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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 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.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. Age determination of raccoons

    Science.gov (United States)

    Grau, G.A.; Sanderson, G.C.; Rogers, J.P.

    1970-01-01

    Age criteria, based on 61 skulls and eye lenses from 103 known-age captives, are described for separating raccoons (Procyon lotor) into eight age-classes as follows: young-of-the-year, 1, 2, 3, 4, 5, 6-7, > 7 years. Criteria studied were eye lens nitrogen, cranial suture closure, tooth wear and incisor cementum layers. Lens nitrogen increased rapidly up to 12 months of age, but at much reduced rate thereafter. Total lens nitrogen was useful only in separating young-of-the-year from adults. The closure sequence for five cranial sutures accurately divided the total known-age sample of males into seven groups, and the adults into five groups. The tooth wear criteria divided the known-age sample into five relative age groups, but aging of individuals by this method was inaccurate. Histological sectioning of known-age teeth was the best method of observing layering in the cementum tissue. The technique of basing estimation of age on cementum ring counts, although subjective, was accurate for aging individuals through their fourth year but tended to underestimate the age of animals over 4 years old. However, suture closure or tooth wear can be used to identify males over 4 years old. In field studies, technical difficulties limit the utility of age estimation by cementum layers. Maximum root thickness of the lower canine was accurate in determining the sex of individuals from 5 months to ,at least 48 months of age.

  9. 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.

  10. 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...

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. Determination of total and methyl mercury in human permanent healthy teeth by electrothermal atomic absorption spectrometry after extraction in organic phase.

    Science.gov (United States)

    Saber-Tehrani, M; Givianrad, M H; Hashemi-Moghaddam, H

    2007-02-28

    A simple and sensitive method has been developed for determination of inorganic and methyl mercury in biological samples by ETAAS. For determination of methyl mercury; it was transferred to toluene phase by acid leaching extraction method. For total mercury after digestion of samples; it was extracted to toluene phase by means of the chelating agent diethyldithiocarbamate. Formation of complex between MeHg and diethyldithiocarbamate enhance the MeHg signal and increases the reproducibility. Furthermore, Pd-DDC was used as modifier for both mercury and methyl mercury determinations. The optimization performance was independently carried out by modifying the parameters such as temperature of mineralization, atomization and gas flow rate for methylmercury and inorganic mercury in ETAAS. The limits of detection were 0.15 and 0.12mugg(-1) for methyl mercury and total mercury, respectively. The repeatability of the measurements of whole procedure were 15.8% for methyl mercury and 16.9% for total mercury determination. The accuracy of the method has been investigated by means of spiking different amounts of methylmercury and inorganic mercury to the samples. The recoveries were found within the range of 88-95% for methyl mercury and 85-92% for total mercury. For determination of total mercury, the method was validated by CVAAS. The obtained results by the present procedure were in good agreement with those of the CVAAS. The proposed method was applied for 30 human permanent healthy teeth (without filling) which significant positive correlations were found among number of amalgam filling and total mercury and MeHg.

  17. 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

  18. 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.

  19. Application of age estimation methods based on teeth eruption: how easy is Olze method to use?

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    De Angelis, D; Gibelli, D; Merelli, V; Botto, M; Ventura, F; Cattaneo, C

    2014-09-01

    The development of new methods for age estimation has become with time an urgent issue because of the increasing immigration, in order to estimate accurately the age of those subjects who lack valid identity documents. Methods of age estimation are divided in skeletal and dental ones, and among the latter, Olze's method is one of the most recent, since it was introduced in 2010 with the aim to identify the legal age of 18 and 21 years by evaluating the different stages of development of the periodontal ligament of the third molars with closed root apices. The present study aims at verifying the applicability of the method to the daily forensic practice, with special focus on the interobserver repeatability. Olze's method was applied by three different observers (two physicians and one dentist without a specific training in Olze's method) to 61 orthopantomograms from subjects of mixed ethnicity aged between 16 and 51 years. The analysis took into consideration the lower third molars. The results provided by the different observers were then compared in order to verify the interobserver error. Results showed that interobserver error varies between 43 and 57 % for the right lower third molar (M48) and between 23 and 49 % for the left lower third molar (M38). Chi-square test did not show significant differences according to the side of teeth and type of professional figure. The results prove that Olze's method is not easy to apply when used by not adequately trained personnel, because of an intrinsic interobserver error. Since it is however a crucial method in age determination, it should be used only by experienced observers after an intensive and specific training.

  20. 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

  1. 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

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

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    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.

  3. 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.

  4. Reliability of conventional shade guides in teeth color determination

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    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.

  5. Clinical and radiographic sequelae to primary teeth affected by dental trauma: a 9-year retrospective study.

    Science.gov (United States)

    Costa, Vanessa Polina Pereira; Goettems, Marilia Leão; Baldissera, Elaine Zanchin; Bertoldi, Andréa Dâmaso; Torriani, Dione Dias

    2016-08-18

    This retrospective study aimed at determining the predicted risks of clinical and radiographic complications in primary teeth following traumatic dental injuries, according to injury type, severity and child's age. Data were collected from records of children treated at a Dental Trauma Center in Brazil for nine years. Records of 576 children were included; clinical sequelae were assessed in 774 teeth, and radiographic sequelae, in 566 teeth. A total of 408 teeth (52.7%) had clinical sequelae and 185 teeth (32.7%), radiographic sequelae. The type of injury with the highest number of clinical sequelae was the crown-root fracture (86.4%). Clinical sequelae increased with injury severity (p teeth with enamel fracture, and 26.0% (95%CI 14-40) for teeth with enamel dentin fracture as well as enamel dentin pulp fracture. Risk of periapical radiolucency was higher for teeth with enameldentinpulp fracture (61.1% 95%CI 35-82) and those with subluxation (15.8% 95%CI 10-22). Risk of premature loss was 27.3% (95%CI 13-45) for teeth with extrusive luxation, and 10.2% (95%CI 5-17) for those with intrusive luxation. The assessment of predicted risks of sequelae showed that teeth with hard tissue trauma tended to present color change, periapical radiolucency and premature loss, whereas teeth with supporting tissue trauma showed color change, abnormal position, premature loss and periapical radiolucency as the most common sequelae. Knowledge about the predicted risks of complications may help clinicians establish appropriate treatment plans.

  6. 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

  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)

    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...

  8. 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

  9. 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.

  10. Bucco-lingual dimension of teeth - An aid in sex determination

    OpenAIRE

    Prathibha Rani, R. M.; V G Mahima; Karthikeya Patil

    2009-01-01

    Background: Bucco-lingual (B-L) dimensions of permanent teeth are known to exhibit sexual dimorphism. Objectives: Sexual dimorphism of B-L dimensions is known to be population specific. This study involves the measurement of B-L dimensions of all teeth except third molars of 99 native residents of Mysore district, Karnataka in the age group of 19-30 years. Materials and Methods: The B-L dimensional measurements of 28 teeth, except third molars, of 50 males and 49 females in the age group ...

  11. Age of menopause and determinants of menopause age: A PAN India survey by IMS

    Directory of Open Access Journals (Sweden)

    Maninder Ahuja

    2016-01-01

    Results: Average age of menopause of an Indian woman is 46.2 years much less than their Western counter parts (51 years. A definite rural and urban division was also seen. There was a correlation between the age of menopause and social and economic status, married status, and parity status.

  12. Preservation of Hypermobile Teeth by Establishing Posterior Occlusal Support Using Implant Prostheses: A 5-Year Follow-Up.

    Science.gov (United States)

    Doh, Re-Mee; Park, Wonse; Kim, Kee-Deog; Jung, Bock-Young

    2015-08-01

    For patients with periodontally compromised, hypermobile teeth, implant-supported fixed dental prostheses (FDPs) or removable dentures are often used after extracting mobile teeth. The loss of native teeth may carry social consequences, depending upon the patient's age, state of health, and degree of social functioning. This report represents successful stabilization and preservation of questionable, hypermobile teeth that have been damaged by traumatic occlusion due to the loss of posterior support with a cross-arch splinted FDP, as well as the implementation of posterior support using implant-supported prostheses.

  13. 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)

  14. Dental age estimation in Japanese individuals combining permanent teeth and third molars.

    Science.gov (United States)

    Ramanan, Namratha; Thevissen, Patrick; Fleuws, Steffen; Willems, G

    2012-12-01

    The study aim was, firstly, to verify the Willems et al. model on a Japanese reference sample. Secondly to develop a Japanese reference model based on the Willems et al. method and to verify it. Thirdly to analyze the age prediction performance adding tooth development information of third molars to permanent teeth. Retrospectively 1877 panoramic radiographs were selected in the age range between 1 and 23 years (1248 children, 629 sub-adults). Dental development was registered applying Demirjian 's stages of the mandibular left permanent teeth in children and Köhler stages on the third molars. The children's data were, firstly, used to validate the Willems et al. model (developed a Belgian reference sample), secondly, split ino a training and a test sample. On the training sample a Japanese reference model was developed based on the Willems method. The developed model and the Willems et al; model were verified on the test sample. Regression analysis was used to detect the age prediction performance adding third molar scores to permanent tooth scores. The validated Willems et al. model provided a mean absolute error of 0.85 and 0.75 years in females and males, respectively. The mean absolute error in the verified Willems et al. and the developed Japanese reference model was 0.85, 0.77 and 0.79, 0.75 years in females and males, respectively. On average a negligible change in root mean square error values was detected adding third molar scores to permanent teeth scores. The Belgian sample could be used as a reference model to estimate the age of the Japanese individuals. Combining information from the third molars and permanent teeth was not providing clinically significant improvement of age predictions based on permanent teeth information alone.

  15. 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.

  16. 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) ...

  17. 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.

  18. 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)

  19. 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

  20. 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

  1. 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

  2. Determination of Geometrical Parameters for Semi-Rolling Bevel Precessional Gears With Straight Teeth

    Science.gov (United States)

    Syzrantsev, V.; Syzrantseva, K.; Milanovic, M.; Pazyak, A.

    2016-08-01

    The aim of this paper is to analyse the semi-rolling bevel precessional gear with straight teeth. The given method of cutting pinion and gear teeth significantly simplifies its manufacture technology. Authors have given a system of equations to study the analysis of generating pinion tooth surfaces and geometry of meshing for semi-rolling bevel precessional gear with straight teeth. A computer program was developed to enable implement formulas provided in the paper. By using this program authors obtained contact lines on the pinion tooth surface and number of tooth pairs in gears mesh.

