laser ablation inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Galiova, Michaela; Kaiser, Jozef; Fortes, Francisco J.; Novotny, Karel; Malina, Radomir; Prokes, Lubomir; Hrdlicka, Ales; Vaculovic, Tomas; Nyvltova Fisakova, Miriam; Svoboda, Jiri; Kanicky, Viktor; Laserna, Javier J.

    2010-05-01

    Laser-induced breakdown spectroscopy (LIBS) and laser ablation (LA) inductively coupled plasma (ICP) mass spectrometry (MS) were utilized for microspatial analyses of a prehistoric bear (Ursus arctos) tooth dentine. The distribution of selected trace elements (Sr, Ba, Fe) was measured on a 26 mmx15 mm large and 3 mm thick transverse cross section of a canine tooth. The Na and Mg content together with the distribution of matrix elements (Ca, P) was also monitored within this area. The depth of the LIBS craters was measured with an optical profilometer. As shown, both LIBS and LA-ICP-MS can be successfully used for the fast, spatially resolved analysis of prehistoric teeth samples. In addition to microchemical analysis, the sample hardness was calculated using LIBS plasma ionic-to-atomic line intensity ratios of Mg (or Ca). To validate the sample hardness calculations, the hardness was also measured with a Vickers microhardness tester.

  20. Multielemental analysis of prehistoric animal teeth by laser-induced breakdown spectroscopy and laser ablation inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) and laser ablation (LA) inductively coupled plasma (ICP) mass spectrometry (MS) were utilized for microspatial analyses of a prehistoric bear (Ursus arctos) tooth dentine. The distribution of selected trace elements (Sr, Ba, Fe) was measured on a 26 mmx15 mm large and 3 mm thick transverse cross section of a canine tooth. The Na and Mg content together with the distribution of matrix elements (Ca, P) was also monitored within this area. The depth of the LIBS craters was measured with an optical profilometer. As shown, both LIBS and LA-ICP-MS can be successfully used for the fast, spatially resolved analysis of prehistoric teeth samples. In addition to microchemical analysis, the sample hardness was calculated using LIBS plasma ionic-to-atomic line intensity ratios of Mg (or Ca). To validate the sample hardness calculations, the hardness was also measured with a Vickers microhardness tester.

  1. EPR dosimetry of teeth in past and future accidents. A prospective look at a retrospective method

    International Nuclear Information System (INIS)

    Accurate assessments of doses received by individuals exposed to radiation from nuclear accidents and incidents such as those at Hiroshima and Nagasaki, the Nevada test site, Chelyabinsk and Mayak are required for epidemiological studies seeking to establish relationships between radiation dose and health effects. One method of retrospective dosimetry which allows for measurement of cumulative gamma ray doses received by exposed individuals is electron paramagnetic resonance spectroscopy (EPR) of tooth enamel. Tooth enamel stores and retains, indefinitely, information on absorbed radiation dose; and teeth are available in every population as a result of dental extraction for medical reasons including periodontal disease and impacted wisdom teeth. In the case of children, deciduous teeth, which are shed between the ages of 7 and 13, can be a very important dosimetric source if documented collection is implemented shortly following an accident. (author)

  2. Utility of telomere length measurements for age determination of humpback whales

    Directory of Open Access Journals (Sweden)

    Morten Tange Olsen

    2014-12-01

    Full Text Available This study examines the applicability of telomere length measurements by quantitative PCR as a tool for minimally invasive age determination of free-ranging cetaceans. We analysed telomere length in skin samples from 28 North Atlantic humpback whales (Megaptera novaeangliae, ranging from 0 to 26 years of age. The results suggested a significant correlation between telomere length and age in humpback whales. However, telomere length was highly variable among individuals of similar age, suggesting that telomere length measured by quantitative PCR is an imprecise determinant of age in humpback whales. The observed variation in individual telomere length was found to be a function of both experimental and biological variability, with the latter perhaps reflecting patterns of inheritance, resource allocation trade-offs, and stochasticity of the marine environment.

  3. Epicyclic teeth degradation of superficial layers

    International Nuclear Information System (INIS)

    Since the installation of the circulating pumps which equip the 600, 700, 900 and 1300 MW power stations, many gear teeth surfaces and rupture failures have been observed in gear reduction assemblies. Surface controls through fibroscopy were therefore set up and used systematically. Frosting, micropitting, spalling, affect both the nitrided and case-hardened surfaces and can lead to rupture. The extent of micropitting and the corresponding wear have been studied jointly by INSA (LMC) and EDF (GDL) in order to determine surface life. Results show that, in these applications, the ratio between surface roughness and elastrohydrodynamic film thickness is too high and contributes to the initiation of failures. The following palliatives are presently tested on site, namely: - improvement in root tooth profile and gear architecture, - surface treatment optimisation, - surface roughness reduction, - effective lubricant viscosity increase by lowering the operating temperature and increasing the nominal viscosity of the oil

  4. Computing Contact Stresses In Gear Teeth

    Science.gov (United States)

    Oswald, Fred B.; Somprakit, Paisan; Huston, Ronald L.

    1995-01-01

    Improved method of computing contact stresses in gear teeth accounts for complicating effects like those of static and sliding friction. Provides iterative procedure for determination of contact region and nodal contact forces along with contact stresses. Method based on equations and computational procedure incorporating these effects routinely.

  5. Pulpal sequelae after trauma to anterior teeth among adult Nigerian dental patients

    Directory of Open Access Journals (Sweden)

    Adekoya-Sofowora Comfort A

    2007-08-01

    Full Text Available Abstract Background Epidemiological studies show that about 11.6% to 33.0% of all boys and about 3.6% to 19.3% of all girls suffer dental trauma of varying severity before the age of 12 years. Moderate injuries to the periodontium such as concussion and subluxation are usually associated with relatively minor symptoms and hence may go unnoticed by the patient or the dentist, if consulted. Patients with these kinds of injuries present years after a traumatic accident most of the time with a single discoloured tooth. This study sets out to document the incidence of various posttraumatic sequelae of discoloured anterior teeth among adult Nigerian dental patients. Methods One hundred and sixty eight (168 traumatized discoloured anterior teeth in 165 patients were studied. Teeth with root canal treatment were excluded from the study. Partial obliteration was recorded when the pulp chamber or root canal was not discernible or reduced in size on radiographs, total obliteration was recorded when pulp chamber and root canal were not discernible. A retrospective diagnosis of concussion was made from patient's history of trauma to the tooth without abnormal loosening, while subluxation was made from patient's history of trauma to the tooth with abnormal loosening. Results Of the 168 traumatized discoloured anterior teeth, 47.6% and 31.6% had partial and total obliteration of the pulp canal spaces respectively, 20.8% had pulpal necrosis. Concussion and subluxation injuries resulted more in obliteration of the pulp canal space, while fracture of the teeth resulted in more pulpal necrosis (p st and 2nd decade of life resulted more in obliteration of the pulp canal space, while injuries sustained in the 3rd decade resulted in more pulpal necrosis. Conclusion Calcific metamorphosis developed more in teeth with concussion and subluxation injuries. Pulpal necrosis occurred more often in traumatized teeth including fractures.

  6. Assessment of Lead in Human Deciduous Teeth as Indicator for Environment Pollution

    International Nuclear Information System (INIS)

    The study was carried out on 232 shed and extracted human primary teeth from 227 children ranging from 6 to 13 years of age, both genders were involved, collected from public dental health services and private clinics, from Helwan as an industrial area and Heliopolis as a non industrial area at Cairo, Egypt. Only teeth without fillings were used, and carious substance was removed from carious lesions before the analysis was carried out. The statistical results demonstrate that, Pb concentration is highly significantly increased (P≤0.001) in primary teeth of Helwan groups than in Heliopolis one; also the Pb concentration is increased in the presence of roots and caries (P≤0.001) and it affected by the tooth group. The tooth lead concentrations showed a falling gradient from the incisors to the molars (P≤ 0.001)

  7. Measurement and evaluation of the 14C concentration in the collagen of the teeth among the Chinese

    International Nuclear Information System (INIS)

    Objective: The concentration of 14C in the collagen of the teeth among people with different ages was measured to understand concentration of 14C in the environment and human body of China influenced by 14C produced by nuclear weapon tests in the world in the past decades. Methods: Forth-eight eighth permanent teeth of some Shanghai residents born from 1920 to 1977 were collected. The teeth were cleaned and decalcified for the extraction of collagen and then were oxidized by high temperature and reduced into carbide graphite. The 14C was measured using an accelerator mass spectrometer (AMS), and the concentration of 14C was obtained by correction of 13C. Results: The concentration of 14C in the collagen of the teeth showed apparent variation in people born in different years: those born before 1940 around the level of background and those born from 1941 gradually increase, those born 1951 reached the peak value-58%, those born after 1951 presented a tendency of decrease. Conclusion: The results of this study indicated there is the same tendency of change in concentration of 14C in teeth and previously reported human tissue and plant. Also there is same variation in concentration of 14C in both Chinese and Japanese teeth; it also correlates with the numbers of atmospheric testing of nuclear weapons in the world

  8. Nuclear physics techniques for determination of rocks age

    International Nuclear Information System (INIS)

    The low background nuclear physics techniques were used for measure age geologic samples of micas (biotite, lepidolite, muscovite, phlogopite) by means of detection a gamma radiation from radioisotopes. The nuclear reactions 87Sr(gamma,gamma)87mSr, 87Rb(gamma,n)86Rb and 85Rb(gamma,n)84Rb was used. Application of a braking radiation of the powerful accelerator of electrons has allowed simultaneously to measure an element composition of samples

  9. DETERMINATION OF FLUORINE IONS PENETRATION DEGREE INTO ENAMEL BY EMPA

    OpenAIRE

    Beloica, D.; Vulovik, M.; Gržetik, I.; Golijanin, D.; Pavikevik, M.

    1984-01-01

    Exogen application of different preparations was done at completely healthy teeth of children up to 11 years. A month after application of fluorine, the relative teeth were extracted and the same were prepared by stamdard methods for investigation by electron microprobe ARL, type SEMQ. The results obtained showed that the highest degree of fluorine ions migration was stimulated by organic "fluorite" (amin fluoride). Very poor results were obtained by NaF, while the values obtained by "fluor-p...

  10. Intrusion of anterior teeth to improve smile esthetics

    OpenAIRE

    Chandrasekharan, Deepak; Balaji, S. M.

    2010-01-01

    A gummy smile is probably one of the most common causes of an unaesthetic smile. Causes include overeruption of maxillary anterior teeth and maxillary vertical excess. Intrusion of maxillary anterior teeth with Orthodontics and Le forte I superior repositioning may form a part of the solution. Of late the use of micro implants have improved the smile esthetics of borderline surgical cases by allowing the Orthodontist to intrude teeth more than what was possible with conventional Orthodontics.

  11. Marine reservoir corrections for bowhead whale radiocarbon age determinations

    International Nuclear Information System (INIS)

    Twenty-two pairs of radiocarbon dates on driftwood and bowhead whale (Balaena mysticetus) bones from raised beaches, dates on whale bone and terrestrial plant detritus from a stratigraphic section, and 25 additional dates on whale bones from the lowest (≤ 1 ka BP) raised beaches in the eastern Canadian Arctic suggest that a marine reservoir correction of about -200 years is appropriate for normalized age determinations on bone collagen from the bowhead whale in this region. This is less than the correction (-400 years) normally applied to carbonate shells of marine molluscs from this region. The carbon in bowhead collagen appears to be derived from the whales' zooplankton food rather than from marine bicarbonate. (author). 39 refs., 1 tab., 3 figs

  12. Clinical research of teeth damage from radiotherapy

    International Nuclear Information System (INIS)

    Objective: To analyze various factors inducing teeth damage from radiotherapy and the preventive and treatment methods. Methods: One hundred cases of patients treated by radiotherapy were divided into two groups. In group one there were 60 cases whose teeth were irradiated during treatment; in group two there were 40 cases whose teeth were not irradiated during treatment. Results: The caries incidence was 60% for group one and 15% for group two (P<0.01). By auto-control in 15 patients, the caries incidence on the sick side was obviously higher than that of the healthy side. Hundred percent caries incidence was found in 6 cases who received a dosage of 70 Gy. Conclusion: The authors believe that radiation damage to the teeth is associated with the following factors: 1. The dosage and location of irradiation are closely related to caries incidence; 2. The active dentinoblasts are very sensitive to radiation; 3. Damage to the salivary glands from radiotherapy can result in reduction of salvia and pH value, leading to a high growth rate of Streptococcus mutans. Following preventive measures could be considered in future cases: to apply a caries prevention coating or protective dental crown and TPS, to adjust the dose and time of irradiation, to select conformal radiotherapy technique. The key points for protecting the teeth and salivary gland from caries and damage are protection of the proliferation ability of pulp cells, anti-inflammation, promotion of microcirculation, and strengthening body resistance

  13. Exodontics: extraction of teeth in the dog and cat.

    Science.gov (United States)

    Gengler, Bill

    2013-05-01

    Dental disease can have a profound effect on the comfort and well-being of pets. Oral disease can be difficult to detect. Patients often hide their discomfort. The identification and treatment or removal of diseased teeth are the responsibility of the veterinarian. When diseased teeth cannot be saved by specialized care, extraction of teeth is necessary. Proper extraction of teeth in dogs and cats can be challenging and frustrating, but with review of the oral anatomy, proper instrumentation, and gentle tissue-handling techniques, this can be a rewarding part of clinical practice. PMID:23643022

  14. A Proposed Mechanism for Congenitally Missing Teeth: Basic and Clinical Evidence

    Directory of Open Access Journals (Sweden)

    Gajanan Kulkarni

    2011-05-01

    Full Text Available Introduction: Although the de-velopment of normal dentition has been explored extensively, the mechanisms underlying congenitally missing teeth are far less understood.The hypothesis: Congenital absence of teeth occurs due to arrested development of a tooth primordium followed by involution, only at a stages preceding mineralized tissue formation.Evaluation of the hypothesis: We compared H & E stained serial sagittal sections of wild-type and EL mice that are congenitally missing 3rd molars (3M. 3M development was followed longitudinally in both types of mice. Occurrence of apoptosis was examined using a fluorescent TUNEL assay. To determine if a similar process might account for congenital ab-sence of human teeth, we examined serial radiographs of developing dentitions. In EL mice, congenital absence of 3M is caused, not by a failure of initiation of tooth development rather; tooth development is initiated and subsequently ar-rested during early cap stage. This arrested tooth primordium is subsequently removed physiologically by apoptosis. Examination of serial radiographs where missing teeth were identified lent further evi-dence to support this hypothesis. Follicle spaces, with no calcified tissue within them, were noted at early stages which were seen to remodel and eventually blend with adjacent bone. Permanent teeth failed to develop in those locations. Based on the animal and human data, we propose a new model for congenital absence of teeth. Validation of this model could have profound clinical implications. If the genetic me-chanisms involved in this proposed mechanism can be elucidated, it might lead to non-surgical management of supernumerary teeth.