  3. 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

  4. 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. 

  5. 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.

  6. 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.

  7. Prevalence and characteristics of supernumerary teeth: A survey on 7348 people

    OpenAIRE

    Demiriz, Levent; Durmuşlar, Mustafa Cenk; Mısır, Ahmet Ferhat

    2015-01-01

    Objective: The aim of the present study was to determine the prevalence of supernumerary teeth with by evaluating a large group of adult patients in Turkey and to investigate the characteristics of supernumerary teeth with their complications and treatment options. Study Design: This descriptive and retrospective study was carried out in 7348 adult patients aged over 18 years (3212 females and 4136 males). The characteristics of the supernumerary teeth were noted and the diagnosis was made du...

  8. 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...

  9. Age determination of mallards

    Science.gov (United States)

    Krapu, G.L.; Johnson, D.H.; Dane, C.W.

    1979-01-01

    A technique for distinguishing adult from yearling wild mallards (Anas platyrhynchos), from late winter through the nesting season, was developed by applying discriminant analysis procedures to selected wing feather characters of 126 yearlings and 76 adults (2-year-olds) hand-reared from wild eggs during 1974, 1975, and 1977. Average values for feather characters generally increased as the birds advanced from yearlings to adults. Black-white surface area of greater secondary covert 2 was the single most reliable aging character identified during the study. The error rate was lowest in females (3%) when discriminant functions were used with measurements of primary 1 weight and black-white area of greater secondary covert 2 and in males (9%) when the functions were used with black-white area of greater secondary coverts 1, 2, and 3. Methodology precludes aging of birds in the field during capture operations.

  10. 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.

  11. 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.

  12. Age estimation of blood stains by hemoglobin derivative determination using reflectance spectroscopy

    NARCIS (Netherlands)

    R.H. Bremmer; A. Nadort; T.G. van Leeuwen; M.J.C. van Gemert; M.C.G. Aalders

    2011-01-01

    Blood stains can be crucial in reconstructing crime events. However, no reliable methods are currently available to establish the age of a blood stain on the crime scene. We show that determining the fractions of three hemoglobin derivatives in a blood stain at various ages enables relating these ti

  13. 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...

  14. 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%.

  15. 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).

  16. 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.

  17. 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

  18. 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

  19. 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.

  20. 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.

  1. 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...

  2. 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' ...

  3. Effect of Static and Cyclic Loading on Ceramic Laminate Veneers Adhered to Teeth with and Without Aged Composite Restorations

    NARCIS (Netherlands)

    Gresnigt, Marco M. M.; Ozcan, Mutlu; Kalk, Warner; Galhano, Graziela

    2011-01-01

    Purpose: Existing composite restorations on teeth are often remade prior to the cementation of fixed dental prostheses. The aim of this study was to evaluate the effect of static and cyclic loading on ceramic laminate veneers adhered to aged resin composite restorations. Materials and Methods: Eight

  4. 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 ...

  5. 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.

  6. 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.

  7. 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)

  8. Determination of gestational age by ultrasonography - wrong, wrong and wrong again. Bestemmelse av foedselstermin ved tidlig ultralydundersoekelse - galt, galere, galest

    Energy Technology Data Exchange (ETDEWEB)

    Bratlid, D. (Rikshospitalet, Oslo (Norway))

    1991-04-01

    The article is a critical review of principal weaknesses in the current use of ultrasonography for determination of gestational age and discusses the fact that the method in its practical use disregards any biological variation in biparietal diameter. It is concluded that second trimester determination of gestational age by ultrasonography has an accuracy no greater than +-1.5 weeks. This is comparable to the accuracy of the clinical assessment of maturation in the newborn baby. Ultrasonography as the main indicator of gestational age should be used only when the pregnant woman's own menstrual history is obviously incorrect. 6 refs., 1 fig.

  9. 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

  10. Sex determination in modern Greeks using diagonal measurements of molar teeth.

    Science.gov (United States)

    Zorba, Eleni; Moraitis, Konstantinos; Eliopoulos, Constantine; Spiliopoulou, Chara

    2012-04-10

    Sex determination is a necessary step in the investigation of unidentified human remains from a forensic context. Teeth, as one of the strongest tissues in the human body, can be used for this purpose. Most studies of sexual dimorphism in teeth are based on the traditional mesiodistal and buccolingual crown measurements. The purpose of this study is to examine the degree of sexual dimorphism in permanent molars of modern Greeks using crown and cervical diagonal diameters, and to evaluate their applicability in sex determination. A total of 344 permanent molars in 107 individuals (53 male and 54 female) from the Athens Collection were examined. Crown and cervical diagonal diameters of both maxillary and mandibular molars were measured. It was found that males have larger molars than females and in 19 out of 24 dimensions measured male molars exceeded female molars significantly (Pdiagonal diameters have found to be more sexually diamorphic than crown diagonal diameters. In discriminant function analysis the variables entered more frequently were the cervical diagonal diameters mainly of mandibular molars. Classification accuracy was found to be 93% for the total sample, 77.4% for upper jaw, and 88.4% for the lower jaw. Accuracy rates were higher for cervical than crown diagonal diameters. The data generated from the present study suggest that this metric method can be useful and reliable for sex determination, especially when the traditional dental measurements are not applicable.

  11. 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

  12. 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.

  13. 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.

  14. The reliability of chronological age determination by means of mandibular third molar development in subjects in Croatia.

    Science.gov (United States)

    Legović, Mario; Sasso, Anja; Legović, Izak; Brumini, Gordana; Cabov, Tomislav; Slaj, Martina; Vancura, Irena; Lapter, Marina

    2010-01-01

    The aim of this study was to determine the development of the mandibular third molar and its relation to chronological age. The evaluated material consisted of 979 orthopantomograms of patients of Croatian Caucasian origin aged between 5.7 and 14.6 years. Third molar developmental stages were evaluated according to the stages proposed by Nolla. The frequencies of different stages of mineralization and the mean value of the mineralization of the mandibular third molars with regard to age, gender, and size of the mandible were determined and the coefficient of correlation determined between the age of the subject and the stage of development of the mandibular molars. Statistically significant correlation was determined between mineralization of the mandibular third molar and chronological age of the subjects (boys, mandibular left third molar r = 0.779, right third molar r = 0.793; girls, mandibular left third molar r = 0.746, right third molar r = 0.725). It can be concluded that the accuracy of age estimation based on Nolla's method is applicable for Croatian children.

  15. 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.)

  16. 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.

  17. 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...

  18. Comparative evaluation of the accuracy of two electronic apex locators in determining the working length in teeth with simulated apical root resorption: An in vitro study

    Science.gov (United States)

    Saraswathi, Vidya; Kedia, Archit; Purayil, Tina Puthen; Ballal, Vasudev; Saini, Aakriti

    2016-01-01

    Introduction: Accurate determination of working length (WL) is a critical factor for endodontic success. This is commonly achieved using an apex locator which is influenced by the presence or absence of the apical constriction. Hence, this study was done to compare the accuracy of two generations of apex locators in teeth with simulated apical root resorption. Materials and Methods: Forty maxillary central incisors were selected and after access preparation, were embedded in an alginate mold. On achieving partial set, teeth were removed, and a 45° oblique cut was made at the apex. The teeth were replanted and stabilized in the mold, and WL was determined using two generations of apex locators (Raypex 5 and Apex NRG XFR). Actual length of teeth (control) was determined by visual method. Statistical Analysis: Results were subjected to statistical analysis using the paired t-test. Results: Raypex 5 and Apex NRG was accurate for only 33.75% and 23.75% of samples, respectively. However, with ±0.5 mm acceptance limit, they showed an average accuracy of 56.2% and 57.5%, respectively. There was no significant difference in the accuracy between the two apex locators. Conclusion: Neither of the two apex locators were 100% accurate in determining the WL. PMID:27656055

  19. 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.

  20. Age determination of blood spots in forensic medicine by force spectroscopy.

    Science.gov (United States)

    Strasser, Stefan; Zink, Albert; Kada, Gerald; Hinterdorfer, Peter; Peschel, Oliver; Heckl, Wolfgang M; Nerlich, Andreas G; Thalhammer, Stefan

    2007-07-20

    We present a new tool for the estimation of the age of bloodstains, which could probably be used during forensic casework. For this, we used atomic force microscopy (AFM) for high-resolution imaging of erythrocytes in a blood sample and the detection of elasticity changes on a nanometer scale. For the analytic procedure we applied a fresh blood spot on a glass slide and started the AFM detection after drying of the blood drop. In a first step, an overview image was generated showing the presence of several red blood cells, which could easily be detected due to their typical "doughnut-like" appearance. The consecutively morphological investigations in a timeframe of 4 weeks could not show any alterations. Secondly, AFM was used to test the elasticity by recording force-distance curves. The measurements were performed immediately after drying, 1.5 h, 30 h and 31 days. The conditions were kept constant at room temperature (20 degrees C) and a humidity of 30%. The obtained elasticity parameters were plotted against a timeline and repeated several times. The elasticity pattern showed a decrease over time, which are most probably influenced by the alteration of the blood spot during the drying and coagulation process. The preliminary data demonstrates the capacity of this method to use it for development of calibration curves, which can be used for estimation of bloodstain ages during forensic investigations.

  1. 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.

  2. Age Determination by X-ray Fluorescence Rubidium-Strontium Ratio Measurement in Lepidolite.

    Science.gov (United States)

    Herzog, L F

    1960-07-29

    X-ray fluorescence analysis of several lepidolites whose rubidium and strontium concentrations had already been determined by neutron activation and stable isotope dilution, or both, indicates that this technique can be used for rapid nondestructive reconnaissance rubidiumstrontium studies, and that an x-ray analysis method comparable in accuracy to isotope dilution can probably be developed for dating Precambrian lepidolites, as the simple technique presently used has many obvious possibilities for improvement.

  3. 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

  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. Posterior neonatal teeth

    Directory of Open Access Journals (Sweden)

    A Kumar

    2011-01-01

    Full Text Available Teeth which are present in the oral cavity of newborn infant at the time of birth are called "natal teeth" and which erupts in first month of postnatal life are called as "neonatal teeth." The incidence of these teeth is 1 in 2000 to 1 in 3500 live birth. The most common natal teeth reported are mandibular central incisors followed by maxillary incisors and mandibular canine. The natal or neonatal tooth in maxillary molar region is a rare occurrence. This article represents a rare case of bilateral neonatal maxillary molar teeth.