  15. Impacted teeth in the maxilla: usefulness of 3D Dental-CT for preoperative evaluation

    International Nuclear Information System (INIS)

    Objective: To compare the shapes of roots of impacted teeth shown in three-dimensional computed tomographic images (3D Dental-computed tomography (CT) images) and plain radiographs and to determine whether 3D Dental-CT images are useful for examination before performing an operation for extraction of a maxillary impacted tooth. Methods and patients: Images obtained from patients who had impacted teeth in the maxilla, including impacted mesial supernumerary teeth in 13 patients, impacted incisors in two patients, impacted canines in 11 patients, impacted premolars in four patients and impacted molars in three patients, were used in this study. In all patients, plain radiographs and 3D Dental-CT images were retrospectively reviewed by an oral radiologist for evidence of root dilaceration before operations to extract the impacted teeth were performed. The findings in the images were compared with intraoperative findings in all cases. Results: The mean specificity and sensitivity of plain radiographs were 95 and 8%, respectively, while those of 3D Dental-CT images were 100 and 77%, respectively. There was a statistically significant (P<0.01) difference between the depiction capabilities of plain radiographs and 3D Dental-CT images with regard to dilacerations of roots of impacted teeth. Discussion and conclusion: CT may enable radiologists to make a quick and accurate diagnosis of tooth impaction. 3D Dental-CT images are useful for determining the root shape of an impacted tooth in the maxilla

  16. Lifestyle and dietary factors determine age at natural menopause.

    Science.gov (United States)

    Sapre, Shilpa; Thakur, Ratna

    2014-01-01

    A literature search was done using PubMed. The age at natural menopause (ANM) depends on various factors like genetic, environmental, socioeconomic, reproductive, dietary, and lifestyle of which some like nulliparity, vegetarian diet, smoking, high fat intake, cholesterol, and caffeine accelerates; while others like parity, prior use of oral contraceptive pills, and Japanese ethnicity delays the ANM. ANM is an important risk factor for long-term morbidity and mortality; and hence, the need to identify the modifiable risk factors like diet and lifestyle changes. Delayed menopause is associated with increased risk of endometrial and breast cancer, while early ANM enhances the risk for cardiovascular diseases and osteoporosis. The correlation between diet and ANM has not been extensively studied; however, whatever studies have been done till now point towards role of high intake of total calories, fruits, and proteins in delaying the ANM, while high polyunsaturated fat intake accelerates it. The role of dietary soy, total fat, saturated fat, red meat, and dietary fiber in determining the ANM has been controversial and needs further studies to substantiate it. The lifestyle factors like current smoking and vigorous exercise have been significantly associated with early menopause, while moderate alcohol consumption delays the ANM. Large prospective studies are needed to study the association of ANM and other modifiable factors like passive smoking fish consumption, soy, and various types of tea. The knowledge of modifiable determinants of ANM can help in setting up menopausal clinics and initiating health programs specially in developing countries. PMID:24672198

  17. Prevalence of impacted and supernumerary teeth in the North Indian population

    OpenAIRE

    Santosh, Patil; Maheshwari, Sneha

    2014-01-01

    Objectives: Dental impaction is a very frequent problem. Supernumerary teeth, or hyperdontia, are the presence of additional teeth to the normal series in the either of the dentition. The presence of impacted and/or supernumerary teeth can cause various complications. The objective of the present study was to determine the prevalence of impacted and supernumerary teeth in the North Indian population. Study Design: The panoramic radiographic records of 4750 patients attending the Department of...

  18. Comparison of Microwave Versus Conventional Decalcification of Teeth Using Three Different Decalcifying Solutions

    Science.gov (United States)

    Srinivasyaiah, Archana; Nitin, Priyanka; Hegde, Usha

    2016-01-01

    Background: In routine histopathology, decalcification of teeth is an essential and important step during tissue processing. The present study was attempted to decalcify teeth using microwave method and to compare it with conventional decalcification method. Aim: To compare microwave decalcification with conventional decalcification method with respect to the speed of decalcification, preservation of tissue structure, and efficacy of staining. Materials and Methods: A total of 72 single-rooted premolars were used for both conventional and microwave decalcification methods. Three different types of decalcifying agents at 5% and 7% were used. Decalcifying agents included nitric acid, formic acid, and trichloroacetic acid, each at 5% and 7%. About 6 teeth were included in each category and were decalcified by both conventional and microwave method. After decalcification, all the teeth were examined macroscopically and microscopically. Cramer's V-test was used to determine the statistical significance. Results: The results have shown that microwave method using 5% and 7% nitric acid were the fastest. Structural details and good staining characteristics were better in teeth decalcified by 5% nitric acid and 5% trichloroacetic acid by both the methods. Conclusions: 5% nitric acid by microwave method proved to be the best decalcifying agent as it was fast and gave good structural details and staining characteristics. PMID:27365920

  19. Clinical Manifestations of pathology of temporomandibular joints and masticatory muscles in patients with teeth occlusion and teeth row disturbances

    Directory of Open Access Journals (Sweden)

    A.V. Lepilin

    2010-06-01

    Full Text Available The aim of the research is a literature review about the problem of temporomandibular joints and masticatory muscles in patients with teeth occlusion and teeth row disturbances. Teeth occlusion and teeth row disturbances are widespread pathology of maxillofacial area, that can lead to different pathology alterations of masticatory system including musculo-articular dysfunction. Some specialists consider that the key factor of pathogenesis of musculo-articular dysfunction is occlusion disturbances, by the other opinion - discoordination of muscle contraction. Thus occlusive and muscular disorders are leading in pathogenesis and clinic of musculo-articular dysfunction

  20. Addition to the methodology of research into permanent teeth hardness

    Directory of Open Access Journals (Sweden)

    Gnjato Sanja

    2010-01-01

    Full Text Available This paper examines permanent teeth hardness (microhardness using the Vickers method. An original methodology was developed and adopted for preparing the experimental material, i.e. the cross sections into four characteristic locations on the tooth: corona dentis, cervix dentis, pars medialis radicis dentis and apex radicis dentis. A new 'hardness profile' was introduced, which connects hardness and location along the cross section of the tooth. Hardness was measured 664 times on experimental cross sections with total a average hardness of 73.17 HV according to Vickers and a standard deviation of 55.68 HV. The derived descriptive statistical indicators of tooth hardness were calculated for equivalent cross sections, individual teeth, teeth groups and tooth localizations. Two algorithms were developed for determining the rank of tooth hardness - one for estimating the rank of arithmetic mean of the hardness of the cross sections of the teeth, and the other for estimating the rank of hardness for individual teeth. .

  1. Cavity lining in primary teeth.

    Science.gov (United States)

    Chauhan, Ravi

    2016-03-01

    Data sourcesEmbase, Medline, Cochrane Central, Biomed Central and Open Grey databases and bibliographies of identified studies.Study selectionRandomised controlled trials investigating humans with primary caries lesions receiving operative treatment involving caries removal and restoration, with minimum two treatment groups comparing different cavity treatments before restoration (no lining versus lining) were included.Data extraction and synthesisData were extracted independently by two reviewers and study quality assessed using the Cochrane risk of bias tool. Random effect meta-analysis was carried out.ResultsThree studies involving a total of 89 patients were included. All the studies involved primary teeth and were conducted in Brazil. Follow-up periods ranged from 26-53 months. All the studies were considered to be at high risk of bias. Restoring the cavity without lining did not significantly affect the risk of failure. The quality of the evidence was low.ConclusionsCurrent evidence does not support strong recommendations to use or not to use liners after caries removal and before restoring cavities. Our findings are restricted to primary teeth after selective excavation, with only one liner (calcium hydroxide) being used for comparison. PMID:27012571

  2. Work characteristics and determinants of job satisfaction in four age groups: university employees’ point of view

    OpenAIRE

    Bos, Judith T; Donders, Nathalie C. G. M.; Bouwman-Brouwer, Karin M.; Van der Gulden, Joost W. J.

    2009-01-01

    Purpose To investigate (a) differences in work characteristics and (b) determinants of job satisfaction among employees in different age groups. Methods A cross-sectional questionnaire was filled in by 1,112 university employees, classified into four age groups. (a) Work characteristics were analysed with ANOVA while adjusting for sex and job classification. (b) Job satisfaction was regressed against job demands and job resources adapted from the Job Demands-Resources model. Results Statistic...

  3. Effects Of Aging On Embrittlement By Hydrogen

    Science.gov (United States)

    Lassila, D. H.; Birnbaum, H. K.

    1989-01-01

    Report discusses study of grain-boundary fracture of hydrogen-charged nickel under conditions in which hydrogen is immobile. Thermally-charged nickel specimens aged at several temperatures for various periods of time to allow hydrogen to diffuse. Specimens then quenched and tested in liquid nitrogen (at temperature of 77 K) so distribution of hydrogen produced by aging maintained.

  4. Analytical method for the K/Ca age determination of geological samples

    International Nuclear Information System (INIS)

    An analytical procedure for the K/Ca age determination of geological samples is described, the relevant equations are developed and two alternative analytical methods are discussed according to their precision. An important precondition for the feasibility of the K/Ca method is the measurement of precise Ca isotope ratios. The ratio 40Ca/42Ca is used to determine the relative radiogenic 40Ca portion, whereas the 42Ca/44Ca ratio is taken as an internal standard. K and Ca in minerals are determined by flame atomic emission spectrometry with an internal lithium standard and by isotope dilution mass spectrometry, respectively. The contamination problem during the reprocessing of the samples is discussed. The results achieved by dating a langbeinite and a microcline sample by the K/Ca method agree well with those achieved by other age determination methods. The standard deviation of the K/Ca method in analyzing several feldspars ranges from 1.8-7.6%. (orig.)

  5. Bovine teeth as substitute for human teeth in dental research: a review of literature.

    Science.gov (United States)

    Yassen, Ghaeth H; Platt, Jeffrey A; Hara, Anderson T

    2011-09-01

    The aim of this paper was to review in vitro and in situ studies that directly compared the use of bovine teeth as a substitute for human teeth in dental experiments. A PubMed search was conducted for papers published from 1953 to December 30, 2010 using the following keywords: "human bovine enamel" or "human bovine dentin" or "human bovine teeth". The abstracts of the studies resulting from the keyword search were read, and all papers that compared human and bovine teeth were fully read. Only original articles written in English and directly comparing human and bovine substrates were included in the review. The search was supplemented by manual searches of the reference lists from each identified paper. Out of 76 studies initially selected, 68 fulfilled the selection criteria for inclusion. The studies covered seven categories: dental morphology, chemical composition, physical properties, dental caries, dental erosion/abrasion, bonding/adhesive strength, and marginal microleakage. Inconsistent data exist regarding whether bovine teeth can be considered an appropriate substitute for human teeth in dental research. Morphological, chemical compostion and physical property differences between the two substrates must be considered when interpreting results obtained from any experiment using bovine tooth substrate. PMID:21959653

  6. The impact of having natural teeth on the QoL of frail dentulous older people. A qualitative study

    Directory of Open Access Journals (Sweden)

    Niesten Dominique

    2012-10-01

    Full Text Available Abstract Background In order to adapt oral care and treatment to the demands of the growing group of frail dentulous older people, it is important to understand how and to which extent having natural teeth contributes to the quality of life (QoL of frail older people and how frailty influences their perspective. Methods A qualitative approach was used. Interviews with 38 Dutch frail older dentulous people were tape-recorded, transcribed, coded for content and analyzed. Additional information was collected which included age, gender, living situation, use of dental prostheses, self-reported oral health status, chronic disorders, and an index for frailty. Results Seven themes were identified in the relationship between natural teeth and the QoL of the participants: pride and achievement; intactness; sense of control; oral function; appearance; comfort; along with coping and adapting to disabilities. Having natural teeth generally had a positive effect on QoL. Positive effects through pride and achievement, intactness, and sense of control were most apparent for the most severely frail. They compared themselves with peers who are more often edentate, and valued the good state of their teeth against the background of their declining health, especially those with disabilities causing severe chronic pain or impaired fine-motor skills. The effect of coping with and adaptation to tooth loss was also most apparent for the most severely frail. There was a gender effect in that the men generally cared less about having natural teeth than women, regardless of their level of frailty. Conclusions QoL of frail older people is positively influenced by natural teeth, and this effect seems to increase with increasing frailty. Preservation of teeth contributes to a positive body image and self-worth. Oral care for frail people should aim to preserve natural teeth if possible.

  7. Age determination of fish from scales; method and application to fish cultural problems

    Science.gov (United States)

    Hile, Ralph

    1936-01-01

    THE SCIENCE of "scale reading", or determination of the age of fish from the examination of their scales, is less than 40 years old. Yet today the publications on the subject are to be numbered by the hundreds, and there is scarcely any phase of fish and fishery work that has not been benefited by this powerful tool for investigation. Fish culture is no exception to this rule. It is because of the increasing interest of fish culturists in scale reading and their numerous requests for information on the subject, that I have been asked to prepare a brief discussion of the method of age determination in fishes.

  8. Take Care of Your Child's Teeth

    Science.gov (United States)

    ... Your Child’s Teeth Print This Topic En español Take Care of Your Child’s Teeth Browse Sections The Basics ... important. Baby teeth hold space for adult teeth. Take care of your child’s teeth to protect your child ...

  9. Clinical and radiological evaluation of impaction of supernumerary teeth

    OpenAIRE

    Tuna, Elif-Bahar; Kurklu, Esma; Gencay, Koray; Ak, Gulsum

    2013-01-01

    Abstract Objective: To describe the clinical and radiological features of children with inverted supernumerary teeth. Study Design: Thirty eight patients with inverted supernumerary teeth (ST) were enrolled in this descriptive and restrospective study. Data from patient records including age, gender, status of dentition, number of ST, number of ST in inverted position, coexistence of ST in inverted and normal direction of eruption, location, orientation, morphology, clinical...

  10. Clinical and radiological evaluation of inverse impaction of supernumerary teeth

    OpenAIRE

    Tuna, Elif B.; Kurklu, Esma; Gencay, Koray; Ak, Gulsum

    2013-01-01

    Objective: To describe the clinical and radiological features of children with inverted supernumerary teeth. Study Design: Thirty eight patients with inverted supernumerary teeth (ST) were enrolled in this descriptive and restrospective study. Data from patient records including age, gender, status of dentition, number of ST, number of ST in inverted position, coexistence of ST in inverted and normal direction of eruption, location, orientation, morphology, clinical complications, management ...

  11. A histological study of the innervation of developing mouse teeth.

    OpenAIRE

    Mohamed, S. S.; Atkinson, M E

    1983-01-01

    The innervation of developing mouse teeth between initial formation and crown formation was investigated using silver-stained serial sections. The developing innervation correlated with the stage of development of individual teeth rather than the chronological age of the mice. Nerves approached the developing dental papilla during the bud stage and formed a basal plexus below the dental papilla in the early cap stage. Nerve fibres from this plexus spread into the dental follicle as it began t...

  12. Using colours to determine the stellar ages and metallicities of distant galaxies

    CERN Document Server

    Li, Zhongmu

    2013-01-01

    The determination of stellar populations of galaxies are important for studying the formation and evolution of galaxies, because all galaxies contain many stars and they evolve with galaxies. Spectra data are usually used to determine the stellar populations of nearby galaxies as they have the ability to disentangle the degeneracy between stellar age and metallicity. However, it is difficult to give similar studies to distant (e.g., $z >$ 0.3) galaxies because of the lack of reliable spectra data. This is actually limited by current observational equipments and methods. In fact, the information of the stellar ages and metallicities of distant galaxies are crucial for solving the problem of galaxy formation and evolution. Colours can give us some information of the stellar populations of distant galaxies. In the paper, I introduce our works about using colours to estimate the ages and metallicities of the stellar populations of galaxies. Some potential colours for studying stellar-population parameters (age an...