  6. 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.

  7. An evaluation of Knutson's formula for estimating age-specific DMF teeth.

    Science.gov (United States)

    Korts, D C; Poulsen, S; Kingman, A

    1978-07-01

    The present study evaluated a formula suggested by Knutson for obtaining an age-specific estimate of mean DMFT in a population on the basis of the age-specific percentage of individuals with 1 or more DMFT. A total of 149 previously collected age-specific data sets from low-flouride areas in the U.S.A. were used, and the two parameters K and B were estimated using the method of weighted least squares. The analysis showed that the formula could be used with good accuracy for certain restrictions of age (5--11 years) and percentage of individuals with 1 or more DMFT (less than or equal to 70%).

  8. Vegetation abundance in lowland flood plain lakes determined by surface area, age and connectivity

    NARCIS (Netherlands)

    Geest, van G.J.; Roozen, F.C.J.M.; Coops, H.; Roijackers, R.M.M.; Buijse, A.D.; Peeters, E.T.H.M.; Scheffer, M.

    2003-01-01

    The authors analyzed the vegetation structure of 215 lakes in the flood plain of the river Lower Rhine in relation to environmental variables related to hydrological connectivity, lake morphometry, lake age and land use on adjacent land1. We analysed the vegetation structure of 215 lakes in the floo

  9. 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

  10. 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

  11. 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

  12. 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.

  13. [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

  14. 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.

  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. 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...

  17. 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.

  18. Chelating resin-based extraction of DNA from dental pulp and sex determination from incinerated teeth with Y-chromosomal alphoid repeat and short tandem repeats.

    Science.gov (United States)

    Tsuchimochi, Tsukasa; Iwasa, Mineo; Maeno, Yoshitaka; Koyama, Hiroyoshi; Inoue, Hiroyuki; Isobe, Ichiro; Matoba, Ryoji; Yokoi, Motoo; Nagao, Masataka

    2002-09-01

    A procedure utilizing Chelex 100, chelating resin, was adapted to extract DNA from dental pulp. The procedure was simple and rapid, involved no organic solvents, and did not require multiple tube transfers. The extraction of DNA from dental pulp using this method was as efficient, or more so, than using proteinase K and phenol-chloroform extraction. In this study, the Chelex method was used with amplification and typing at Y-chromosomal loci to determine the effects of temperature on the sex determination of the teeth. The extracted teeth were incinerated in a dental furnace for 2 minutes at 100 degrees C, 200 degrees C, 300 degrees C, 400 degrees C, and 500 degrees C. After the isolation of DNA from the dental pulp by the Chelex method, alphoid repeats, and short tandem repeats, the human Y chromosome (DYZ3), DYS19, SYS389, DYS390, and DYS393 could be amplified and typed in all samples incinerated at up to 300 degrees C for 2 minutes. The DYS389 locus in some samples could not be amplified at 300 degrees C for 2 minutes. An autopsy case is described in which genotypings of DYS19, DYS390, and DYS393 from dental pulp obtained from a burned body were needed. The data presented in this report suggest that Chelex 100-based DNA extraction, amplification, and typing are possible in burned teeth in forensic autopsy cases.

  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. Sexual dimorphism in permanent teeth of modern Greeks.

    Science.gov (United States)

    Zorba, Eleni; Moraitis, Konstantinos; Manolis, Sotiris K

    2011-07-15

    Sex determination is considered an important step in reconstructing the biological profile of unknown individuals from a forensic context. Forensic anthropologists have long used teeth as an additional tool for sex determination as they resist postmortem destruction. In this case the use of population-specific data is necessary since sexual dimorphism varies between different populations. Currently there are no odontometric standards for determining sex in Greek populations. The purpose of this study is to examine the degree of sexual dimorphism in permanent teeth of modern Greeks. A total of 839 permanent teeth in 133 individuals (70 males and 63 females) from the Athens Collection were examined. Mesiodistal and buccolingual crown and cervical diameters of both maxillary and mandibular teeth were measured. It was found that males have bigger teeth than females and in 65 out of 88 dimensions measured, male teeth exceeded female teeth significantly (P<0.05). Canines were the most dimorphic teeth followed by first premolars, maxillary second premolar and mandibular second molar. Although other teeth were also sexually dimorphic they did not have a statistically significant difference in all dimensions. The most dimorphic dimension was buccolingual cervical diameter followed by buccolingual crown diameter. A comparison of sexual dimorphism in teeth between different populations showed that it differs among different groups. European population groups presented the highest degree of sexual dimorphism in teeth whereas Native South Americans the lowest.

  2. 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.

  3. The determination of male adult age at death by central and posterior coxal analysis--a preliminary study.

    Science.gov (United States)

    Rougé-Maillart, Clotilde; Telmon, Norbert; Rissech, Carme; Malgosa, Assumption; Rougé, Daniel

    2004-03-01

    In forensic anthropological analysis, the pelvis is of particular interest as it is often a comparatively well-preserved part of the skeleton. This study in age determination uses the acetabulum, the central element of the pelvis, as a complement to the examination of the auricular surface. The test sample consisted of 30 individuals. First, the authors studied the auricular surface using the Lovejoy criteria. Second, they isolated four criteria based on chronological changes in the acetabulum. Third, they conducted an evaluation of each of these variables. The study examines the correlation between these criteria and the age of the individuals. A significant correlation was found between the acetabular criteria and age, and between the acetabular criteria and the Lovejoy criteria of the auricular surface. For forensic purposes, the acetabulum is an effective predictor in the determination of age. This newly proposed method explores the same criteria of ageing as the Lovejoy method. The combination of the two methods produces relatively consistent results in the estimation of age.

  4. Reasons underlying the extraction of permanent teeth in patients attending Peoples Dental College and Hospital.

    Science.gov (United States)

    Dixit, L P; Gurung, C K; Gurung, N; Joshi, N

    2010-12-01

    Extraction of permanent teeth is common in Nepal. The study was undertaken to determine the causes and pattern of missing permanent teeth among patients attending Peoples Dental College and Hospital (PDCH) and to see if there is any association between variables like socio economic status, patient education level, dental visit and extraction of permanent teeth. A prospective cross sectional survey was carried out in patients attending the Department of Oral Surgery in PDCH between August 2006 and October 2006. The data was collected by trained clinician through clinical examination and using semi- structured questionnaires. Computer software SPSS 15 was used for statistical analysis. In age groups caries was the most common reason for extraction of teeth. In age groups > 30 years, 55.6% periodontal disease was the most common reason for extraction of teeth. Distribution by type of teeth and dental disease was highly significant where. Dental caries was the reason for extraction of first permanent molar. Distribution by education level and visit to dentist was highly significant. About 93.1% of the people who were illiterate visited the dental surgeon while in pain and 76.0% of the university level graduates visited the dentist while in pain. Caries and its sequel remain the most important cause of tooth loss throughout adult life along with periodontal diseases at later stages.

  5. 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...

  6. 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...

  7. 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.

  8. 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

  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. Age determination of blue-winged teal

    Science.gov (United States)

    Dane, C.W.

    1968-01-01

    Primary feather length, markings on the greater secondary coverts, and the degree of bill spotting were evaluated as characters for use in the spring to distinguish first-year, blue-winged teal (Anas discors) females from older ones. The length of the 10th primary feather did not prove suitable to separate different aged females. Extreme primary lengths might be used to determine the age of some males. In females that have been through a postnuptial molt the greater secondary coverts have a more symmetrical, and more acutely angled, white, inverted 'V'-marking. Any female with a 'V' subjectively classified as good has gone through at least one postnuptial molt, and a female with no sign of a 'V' on the coverts is a juvenile or yearling before her first postnuptial molt. By measuring the longest bill spot on the upper mandible of each known-age female, it was possible to determine the age of some female teal. Because the spots fade during the breeding season, no lower size limit could be set to delineate first-year females at that time of year, but any nest-trapped hen with a spot longer than 10 mm was considered to be older than 1 year. Upper and lower limits were also established to distinguish some yearlings and 2-year-olds in the fall.

  11. 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

  12. 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. ...

  13. [Natal and neonatal teeth].

    Science.gov (United States)

    Baumgart, Manuela; Lussi, Adrian

    2006-01-01

    Natal teeth have been defined as teeth which are present at birth, while neonatal teeth erupt during the first 30 days. Their occurrence is rare, the prevalence ranges from 1:2000 to 1:3000 with a higher frequency in the lip and palate clefts and syndroms. In about 85% natal or neonatal teeth are lower central incisors (60% in pairs), rare are upper teeth, molars and multiple teeth. In almost 90% they are part of the deciduous dentition. A lot of possible causes of early eruption are discussed, but only the relation to hereditary factors seems to be evident. An autosomal dominant trait is often described. The appearance of these teeth is dependent on the degree of maturity, but most of the time it is loose, small, discoloured and hypoplastic. Histologically, enamel hypoplasia with normal prism structure is apparent. No significant disturbances of the dentin structures are observed, only cervically dentin becomes atubular with spaces and enclosed cells. A large vascular pulp and failure of root formation are further investigations. Our microhardness measurements showed values from 24.3-32.4 KHN for enamel and 48.3-62.2 KHN for dentin, while normal deciduous teeth have an enamel hardness of 322.0 +/- 17.5 KHN. The thickness of enamel was never more than 280 microm compared to up to 1200 microm in normal teeth. This shows the retarded development of natal and neonatal teeth, because mineralization has not finished at the time of birth. In accordance with developmental age tooth structure and appearence are normal. In consideration of complications as Riga-Fede-disease, feeding problems, possibility of infection and hypermobility most of the time extraction is the treatment of choice, but in the interest of protecting the child this decision should be made carefully. PMID:17051960

  14. Teeth movement in denture and implant-supported prosthesis influenced by microwave flask systems

    Science.gov (United States)

    Consani, Rafael L.X.; Sonehara, Leonardo G.; Mesquita, Marcelo F.; Barão, Valentim A.R.; Caetano, Conrado R.