  13. 29 CFR Appendix D to Part 4044 - Tables Used To Determine Expected Retirement Age

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 9 2010-07-01 2010-07-01 false Tables Used To Determine Expected Retirement Age D Appendix... 4044—Tables Used To Determine Expected Retirement Age TABLE I-10—Selection of Retirement Rate Category... Participant's earliest retirement age at valuation date. Unreduced retirement age 60 61 62 63 64 65 66 67...

  14. Social relations as determinant of onset of disability in aging

    DEFF Research Database (Denmark)

    Avlund, Kirsten; Holstein, Bjørn E; Due, Pernille

    2013-01-01

    The purpose of the study was to analyze whether social relations are related to onset of disability among old people at 1.5 year follow-up and whether these relations vary by age and gender. The study is based on baseline and 1.5 year follow-up data on 1396 older non-disabled adults. Social...... relations were measured by questions about diversity in social relations, social participation, satisfaction with social relations and instrumental social support. Onset of disability was described as developing need of help in at least one of six mobility activities. The results showed that a large...... network of social relations provides protection against disability by reducing risk of developing disability....

  15. Social relations as determinant of onset of disability in aging

    DEFF Research Database (Denmark)

    Avlund, Kirsten; Lund, Rikke; Holstein, Bjørn E;

    2003-01-01

    The purpose of the study was to analyze whether social relations are related to onset of disability among old people at 1.5 year follow-up and whether these relations vary by age and gender. The study is based on baseline and 1.5 year follow-up data on 1396 older non-disabled adults. Social...... relations were measured by questions about diversity in social relations, social participation, satisfaction with social relations and instrumental social support. Onset of disability was described as developing need of help in at least one of six mobility activities. The results showed that a large...... network of social relations provides protection against disability by reducing risk of developing disability....

  16. Nongenetic Determinants of Age at Menarche: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Anna Yermachenko

    2014-01-01

    Full Text Available Background. The acceleration of pubertal development is an important medical and social problem, as it may result in increased morbidity and mortality in later life. This systematic review summarizes relevant data about nongenetic factors, which contribute to age at menarche (AAM, and suggests those which may be the most important. Methods. The available literature from 1980 till July 2013 was searched using PubMed and Google Scholar databases. Finally, 154 papers were selected for the analysis. Results. Environmental factors, which may affect AAM, vary in populations of different ethnicity. The prenatal, infancy, and early childhood periods are the most susceptible to these factors. Body weight, high animal protein intake, family stressors (e.g., single parenting, and physical activity seem to influence AAM in most populations. Conclusions. The data about influence of nongenetic factors on AAM are still inconsistent. The factors affecting prenatal and early childhood growth seem to have a larger effect on further sexual maturation. Further studies are needed in order to validate the association between other environmental determinants and AAM in different ethnical groups.

  17. Characterization of crocodile teeth: correlation of composition, microstructure, and hardness.

    Science.gov (United States)

    Enax, Joachim; Fabritius, Helge-Otto; Rack, Alexander; Prymak, Oleg; Raabe, Dierk; Epple, Matthias

    2013-11-01

    Structure and composition of teeth of the saltwater crocodile Crocodylus porosus were characterized by several high-resolution analytical techniques. X-ray diffraction in combination with elemental analysis and infrared spectroscopy showed that the mineral phase of the teeth is a carbonated calcium-deficient nanocrystalline hydroxyapatite in all three tooth-constituting tissues: Dentin, enamel, and cementum. The fluoride content in the three tissues is very low (<0.1 wt.%) and comparable to that in human teeth. The mineral content of dentin, enamel, and cementum as determined by thermogravimetry is 71.3, 80.5, and 66.8 wt.%, respectively. Synchrotron X-ray microtomography showed the internal structure and allowed to visualize the degree of mineralization in dentin, enamel, and cementum. Virtual sections through the tooth and scanning electron micrographs showed that the enamel layer is comparably thin (100-200 μm). The crystallites in the enamel are oriented perpendicularly to the tooth surface. At the dentin-enamel-junction, the packing density of crystallites decreases, and the crystallites do not display an ordered structure as in the enamel. The microhardness was 0.60±0.05 GPa for dentin, 3.15±0.15 GPa for enamel, 0.26±0.08 GPa for cementum close to the crown, and 0.31±0.04 GPa for cementum close to the root margin. This can be explained with the different degree of mineralization of the different tissue types and is comparable with human teeth. PMID:24091039

  18. Evaluation of uranium incorporation from contaminated areas using teeth as bio-indicators - A case study

    International Nuclear Information System (INIS)

    The Southwest region of the Bahia state in Brazil hosts the largest uranium reserve of the country (100 kton in uranium, only), plus the cities of Caetite, Lagoa Real and Igapora. In this work, aim was at the investigation of uranium burdens on residents of these cities by using teeth as bio-indicators, as a contribution for possible radiation protection measures. Thus, a total of 41 human teeth were collected, plus 50 from an allegedly uranium free area (the control region). Concentrations of uranium in teeth from residents of 5- to 87-y old were determined by means of a high-resolution inductively coupled plasma mass spectrometer (ICP-MS). The highest uranium concentration in teeth was measured from samples belonging to residents of Caetite (median equal to 16 ppb). Assuming that the uranium concentrations in teeth and bones are similar within 10-20% (for children and young adults), it concluded that uranium body levels in residents of Caetite are at least one order of magnitude higher than the worldwide average. This finding led to conclude that daily ingestion of uranium, from food and water, is equally high. (authors)

  19. ESR dating of teeth from Brazilian megafauna

    Science.gov (United States)

    Oliveira, L. C.; Kinoshita, A.; Barreto, A. M. F.; Figueiredo, A. M.; Silva, J. L. L.; Baffa, O.

    2010-11-01

    The study of radiation defects created in biomaterials, such as bone and teeth, can be used in dating with importance to palaeontology and archaeology. Two Stegomastodon teeth (AL1 and AL2) from north-eastern Brazilian megafauna were studied by electron spin resonance (ESR) spectroscopy. The samples were collected in Fazenda Ovo da Ema, (913349 / 3714965) UTM, Alagoas state, Brazil. The dating of these samples can contribute to the better knowledge of megafauna presence in this region as well as to the events associated to the extinction of these species.

  20. Correlating the end-Triassic mass extinction and basalt volcanism of the Central Atlantic Magmatic Province at the 100,000-year level by high-precision U-Pb age determinations

    Science.gov (United States)

    Schoene, Blair; Guex, Jean; Bartolini, Annachiara; Schaltegger, Urs; Blackburn, Terrence J.

    2010-05-01

    The end-Triassic mass extinction is one of the five largest extinctions in Earth history, though considerable uncertainty remains in terms of its duration, causes and effects. Many workers suggest that the extinction was related directly or indirectly to adverse climate following the onset of the Central Atlantic Magmatic Province (CAMP), which erupted > 2.5x106 km3 of basalt in less than 1 Ma. However, there remains a need for precise and accurate geochronology to correlate the onset of CAMP volcanism, recorded uniquely in terrestrial sections, with the well-documented marine extinction event. We provide new chemical abrasion ID-TIMS U-Pb age determinations on ash bed and basaltic zircons using the well-calibrated EARTHTIME 202Pb-205Pb-233U-235U tracer solution, yielding data that are up to 70% more precise compared to single-Pb/single-U tracers. We show that the Triassic-Jurassic boundary (TJB) and end-Triassic biological crisis from two independent marine stratigraphic sections in northern Peru and in Nevada (USA) correlate with the onset of terrestrial flood volcanism in the Central Atlantic Magmatic Province (CAMP) to <150 ka. Ash bed samples reveal complicated U-Pb systematics, showing ranges in 206Pb/238U zircon dates of up to 2 Ma, representing a range of growth histories prior to eruption. Therefore, we use the youngest single closed-system zircon to approximate the eruption date. Three volcanic ash beds from the Pucara basin, northern Peru, bracket the TJB to a 206Pb/238U age of 201.31 ± 0.18/0.31/0.43 Ma (internal uncertainties/ with tracer calibration uncertainty/ with decay constant uncertainties). The first discovered ash bed from the New York canyon, Nevada, 1.5 m above TJB requires a boundary age of less than 201.33 ± 0.13 Ma. We also provide data from two laboratories which yield a new 206Pb/238U zircon age of 201.28 ± 0.02/0.22/0.31 Ma for the North Mtn. basalt, the lowest CAMP basalt from the Fundy basin, Nova Scotia. This narrows the

  1. Evaluation of Lead, Cadmium, Zinc and Copper Levels in Blood, Hair and Teeth of Children

    International Nuclear Information System (INIS)

    There is a general agreement that children are a population that suffered increased risk of lead (Pb) and cadmium (Cd) exposure with adverse health effects. The aim of this study is to evaluate the environmental exposure to Pb and Cd in children living in Cairo since birth and their effects on other essential elements such as zinc (Zn) and copper (Cu). The relationships between these indicators for exposure and children characteristics such as sex, weight, height, blood pressure and smoking habits of parents were also estimated. Forty children (23 males and 17 females) aged 5-7 years had been included in this study. Levels of elements in the samples were determined using atomic absorption spectroscopy. The levels of Pb in blood (Pb-B), hair (Pb-H) and teeth (Pb-T) were 18.17 ± 5.35 fig/dl, 6.29 ± 2.07 fig/g and 8.07± 1.98 fig/g, respectively. Significant differences were observed between boys and girls as regards Pb-H (P<0.001)and Pb-T(P<0.05). The Cd levels were 0.603 ±0.08 μg/dl in blood (Cd-B), 0.933 ± 0.18 fig/g in hair (Cd-H) and 4.825± 0.57 μg/g in teeth (Cd-T). Boys showed higher significant increases in Cd-B than girls (P < 0.001). Concerning Zn, the levels were 57.43± 6.86 μg/dl,148.18± 11.76μg/g and 100.32± 20.28 μg/dl in blood (Zn-B), hair (Zn-H) and teeth(Zn-T),correspondingly Girls displayed significant higher levels of Zn-H than boys (P < 0.05). Regarding Cu in blood (Cu-B), in hair (Cu-H) and in teeth (Cu-T), they were 113.42± 9.89 μg/dl, 17.9±4.18 μg/g and 10.6± 3.04 μg/g, respectively. Girls showed significant higher levels of Cu-H than boys (P < 0.05). The passive smoking children exhibited significant increased levels of Pb, Cd and Cu in blood, hair and teeth when compared to the non-exposed children. On the other hand, passive smoking leads to decrease in Zn concentrations in the three studied samples. The proper mechanism of Zn affection was explained by interactions with Cd, Pb and Cu. Correlation between Pb and Cd with

  2. Scanning electron microscopy and electron probe X-ray microanalysis (SEM-EPMA) of pink teeth

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, N.; Watanabe, G.; Harada, A.; Suzuki, T.

    1988-11-01

    Samples of postmortem pink teeth were investigated by scanning electron microscopy and electron probe X-ray microanalysis. Fracture surfaces of the dentin in pink teeth were noticeably rough and revealed many more smaller dentinal tubules than those of the control white teeth. Electron probe X-ray microanalysis showed that the pink teeth contained iron which seemed to be derived from blood hemoglobin. The present study confirms that under the same circumstance red coloration of teeth may occur more easily in the teeth in which the dentin is less compact and contains more dentinal tubules.

  3. Scanning electron microscopy and electron probe X-ray microanalysis (SEM-EPMA) of pink teeth

    International Nuclear Information System (INIS)

    Samples of postmortem pink teeth were investigated by scanning electron microscopy and electron probe X-ray microanalysis. Fracture surfaces of the dentin in pink teeth were noticeably rough and revealed many more smaller dentinal tubules than those of the control white teeth. Electron probe X-ray microanalysis showed that the pink teeth contained iron which seemed to be derived from blood hemoglobin. The present study confirms that under the same circumstance red coloration of teeth may occur more easily in the teeth in which the dentin is less compact and contains more dentinal tubules

  4. Taking Care of Your Teeth

    Science.gov (United States)

    ... important to keeping teeth healthy. When you eat sugary foods or drink sodas frequently throughout the day, the enamel that protects your teeth is constantly exposed to acids. Hard candies, cough ... foods containing sugar. Sugary or starchy foods eaten with a meal are ...

  5. 改良腭弓矫治后牙锁节对后牙功能恢复的影响%Influence of promote palatine arch treating buccal teeth lock on occlusion function recovery of buccal teeth

    Institute of Scientific and Technical Information of China (English)

    马宁; 孙应明; 白槐延

    2002-01-01

    @@ Background: Buccal teeth occlusion lock is a kind of common malocclusion malformation in orthodonic clinic. Traditional treatment to buccal teeth occlusion lock is interactive traction of upper and lower buccal teeth.This treatment had shortcoming such as insufficient anchorage and elongation of buccal teeth.We adopted promote fix palatine arch therapy, which recovery patients' occlusion function by clinical observation.

  6. The longevity of different restorations in primary teeth

    DEFF Research Database (Denmark)

    Qvist, Vibeke; Poulsen, Agneta; Teglers, Poul Thorpen;

    2010-01-01

    This paper reviews three published papers and adds results from a fourth study which aimed to determine which restorative material would be the best alternative(s) to amalgam (AM) in primary teeth.......This paper reviews three published papers and adds results from a fourth study which aimed to determine which restorative material would be the best alternative(s) to amalgam (AM) in primary teeth....

  7. Minor and trace elements in human bones and teeth

    International Nuclear Information System (INIS)

    Chemical elements play a great role in the metabolism of bones and teeth. Some elements are beneficial (F at non toxic concentrations in bones and teeth, supplementation of Cu, Mn and Zn along with Ca to delay or prevent the onset of osteoporosis) and some others (chronic exposure to Pb even at moderate concentrations, and excessive exposures to F as in fluorosis situations) are detrimental for the normal functioning of the skeleton. Knowledge on the roles played by both groups of elements can be enhanced if reliable compositional picture is available for scrutiny. The present survey was undertaken to assess the literature status on chemical composition of bones and teeth, and revealed that much needs to be done in order to have tangible collection of meaningful data. In this context, there is a desperate need for harmonization (types of samples chosen, procedures adopted to process the specimens, and finally the determination of analytes) to generate comparable data. To begin with, it is necessary to develop a bioanalytical protocol that exemplifies the merits and demerits of analyzing bones and teeth. Identification of any particular type of bone as a representative sample for the whole skeleton appears to be a far cry. Even if such a representative segment of a particular bone is identified, the logistics related to medico-legal (autopsy) and anatomical (biopsy) parameters will prevail as decisive factors. For the sake of gaining a comprehensive insight into the distribution of various trace elements in different types of bones, it is necessary to carry out controlled investigations on different types of bones (and cortical and trabecular segments from the same sources) from the same cadaver under well defined sampling conditions. On the analytical side, development of hard tissue RMs for whole bone, as well as for cortical, trabecular and marrow segments separately, would be very helpful for future investigations. (author)

  8. Estimation of dental age by Nolla’s method using orthopantomographs among rural free residential school children

    Directory of Open Access Journals (Sweden)

    Nandlal B, Karthikeya Patil, Ravi S

    2014-04-01

    Full Text Available Introduction: Teeth and dental restorations are resistant to destruction by fire and the elements are therefore useful in identification. This permits accurate identification of a missing child or remains. The Rural Residential free school at Suttur houses a large number of inmates and hence dental records are kept for their identification. Objective: Estimation of Age of children. Methods: Orthopantomographs were used to study for estimation of age of children, using a Nolla’s method of dental age estimation. Results: In this study Nolla’s method underestimated the chronological age of the individuals and underestimation of age increased as the chronological age of the individuals increased. Conclusion: Studies involving larger sample size and population specific data needs to be developed.

  9. Determining the prevalence of obesity in the 6-11 age group active and sedentary children

    OpenAIRE

    Yücesir, İlker; Bektaş, İlknur

    2015-01-01

    AbstractOperating one of the four primary schools in the state, including three special, 6-11 girls between the ages of moving or still being carried out to determine the effect of high-frequency weightedand obese. Mean age =8.29±1.50, which research was con­ducted on 596 girls. Children’s height and weight were measured in this study, body mass index was calculated by comparing the values inage-appropriateper centile values, low, normal, high weighted and obese children were determined. Pare...

  10. Automated Determination of Bone Age in a Modern Chinese Population

    OpenAIRE

    Zhang, Shao-yan; Liu, Gang; Ma, Chen-Guo; Han, Yi-San; Shen, Xun-Zhang; XU, RUI-LONG; Thodberg, Hans Henrik

    2013-01-01

    Rationale and Objective. Large studies have previously been performed to set up a Chinese bone age reference, but it has been difficult to compare the maturation of Chinese children with populations elsewhere due to the potential variability between raters in different parts of the world. We re-analysed the radiographs from a large study of normal Chinese children using an automated bone age rating method to establish a Chinese bone age reference, and to compare the tempo of maturation in the...

  11. A revision of hominin fossil teeth from Fontana Ranuccio (Middle Pleistocene, Anagni, Frosinone, Italy).

    Science.gov (United States)

    Rubini, Mauro; Cerroni, Vittorio; Festa, Giulia; Sardella, Raffaele; Zaio, Paola

    2014-12-01

    The Fontana Ranuccio hominin teeth (FR, Latium, Italy) are dated to the Middle Pleistocene. In previous studies these teeth were classified as two lower (left and right) second molars, one lower left central incisor and a badly worn incisor crown, the exact position of which could not be determined. In 2012 these remains were acquired by the Anthropological Service of S.B.A.L. (Italian Ministry of Culture) and for this reason re-analysed. In a thorough revision we have reassessed them both morphologically and dimensionally as two lower (left and right) first molars, one lower left lateral incisor and a possible upper left canine. The comparison with penecontemporaneous and diachronic samples shows that the Fontana Ranuccio teeth are morphologically similar to Atapuerca-Sima de los Huesos, Arago XIII and Neanderthal samples. PMID:25440134

  12. Potentiometric stripping analysis of lead and cadmium leaching from dental prosthetic materials and teeth

    Directory of Open Access Journals (Sweden)

    GORAN M. NIKOLIC

    2004-07-01

    Full Text Available Potentiometric stipping analysis (PSA was applied for the determination of lead and cadmium leaching from dental prosthetic materials and teeth. The soluble lead content in finished dental implants was found to be much lower than that of the individual components used for their preparation. Cadmium was not detected in dental implants and materials under the defined conditions. The soluble lead and cadmium content of teeth was slightly lower than the lead and cadmium content in whole teeth (w/w reported by other researchers, except in the case of a tooth with removed amalgam filling. The results of this work suggest that PSA may be a good method for lead and cadmium leaching studies for investigation of the biocompatibility of dental prosthetic materials.

  13. Size variation in samples of fossil and recent murid teeth

    NARCIS (Netherlands)

    Freudenthal, M.; Martín Suárez, E.

    1990-01-01

    The variability coefficient proposed by Freudenthal & Cuenca Bescós (1984) for samples of fossil cricetid teeth, is calculated for about 200 samples of fossil and recent murid teeth. The results are discussed, and compared with those obtained for the Cricetidae.

  14. How Acid Reflux Disease Damages Teeth

    Science.gov (United States)

    ... more Seniors' Oral Health How to Keep Your Teeth for a Lifetime Tooth loss is simply the ... your desktop! more... How Acid Reflux Disease Damages Teeth Article Chapters How Acid Reflux Disease Damages Teeth ...

  15. Evaluation of the Root and Canal Morphology of Mandibular Permanent Anterior Teeth in an Iranian Population by Cone-Beam Computed Tomography

    Directory of Open Access Journals (Sweden)

    Mohsen Aminsobhani

    2013-01-01

    Full Text Available Objective: To evaluate differences in the root and canal configurations of mandibular permanent anterior incisors and canines in an Iranian population by means of Cone Beam CT (CBCT images.Materials and Methods: Four hundred CBCT images of mandibular permanent incisors and canines that met the inclusion criteria were evaluated. Vertucci´s classification was used to evaluate the number of roots, number of root canals, root lengths, root curvatures and canal types.Results: Totally 632 central incisors, 614 lateral incisors and 608 canines were evaluated. The average length of the mandibular central, lateral incisors and canines was 21.3±0.10, 21.9± 0.13 and 25.1± 0.11 mm, respectively. All of the mandibular central and lateral incisors had one root, but the incidence of single-rooted mandibular canines and two-rooted mandibular canines was 96.3% and 4.7%, respectively. The majority of mandibular central, lateral incisors and canines had one canal (72.7%, 70.6% and 71.8%, respectively. Five types of Vertucci canal configurations were seen in the evaluated teeth. Type 1 Vertucci configuration was the most prevalent configuration (72.3%, 70.6% and 71.8% for the central, lateral incisors and canines, respectively, and type 5 Vertucci canal configuration was the least prevalent type seen (3.3%, 3.2% and 2.3% for the central, lateral incisors and canines, respectively. The most frequent root curvatures in these teeth were distally and buccally. No significant difference was seen between male and female patients regarding any of the parameters evaluated in this study (p>0.05.Conclusion: More attention should be given to the detection of additional canals and the recognition of canal curvature in Iranian patients.

  16. Triple Teeth: Report of an Unusual Case

    OpenAIRE

    Prashant Babaji; M. A. Prasanth; Ajith R. Gowda; Soumya Ajith; Henston D'Souza; Ashok, K. P.

    2012-01-01

    Fusion or synodontia is a union of two or more than two developing teeth. Commonly fusion occurs between teeth of the same dentition, mixed dentition, or between normal and supernumerary teeth. Fused primary teeth present with several clinical problems like caries, periodontal problem, arch asymmetry, delayed eruption, ectopic eruption of succedaneous teeth, aesthetic, and other complications. This paper presents a rare and unusual case of triple teeth in mandibular primary dentition.

  17. Job Satisfaction, Work Environment, and Successful Aging: Determinants to Remain in Older Acute Care Nurses

    OpenAIRE

    Wargo-Sugleris, Michele

    2015-01-01

    Michele Wargo-SuglerisDoctor of Philosophy in NursingUniversity of California, Los Angeles, 2013Professor Emeritus Linda R. Phillips, ChairThis study investigated the determinants of job satisfaction, work environment, and successful aging in association with retire among older registered nurses (RNs). In addition, this study was designed to further understand what motivates nurses to remain employed in their current positions by investigating the relationship among these determinants and th...

  18. Utility of telomere length measurements for age determination of humpback whales

    DEFF Research Database (Denmark)

    Olsen, Morten Tange

    2014-01-01

    This study examines the applicability of telomere length measurements by quantitative PCR as a tool for minimally invasive age determination of free-ranging cetaceans. We analysed telomere length in skin samples from 28 North Atlantic humpback whales (Megaptera novaeangliae), ranging from 0 to 26...

  19. Amount and type of alcohol consumption and missing teeth among community-dwelling older adults

    DEFF Research Database (Denmark)

    Heegaard, Karen; Avlund, Kirsten; Holm-Pedersen, Poul;

    2011-01-01

    Objectives: To study if an association between total weekly intake of alcohol, type-specific weekly alcohol intake, alcoholic beverage preference, and the number of teeth among older people exists. Methods: A cross-sectional study including a total of 783 community-dwelling men and women aged 65...... highest intake of one beverage type compared with two other types), and the number of remaining teeth (=20 versus >20 remaining teeth). Results: The odds ratio (OR) of having a low number of teeth decreased with the total intake of alcohol in women, with ORs for a low number of teeth of 0.40 [95 percent...... among women. Men who preferred beer showed a decreased risk for a low number of teeth compared with men with other alcohol preferences. Conclusion: In this study, alcohol consumption, wine drinking, and wine and spirits preference among women were associated with a higher number of teeth compared with...

  20. Do We Need National Standards with Teeth?

    Science.gov (United States)

    Usiskin, Zalman

    2007-01-01

    The author, director of the University of Chicago School Mathematics Project, tackles the following question: Should the United States have national standards with teeth, that is, a single set of standards tied to assessments and agreed to by the states? Proponents advance five main arguments for implementing such a standard. In his rebuttal, the…

  1. Elephant teeth from the atlantic continental shelf

    Science.gov (United States)

    Whitmore, F.C., Jr.; Emery, K.O.; Cooke, H.B.S.; Swift, D.J.P.

    1967-01-01

    Teeth of mastodons and mastodons have been recovered by fishermen from at least 40 sites on the continental shelf as deep as 120 meters. Also present are submerged shorelines, peat deposits, lagoonal shells, and relict sands. Evidently elephants and other large mammals ranged this region during the glacial stage of low sea level of the last 25.000 years.

  2. Outcome of root canal treatment in dogs determined by periapical radiography and cone-beam computed tomography scans

    NARCIS (Netherlands)

    F.W.G. de Paula-Silva; B. Hassan; L.A.B. da Silva; M.R. Leonardo; M.K. Wu

    2009-01-01

    The purpose of this study was to compare the favorable outcome of root canal treatment determined by periapical radiographs (PRs) and cone beam computed tomography (CBCT) scans. Ninety-six roots of dogs' teeth were used to form four groups (n= 24). In group 1, root canal treatments were performed in

  3. Ecological determinants of mean family age of angiosperm trees in forest communities in China

    Science.gov (United States)

    Qian, Hong; Chen, Shengbin

    2016-01-01

    Species assemblage in a local community is determined by the interplay of evolutionary and ecological processes. The Tropical Niche Conservatism hypothesis proposes mechanisms underlying patterns of biodiversity in biological communities along environmental gradients. This hypothesis predicts that, among other things, clades in areas with warm or wet environments are, on average, older than those in areas with cold or dry environments. Focusing on angiosperm trees in forests, this study tested the age-related prediction of the Tropical Niche Conservatism hypothesis. We related the mean family age of angiosperm trees in 57 local forests from across China with 23 current and paleo-environmental variables, which included all major temperature- and precipitation-related variables. Our study shows that the mean family age of angiosperm trees in local forests was positively correlated with temperature and precipitation. This finding is consistent with the age-related prediction of the Tropical Niche Conservatism hypothesis. Approximately 85% of the variance in the mean family age of angiosperm trees was explained by temperature-related variables, and 81% of the variance in the mean family age of angiosperm trees was explained by precipitation-related variables. Climatic conditions at the Last Glacial Maximum did not explain additional variation in mean family age after accounting for current environmental conditions. PMID:27354109

  4. OSL age determinations of Pleistocene fluvial deposits in Central Amazonia

    Directory of Open Access Journals (Sweden)

    Emílio A.A. Soares

    2010-09-01

    Full Text Available Absolute dating methods have been used in chronological studies of geological processes and sedimentary units of Quaternary age in Central Amazonia, Brazil. Although radiocarbon dating has been very useful in archaeological research and soil studies, the temporal interval of this method is inefficient in evaluating the sedimentation aspects and geological events from the beginning of the Quaternary in the Amazon basin. The use of crystal luminescence dating has been one of the most promising tool for determining the absolute dating of Quaternary deposits in the Amazonian region. Optically stimulated luminescence (OSL dating, following the MAR and SAR protocols, in a tectonic-sedimentary study of Quaternary fluvial deposits in the confluence area of the Negro and Solimões rivers, indicated ages from 1.3 (Holocene to about 67.4 kyears (Late Pleistocene for these sediments. Low radioactive isotope concentrations were found about 2ppm for 235U and 238U; 5ppm for 232Th; and the 40K concentrations were almost zero. A comparison was made between MAR and SAR protocols taking into account the fluvial depositional process.Métodos de datação absoluta têm sido usados em estudos cronológicos de processos geológicos e unidades sedimentares de idade quaternária na Amazônia Central, Brasil. Embora as datações pelo 14C tenham sido muito úteis na pesquisa arqueológica e estudos de solos, o intervalo de tempo abrangido por este método é ineficiente para avaliar aspectos da sedimentação e eventos geológicos do início do Quaternário na bacia Amazônica. O uso da datação por luminescência de cristais tem sido uma das ferramentas mais promissoras para a determinação da idade absoluta de depósitos quaternários na região amazônica. A datação por luminescência opticamente estimulada (LOE, seguindo os protocolos MAR e SAR, em um estudo tectono-sedimentar de depósitos aluviais quaternários da área de confluência dos rios Negro e Solim

  5. Understanding the Crystallinity Indices Behavior of Burned Bones and Teeth by ATR-IR and XRD in the Presence of Bioapatite Mixed with Other Phosphate and Carbonate Phases

    OpenAIRE

    Giampaolo Piga; David Gonçalves; T. J. U. Thompson; Antonio Brunetti; Assumpció Malgosa; Stefano Enzo

    2016-01-01

    We have critically investigated the ATR-IR spectroscopy data behavior of burned human teeth as opposed to the generally observed behavior in human bones that were subjected to heat treatment, whether deliberate or accidental. It is shown that the deterioration of the crystallinity index (CI) behavior sometimes observed in bones subjected to high temperature appears to be of higher frequency in the case of bioapatite from teeth. This occurs because the formation of the β-tricalcium phosphate (...

  6. Simulation of a flow around biting teeth

    Science.gov (United States)

    Narusawa, Hideaki; Yamamoto, Eriko; Kuwahara, Kunio

    2008-11-01

    We simulated a flow around biting teeth. The decayed tooth is a disease that a majority of people are annoyed. These are often generated from a deep groove at occlusal surface. It is known that a person who bites well doesn't suffer from a decayed tooth easily. Biting forces reach as much as 60 kg/cm^2 by an adult male, and when chewing, upper and lower teeth approach to bite by those forces. The crushed food mixed with saliva becomes high viscosity fluid, and is pushed out of ditches of teeth in the direction of the cheek or the tongue. Teeth with complex three dimension curved surface are thought to form venturi at this time, and to generate big pressure partially. An excellent dental articulation will possibly help a natural generation of a flow to remove dental plaque, i.e. the cause of the decayed tooth. Moreover, the relation of this flow with the destruction of the filled metal or the polymer is doubted. In this research, we try to clarify the pressure distributions by this flow generation as well as its dynamics when chewing. One of our goals is to enable an objective design of the shape of the dental fillings and the artificial tooth. Tooth has a very small uneven ground and a bluff body. In this case, to calculate a computational numerical simulation to solve the Navier-Stokes equations three dimension Cartesian coordinate system is employed.