    2015-01-01

    Background/Aims This study evaluated the teeth movement in maxillary dentures and mandibular implantsupported prostheses processed by microwave flasks. Methods A model mounted on articulator was used to manufacture Co-Cr frameworks. Pins were placed for measurements on the incisal edge of upper and lower central incisors (I), buccal cusp of first upper and lower premolars (PM), and mesiobuccal cusps of upper and lower second molars (M). Distances I-I (incisor to incisor), PM-PM (premolar to premolar), M-M (molar to molar), RI-RM (right incisor to right molar), and LI-LM (left incisor to left molar) were measured before and after processing using a microscope (0.0005 mm). Vertical misfit between abutment and implant platform was evaluated for regions A (left distal implant), B (left median implant), C (medial implant), D (right median implant), and E (right distal implant) in predetermined labial and lingual sites. Prostheses were divided into groups G1 – conventional flask, and G2 – experimental HH flask. Acrylic resin was microwaved at 1400 W (30% for 3 min, 0% for 3 min, and 60% for 3 min). Horizontal teeth displacement and vertical misfit between abutment and implant platform were considered before and after procedures. Data were submitted to three-way ANOVA and Tukey's test (α = 0.05). Results Except for M-M distance, the teeth showed displacements without statistical difference for prosthesis and flask factors. There was no significant difference for vertical misfit values for both flasks. Conclusion Diferente flasks did not cause significant changes in the teeth displacement, except for M-M. Vertical misfit values were not influenced by the flasks. PMID:26605143

  15. Frequency of intrusive luxation in deciduous teeth and its effects.

    Science.gov (United States)

    Carvalho, Vivian; Jacomo, Diana Ribeiro; Campos, Vera

    2010-08-01

    The aims of this study were three-fold: First, to determine the prevalence of partial and total intrusion of the primary anterior teeth. Second, to investigate the sequelae of total and partial intrusive luxation in the primary anterior teeth and in their successors and finally, to establish whether the sequelae on both deciduous and permanent teeth were related to the child's age at the time of the intrusion. Data collected from records of 169 boys and 138 girls, all between the ages of zero and 10 years, who were undergoing treatment during the period of March 1996 to December 2004. The sample was composed of 753 traumatized deciduous teeth, of which 221 presented intrusive luxation injury. Children with ages ranging from one to 4 years were the most affected with falls being the main cause of intrusion. Of all intruded teeth 128 (57.9%) were totally intruded and 93 (42.1%) partially. Pulp necrosis/premature loss and color change were the most frequent sequelae in both total and partial intrusions. Concerning permanent dentition, the most common disturbances were color change and/or enamel hypoplasia. Both types of intrusion caused eruption disturbance. Total intrusion was the most frequent type of intrusive luxation. There was no significant correlation between the child's age at the time of intrusion and the frequency of subsequent sequela on primary injured teeth (P = 0.035), between the age at the time of injury and the developmental disturbances on permanent teeth (P = 0.140).

  16. 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...

  17. 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...

  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. 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 ...

  20. 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

  1. 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.

  2. 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.

  3. Measurement of the refractive index of human teeth by optical coherence tomography

    Science.gov (United States)

    Meng, Zhuo; Yao, X. Steve; Yao, Hui; Liang, Yan; Liu, Tiegen; Li, Yanni; Wang, Guanhua; Lan, Shoufeng

    2009-05-01

    We describe a novel method based on optical coherence tomography (OCT) for the accurate measurement of the refractive index of in vitro human teeth. We obtain the refractive indices of enamel, dentin, and cementum to be 1.631+/-0.007, 1.540+/-0.013, and 1.582+/-0.010, respectively. The profile of the refractive index is readily obtained via an OCT B scan across a tooth. This method can be used to study the refractive index changes caused by dental decay and therefore has great potential for the clinical diagnosis of early dental caries.

  4. Production Rates of Noble Gases in the Near-Surface Layers of Europa by Energetic Charged Particles and the Potential for Determining Exposure Ages

    Science.gov (United States)

    Swindle, T. D.; Reedy, R. C.; Masarik, J.

    2003-01-01

    The surface of Europa is expected to be extremely active, undergoing tectonic and/or tidal geological activity and sputtering/ deposition, as well as impact cratering. Determination of the actual age of the surface at one or more places would greatly simplify trying to sort out what processes are occurring, and at what rate. If there is K present, as the spectral and compositional modeling discussed predict, it should be possible, in principle, to determine K-Ar crystallization ages. Whether or not there is K present, a consideration of the environment suggests we can determine an energetic particle exposure age if we can make in situ measurements of the abundances of major elements and of noble gas isotopes. This requires instrumentation that is within reach of current technology. In this paper, we calculate production rates for noble-gas isotopes in a simplified Europan surface, to quantify the amount of light noble gases produced by exposure to energetic particles.

  5. 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)

  6. 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)

  7. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Hung Kyu [Department of Dental Radiology, College of Dentistry, Seoul National University, Seoul (Korea, Republic of)

    1977-11-15

    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.

  9. 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

  10. 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

  11. 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

  12. 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...

  13. 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

  14. 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...

  15. Microtomography evaluation of dental tissue wear surface induced by in vitro simulated chewing cycles on human and composite teeth

    Directory of Open Access Journals (Sweden)

    Rossella Bedini

    2012-01-01

    Full Text Available In this study a 3D microtomography display of tooth surfaces after in vitro dental wear tests has been obtained. Natural teeth have been compared with prosthetic teeth, manufactured by three different polyceramic composite materials. The prosthetic dental element samples, similar to molars, have been placed in opposition to human teeth extracted by paradontology diseases. After microtomography analysis, samples have been subjected to in vitro fatigue test cycles by servo-hydraulic mechanical testing machine. After the fatigue test, each sample has been subjected again to microtomography analysis to obtain volumetric value changes and dental wear surface images. Wear surface images were obtained by 3D reconstruction software and volumetric value changes were measured by CT analyser software. The aim of this work has been to show the potential of microtomography technique to display very clear and reliable wear surface images. Microtomography analysis methods to evaluate volumetric value changes have been used to quantify dental tissue and composite material wear.

  16. 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.

  17. 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

  18. 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.

  19. Frequency of Intracranial Aneurysms Determined by Magnetic Resonance Angiography in Children (Mean Age 16) Having Operative or Endovascular Treatment of Coarctation of the Aorta (Mean Age 3).

    Science.gov (United States)

    Donti, Andrea; Spinardi, Luca; Brighenti, Maurizio; Faccioli, Luca; Leoni, Chiara; Fabi, Marianna; Trossello, Marco P; Gargiulo, Gaetano D; Bonvicini, Marco

    2015-08-15

    Coarctation of the aorta (CofA) has been associated with an increased risk of intracranial aneurysm (IA). This magnetic resonance angiography (MRA) study investigates the prevalence of IAs in 80 children treated in early life for CofA. MRA was performed at mean age of 15.7 ± 7.1 years, and surgical or endovascular treatment for CofA occurred at a mean age of 2.6 ± 4.4 years. No IA was found. In contrast with earlier findings in adult patients with late treatment for CofA, this first systematic study of very early treated patients for CofA failed to confirm the association between CofA and IAs. Our results call the abnormal developmental relation between CofA and IAs into question and suggest that modifiable risk factors like hypertension may be responsible for IA development in patients with CofA with adult diagnosis and treatment. In conclusion, our data suggest that early treatment of CofA can reduce the formation of IAs in children so as to make MRA screening less valuable in this young population.

  20. 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

  1. 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.

  2. 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

  3. [Clinical anatomy of the horse: teeth and dentition].

    Science.gov (United States)

    Staszyk, C

    2015-01-01

    The routine inspection of the equine oral cavity allows a numerical assessment of the teeth and provides information about positional changes within the dentition. By use of appropriate dental equipment, the occlusal surfaces of all teeth can be inspected and diagnosed. However, neither the teeth nor their occlusal surfaces are constant structures. Instead, equine teeth and, in particular, their occlusal surfaces are subjected to continuous morphological and positional changes due to the effects of aging and the equine-specific high amount of occlusal wear. Therefore, it is mandatory to define anatomical criteria, which allow us to distinguish between anatomical variations and pathological conditions. Moreover, an unambiguous nomenclature with regard to the equine-specific dental anatomy is essential. This article provides a tutorial overview of the equine dental anatomy as well as recent findings in the field of equine dentistry. Special attention is paid to dynamic changes within both individual teeth and dentition.

  4. 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.

  5. 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.

  6. 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)

  7. 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.

  8. 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...

  9. 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 ...

  10. 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

  11. 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

  12. 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.

  13. 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

  14. 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.

  15. [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

  16. Deciduous teeth occlusal caries detection with 655-nm diode laser confirmed by surface scanning electron microscopy

    Science.gov (United States)

    Duarte, Danilo; Fonseca, Yara P. C.; Zanin, Fatima A. A.; Brugnera, Aldo, Jr.

    2000-03-01

    The morphological complexity of the occlusal surface of deciduous molar teeth is considered as a factor to increase vulnerability to caries lesion. Occlusal surface of these teeth shows sulcus, pits and fissures which allow retention of both micro-organisms and food debris which make them more susceptible to caries. In the last decades there was a significant reduction on caries of smooth surface but not on the occlusal surface where dentinal caries develops under fissures which are apparently caries-free under eye observation. This is known as a hidden caries. The occlusal surface of sound extracted deciduous molar teeth were examined using a 655 nm diode laser (DIAGNOdent - KaVo) in order to detect hidden caries. When there was indication of a hidden caries, the area was examined using SEM and confirm or not the diagnosis. The authors concludes that the diagnosis of caries using 655 diode laser is reliable and precise method.

  17. 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)

  18. 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.

  19. 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

  20. 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

  1. Age determination of nephrite by in-situ SIMS U-Pb dating syngenetic titanite: A case study of the nephrite deposit from Luanchuan, Henan, China

    Science.gov (United States)

    Ling, Xiao-Xiao; Schmädicke, Esther; Li, Qiu-Li; Gose, Jürgen; Wu, Rui-Hua; Wang, Shi-Qi; Liu, Yu; Tang, Guo-Qiang; Li, Xian-Hua

    2015-04-01

    Nephrite is a kind of valuable jade which forms during metamorphism under greenschist facies conditions. Most investigations focus on the genesis of nephrite, however, the formation age of nephrite remains poorly constrained due to the lack of suitable dating methods. In this paper, the petrological, chemical characteristics, and mineral inclusions of nephrite collected from Luanchuan, Henan, China have been studied by optical and electron microscopy and wavelength-dispersive electron microprobe (EMP). The petrological observations show that nephrite consists mainly of tremolite, minor calcite and titanite, occasionally with rutile, quartz, serpentine, chlorite, pyrite, and apatite. The titanite and tremolite which are intergrown with each other share low-energy grain boundaries. It indicates that the two phases are equilibrated and can be considered as cogenetic. The chemical composition of tremolite is high in Si, Mg, Ca, but low in Fe, Cr, and Ni, which indicates that the nephrite from Luanchuan belongs to the dolomite type rather than the serpentinite type. The petrography of different nephrite structures suggests that the grain size of tremolite was determined by the stress intensity undergone during the nephrite formation progress. In-situ Secondary Ion Mass Spectrometer (SIMS) U-Pb dating of titanite from nephrite yielded an age of 361 ± 4 Ma, which is the first estimate for the time of formation of the Luanchuan nephrite deposit. This investigation provides a powerful in-situ dating method to unravel the age of nephrite, which could be served as a tool for future research on other nephrite deposits.

  2. 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...

  3. 正畸内收前牙所致牙体及牙周组织的不利改建%The adverse reconstruction of teeth and periodontal tissue caused by anterior teeth retraction

    Institute of Scientific and Technical Information of China (English)

    钱丽雯(综述); 钱玉芬(审校)

    2013-01-01

    内收前牙在安氏Ⅱ类错牙合畸形(上颌前突)及双颌前突患者正畸治疗中是不可或缺的步骤。内收前牙的关键在于能够高效移动牙齿的同时将对牙齿及其支持组织的损害减小至最低限度,然而临床上牙槽骨吸收、牙根吸收及牙龈退缩等现象在上述患者中很常见,有时甚至影响到正畸治疗的整体效果。本文对正畸内收前牙所导致牙体及牙周组织的不利改建及可能原因进行综述。%In cases of bimaxillary protrusion and Angle ClassⅡmalocclusion(maxilla hyperplasia),extraction of premo-lars and orthodontic treatment with retraction of the anterior teeth is a widely used approach. Minimizing the damage to teeth and their supporting tissue when moving teeth efficiently is needed. However many findings have shown that alveo-lar bone loss,root resorption and gingival recession occur after retracting the anterior teeth. Sometimes it even affects the overall effect of orthodontic treatment. This paper made a review of the adverse reconstruction of teeth and periodontal tis-sue caused by anterior teeth retraction and its possible risk factors.

  4. 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.

  5. 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) ...

  6. 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...

  7. 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

  8. Photochemical Age Determinations in the Phoenix Metropolitan Area

    Energy Technology Data Exchange (ETDEWEB)

    Kleinman, Lawrence I.; Daum, Peter H.; Lee, Y.- N.; Nunnermacker, L. J.; Springston, S. R.; Weinstein-Lloyd, J.; Hyde, P.; Doskey, Paul; Rudolph, Jochen; Fast, Jerome D.; Berkowitz, Carl M.

    2003-02-05

    An extensive VOC data set was gathered as part of a photochemical oxidant field campaign conducted in the Phoenix air basin in the late spring of 1998. Sampling was done at the surface and by aircraft at mid-boundary layer height; in regions with emission sources and downwind in the urban plume. VOC concentration ratios were used to calculate photochemical age, defined as the time integrated exposure of an air mass to OH radical. Based on the VOC ratios of 15 compounds (with OH reactivity varying between acetylene and p,m-xylene), we present estimates for photochemical age and dilution factors for several regions within the air basin. Geographic trends are in agreement with the expectation that pollutants are transported in a generally eastward direction so that older and more dilute mixtures occur to the east of the city. Photochemical ages determined from aircraft samples agree with those determined at a downwind surface site. The bias in photochemical age that occurs because fresh pollutants are added to an aged mixture has been quantified by using a particle trajectory model. A combination of trajectory results (actual age of the pollutants in an air mass) and photochemical age yields an estimate of the average OH concentration experienced by the air parcel. OH obtained in this way is somewhat lower, but has the same trends as OH concentrations calculated using a photochemical box model that is constrained with observed concentrations coincident with the VOC samples.

  9. Microleakage of composite resin restoration in cavities prepared by Er:YAG laser irradiation in primary teeth.

    Science.gov (United States)

    Yamada, Y; Hossain, M; Nakamura, Y; Murakami, Y; Matsumoto, K

    2002-03-01

    AIM: The purposes of this study were to investigate the surface morphology of cavities prepared by Er:YAG laser irradiation and to compare the microleakage degree after composite resin restoration with etched bur cavities in primary teeth, in vitro. MATERIALS AND METHODS: On the buccal (facial) and lingual (palatal) surfaces of 25 primary teeth, a round cavity was prepared with the Er:YAG laser system and with a high-speed diamond bur, respectively. Five cavities from each group were investigated by scanning electron microscopy (SEM). The remaining cavities were filled with a composite resin and subjected to a microleakage test (0.6% rodamine B solution) under thermocycling. Only bur cavities were acid-etched before filling. Statistical analysis was performed using the Mann-Whitney's U test; a value of p adhesion between the restorative material and dental hard tissues; there was also no gap at the interface. DISCUSSION: The highly irregular surface or the removal of the debris-like smear layer after laser irradiation may facilitate good adhesion of composite resin with enamel or dentine, and these surfaces might play a major role in decreasing microleakage of laser cavities. CONCLUSION: It can be concluded that cavities prepared by Er:YAG laser are capable of decreasing microleakage of composite resin restorations in primary teeth, and the efficiency is similar to etched bur cavities.

  10. Juvenile (age 13-18) smoking incidence determinants in Greece.

    Science.gov (United States)

    Vasilopoulos, Aristidis; Gourgoulianis, Konstantinos; Hatzoglou, Chryssi; Roupa, Zoe

    2015-10-01

    Smoking is a form of medical addiction, usually adopted during adolescence. The aim was to determine the prevalence of smoking in adolescents, aged 13-18 years old, to investigate their attitudes towards smoking and determine the contribution of social influences to onset and continuation of smoking. An anonymous self-report questionnaire was filled in by 873 high school students of Central Greece. Smoking incidence was 19.2%, with a 13.7% of regular smokers. The presence of a smoker in the family and a smoker friend were correlated with increased smoking rates. School grades were correlated negatively with smoking attitude and positively with allowance. Age was correlated negatively with social influence. Social influence appears stronger on younger ages and is a main determinant of smoking behavior. A more susceptible attitude towards smoking is formed during late adolescence. Certain social predictive factors for attitude towards smoking are proposed. PMID:24628676

  11. 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

  12. Age determination of female redhead ducks

    Science.gov (United States)

    Dane, C.W.; Johnson, D.H.

    1975-01-01

    Eighty-seven fall-collected wings from female redhead ducks (Aythya americana) were assigned to the adult or juvenile group based on 'tertial' and 'tertial covert' shape and wear. To obtain spring age-related characters from these fall-collected groupings, we considered parameters of flight feathers retained until after the first breeding season. Parameters measured included: markings on and width of greater secondary coverts, and length, weight, and diameter of primary feathers. The best age categorization was obtained with discriminant analysis based on a combination of the most accurately measured parameters. This analysis, applied to 81 wings with complete measurements, resulted in only 1 being incorrectly aged and 3 placed in a questionable category. Discriminant functions used with covert markings and the three 5th primary parameters were applied to 30 known-age juvenile, hand-reared redhead females, 28 were correctly aged, none was incorrectly aged, and only 2 were placed in the questionable category.

  13. Structure, composition, and mechanical properties of shark teeth.

    Science.gov (United States)

    Enax, Joachim; Prymak, Oleg; Raabe, Dierk; Epple, Matthias

    2012-06-01

    The teeth of two different shark species (Isurus oxyrinchus and Galeocerdo cuvier) and a geological fluoroapatite single crystal were structurally and chemically characterized. In contrast to dentin, enameloid showed sharp diffraction peaks which indicated a high crystallinity of the enameloid. The lattice parameters of enameloid were close to those of the geological fluoroapatite single crystal. The inorganic part of shark teeth consisted of fluoroapatite with a fluoride content in the enameloid of 3.1 wt.%, i.e., close to the fluoride content of the geological fluoroapatite single crystal (3.64 wt.%). Scanning electron micrographs showed that the crystals in enameloid were highly ordered with a special topological orientation (perpendicular towards the outside surface and parallel towards the center). By thermogravimetry, water, organic matrix, and biomineral in dentin and enameloid of both shark species were determined. Dentin had a higher content of water, organic matrix, and carbonate than enameloid but contained less fluoride. Nanoindentation and Vicker's microhardness tests showed that the enameloid of the shark teeth was approximately six times harder than the dentin. The hardness of shark teeth and human teeth was comparable, both for dentin and enamel/enameloid. In contrast, the geological fluoroapatite single crystal was much harder than both kinds of teeth due to the absence of an organic matrix. In summary, the different biological functions of the shark teeth ("tearing" for Isurus and "cutting" for Galeocerdo) are controlled by the different geometry and not by the chemical or crystallographic composition.

  14. Microleakage in primary teeth restored by conventional or bonded amalgam technique.

    Science.gov (United States)

    Myaki, S I; Rodrigues, C R; Raggio, D P; Flores, T A; Matson, M R

    2001-01-01

    The aim of this in vitro study was to evaluate marginal leakage in class V restorations in primary teeth restored with amalgam, using three different techniques. Thirty maxillary anterior primary teeth, clinically sound and naturally exfoliated, were used. In group 1 (n = 10), two thin layers of a copal varnish (Cavitine) were applied. In group 2 (n = 10), Scotchbond Multi-Purpose Plus, a dual adhesive system, was used according to manufacturer instructions. In group 3 (n = 10), One-Step adhesive system in combination with a low-viscosity resin (Resinomer) were used according to manufacturer instructions. All samples were restored with a high-copper dental amalgam alloy (GS 80, SDI). After restoration, the samples were stored in normal saline at 37 degrees C for 72 h. The specimens were polished, thermocycled (500 cycles, 5 degrees and 55 degrees C, 30-s dwell time) and impermeabilized with fingernail polish to within 1.0 mm of the restoration margins. The teeth were then placed in 0.5% methylene blue for 4 h. Finally, the samples were sectioned and evaluated for marginal leakage. The Kruskal-Wallis test showed that the filled adhesive resin (group 3) had the least microleakage. There was no significant difference between groups 1 and 2.

  15. Determining Ages of APOGEE Giants with Known Distances

    Science.gov (United States)

    Feuillet, Diane K.; Bovy, Jo; Holtzman, Jon; Girardi, Léo; MacDonald, Nick; Majewski, Steven R.; Nidever, David L.