  7. Relative age determination of Rattus tiomanicus using allometric measurements

    OpenAIRE

    Verwilghen, Aude; Rabillard, Marie-Agnes; Chaval, Yannick; Rieffel, Dominique; Sinaga, Martua Hasiholan; Naim, Mohd; Caliman, Jean-Pierre; Giraudoux, Patrick; Raoul, Francis

    2015-01-01

    For sustainable oil palm production, barn owl (Tyto alba) predation should be enhanced and monitored to better understand its impact on rodent population dynamics, notably for selective predation based on age or size. Our aim was to assess the best combination of osteometric variables that predict eye lens weight and thus the relative age of an individual Rattus tiomanicus based on pellet remains. We captured 161 individuals in an oil palm plantation in Indonesia and measured 15 osteometric v...

  8. Computer system for determination of cultural relic's age

    International Nuclear Information System (INIS)

    The computer is described in which thermoluminescent dosimeter is used for measuring ancient porcelain's age. The calculating formula of cultural relic's age, the working principle of the computer interface circuit and the design strategy of software are given. This system has been put into practical use for two years. The performance is stable and the operation is convenient. The calculation speed is raised as well as the calculation precision is guaranteed. All kinds of original data can be stored

  9. Evaluation of crown mesiodistal diameter of permanent teeth

    Directory of Open Access Journals (Sweden)

    H. Ravanmehr

    1994-06-01

    Full Text Available The aim of this study was to evaluate mesiodistal diameter of permanent teeth and evaluating it's distribution in Iran. In current study, 850 plastery impressions or 16590 teeth were precisely measured by a digital coulis with 0.01 mm accuracy.The obtained measures of the permanent teeth are shown in table 1. Table (4 demonstrates the symmetry of left and right maxillary and mandibular teeth. Obtainedmeasurements in Table 1 were compared with Gran's measures (Table 2 which are shown in Table (3.Bolton analysis was done and results were found close to the BolType text or a website address or translate a document.ton measures. It was concluded that it is better to replace measurements of our society instead of Bolton's. Since we found minor difference with the measures of other researchers, especially for teeth anterior to first molar, using our measures in treatment plans would not bring about any problem.

  10. Strontium in 19th century Australian children's teeth

    International Nuclear Information System (INIS)

    The enamel of teeth from 57 children, who died in the mid to late 1800s, were analysed to investigate strontium (Sr) concentrations in historic teeth. Teeth were analysed using proton induced X-ray emission at the Australian Nuclear Science and Technology Organisation (ANSTO). Where available, multiple teeth were analysed for each individual including permanent (molars and premolars) and deciduous teeth (molars). Preliminary results show that Sr does not appear to be affected by the postmortem environment. Sr levels in permanent molars strongly correlate with levels in the premolars but not with the deciduous molars. Concerns are raised over the large variation seen in Sr levels and the effect it would have on the interpretation of Sr levels in studies with small sample sizes

  11. Fluorine concentrations in teeth studied by /sup 19/F(p,α/sub o/)/sup 16/O nuclear reaction

    International Nuclear Information System (INIS)

    The fluorine concentrations has been determined in the enamel, dentine and cementum of a significative set of dental samples (healthy, fluorotic and decayed), by using /sup 19/F(rho,α/sub o/) /sup 16/O reaction, in the resonant region around 1350 KeV proton beam, and by recording the alpha particles emitted at 6.9 MeV. CrF/sub 3/ samples, as standard thin and thick films, has been used for quantitative analysis. In these films protons (0.5 / 1.5 MeV) and helium (4.0 / 7.0 MeV) stopping powers are very similar to those in dental tissue, supposed as hydroxyapatite (Ca/sub 10/(PO/sub 4/)/sub 6/(OH)/sub 2/). Fluorine depth profiles show an accumulation in the first superficial layers (1 / 2 μm) and about a factor two reduction at 4 / 5 μm. Results show an average concentration of surface fluorine in the healthy enamel of the order of 10/sup -3/ g/g (for 1 g of hydroxyapatite), concentration about ten times higher in fluorotic enamel and very low concentration, close to the minimum detectable limit (MDL = 0.3 mg/g), in the carried zones

  12. Elemental composition of human teeth with emphasis on trace constituents: a review

    Energy Technology Data Exchange (ETDEWEB)

    Sachs, W H

    1978-04-01

    Literature covered by the current review is based on a search of Chemical Abstracts, 1917 through 1975. Early studies, pre-dating 1940, are referenced primarily for historical interest. Emphasis is on the micro-constituents of human teeth, those present at concentrations less than a few tenths of a percent by weight. Within this category of data, we have been primarily concerned with the radiochemically stable nuclides. The important relationship between caries and trace elements is covered only insofar as carious teeth exhibit properties with respect to trace element composition that differ from normal teeth. Having made these disclaimers, we note that an attempt has been made to cover the literature exhaustively; although some important results have undoubtedly been overlooked. It is our hope, however, that sufficient material has been included in this review to facilitate further recovery of data by interested individuals. In Chapter 1, analytical techniques that have been employed in this field are briefly presented; discussion centers on problems associated with preparation of specimens for analysis. Chapter 2 is devoted to topical coverage of data on the inorganic composition of teeth. An element-by-element tabulation of concentration data is provided, our statistical analysis of selected data explained, and evidence concerning several major factors thought to influence dental composition evaluated. These include provenance, age, sex, distribution, and tooth type/intermouth variation.

  13. Marble Ageing Characterization by Acoustic Waves

    Science.gov (United States)

    Boudani, Mohamed El; Wilkie-Chancellier, Nicolas; Martinez, Loïc; Hébert, Ronan; Rolland, Olivier; Forst, Sébastien; Vergès-Belmin, Véronique; Serfaty, Stéphane

    In cultural heritage, statue marble characterization by acoustic waves is a well-known non-destructive method. Such investigations through the statues by time of flight method (TOF) point out sound speeds decrease with ageing. However for outdoor stored statues as the ones in the gardens of Chateau de Versailles, ageing affects mainly the surface of the Carrara marble. The present paper proposes an experimental study of the marble acoustic properties variations during accelerated laboratory ageing. The surface degradation of the marble is reproduced in laboratory for 29 mm thick marble samples by using heating/cooling thermal cycles on one face of a marble plate. Acoustic waves are generated by 1 MHz central frequency contact transducers excited by a voltage pulse placed on both sides of the plate. During the ageing and by using ad hoc transducers, the marble samples are characterized in transmission, along their volume by shear, compressional TOF measurements and along their surface by Rayleigh waves measurements. For Rayleigh waves, both TOF by transducers and laser vibrometry methods are used to detect the Rayleigh wave. The transmission measurements point out a deep decrease of the waves speeds in conjunction with a dramatic decrease of the maximum frequency transmitted. The marble acts as a low pass filter whose characteristic frequency cut decreases with ageing. This pattern occurs also for the Rayleigh wave surface measurements. The speed change in conjunction with the bandwidth translation is shown to be correlated to the material de-structuration during ageing. With a similar behavior but reversed in time, the same king of phenomena have been observed trough sol-gel materials during their structuration from liquid to solid state (Martinez, L. et all (2004). "Chirp-Z analysis for sol-gel transition monitoring". Ultrasonics, 42(1), 507-510.). A model is proposed to interpret the acoustical measurements

  14. Image analysis of the eruptive positions of third molars and adjacent second molars as indicators of age evaluation in Thai patients

    International Nuclear Information System (INIS)

    This study was performed to determine the relationship between the stage of tooth eruption (both vertical and mesio-angular) and chronological age. Indirect digital panoramic radiographs were used to measure the distances from the dentinoenamel junction (DEJ) of the second molars to the occlusal plane of the second molar teeth and of the adjacent third molars in 264 Thai males and 437 Thai females using ImageJ software. The ratio of those distances was calculated by patient age, and the correlation coefficient of the ratio of the third molar length to the second molar length was calculated. The correlation between the height of the vertically erupted upper third molar teeth and age was at the intermediate level. The age range of ≥15 to <16 years was noted to be the range in which the correlation between the chronological age determined from the eruptional height and actual chronological age was statistically significant. The mean age of the female subjects, in which the position of the right upper third molar teeth was at or above the DEJ of the adjacent second molar but below one half of its coronal height was 19.9±2.6 years. That for the left side was 20.2±2.7 years. The mean ages of the male subjects were 20.1±3.3 years and 19.8±2.7 years for the right and left sides, respectively. It might be possible to predict chronological age from the eruption height of the wisdom teeth.

  15. Image analysis of the eruptive positions of third molars and adjacent second molars as indicators of age evaluation in Thai patients

    Energy Technology Data Exchange (ETDEWEB)

    Mahasantipiya, Phattaranant May; Pramojanee, Sakarat; Thaiupathump, Trasapong [Chiang Mai University, Chiang Mai (Thailand)

    2013-12-15

    This study was performed to determine the relationship between the stage of tooth eruption (both vertical and mesio-angular) and chronological age. Indirect digital panoramic radiographs were used to measure the distances from the dentinoenamel junction (DEJ) of the second molars to the occlusal plane of the second molar teeth and of the adjacent third molars in 264 Thai males and 437 Thai females using ImageJ software. The ratio of those distances was calculated by patient age, and the correlation coefficient of the ratio of the third molar length to the second molar length was calculated. The correlation between the height of the vertically erupted upper third molar teeth and age was at the intermediate level. The age range of ≥15 to <16 years was noted to be the range in which the correlation between the chronological age determined from the eruptional height and actual chronological age was statistically significant. The mean age of the female subjects, in which the position of the right upper third molar teeth was at or above the DEJ of the adjacent second molar but below one half of its coronal height was 19.9±2.6 years. That for the left side was 20.2±2.7 years. The mean ages of the male subjects were 20.1±3.3 years and 19.8±2.7 years for the right and left sides, respectively. It might be possible to predict chronological age from the eruption height of the wisdom teeth.

  16. Evaluation of the overlapping of posterior teeth in two techniques of improved interproximal panoramic program and standard panoramic

    Directory of Open Access Journals (Sweden)

    Goodarzi pour D

    2010-06-01

    Full Text Available "nBackground and Aims: Overlapping of the proximal surfaces of posterior teeth in the panoramic radiography is a major concern. Therefore, an option has been developed in the panoramic unit of Planmeca Promax, namely improved interproximal mode. This mode causes lower horizental angle with the teeth contact region during the unit rotation decreasing overlapping of the panoramic images of the posterior teeth especially premolar teeth. The present study was done to compare the overlapping of posterior teeth using two techniques of improved interproximal panoramic program and standard panoramic. "nMaterials and Methods: In this diagnostic study, 32 patients requiring panoramic radiographies at their posterior teeth during their routine diagnosis and treatment process with the mean age of 27.3 years were participated. No patients showed crowding of posterior teeth or missed and restored posterior teeth. The participants' panoramic radiographies were randomly taken by two techniques of improved interproximal panoramic and standard panoramic using Planmeca Promax device. The overlapping of the panoramic images was blindly assessed by an oral radiologist. The overlapping in both techniques was reported by frequency and percentage. The comparisons were done by Chi-square test between two techniques and the odds ratio of overlapping was estimated using regression analysis. "nResults: In standard panoramic techniques, 38.5% (148 contacts of 384 contacts of the proximal surfaces overlapped while the overlapping of the proximal surfaces was observed in 18.8% (72 contacts of 384 overall contacts in improved interproximal technique. Significant differences were noted between two techniques regarding overlapping (P<0.001. Also 66.4% and 39.1% of 4-5 teeth contacts overlapped in standard and improved techniques. The values were reported to be 39.1% and 12.5% in contacts of 5-6 teeth and 10.2% and 4.7% in the contacts of 6-7 teeth in both techniques

  17. Prevalence and characteristics of supernumerary teeth in east-northern Turkish population

    Directory of Open Access Journals (Sweden)

    Gulsum Coskun

    2012-10-01

    Full Text Available

    Objectives: The aim of the present study was to determine the frequency and the distribution of supernumerary teeth (ST in patients from east-northern Turkey.

    Materials and Methods: A retrospective study was performed using panoramic radiographs of 1876 patients [673 females (mean age: 13.05±2.79 years and 1203 males (mean age: 13.63±3.18 years] ranging in age from 7 to 34 years (mean age: 13.39±3.05 years. Demographic variables including age and sex, the type, number, eruption status of the ST were recorded. In addition, associated pathologies or complications (displacement, eruption failure, resorption of adjacent tooth, and cyst formation caused by ST were also recorded. The Pearson chi-squared test was used to determine potential differences between genders.

    Results: ST were detected in 15 patients (0.75 %. The frequency of males and females with ST was 1.16 % and 0.49 %, respectively (P= 0.944. The most commonly observed ST was premolar (33.33% followed by mesiodens (26.67%, distomolar (20.0%, lateral (13.33%, paramolar (6.67%, respectively. Most of the ST were found to be unilateral, impacted, and in the maxilla. Complications associated with ST were observed in 20.0% of the patients with ST.

    Conclusions: The frequency of ST in east-northern Turkish general population was found to be 0.75% with no gender difference (p>0.05. The most commonly observed ST was premolar followed by mesiodens.

  18. Midlife Determinants Associated with Sedentary Behavior in Old Age

    DEFF Research Database (Denmark)

    van der Berg, Julianne D; Bosma, Hans; Caserotti, Paolo; Eiriksdottir, Gudny; Arnardottir, Nanna Yr; Martin, Kathryn R; Brychta, Robert J; Chen, Kong Y; Sveinsson, Thorarinn; Johannsson, Erlingur; Launer, Lenore J; Gudnason, Vilmundur; Jonsson, Palmi V; Stehouwer, Coen D A; Harris, Tamara B; Koster, Annemarie

    2014-01-01

    Sedentary behavior is associated with adverse health effects. To prevent sedentary behavior and limit health risks, insights into associated determinants are essential. Sedentary behavior should be viewed as a distinct health behavior, therefore its determinants should be independently identified...

  19. Age estimation in 25-45 yrs. old females by physical and radiological methods

    Directory of Open Access Journals (Sweden)

    Vikrant Kasat

    2010-01-01

    Full Text Available Aim:The purpose of this study was to estimate the age in living females in the later years (25 to 45 years from general physical features and radiographic changes in the sternum and the mandible. Materials and Methods:A cross-sectional study was conducted on 64 females (32 subjects in each study and control group. All the subjects were physically examined for graying of scalp, body, pubic hair, and for wrinkling of skin of the forehead, temporal region, and below the eyes. A right lateral view of the chest was taken to determine fusion of the components of the sternum. Combined Hair Score, Combined Skin Score, and Combined Bone Fusion Score were calculated. An orthopantomogram of each patient was traced for lower jaw, mandibular canal and teeth, and D 1 , D 2 , A values were calculated. SPSS Software Version 10.1 was used for the execution of the regression command on the 32 cases of the control group, whose ages were known. Results:Combined skin score, mandible right D 2 , mandible right angle, and mandible left angle turned out significant in the prediction of age. Using the regression equation obtained, the age of the 32 subjects in the study group was estimated. In 9.3% of cases, the predicted ages exactly matched the actual ages. A variation of 1−4 years was seen in 75% of the cases. A variation of 6−7 years was seen in 15.6% of the cases. Conclusion:This study succeeded in most instances in predicting the ages of the study group and in arriving at a formula for age estimation between the ages of 25 and 45 years without using any invasive, costly, time - consuming, or troublesome method.

  20. Isotopic age-determinations in Bergslagen, Sweden. 8

    International Nuclear Information System (INIS)

    Biotite Rb-Sr data from 1.70-1.65 Ga ol rocks of the Gothian Trans-Scandinavian Smaland-Vaermland Granitic Belt and from 1.90-1.84 Ga old rocks of the adjoining Svecokarelian Berglagen Region indicate complete Sveconorwegian resetting 0.90 Ga ago, but a K-Ar analysis of the same biotites and of coexisting hornblendes yields significantly older ages. Some biotites and hornblendes have exceptionally high apparent ages, much oldre than those of the host rocks, pointing to the presence of excess radiogenic argon. The other K-Ar mineral ages are intermediate between the age of the host rocks and the 0.90 Ga old Sveconorwegian resetting. The hornblendes and biotites with intermediate ages show a weak positive correlation between radiogenic argon content and whole-rock potassium content. It is concluded that there was only limited mobility of radiogenic argon during the Sveconorwegian event. Apperently, the physicochemical conditions during Sveconorwegian recrystallisation were suitable for complete resetting of the Rb-Sr biotite systems, whereas the behaviour of radiogenic argon in the biotites and hornblendes was complex, leading to anomalous K-Ar dates (author). 34 refs.; 4 figs.; 3 tabs

  1. Investigation of the relation between environmental radioactivity and radioactivity in human teeth who lives in this environment

    International Nuclear Information System (INIS)

    This work presents total alpha-beta radioactive concentrations in human teeth collected in Black Sea and Chukurova (near Mediterranean Sea) which are two different regions in Turkey. These tooth samples were measured by using 10 Channel Low-Level Counter. Thirty five human teeth samples taken from people living in these two regions were classified according to the age of bones and compared with each others. From the results, it was found that beta activity results obtained from Black Sea region were higher than that of Chukurova region an it was also concluded that total alpha and beta radioactivity measurements in adult and child were variable

  2. Late Bronze Age hoard studied by PIXE

    International Nuclear Information System (INIS)

    The hoards of metallic objects belonging to the Late European Bronze Age can be interpreted differently depending on the type, number and composition of the artefacts. PIXE analysis has been performed in nine items from the Hoard of Freixanda in Portugal comprising four socket axes, a palstave axe, a ring, a chisel, a dagger, and a casting debris. Besides the composition of the main matrix elements, that is Cu and Sn, the amount of trace elements of interest like, As, Pb, Ni, and Ag has been determined using this ion beam technique. The high tin content alloy and the high purity of the metals from the Freixanda hoard are characteristic of the Portuguese and Spanish Late Bronze Age metallurgy, supporting the idea of a regional production.

  3. High-resolution X-ray microdiffraction analysis of natural teeth

    International Nuclear Information System (INIS)

    In situ microzone X-ray diffraction analysis of natural teeth is presented. From our experiment, layer orientation and continuous crystal variations in teeth could be conveniently studied using fast online measurements by high-resolution X-ray microdiffraction equipment. The main component of natural teeth was determined many years ago as calcium phosphate, mostly in the form of hydroxyapatite with different crystallites. In the past, the method used in tooth crystal investigation has been mainly powder X-ray diffraction analysis, but this method has its drawbacks, i.e. the destruction of the natural tooth structure and the difficulty in examining the preferred orientation in different layers of the tooth. During the last century, microzone X-ray diffraction on the tooth surface was carried out, but, as the technology was less sophisticated, the results obtained were not very detailed. The newly developed microdiffraction equipment permits analysis of the microzone of teeth in situ. To test this new microdiffraction equipment, microdiffraction analysis of one natural healthy deciduous molar tooth and one carious deciduous molar tooth has been performed, using a Bruker D8 instrument. Phase analysis of the two teeth was performed; the crystal size at six test points in the natural healthy tooth was calculated by reflection (211), and the crystal preferred orientation of reflection (300) and reflection (002) at six test points in the natural healthy tooth were compared. The results showed that the tooth was a kind of biological mixed crystal composed of several crystal phases, the main crystal phase being hydroxyapatite. The crystal size grew larger going from the dentin to the enamel. The crystal preferred orientation mainly existed in the enamel, especially in the reflection (002). From our experiment, layer orientation and continuous crystal variations in teeth could be conveniently studied using fast online measurements by high-resolution X-ray microdiffraction

  4. Elemental Analysis of Bone, Teeth, Horn and Antler in Different Animal Species Using Non-Invasive Handheld X-Ray Fluorescence

    OpenAIRE

    Kittisak Buddhachat; Sarisa Klinhom; Puntita Siengdee; Brown, Janine L.; Raksiri Nomsiri; Patcharaporn Kaewmong; Chatchote Thitaram; Pasuk Mahakkanukrauh; Korakot Nganvongpanit

    2016-01-01

    Mineralized tissues accumulate elements that play crucial roles in animal health. Although elemental content of bone, blood and teeth of human and some animal species have been characterized, data for many others are lacking, as well as species comparisons. Here we describe the distribution of elements in horn (Bovidae), antler (Cervidae), teeth and bone (humerus) across a number of species determined by handheld X-ray fluorescence (XRF) to better understand differences and potential biologic...

  5. Age and sex determination of juvenile band-tailed pigeons

    Science.gov (United States)

    White, J.A.; Braun, C.E.

    1978-01-01

    Captive band-tailed pigeons (Columbafasciata) were studied to document progression of molts and plumages from juvenal to adult age. Immature pigeons began the post-juvenal molt at 35 days which continued up to 340 days. The only 3 plumage characters useful for identification and estimation of age were presence of juvenal lesser, middle, and greater secondary coverts, juvenal secondaries, and juvenal primaries. While juvenal primaries were still present, hatching dates could be estimated up to 252 days (N = 84). Secondary feather presence and molt stage could be used to identify juvenile pigeons for more than 340 days (N = 24). Using coloration of the crown and breast feathers, 96 percent of the immature pigeons examined (106 of 110) at 80 days of age were classified accurately as to sex.

  6. Quantifying yeast chronological life span by outgrowth of aged cells.

    Science.gov (United States)

    Murakami, Christopher; Kaeberlein, Matt

    2009-01-01

    The budding yeast Saccharomyces cerevisiae has proven to be an important model organism in the field of aging research. The replicative and chronological life spans are two established paradigms used to study aging in yeast. Replicative aging is defined as the number of daughter cells a single yeast mother cell produces before senescence; chronological aging is defined by the length of time cells can survive in a non-dividing, quiescence-like state. We have developed a high-throughput method for quantitative measurement of chronological life span. This method involves aging the cells in a defined medium under agitation and at constant temperature. At each age-point, a sub-population of cells is removed from the aging culture and inoculated into rich growth medium. A high-resolution growth curve is then obtained for this sub-population of aged cells using a Bioscreen C MBR machine. An algorithm is then applied to determine the relative proportion of viable cells in each sub-population based on the growth kinetics at each age-point. This method requires substantially less time and resources compared to other chronological lifespan assays while maintaining reproducibility and precision. The high-throughput nature of this assay should allow for large-scale genetic and chemical screens to identify novel longevity modifiers for further testing in more complex organisms. PMID:19421136

  7. Pulp microbiology of complete teeth with idiopathic apical lesions.

    OpenAIRE

    Patricia Rodríguez; Jesús Alberto Calero

    2009-01-01

    Introduction: Periapical changes named as lesions, in teeth with full crown integrity and without history of trauma, do not show a clear aetiology. Objective: To determine the presence of microorganisms in pulp dental tissue will clarify the cause of its death and therefore the damage to periodontal tissues. Materials and methods: From people between 10 and 39 years old, 23 teeth were selected. The samples were taken with paper points and 0.8 sterile files, and were transported in VMGA III me...

  8. Mesiodens with an unusual morphology and multiple impacted supernumerary teeth in a non-syndromic patient

    OpenAIRE

    Srivatsan Pavithra; Aravindha Babu N

    2007-01-01

    Supernumerary teeth are a relatively frequent disorder of odontogenesis characterized by an excess number of teeth. Mesiodens is the most common type of supernumerary tooth found in the premaxilla between the two central incisors. They can be supplemental (resembling natural teeth), conical, tuberculate or molariform. We present the case of a 19 year-old girl who presented with a mesiodens of an unusual morphology and multiple impacted supernumerary teeth not associated with any syndrome.

  9. Mesiodens with an unusual morphology and multiple impacted supernumerary teeth in a non-syndromic patient

    Directory of Open Access Journals (Sweden)

    Srivatsan Pavithra

    2007-01-01

    Full Text Available Supernumerary teeth are a relatively frequent disorder of odontogenesis characterized by an excess number of teeth. Mesiodens is the most common type of supernumerary tooth found in the premaxilla between the two central incisors. They can be supplemental (resembling natural teeth, conical, tuberculate or molariform. We present the case of a 19 year-old girl who presented with a mesiodens of an unusual morphology and multiple impacted supernumerary teeth not associated with any syndrome.

  10. Direct Age Determination of a Subtropical Freshwater Crayfish (Redclaw, Cherax quadricarinatus) Using Ossicular Growth Marks.

    Science.gov (United States)

    Leland, Jesse C; Bucher, Daniel J; Coughran, Jason

    2015-01-01

    Recent studies have reported that crustacean age determination is possible. We applied a direct ageing method (i.e. transverse cross sectioning of gastric ossicles) to a subtropical freshwater crayfish (Cherax quadricarinatus) sourced from an aquaculture population. Growth mark periodicity and the potential for chronological depositions were investigated by staining C. quadricarinatus with calcein and examining their ossicles a year later. Pterocardiac ossicles were superior to other ageing structures (i.e. other ossicles and eyestalks) and produced repeatable between-reader counts (87% were corroborated and 13% varied by ±1). C. quadricarinatus size-at-age data (for an aquaculture population) was described by a von Bertalanffy growth equation (L∞ = 32 mm occipital carapace length; K = 0.64; t0 = -0.18; R2 = 0.81). Ossicular growth marks did not correspond to moult history. The calcein stain was retained over an annual cycle comprising multiple moults, demonstrating that pterocardiac ossicles retain chronological information. The maximum age (3+) corroborated other indirectly-obtained longevity estimates for C. quadricarinatus. Multiple lines of evidence indicate that the growth marks in C. quadricarinatus ossicles are probably deposited annually during winter. The ability to extract age information from subtropical decapods provides substantial opportunities for advancing fisheries and conservation research globally, but further research is needed to provide a definitive validation and elucidate the mechanism governing the accrual of ossicular growth marks. PMID:26309228

  11. Direct Age Determination of a Subtropical Freshwater Crayfish (Redclaw, Cherax quadricarinatus Using Ossicular Growth Marks.

    Directory of Open Access Journals (Sweden)

    Jesse C Leland

    Full Text Available Recent studies have reported that crustacean age determination is possible. We applied a direct ageing method (i.e. transverse cross sectioning of gastric ossicles to a subtropical freshwater crayfish (Cherax quadricarinatus sourced from an aquaculture population. Growth mark periodicity and the potential for chronological depositions were investigated by staining C. quadricarinatus with calcein and examining their ossicles a year later. Pterocardiac ossicles were superior to other ageing structures (i.e. other ossicles and eyestalks and produced repeatable between-reader counts (87% were corroborated and 13% varied by ±1. C. quadricarinatus size-at-age data (for an aquaculture population was described by a von Bertalanffy growth equation (L∞ = 32 mm occipital carapace length; K = 0.64; t0 = -0.18; R2 = 0.81. Ossicular growth marks did not correspond to moult history. The calcein stain was retained over an annual cycle comprising multiple moults, demonstrating that pterocardiac ossicles retain chronological information. The maximum age (3+ corroborated other indirectly-obtained longevity estimates for C. quadricarinatus. Multiple lines of evidence indicate that the growth marks in C. quadricarinatus ossicles are probably deposited annually during winter. The ability to extract age information from subtropical decapods provides substantial opportunities for advancing fisheries and conservation research globally, but further research is needed to provide a definitive validation and elucidate the mechanism governing the accrual of ossicular growth marks.

  12. Determinants of labor market choices : age differentials and family circumstances

    OpenAIRE

    Kutyavina, Marina

    2015-01-01

    My research explores the interactions between labor market choices, public programs, and family circumstances. In the following three chapters, I study the relationship between labor market conditions and job search behavior of workers of differing ages, the effect of children's events on parental retirement timing, as well as the impact of UI extensions on recipients' spouses

  13. Age and dose as determinants of times of appearance of radium-induced osteosarcomas in humans

    International Nuclear Information System (INIS)

    Determinants of time-until-tumor for bone sarcomas in US radium cases have been reevaluated. For the 57 measured female bone sarcoma cases exposed to 226Ra and/or 228Ra, ages at appearance of tumor are more strongly correlated with radium intake doses than are latency periods. Ages at appearance of tumor increase as initial radium intakes decrease. As many lower dose cases were iatrogenic cases exposed in mid-adult life, rather than about age 22 as for the dial worker cases, these results may be artifactual, resulting from an increased susceptability to sarcoma induction at older ages. Alternatively the time of appearance of a sarcoma may be in part directly determined by age. Both explanations find support in the literature. These results suggest that 226228Ra-induced bone sarcomas do have an expression period. The downturn in sarcoma incidence at very high doses may result from truncation of the expression period on its early side by the minimum induction period

  14. The determination of the age of Globular Clusters a statistical approach

    CERN Document Server

    Rengel, M; Bruzual, A G; Rengel, Miriam; Mateu, Juan; Bruzual, Gustavo

    2001-01-01

    We present a statistical approach for determining the age of Globular Clusters (GCs) that allows estimating the age derived from CMDs more accurately than the conventional methods of the isochrone fitting. We measure how closely a set of synthetic CMDs constructed from different evolutionary models resemble the observed ones by determining the likelihood using Saha and Chi-square statistics. The model which best matches the observational data, of a set of plausible ones, is the one with the highest value of the estimator. We apply this method to a set of three different evolutionary models presented by three different authors. Each of theses sets consists again of many different models of various chemical abundances, ages, input physics and there alike. We subsequently derive the age of GCs NGC 6397, M92 and M3. With a confidence level of 99%, we find that the best estimate of the age is 14.0 Gyrs within the range of 13.8 to 14.4 Gyrs for NGC 6397, 14.75 Gyrs within the range of 14.50 to 15.40 Gyrs for M92, a...

  15. Sources of patients’ knowledge on the treatment of missing teeth with implants

    Directory of Open Access Journals (Sweden)

    Szymanska Jolanta

    2014-06-01

    Full Text Available The number of patients who take the decision to have implantoprosthetic treatment keeps increasing. The aim of this study was to determine the sources of knowledge about possibilities of treating missing teeth with implants. The survey was conducted among 464 patients of both sexes aged from 20 to 74 years, treated with dental implants at the Non-Public Healthcare Centre “Dental” in Tomaszów Mazowiecki. The patients answered questions in an anonymous questionnaire. The questions included age, place of residence and source of knowledge about implants. Persons aged up to 40 years frequently obtained knowledge about the possibility of using implants from the media; patients aged 40-60 years - from their dentist, and people over 60 years of age - from family or friends. Persons living in rural areas or small town frequently acquired knowledge of the possibility of dental implants from the dentist, the city residents - from family or friends. The results of the survey indicate that the dentist is most commonly the main source of information about the possibility of replacing the missing teeth with implants, less family and friends and the media. The source of acquiring knowledge in this field varies depending on the age and place of residence of the persons concerned.