    2016-01-01

    We present a sample of 705 local giant stars observed using the New Mexico State University 1 m telescope with the Sloan Digital Sky Survey-III/Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectrograph, for which we estimate stellar ages and the local star formation history (SFH). The high-resolution (R ˜ 22,500), near infrared (1.51-1.7 μm) APOGEE spectra provide measurements of stellar atmospheric parameters (temperature, surface gravity, [M/H], and [α/M]). Due to the smaller uncertainties in surface gravity possible with high-resolution spectra and accurate Hipparcos distance measurements, we are able to calculate the stellar masses to within 30%. For giants, the relatively rapid evolution up the red giant branch allows the age to be constrained by the mass. We examine methods of estimating age using both the mass-age relation directly and a Bayesian isochrone matching of measured parameters, assuming a constant SFH. To improve the SFH prior, we use a hierarchical modeling approach to constrain the parameters of the model SFH using the age probability distribution functions of the data. The results of an α-dependent Gaussian SFH model show a clear age-[α/M] relation at all ages. Using this SFH model as the prior for an empirical Bayesian analysis, we determine ages for individual stars. The resulting age-metallicity relation is flat, with a slight decrease in [M/H] at the oldest ages and a ˜0.5 dex spread in metallicity across most ages. For stars with ages ≲1 Gyr we find a smaller spread, consistent with radial migration having a smaller effect on these young stars than on the older stars.

  16. 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.

  17. 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...

  18. 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...... collections correlated well. Foot length was independent of gender, Environmental Tobacco Smoke, maternal smoking and alcohol consumption. CONCLUSION: Foot length correlated linearly to embryonic and foetal age, and was unaffected by gender, ETS, maternal smoking and alcohol consumption....

  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. 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.

  1. 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

  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. 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.

  4. 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

  5. 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

  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. 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....

  8. 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

  9. Assessment of age at death by microscopy

    DEFF Research Database (Denmark)

    Lynnerup, Niels; Frohlich, Bruno; Thomsen, Jørgen L

    2006-01-01

    The microscopic method of age at death determination was introduced by Kerley in 1965 [E.R. Kerley, The microscopic determination of age in human bone, Am. J. Phys. Anthropol, 23 (1965) 149-163.]. However, even though the method has been revised several times, there remain some fundamental issues...... the regions of interest, as well as for dealing with border phenomena, and we only counted secondary osteons. Our results show a statistically significant increase in the median number of osteons per area unit with increasing age at death. However, this was after exclusion of one outlier. This result...

  10. 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.

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

    Science.gov (United States)

    Duhan, Himanshu; Pandit, Inder Kumar; Srivastava, Nikhil; Gugnani, Neeraj; Gupta, Monika; Kochhar, Gulsheen Kaur

    2015-01-01

    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. PMID:26759595

  12. 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.

  13. 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

  14. 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.

  15. 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

  16. 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.

  17. 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 ...

  18. 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

  19. 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...

  20. Decayed, Missing, and Filled Teeth Index and Periodontal Health in Osteoporotic Patients Affected by BRONJ: An Observational Study

    Directory of Open Access Journals (Sweden)

    Giacomo Oteri

    2013-01-01

    Full Text Available The aim of this paper is to describe the incidence of decayed, missing, and filled teeth (DMFT and periodontal disease in 32 osteoporotic patients affected by bisphosphonate-related osteonecrosis of the jaw (BRONJ. Moreover, an investigation between the obtained data and 20 patients treated with bisphosphonate drugs and with no evidence of ONJ has been performed. Osteonecrosis of the jaws is a rare complication in a subset of patients receiving bisphosphonate drugs. Based on a growing number of case reports and institutional reviews, this kind of therapy can cause exposed and necrotic bone specifically in the jawbones. From April 2009 to June 2012, 32 osteoporotic patients treated with oral or intravenous (I.V. bisphosphonates have been recorded. The patients’ oral health has been compared with 20 bisphosphonates patients with no ONJ. The incidence of decayed, missing, and filled teeth (DMFT and periodontal disease was recorded in all patients and student’s t-test was applied for comparing the two investigated groups data. Data demonstrated how the poor dental hygiene and periodontal disease of the BRONJ patients’ are connected with the occurrence of jawbone necrosis.

  1. 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...

  2. 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...

  3. 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.

  4. 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

  5. 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...

  6. 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.

  7. 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

  8. Correlation between three color coordinates of human teeth.

    Science.gov (United States)

    Lee, Yong-Keun

    2014-11-01

    The objective was to determine whether there were significant correlations in the three color coordinates within each of two color coordinate systems, such as the Commission Internationale de l’Eclairage (CIE) L*a*b* system, and the lightness, chroma, and hue angle system, of human vital teeth. The color of six maxillary and six mandibular anterior teeth was measured by the Shade Vision System. Pearson correlations between each pair of the color coordinates were determined (α=0.01 ). The influence of two color coordinates on the other color coordinate was determined with a multiple regression analysis (α=0.01 ). Based on correlation analyses, all the color coordinate pairs showed significant correlations except for the chroma and hue angle pair. The CIE L* was negatively correlated with the CIE a*,b*, and chroma, but positively correlated with the hue angle. The CIE a* was positively correlated with the CIE b* and chroma. Tooth color coordinates were correlated each other. Lighter teeth were less chromatic both in the CIE a* and b* coordinates. Therefore, it was postulated that the three color coordinates of human teeth were harmonized within certain color attribute ranges, and a lack of correlations in these coordinates might indicate external/internal discolorations and/or anomalies of teeth.

  9. Prevalence of prematurely lost primary teeth in 5–10-year-old children in Thamar city, Yemen: A cross-sectional study

    Science.gov (United States)

    Murshid, Sakhr A.; Al-Labani, Mohammed A.; Aldhorae, Khalid A.; Rodis, Omar M. M.

    2016-01-01

    Objectives: The premature loss of primary teeth is a potential risk factor for poor arch length development. Adequate arch length is important to the progression of the permanent teeth. Poor arch length can lead to crowding, ectopic eruption, or impaction of these teeth. This study is designed to assess the prevalence of premature loss of primary teeth in the 5-10-year-old age group. Materials and Methods: The study group included 185 children, that is, 91 boys and 94 girls. The dental examination was conducted by an experienced examiner under sufficient artificial light. Data including patient age and missing teeth were collected. Descriptive statistics were applied for data analysis, and from the results, Chi-square tests were used at a level of significance of 5% (P space problems associated with the early loss of primary teeth would help in reducing malocclusion problems. PMID:27652244

  10. '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)

  11. 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.

  12. 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.

  13. 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)

  14. 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...

  15. Towards an accurate determination of the age of the Universe

    CERN Document Server

    Jiménez, R

    1998-01-01

    In the past 40 years a considerable effort has been focused in determining the age of the Universe at zero redshift using several stellar clocks. In this review I will describe the best theoretical methods to determine the age of the oldest Galactic Globular Clusters (GC). I will also argue that a more accurate age determination may come from passively evolving high-redshift ellipticals. In particular, I will review two new methods to determine the age of GC. These two methods are more accurate than the classical isochrone fitting technique. The first method is based on the morphology of the horizontal branch and is independent of the distance modulus of the globular cluster. The second method uses a careful binning of the stellar luminosity function which determines simultaneously the distance and age of the GC. It is found that the oldest GCs have an age of $13.5 \\pm 2$ Gyr. The absolute minimum age for the oldest GCs is 10.5 Gyr and the maximum is 16.0 Gyr (with 99% confidence). Therefore, an Einstein-De S...

  16. Evaluation of age determination techniques for gray wolves

    Science.gov (United States)

    Landon, D.B.; Waite, C.A.; Peterson, R.O.; Mech, L.D.

    1998-01-01

    We evaluated tooth wear, cranial suture fusion, closure of the canine pulp cavity, and cementum annuli as methods of age determination for known- and unknown-age gray wolves (Canis lupus) from Alaska, Minnesota, Ontario, and Isle Royale, Michigan. We developed age classes for cranial suture closure and tooth wear. We used measurement data obtained from known-age captive and wild wolves to generate a regression equation to predict age based on the degree of closure of the canine pulp cavity. Cementum annuli were studied in known- and unknown-age animals, and calcified, unstained thin sections were found to provide clear annulus patterns under polarized transmitted light. Annuli counts varied among observers, partly because of variation in the pattern of annuli in different regions of the cementum. This variation emphasizes the need for standardized models of cementum analysis. Cranial suture fusion is of limited utility in age determination, while tooth wear can be used to estimate age of adult wolves within 4 years. Wolves lt 7 years old could be aged to within 13 years with the regression equation for closure of the canine pulp cavity. Although inaccuracy remains a problem, cementum-annulus counts were the most promising means of estimating age for gray wolves.

  17. 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...

  18. Human dental age estimation combining third molar(s) development and tooth morphological age predictors.

    Science.gov (United States)

    Thevissen, P W; Galiti, D; Willems, G

    2012-11-01

    In the subadult age group, third molar development, as well as age-related morphological tooth information can be observed on panoramic radiographs. The aim of present study was to combine, in subadults, panoramic radiographic data based on developmental stages of third molar(s) and morphological measurements from permanent teeth, in order to evaluate its added age-predicting performances. In the age range between 15 and 23 years, 25 gender-specific radiographs were collected within each age category of 1 year. Third molar development was classified and registered according the 10-point staging and scoring technique proposed by Gleiser and Hunt (1955), modified by Köhler (1994). The Kvaal (1995) measuring technique was applied on the indicated teeth from the individuals' left side. Linear regression models with age as response and third molar-scored stages as explanatory variables were developed, and morphological measurements from permanent teeth were added. From the models, determination coefficients (R (2)) and root-mean-square errors (RMSE) were calculated. Maximal-added age information was reported as a 6 % R² increase and a 0.10-year decrease of RMSE. Forensic dental age estimations on panoramic radiographic data in the subadult group (15-23 year) should only be based on third molar development.

  19. 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

    In a retrospective analysis of data from three studies using a delayed response task in cynomolgus monkeys, we examined the subjects' search patterns and success rates. Twenty-seven monkeys of both sexes, divided into three age groups, were tasked with retrieving two food items hidden in an array...... of six identical opaque cups. Although the task was challenging for all subjects, generating a high level of guesswork, evidence of common behaviors when approaching the spatial memory test were found. The search patterns employed by the monkeys suggest the use of landmark cues, adaption in response...