  16. Lead concentrations in teeth from people living in Kosovo and Austria.

    Science.gov (United States)

    Kamberi, Blerim; Kqiku, Lumnije; Hoxha, Veton; Dragusha, Edmond

    2011-03-01

    The objective of this study was to compare lead concentrations in 86 human permanent teeth extracted from residents of three different geographical regions. The study included 31 permanent teeth from residents of Mitrovica (Kosovo), 32 from Klina (Kosovo) and 23 from Graz (Austria). The concentrations of lead were measured using Agilent 7500c inductively coupled plasma mass spectrometer (ICP-MS) (Agilent, Waldbronn, Germany). The comparisons between groups were based on the geographic area, age and gender. The highest lead level was found in teeth extracted from Mitrovica residents (22.3 mg/kg), followed by Klina (3.2 mg/kg), and Graz (1.7 mg/kg). Lead levels in teeth from Mitrovica residents are significantly higher (p < 0.0001) than in other two groups, possibly due to environmental contamination with lead. Overall results in this study support the concept that tooth lead level may present an important indicator in evaluating environmental exposure of human population to heavy metals. PMID:21667533

  17. Preliminary results of combined ESR/U-series dating of fossil teeth from Longgupo cave, China

    International Nuclear Information System (INIS)

    Longgupo Cave site, located in Wushan County, Chongqing, China has attracted continuous attention since its discovery of hominid remains in association with late Pliocene-early Pleistocene fauna and numerous lithic artefacts. In 2003-2006, new excavation was carried out on this site, allowing the description of a detailed stratigraphy of the highly complex cave in-fillings and the sampling of teeth for combined ESR/U-series analyses. Here we report preliminary dating results of seven herbivorous fossil teeth from different archaeological layers of the lowest geological unit (C III). Uranium-series analyses indicate that no obvious uranium leaching has occurred and all the teeth (except one) underwent a very recent uranium uptake history. The obtained US-ESR results show that the age of six teeth are basically consistent, between similar to 1.4 and 1.8 Ma. At the same time, we observed an inverse correlation of two samples with the stratigraphic sequence. This could be caused by the distinct uranium uptake history of one sample, high uranium content in the enamel for another or bad estimation of external dose rate. Due to the complexity of the stratigraphic sequence, supplementary in situ gamma dose rate measurement should be performed for all the samples during the following excavations in order to confirm this preliminary ESR/U-series chronology. (authors)

  18. Identifying the genomic determinants of aging and longevity in human population studies: Progress and challenges

    OpenAIRE

    Deelen, Joris; Beekman, Marian; Capri, Miriam; FRANCESCHI, Claudio; Slagboom, P. Eline

    2013-01-01

    Human lifespan variation is mainly determined by environmental factors, whereas the genetic contribution is 25–30% and expected to be polygenic. Two complementary fields go hand in hand in order to unravel the mechanisms of biological aging: genomic and biomarker research. Explorative and candidate gene studies of the human genome by genetic, transcriptomic, and epigenomic approaches have resulted in the identification of a limited number of interesting positive linkage regions, genes, and pa...

  19. Texture determination by neutron diffraction

    International Nuclear Information System (INIS)

    Application of neutron diffraction to crystallographic texture determination shows many advantages: possibility of an important grain size, the quantity of material contributing to diffraction is more important than with X rays, good accuracy and complete pole figures are obtained by transmission only eliminating corrections needed with X rays. Texture determination allows control and improvement of material quality. Texture studies give good informations on mechanisms occuring in deformation or recrystallization of polycrystals and on anisotropy of physical and mechanical properties

  20. Aging is a weak but relentless determinant of dementia severity

    OpenAIRE

    Royall, Donald R.; Raymond F. Palmer

    2016-01-01

    Structural Equation Models (SEM) can explicitly distinguish “dementia-relevant” variance in cognitive task performance (i.e., “δ” for dementia). In prior work, δ appears to uniquely account for dementia severity regardless of the cognitive measures used to construct it. In this study, we test δ as a mediator of age's prospective association with future cognitive performance and dementia severity in a large, ethnically diverse longitudinal cohort, the Texas Alzheimer's Research and Care Consor...

  1. Lifestyle and dietary factors determine age at natural menopause

    OpenAIRE

    Sapre, Shilpa; Thakur, Ratna

    2014-01-01

    A literature search was done using PubMed. The age at natural menopause (ANM) depends on various factors like genetic, environmental, socioeconomic, reproductive, dietary, and lifestyle of which some like nulliparity, vegetarian diet, smoking, high fat intake, cholesterol, and caffeine accelerates; while others like parity, prior use of oral contraceptive pills, and Japanese ethnicity delays the ANM. ANM is an important risk factor for long-term morbidity and mortality; and hence, the need to...

  2. ACCELERATED AGING TEST IN DETERMINING THE VIGOUR OF SUNFLOWER SEEDS WITH AND WITHOUT PERICARP

    Directory of Open Access Journals (Sweden)

    K. R. Ducatti

    2014-09-01

    Full Text Available The standard germination test alone is insufficient to attest the quality of seeds, making necessary correlation’s with vigour tests, to determine more accurately the physiological potential of a seeds lot. The accelerated aging test is an option for determine the vigour and consists in submits seeds to high temperatures and humidity, for different periods of time, has not yet standardized. The objective of this work was to analyze the efficiency of the accelerated aging test in the assessment of the effect of a lot of sunflower seed, by three periods of aging (48, 56 and 72 hours in 42 °C temperature, in seeds with and without pericarp (manually removed and relate the results with electrical conductivity test and germination first count. The experimental design was a completely randomized design and the comparison of averages made using Tukey's test at 5% probability. The results showed that standard germination, electrical conductivity and germination first count, the seeds without pericarp showed better performance. In relation to the accelerated aging, only in the period of 72 hours of aging there was no significant difference between the treatments. In this way, the appropriate period to identify differences in force between the treatments was 72 hours, which showed a positive correlation with the germination first count and electrical conductivity.

  3. Procedure for the automatic mesh generation of innovative gear teeth

    Directory of Open Access Journals (Sweden)

    Radicella Andrea Chiaramonte

    2016-01-01

    Full Text Available After having described gear wheels with teeth having the two sides constituted by different involutes and their importance in engineering applications, we stress the need for an efficient procedure for the automatic mesh generation of innovative gear teeth. First, we describe the procedure for the subdivision of the tooth profile in the various possible cases, then we show the method for creating the subdivision mesh, defined by two series of curves called meridians and parallels. Finally, we describe how the above procedure for automatic mesh generation is able to solve specific cases that may arise when dealing with teeth having the two sides constituted by different involutes.

  4. Identifying the genomic determinants of aging and longevity in human population studies: progress and challenges.

    Science.gov (United States)

    Deelen, Joris; Beekman, Marian; Capri, Miriam; Franceschi, Claudio; Slagboom, P Eline

    2013-04-01

    Human lifespan variation is mainly determined by environmental factors, whereas the genetic contribution is 25-30% and expected to be polygenic. Two complementary fields go hand in hand in order to unravel the mechanisms of biological aging: genomic and biomarker research. Explorative and candidate gene studies of the human genome by genetic, transcriptomic, and epigenomic approaches have resulted in the identification of a limited number of interesting positive linkage regions, genes, and pathways that contribute to lifespan variation. The possibilities to further exploit these findings are rapidly increasing through the use of novel technologies, such as next-generation sequencing. Genomic research is progressively being integrated with biomarker studies on aging, including the application of (noninvasive) deep phenotyping and omics data - generated using novel technologies - in a wealth of studies in human populations. Hence, these studies may assist in obtaining a more holistic perspective on the role of the genome in aging and lifespan regulation. PMID:23423909

  5. A RARITY–CASES OF NATAL TEETH

    OpenAIRE

    Wairokpam Bhoomika; Ramakrishna; Oinam Joychandra; Mousumi

    2013-01-01

    ABSTRACT: Prematurely erupted teeth present at birth have been described as “natal teeth/ congenital teeth or fetal teeth”. Such teeth are of great concern to the parent because of several superstitions and beliefs. Other related inconvenien ces or dangers to the infants and mothers are the displacement and aspiration of such teeth cau sing injuries to the oral cavity along with The disturbance during breast feeding. The aim of t his case report is to discuss the...

  6. Pavement Aging Model by Response Surface Modeling

    Directory of Open Access Journals (Sweden)

    Manzano-Ramírez A.

    2011-10-01

    Full Text Available In this work, surface course aging was modeled by Response Surface Methodology (RSM. The Marshall specimens were placed in a conventional oven for time and temperature conditions established on the basis of the environment factors of the region where the surface course is constructed by AC-20 from the Ing. Antonio M. Amor refinery. Volatilized material (VM, load resistance increment (ΔL and flow resistance increment (ΔF models were developed by the RSM. Cylindrical specimens with real aging were extracted from the surface course pilot to evaluate the error of the models. The VM model was adequate, in contrast (ΔL and (ΔF models were almost adequate with an error of 20 %, that was associated with the other environmental factors, which were not considered at the beginning of the research.

  7. CARBON STOCK DETERMINATION IN TEAK (Tectona grandis L. f. AT DIFFERENT AGES

    Directory of Open Access Journals (Sweden)

    Eleusa Maria Almeida

    2010-12-01

    Full Text Available The objective of this study was to evaluate the quantity of carbon in teak (Tectona grandis L.f., with 0.5; 1.5; 2.5; 3.5 and 5.5 years of age, during one year. The teak evaluated belonged to the BRASTECA AGROFLORESTAL LTDA company, located in the municipality of Santo Antônio of Leverger, Mato Grosso, Brazil. The carbon stock for each age was assessed every 90 days by determining the amount of litter dry mass, organic carbon proportion in the soil, root density in the soil and the volume of the staff and crown in the three teak trees randomly selected for harvest. The assessment of the plant size, as height, diameter at chest height and crown projection, was carried out with twenty preserved plants at each age. The dry mass of the roots was determined from the relation between the soil volume and the density of roots of the three plants per age, by making four perforations per plant, with six samples for each, up to 0.90 m of depth. The carbon proportion in the soil and in the litter was obtained by age at each collection through laboratory analysis. The average carbon found per hectare was 122.5 t of C at 0.5 years; 104.3 t of C at 1.5 years; 180.8 t of C at 2.5 years; 303.1 t of C at 3.5 years and 322.3 t of C at 5.5 years, considering the numbers of plants per hectare at the different ages. Afterward, the average distribution of carbon per system component was found to be 90.8% in the soil, 5.04% to the aerial part, 3.04% in the roots and 1.21% in the litter.

  8. Energy absorption build-up factors in teeth

    International Nuclear Information System (INIS)

    Geometric progression fitting method has been used to compute energy absorption build-up factor of teeth [enamel outer surface, enamel middle, enamel dentin junction towards enamel, enamel dentin junction towards dentin, dentin middle and dentin inner surface] for wide energy range (0.015-15 MeV) up to the penetration depth of 40 mean free path. The dependence of energy absorption build-up factor on incident photon energy, penetration depth, electron density and effective atomic number has also been studied. The energy absorption build-up factors increases with the penetration depth and electron density of teeth. So that the degree of violation of Lambert-Beer (I = I0e-μt ) law is less for least penetration depth and electron density. The energy absorption build-up factors for different regions of teeth are not same hence the energy absorbed by the different regions of teeth is not uniform which depends on the composition of the medium. The relative dose of gamma in different regions of teeth is also estimated. Dosimetric implication of energy absorption build-up factor in teeth has also been discussed. The estimated absorption build up factors in different regions of teeth may be useful in the electron spin resonance dosimetry. (author)

  9. On the evolutionary advantage of multi-cusped teeth.

    Science.gov (United States)

    Constantino, Paul J; Bush, Mark B; Barani, Amir; Lawn, Brian R

    2016-08-01

    A hallmark of mammalian evolution is a progressive complexity in postcanine tooth morphology. However, the driving force for this complexity remains unclear: whether to expand the versatility in diet source, or to bolster tooth structural integrity. In this study, we take a quantitative approach to this question by examining the roles of number, position and height of multiple cusps in determining sustainable bite forces. Our approach is to use an extended finite-element methodology with due provision for step-by-step growth of an embedded crack to determine how fracture progresses with increasing occlusal load. We argue that multi-cusp postcanine teeth are well configured to withstand high bite forces provided that multiple cusps are contacted simultaneously to share the load. However, contact on a single near-wall cusp diminishes the strength. Location of the load points and cusp height, rather than cusp number or radius, are principal governing factors. Given these findings, we conclude that while complex tooth structures can enhance durability, increases in cusp number are more likely to be driven by the demands of food manipulation. Structural integrity of complex teeth is maintained when individual cusps remain sufficiently distant from the side walls and do not become excessively tall relative to tooth width. PMID:27558851

  10. POST-MORTEM CHANGES IN TEETH- FORENSIC ISSUES

    Directory of Open Access Journals (Sweden)

    Irina MANOILESCU

    2015-12-01

    Full Text Available Teeth have an increased resistance to environmental factors and decomposition processes, which makes them highly valuable in forensic investigations. The either physical (wind, water, sun, soil type or biological (plant roots, insects, animals environmental factors and the decomposition processes induce post-mortem changes in teeth, which are relevant to forensic investigation in terms of estimating the post-mortem interval or of elucidating the conditions in which the body stood after death. In this paper, based on the data provided in the literature, the authors present the main changes induced by environmental factors and decomposition processes in teeth and refer to their relevance in forensic activity.

  11. Age of a prehistoric "Rodedian" cult site constrained by sediment and rock surface luminescence dating techniques

    DEFF Research Database (Denmark)

    Sohbati, Reza; Murray, Andrew; Porat, N.;

    2015-01-01

    The construction age of a pavement in a “Rodedian” prehistoric cult site in Negev desert, Israel, is established by determining the burial age of (i) a cobble used in the pavement, and (ii) the underlying sediment. The quartz OSL age and the K-feldspar corrected IR50 age from the sediment...

  12. Transplantation of Cryopreserved Teeth: A Systematic Review

    OpenAIRE

    Osathanon, Thanaphum

    2010-01-01

    The aim of this article was to examine the research articles regarding biological and mechanical properties of cryopreserved teeth for potential use in tooth transplantation. A systematic review of literatures was performed by Pubmed searching with assigned key words from January 1, 1990 to June 8, 2009. All articles were examined for inclusion criteria. Secondary search was conducted by hand-search through references of included articles from primary search. A total of 24 articles were obtai...

  13. CAG repeat expansion in Huntington disease determines age at onset in a fully dominant fashion

    Science.gov (United States)

    Lee, J.-M.; Ramos, E.M.; Lee, J.-H.; Gillis, T.; Mysore, J.S.; Hayden, M.R.; Warby, S.C.; Morrison, P.; Nance, M.; Ross, C.A.; Margolis, R.L.; Squitieri, F.; Orobello, S.; Di Donato, S.; Gomez-Tortosa, E.; Ayuso, C.; Suchowersky, O.; Trent, R.J.A.; McCusker, E.; Novelletto, A.; Frontali, M.; Jones, R.; Ashizawa, T.; Frank, S.; Saint-Hilaire, M.H.; Hersch, S.M.; Rosas, H.D.; Lucente, D.; Harrison, M.B.; Zanko, A.; Abramson, R.K.; Marder, K.; Sequeiros, J.; Paulsen, J.S.; Landwehrmeyer, G.B.; Myers, R.H.; MacDonald, M.E.; Durr, Alexandra; Rosenblatt, Adam; Frati, Luigi; Perlman, Susan; Conneally, Patrick M.; Klimek, Mary Lou; Diggin, Melissa; Hadzi, Tiffany; Duckett, Ayana; Ahmed, Anwar; Allen, Paul; Ames, David; Anderson, Christine; Anderson, Karla; Anderson, Karen; Andrews, Thomasin; Ashburner, John; Axelson, Eric; Aylward, Elizabeth; Barker, Roger A.; Barth, Katrin; Barton, Stacey; Baynes, Kathleen; Bea, Alexandra; Beall, Erik; Beg, Mirza Faisal; Beglinger, Leigh J.; Biglan, Kevin; Bjork, Kristine; Blanchard, Steve; Bockholt, Jeremy; Bommu, Sudharshan Reddy; Brossman, Bradley; Burrows, Maggie; Calhoun, Vince; Carlozzi, Noelle; Chesire, Amy; Chiu, Edmond; Chua, Phyllis; Connell, R.J.; Connor, Carmela; Corey-Bloom, Jody; Craufurd, David; Cross, Stephen; Cysique, Lucette; Santos, Rachelle Dar; Davis, Jennifer; Decolongon, Joji; DiPietro, Anna; Doucette, Nicholas; Downing, Nancy; Dudler, Ann; Dunn, Steve; Ecker, Daniel; Epping, Eric A.; Erickson, Diane; Erwin, Cheryl; Evans, Ken; Factor, Stewart A.; Farias, Sarah; Fatas, Marta; Fiedorowicz, Jess; Fullam, Ruth; Furtado, Sarah; Garde, Monica Bascunana; Gehl, Carissa; Geschwind, Michael D.; Goh, Anita; Gooblar, Jon; Goodman, Anna; Griffith, Jane; Groves, Mark; Guttman, Mark; Hamilton, Joanne; Harrington, Deborah; Harris, Greg; Heaton, Robert K.; Helmer, Karl; Henneberry, Machelle; Hershey, Tamara; Herwig, Kelly; Howard, Elizabeth; Hunter, Christine; Jankovic, Joseph; Johnson, Hans; Johnson, Arik; Jones, Kathy; Juhl, Andrew; Kim, Eun Young; Kimble, Mycah; King, Pamela; Klimek, Mary Lou; Klöppel, Stefan; Koenig, Katherine; Komiti, Angela; Kumar, Rajeev; Langbehn, Douglas; Leavitt, Blair; Leserman, Anne; Lim, Kelvin; Lipe, Hillary; Lowe, Mark; Magnotta, Vincent A.; Mallonee, William M.; Mans, Nicole; Marietta, Jacquie; Marshall, Frederick; Martin, Wayne; Mason, Sarah; Matheson, Kirsty; Matson, Wayne; Mazzoni, Pietro; McDowell, William; Miedzybrodzka, Zosia; Miller, Michael; Mills, James; Miracle, Dawn; Montross, Kelsey; Moore, David; Mori, Sasumu; Moser, David J.; Moskowitz, Carol; Newman, Emily; Nopoulos, Peg; Novak, Marianne; O'Rourke, Justin; Oakes, David; Ondo, William; Orth, Michael; Panegyres, Peter; Pease, Karen; Perlman, Susan; Perlmutter, Joel; Peterson, Asa; Phillips, Michael; Pierson, Ron; Potkin, Steve; Preston, Joy; Quaid, Kimberly; Radtke, Dawn; Rae, Daniela; Rao, Stephen; Raymond, Lynn; Reading, Sarah; Ready, Rebecca; Reece, Christine; Reilmann, Ralf; Reynolds, Norm; Richardson, Kylie; Rickards, Hugh; Ro, Eunyoe; Robinson, Robert; Rodnitzky, Robert; Rogers, Ben; Rosenblatt, Adam; Rosser, Elisabeth; Rosser, Anne; Price, Kathy; Price, Kathy; Ryan, Pat; Salmon, David; Samii, Ali; Schumacher, Jamy; Schumacher, Jessica; Sendon, Jose Luis Lópenz; Shear, Paula; Sheinberg, Alanna; Shpritz, Barnett; Siedlecki, Karen; Simpson, Sheila A.; Singer, Adam; Smith, Jim; Smith, Megan; Smith, Glenn; Snyder, Pete; Song, Allen; Sran, Satwinder; Stephan, Klaas; Stober, Janice; Sü?muth, Sigurd; Suter, Greg; Tabrizi, Sarah; Tempkin, Terry; Testa, Claudia; Thompson, Sean; Thomsen, Teri; Thumma, Kelli; Toga, Arthur; Trautmann, Sonja; Tremont, Geoff; Turner, Jessica; Uc, Ergun; Vaccarino, Anthony; van Duijn, Eric; Van Walsem, Marleen; Vik, Stacie; Vonsattel, Jean Paul; Vuletich, Elizabeth; Warner, Tom; Wasserman, Paula; Wassink, Thomas; Waterman, Elijah; Weaver, Kurt; Weir, David; Welsh, Claire; Werling-Witkoske, Chris; Wesson, Melissa; Westervelt, Holly; Weydt, Patrick; Wheelock, Vicki; Williams, Kent; Williams, Janet; Wodarski, Mary; Wojcieszek, Joanne; Wood, Jessica; Wood-Siverio, Cathy; Wu, Shuhua; Yastrubetskaya, Olga; de Yebenes, Justo Garcia; Zhao, Yong Qiang; Zimbelman, Janice; Zschiegner, Roland; Aaserud, Olaf; Abbruzzese, Giovanni; Andrews, Thomasin; Andrich, Jurgin; Antczak, Jakub; Arran, Natalie; Artiga, Maria J. Saiz; Bachoud-Lévi, Anne-Catherine; Banaszkiewicz, Krysztof; di Poggio, Monica Bandettini; Bandmann, Oliver; Barbera, Miguel A.; Barker, Roger A.; Barrero, Francisco; Barth, Katrin; Bas, Jordi; Beister, Antoine; Bentivoglio, Anna Rita; Bertini, Elisabetta; Biunno, Ida; Bjørgo, Kathrine; Bjørnevoll, Inga

    2012-01-01

    Objective: Age at onset of diagnostic motor manifestations in Huntington disease (HD) is strongly correlated with an expanded CAG trinucleotide repeat. The length of the normal CAG repeat allele has been reported also to influence age at onset, in interaction with the expanded allele. Due to profound implications for disease mechanism and modification, we tested whether the normal allele, interaction between the expanded and normal alleles, or presence of a second expanded allele affects age at onset of HD motor signs. Methods: We modeled natural log-transformed age at onset as a function of CAG repeat lengths of expanded and normal alleles and their interaction by linear regression. Results: An apparently significant effect of interaction on age at motor onset among 4,068 subjects was dependent on a single outlier data point. A rigorous statistical analysis with a well-behaved dataset that conformed to the fundamental assumptions of linear regression (e.g., constant variance and normally distributed error) revealed significance only for the expanded CAG repeat, with no effect of the normal CAG repeat. Ten subjects with 2 expanded alleles showed an age at motor onset consistent with the length of the larger expanded allele. Conclusions: Normal allele CAG length, interaction between expanded and normal alleles, and presence of a second expanded allele do not influence age at onset of motor manifestations, indicating that the rate of HD pathogenesis leading to motor diagnosis is determined by a completely dominant action of the longest expanded allele and as yet unidentified genetic or environmental factors. Neurology® 2012;78:690–695 PMID:22323755

  14. Stress analysis of a fixed implant-supported denture by the finite element method (FEM when varying the number of teeth used as abutments

    Directory of Open Access Journals (Sweden)

    Marcos Daniel Septímio Lanza

    2011-12-01

    Full Text Available OBJECTIVES: In some clinical situations, dentists come across partially edentulous patients, and it might be necessary to connect teeth to implants. The aim of this study was to evaluate a metal-ceramic fixed tooth/implant-supported denture with a straight segment, located in the posterior region of the maxilla, when varying the number of teeth used as abutments. MATERIAL AND METHODS: A three-element fixed denture composed of one tooth and one implant (Model 1, and a four-element fixed denture composed of two teeth and one implant (Model 2 were modeled. A 100 N load was applied, distributed uniformly on the entire set, simulating functional mastication, for further analysis of the SEQV (Von Mises principal stresses, which were compared with the flow limit of the materials. RESULTS: In a quantitative analysis, it may be observed that in the denture with one tooth, the maximum SEQV stress was 47.84 MPa, whereas for the denture with two teeth the maximum SEQV stress was 35.82 MPa, both located in the region between the pontic and the tooth. CONCLUSION: Lower stresses were observed in the denture with an additional tooth. Based on the flow limit of the materials, porcelain showed values below the limit of functional mastication.

  15. 20 CFR 410.426 - Determining total disability: Age, education, and work experience criteria.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Determining total disability: Age, education, and work experience criteria. 410.426 Section 410.426 Employees' Benefits SOCIAL SECURITY... Disability or Death Due to Pneumoconiosis § 410.426 Determining total disability: Age, education, and...

  16. Caries induced cytokine network in the odontoblast layer of human teeth

    Directory of Open Access Journals (Sweden)

    Horst Jeremy A

    2011-01-01

    Full Text Available Abstract Background Immunologic responses of the tooth to caries begin with odontoblasts recognizing carious bacteria. Inflammatory propagation eventually leads to tooth pulp necrosis and danger to health. The present study aims to determine cytokine gene expression profiles generated within human teeth in response to dental caries in vivo and to build a mechanistic model of these responses and the downstream signaling network. Results We demonstrate profound differential up-regulation of inflammatory genes in the odontoblast layer (ODL in human teeth with caries in vivo, while the pulp remains largely unchanged. Interleukins, chemokines, and all tested receptors thereof were differentially up-regulated in ODL of carious teeth, well over one hundred-fold for 35 of 84 genes. By interrogating reconstructed protein interaction networks corresponding to the differentially up-regulated genes, we develop the hypothesis that pro-inflammatory cytokines highly expressed in ODL of carious teeth, IL-1β, IL-1α, and TNF-α, carry the converged inflammatory signal. We show that IL1β amplifies antimicrobial peptide production in odontoblasts in vitro 100-fold more than lipopolysaccharide, in a manner matching subsequent in vivo measurements. Conclusions Our data suggest that ODL amplifies bacterial signals dramatically by self-feedback cytokine-chemokine signal-receptor cycling, and signal convergence through IL1R1 and possibly others, to increase defensive capacity including antimicrobial peptide production to protect the tooth and contain the battle against carious bacteria within the dentin.

  17. Mounting ground sections of teeth: Cyanoacrylate adhesive versus Canada balsam

    OpenAIRE

    Manogna R.L. Vangala; Amrutha Rudraraju; Subramanyam, R. V.

    2016-01-01

    Introduction: Hard tissues can be studied by either decalcification or by preparing ground sections. Various mounting media have been tried and used for ground sections of teeth. However, there are very few studies on the use of cyanoacrylate adhesive as a mounting medium. Aims: The aim of our study was to evaluate the efficacy of cyanoacrylate adhesive (Fevikwik™) as a mounting medium for ground sections of teeth and to compare these ground sections with those mounted with Canada balsam. Mat...

  18. Maturasi dan erupsi gigi permanen pada anak periode gigi pergantian (The maturition and eruption of permanent teeth in mixed dentition children)

    OpenAIRE

    Sri Kuswandari

    2014-01-01

    Background: Tooth eruption might used as predictor of child age when the chronologic age is unknown. Beside the dental maturity, tooth eruption is also influenced by some factors, such as caries and tooth extraction. Purpose: The aim of this research was to examine the relationship of maturity and eruption of permanent teeth with chronologic age in mixed dentition period children. Methods: The subjects were patients of Prof. Soedomo Dental Hospital Pediatric Dental Clinic, consist of 38 boys ...

  19. Regional cerebral blood flow in aged diabetic patients without a history of cerebrovascular accident, determined by N-isopropyl- sup 123 I-p-iodoamphetamine with single photon emission CT

    Energy Technology Data Exchange (ETDEWEB)

    Wakisaka, Masanori; Nagamachi, Shigeki; Inoue, Kenjiro; Morotomi, Yasuyuki (National Sanatorium Miyazaki Higashi Hospital (Japan)); Nunoi, Kiyohide; Fujishima, Masatoshi

    1989-07-01

    N-isopropyl-{sup 123}I-p-iodoamphetamine (IMP) was used to determine the regional cerebral blood flow in 9 diabetic patients (average age: 71.8 years) and 9 non-diabetic subjects (average age: 71.7 years), none of whom had a history of cerebrovascular accident. There were no significant differences in the physiological or laboratory data between the diabetic and non-diabetic groups except in fasting plasma glucose and HbA{sub 1}c levels. Areas of hypoperfusion of the cerebral hemispheres were observed in 7 diabetic patients, 5 of whom showed multiple lesions. On the other hand, areas of hypoperfusion were observed only in 4 of the non-diabetic subjects and only 1 of these demonstrated multiple lesions. We evaluated the cerebral blood flow semiquantitatively as follows: the area where the radioactive count was 65% or more of the maximum count of the slice was defined as a region of normal cerebral blood flow (ROI-A); the area where the count was 45% or more as region of brain tissue except for ventricles (RUI-B). The numbers of pixels of ROI-A and ROI-B were counted in each slice and the ROI-A/B ratios of 16 slices were averaged individually. The average percent ROI-A/B ratio was significantly lower in the diabetic group than that in the control group (49.4+-1.9 (Mean+-SEM) vs 56.6+-1.9%, p<0.05). These observations suggest that the area of normal regional cerebral blood flow is reduced in aged diabetics, even in the absence of a history of cerebrovascular accident. (author).

  20. Regional cerebral blood flow in aged diabetic patients without a history of cerebrovascular accident, determined by N-isopropyl-123I-p-iodoamphetamine with single photon emission CT

    International Nuclear Information System (INIS)

    N-isopropyl-123I-p-iodoamphetamine (IMP) was used to determine the regional cerebral blood flow in 9 diabetic patients (average age: 71.8 years) and 9 non-diabetic subjects (average age: 71.7 years), none of whom had a history of cerebrovascular accident. There were no significant differences in the physiological or laboratory data between the diabetic and non-diabetic groups except in fasting plasma glucose and HbA1c levels. Areas of hypoperfusion of the cerebral hemispheres were observed in 7 diabetic patients, 5 of whom showed multiple lesions. On the other hand, areas of hypoperfusion were observed only in 4 of the non-diabetic subjects and only 1 of these demonstrated multiple lesions. We evaluated the cerebral blood flow semiquantitatively as follows: the area where the radioactive count was 65% or more of the maximum count of the slice was defined as a region of normal cerebral blood flow (ROI-A); the area where the count was 45% or more as region of brain tissue except for ventricles (RUI-B). The numbers of pixels of ROI-A and ROI-B were counted in each slice and the ROI-A/B ratios of 16 slices were averaged individually. The average percent ROI-A/B ratio was significantly lower in the diabetic group than that in the control group (49.4±1.9 (Mean±SEM) vs 56.6±1.9%, p<0.05). These observations suggest that the area of normal regional cerebral blood flow is reduced in aged diabetics, even in the absence of a history of cerebrovascular accident. (author)