  20. 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...... the 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...

  1. Caries detection in primary teeth is less challenging than in permanent teeth

    Directory of Open Access Journals (Sweden)

    Fausto M Mendes

    2013-01-01

    Full Text Available Introduction: Most studies about caries detection methods have been performed using permanent teeth. Primary teeth, however, present significant differences from permanent teeth; hence findings of these studies with permanent teeth cannot be extrapolated. The Hypothesis: Our hypothesis is that the caries diagnosis process in primary teeth is less challenging than in permanent teeth. This assertion is based on the fact that primary enamel is thinner and the caries process progresses faster in this type of teeth when compared to permanent teeth. For these reasons, the majority of caries lesions in primary teeth would be more evident and therefore, easily detected through visual inspection. Only a few number of caries lesions would be missed by visual inspection. Thus, adjunct diagnostic methods, such as radiographs, would be unnecessary for primary teeth. Evaluation of the Hypothesis: To evaluate this hypothesis, researchers should conduct studies about the performance of the caries detection methods avoiding selection bias and defining appropriate settings. Clinical trials randomizing the diagnostic strategies would be worthwhile. The evidence supporting the benefits of adjunct methods in detecting caries lesions in primary lesions is limited. However, clinical guidelines have recommended the use of the radiographic method to detect caries in primary teeth in all symptomless children. The confirmation of our hypothesis would lead to the need to re-evaluate such guidelines.

  2. Associations between the number of natural teeth and renal dysfunction.

    Science.gov (United States)

    Choi, Hye Min; Han, Kyungdo; Park, Yong Gyu; Park, Jun-Beom

    2016-08-01

    The purpose of the present study was to investigate the association between the number of natural teeth and measures of kidney dysfunction, such as urinary albumin/creatinine ratio (ACR) and estimated glomerular filtration (eGFR) rate, using nationally representative data.The data used were from the Korea National Health and Nutrition Examination Survey with cross-sectional design, which was conducted between 2011 and 2012; the sample analyzed in this study consisted of a total of 10,388 respondents, each of whom was 19 years or older and had no missing outcome variables. The association between the number of natural teeth and kidney function was assessed by multiple logistic regression and model was adjusted for age, sex, waist conference, smoking, drinking, exercise, education, income, frequency of tooth brushing per day, diabetes, metabolic syndrome, urinary ACR, and eGFR.The mean age, body mass index, and waist circumference were significantly higher among those with lower kidney function (urinary ACR ≥30 mg/g and eGFR ACR and eGFR were associated with loss of natural teeth. As urinary ACR increased, the number of natural teeth decreased accordingly. Conversely, the number of natural teeth increased with an increase in eGFR.This study showed that the number of natural teeth is inversely associated with the presence of kidney disease. Severity of tooth loss may be considered an independent risk indicator for kidney disease among Koreans. More epidemiological studies are warranted to investigate the role of tooth loss in kidney disease, to confirm this relationship and to test possible underlying mechanisms. PMID:27559974

  3. Natal teeth: a review.

    Science.gov (United States)

    Leung, Alexander K C; Robson, William Lane M

    2006-02-01

    The incidence of natal teeth is approximately 1:2,000 to 1:3,000 live births. The most commonly affected teeth are the lower primary central incisors. Natal teeth usually occur in pairs. The eruption of more than two natal teeth is rare. The majority of natal teeth represent the early eruption of normal primary deciduous dentition. Less than 10% of natal teeth are supernumerary. Natal teeth might resemble normal primary dentition in size and shape; however, the teeth are often smaller, conical and yellowish, and have hypoplastic enamel and dentin with poor or absent root formation. Complications include discomfort during suckling, sublingual ulceration, laceration of the mother's breasts and aspiration of the teeth. A dental roentgenogram is indicated to differentiate the premature eruption of a primary tooth from a supernumerary tooth. Tooth extraction is indicated if the tooth is supernumerary or excessively mobile. If the tooth does not interfere with breastfeeding and is otherwise asymptomatic, no treatment is necessary. PMID:16708508

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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

  12. 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...

  13. Standards for permanent teeth emergence time and sequence in Lithuanian children, residents of Vilnius city.

    Science.gov (United States)

    Almonaitiene, Ruta; Balciuniene, Irena; Tutkuviene, Janina

    2012-01-01

    BACKGROUND. Up-to-date population specific standards on the timing and sequence of emergence of the permanent teeth are essential in planning medical care for children. To the best of authors' knowledge, data about emergence time of permanent teeth in Lithuanian children has not been provided. OBJECTIVE. To provide the first standards of permanent teeth emergence time and sequence in Lithuanian children, citizens of Vilnius. MATERIAL AND METHODS. In a cross-sectional study, data were collected from 3596 Lithuanian children, 4 to 16 years of age in randomly selected kindergartens and secondary schools of Vilnius city. During dental examination all erupted permanent teeth, except third molars, were recorded. MiniTab15 statistical software was used to calculate clinical eruption time of permanent teeth. Different comparisons were made to detect inter-jaw, inter-gender and inter-population differences. RESULTS. The earliest teeth to erupt in both genders are lower central incisors around the age of six. The first stage of mixed dentition ends with the eruption of upper lateral incisors around the age of 8 in boys and a half of year earlier in girls. Second transitional period starts after the emergence of first premolars or lower canine in girls and upper first premolar in boys at the age of 9.5. The last tooth to erupt in both genders is the upper second molar at the age of twelve. No significant differences have been found between right and left sides in either jaw. Lower permanent teeth tended to emerge significantly earlier than the upper ones, except for premolars and first molars. Girls preceded boys by 4 to 5 months on average. Lithuanian children on average showed earlier emergence time, especially in premolars, but resemble German and Finnish populations more closely. CONCLUSIONS. No significant asymmetry in permanent teeth emergence time has been found in either jaw. Lower permanent teeth, showed earlier clinical eruption than in the upper jaw in both genders

  14. Wound infection by orthodontic treatment of impacted teeth:a clinical analysis%正畸牵引治疗埋伏阻生牙伤口感染的临床分析

    Institute of Scientific and Technical Information of China (English)

    周平秀; 孟祥勇; 张琳

    2011-01-01

    OBJECTIVE To probe into the orthodontic treatment of impacted teeth in the wound infection.METHODS A total of 108 patients with various types of impacted teeth selected from Apr 2008 to Sep 2010 were treated with preoperative counseling and orthodontics, surgery and orthodontic treatment combination of methods.The incidence of wound infections of the different age in patients were analyzed and compared. RESULTS After the treatment, the incidence of wound infection rate was 23. 15%. With age the incidence of wound infection in patients was increased. Compared with other age groups, 40 to 49 years the incidence of wound infection in patients were markedly improved, the normal healing rate was significantly lower, the difference was also statistically significant (P<0.05). The difference of different teeth infections was not significant (P>0.05). the incidence of Lip (buccal) side impacted teeth was more higher than tongue (palatal) side impacted teeth , there was statistically significant difference (P<0. 05). CONCLUSION The wound infection rate is high in impacted teeth patients treated by orthodontics, especially in older patients who have lip (buccal) side impacted teeth,which should be paid attention to the prevention of wound infection.%目的 探讨正畸牵引治疗埋伏阻生牙伤口感染的临床特点.方法 选择2008年4月-2010年9月医院收治的各类埋伏阻生牙患者108例,采用术前咨询与正畸,手术与正畸矫治相结合的方法进行治疗,比较分析不同年龄、不同牙位患者伤口感染的发生情况.结果 治疗后患者伤口感染发生率23.15%,随着患者年龄的增高伤口感染率逐渐提高,且与其他年龄段相比,40~49岁患者伤口感染率明显提高,正常愈合的感染率明显降低,差异有统计学意义(P<0.05);发生感染的牙位数感染率:中切牙为28%,尖牙为32%,第二前磨牙40%,差异无统计学意义;唇(颊)侧阻生埋伏牙比舌(腭)侧阻生埋伏牙的感

  15. 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...

  16. 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...

  17. The prevalence and determinants of Chinese medicine use by Australian women: analysis of a cohort of 10,287 women aged 56-61 years.

    Science.gov (United States)

    Sibbritt, David; Adams, Jon; Murthy, Vijayendra

    2013-01-01

    This study aimed to examine the factors associated with Chinese medicine use amongst a sample of 10,287 Australian women aged 56-61 years. Data was obtained from a cross-sectional postal questionnaire conducted in 2007, this being the fifth survey of the Australian Longitudinal Study on Women's Health. This representative sample of 10,287 women was randomly selected from the Health Insurance Commission (Medicare) database. The outcome measure was the use of Chinese medicine in the previous 12 months. The predictive factors included demographics, health status measures and health service utilization measures. Statistical analyses included univariate chi-square and ANOVA tests and backward stepwise multiple logistic regression modelling. The use of Chinese medicine amongst women aged 56-61 years appears to be strongly influenced by their country of birth, consultation with a range of CAM practitioners, and the use of some self-prescribed CAM. Interestingly, severe tiredness was the only symptom or diagnosis that predicted Chinese medicine use. Given the substantial prevalence of Chinese medicine use and the finding that the use of Chinese medicine is heavily integrated alongside the use of many other CAM and conventional treatments, it is imperative for the safety of patients that health professionals (across complementary and conventional healthcare) fully recognise the possible Chinese medicine use amongst their practice populations. In order to help inform relevant practice and policy development it is also important that future research further examining women's decision-making, motivations and evaluations regarding Chinese medicine use considers such issues within the context of broader CAM and conventional health care utilization. PMID:23548119

  18. Towards Global Age-Friendly Cities: Determining Urban Features that Promote Active Aging

    OpenAIRE

    Plouffe, Louise; Kalache, Alexandre

    2010-01-01

    At the same time as cities are growing, their share of older residents is increasing. To engage and assist cities to become more “age-friendly,” the World Health Organization (WHO) prepared the Global Age-Friendly Cities Guide and a companion “Checklist of Essential Features of Age-Friendly Cities”. In collaboration with partners in 35 cities from developed and developing countries, WHO determined the features of age-friendly cities in eight domains of urban life: outdoor spaces and buildings...

  19. [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

  20. Mophologic Analysis of the teeth and his relation with the slaughter age of buffalos ANÁLISE MORFOLÓGICA DOS DENTES E SUA RELAÇÃO COM A IDADE DE ABATE DE BÚFALOS

    Directory of Open Access Journals (Sweden)

    Francisco Carneiro Lima

    2008-07-01

    Full Text Available t was evaluated to the morphology of the incisors teeth of 100 buffaloes of slaughterhouses in Sao Luiz, seeking to relate them with your age of slaughter. The dental arches of the buffalos were taken to the laboratory of Anatomy/UEMA, for analysis of the incisors teeth. The results showed that the incisors teeth was composed for 4 pair, disposed in semicircle, denominated of 1ts, 2nd, 3rt and 4th pairs of incisors teeth (tweezers, first medium, seconds medium and songs. It was evidenced two teethings, deciduous and definitive, with forms and varied sizes, and variables levels of dental wear and tear, besides the presence of longitudinal grooves in the surface of the deciduous and definitive teeth with coloration varying from brown clear to darkness. With the dental analysis it was possible to distinguish five groups of animals that are depressed in the Maranhão and the group of smaller animals than 2.5 years and larger than 5.5 years were the more frequently observed. After morphologic and chronological evaluation of the incisors teeth of buffaloes, it was conclude that the buffaloes present a dental morphology similar the others ruminants and that, in function of the dental observation, the depressed buffaloes in Maranhão don’t follow pattern defined for discard.

    KEY WORD: Anatomy, buffaloes, teeth, slaughter.

    Avaliou-se a morfologia dos dentes incisivos de cem bubalinos adultos abatidos em matadouros do município de São Luís, Maranhão, visando relacioná-los com a idade de seu abate. Coletaram-se as arcadas dentárias desses animais, as quais foram levadas para o laboratório de Anatomia do Curso de Medicina Veterinária/UEMA, para análise dos dentes incisivos. Os resultados mostraram

  1. 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...

  2. 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.

  3. 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.

  4. Reciprocal Changes in Phosphoenolpyruvate Carboxykinase and Pyruvate Kinase with Age Are a Determinant of Aging in Caenorhabditis elegans.

    Science.gov (United States)

    Yuan, Yiyuan; Hakimi, Parvin; Kao, Clara; Kao, Allison; Liu, Ruifu; Janocha, Allison; Boyd-Tressler, Andrea; Hang, Xi; Alhoraibi, Hanna; Slater, Erin; Xia, Kevin; Cao, Pengxiu; Shue, Quinn; Ching, Tsui-Ting; Hsu, Ao-Lin; Erzurum, Serpil C; Dubyak, George R; Berger, Nathan A; Hanson, Richard W; Feng, Zhaoyang

    2016-01-15

    Aging involves progressive loss of cellular function and integrity, presumably caused by accumulated stochastic damage to cells. Alterations in energy metabolism contribute to aging, but how energy metabolism changes with age, how these changes affect aging, and whether they can be modified to modulate aging remain unclear. In locomotory muscle of post-fertile Caenorhabditis elegans, we identified a progressive decrease in cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C), a longevity-associated metabolic enzyme, and a reciprocal increase in glycolytic pyruvate kinase (PK) that were necessary and sufficient to limit lifespan. Decline in PEPCK-C with age also led to loss of cellular function and integrity including muscle activity, and cellular senescence. Genetic and pharmacologic interventions of PEPCK-C, muscle activity, and AMPK signaling demonstrate that declines in PEPCK-C and muscle function with age interacted to limit reproductive life and lifespan via disrupted energy homeostasis. Quantifications of metabolic flux show that reciprocal changes in PEPCK-C and PK with age shunted energy metabolism toward glycolysis, reducing mitochondrial bioenergetics. Last, calorie restriction countered changes in PEPCK-C and PK with age to elicit anti-aging effects via TOR inhibition. Thus, a programmed metabolic event involving PEPCK-C and PK is a determinant of aging that can be modified to modulate aging.

  5. 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 ...

  6. A clinical study of the relationship between crowding of teeth, plaque and gingival condition.

    Science.gov (United States)

    Ingervall, B; Jacobsson, U; Nyman, S

    1977-08-01

    A clinical trial was undertaken to assess whether crowded teeth were more likely to accumulate plaque and develop gingivitis than non-crowded teeth. A tooth was considered crowded if it was displaced by 2 mm and/or rotated 15 degrees or more from the normal position in the arch. The material consisted of 50 dental students aged 21 to 32 years. An initial examination comprised assessment of Plaque Index, Gingival Index and pocket depths. After this examination the subjects refrained from using interdental cleaning aids but continued with their normal toothbrushing for 40 days. After re-examination they were instructed in the effective use of dental floss. A final examination was carried out after 140 days. At the start of the trial no difference was found in regard to the Plaque Index between crowded and non-crowded teeth. The Gingival Index for growded front teeth, but not for crowded premolars, was somewhat higher than for the corresponding controls. The cessation of interdental cleaning resulted in a similar increase in plaque accumulation and gingival inflammation in both non-crowded and crowded teeth. The use of dental floss for approximal tooth cleaning resulted in a similar decrease in the Plaque- and Gingival Indices for both types of teeth. The results demonstrate that in a group of young adults, crowding of teeth (1) did not favour plaque accumulation on approximal tooth surfaces and (2) influenced the degree of gingival inflammation only to a minor extent.

  7. A retrospective study of 92 avulsed primary teeth in 69 children assisted at a dental urgency service

    Directory of Open Access Journals (Sweden)

    Orlando Aguirre Guedes

    2013-01-01

    Full Text Available The purpose of this study was to evaluate the epidemiological aspects associated with avulsion of primary teeth. The sample consisted of 92 avulsed teeth of 69 patients seen at the dental urgency service of the Dental School of the Federal University of Goiás, Brazil, from 1998 to 2005. The data obtained from the records included children’s gender and age, causes of tooth avulsion, daily and monthly distribution, type and number of avulsed teeth and the treatment procedures. Frequency distribution and the chi-square test were calculated. The level of significance was set at 5% for all analyses. The highest incidence was found among boys (52.17% aged 4 years (31.88%. The main etiologic factors were falls (82.61% and traffic accidents (5.80%. Most cases occurred during weekdays (82.61%, from March to June (autumn; n=28; 40.58% and from September to December (spring; n=18; 26.09%. Most avulsed teeth were maxillary central incisors (68.48%, followed by maxillary lateral incisors (22.83%. The most frequent treatments were analysis of clinical history and clinical exam (64 teeth; 69.57% and space maintainer (18 teeth; 19.57%. The epidemiological and clinical aspects of tooth avulsion in this study were similar to those reported in other studies. There was a high number of avulsed primary teeth in boys aged less than 4 years and caused by falls.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Syndromes with supernumerary teeth.

    Science.gov (United States)

    Lubinsky, Mark; Kantaputra, Piranit Nik

    2016-10-01

    While most supernumerary teeth are idiopathic, they can be associated with a number of Mendelian syndromes. However, this can also be a coincidental finding, since supernumerary teeth occur in 6% or more of the normal population. To better define this relationship, we analyzed the evidence for specific associations. We excluded conditions with a single affected patient reported, supernumerary teeth adjacent to clefts or other forms of alveolar disruption (as secondary rather than primary findings), and natal teeth, which can involve premature eruption of a normal tooth. Since, the cause of supernumerary teeth shows considerable heterogeneity, certain findings are less likely to be coincidental, such as five or more supernumerary teeth in a single patient, or locations outside of the premaxilla. We found only eight genetic syndromes with strong evidence for an association: cleidocranial dysplasia; familial adenomatous polyposis; trichorhinophalangeal syndrome, type I; Rubinstein-Taybi syndrome; Nance-Horan syndrome; Opitz BBB/G syndrome; oculofaciocardiodental syndrome; and autosomal dominant Robinow syndrome. There is also suggestive evidence of an association with two uncommon disorders, Kreiborg-Pakistani syndrome (craniosynostosis and dental anomalies), and insulin-resistant diabetes mellitus with acanthosisnigricans. An association of a Mendelian disorder with a low frequency manifestation of supernumerary teeth is difficult to exclude without large numbers, but several commonly cited syndromes lacked evidence for clear association, including Hallermann-Streiff syndrome, Fabry disease, Ehlers-Danlos syndrome, Apert and Crouzon syndromes, Zimmermann-Laband syndrome, and Ellis-van Creveld syndrome. © 2016 Wiley Periodicals, Inc. PMID:27250821

  14. [Wisdom teeth: which way to go?].

    Science.gov (United States)

    Yitschaky, O; Segev-Neuhof, M; Laviv, A

    2016-01-01

    The debate regarding prophylactic extraction of mandibular third molar (Wisdom teeth) is not new. There is wide agreement among clinicians and researchers that an extraction in young age is easier and safer, but it may result in overtreatment, which means an unnecessary extraction of teeth that might have been functional and healthy. In order to avoid such overtreatment the clinician is obliged to be able to predict accurately the chances of third molar eruption, years before they are due to erupt. Additionally, the clinician has to estimate the chances for future pathology or infection that will force the patient to extract the tooth in years to come. In order to do so the clinician has to meticulously examine the teeth both clinically (including caries assessment of neighboring teeth, periodontal pocket depth measurements etc.) and radiographically. The purpose of this literature review is to present a balanced approach towards the issue of early prophylactic extraction of mandibular third molar.

  15. 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

  16. Evidence of authentic DNA from Danish Viking Age skeletons untouched by humans for 1,000 years

    DEFF Research Database (Denmark)

    Melchior, Linea; Kivisild, Toomas; Lynnerup, Niels;

    2008-01-01

    , pre-laboratory contamination occurring during excavation and archaeological-/anthropological handling of human remains as well as rapid degradation of authentic DNA after excavation are major obstacles. METHODOLOGY/PRINCIPAL FINDINGS: We avoided some of these obstacles by analyzing DNA from ten Viking...... Age subjects that at the time of sampling were untouched by humans for 1,000 years. We removed teeth from the subjects prior to handling by archaeologists and anthropologists using protective equipment. An additional tooth was removed after standard archaeological and anthropological handling. All pre...... with the "unhandled" teeth and there was no indication of contamination, while the latter was the case with half of the "handled" teeth. The results allowed the unequivocal assignment of a specific haplotype to each of the subjects, all haplotypes being compatible in their character states with a phylogenetic tree...

  17. 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.

  18. 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.

  19. 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...

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. 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 ...

  5. 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 ...

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

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Andre Luis N., E-mail: abarbosa@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Crispim, Verginia R., E-mail: vrcrispim@gmail.com [Coordenacao dos Programas de Pos-Graduacao em Engenharia (UFRJ/CT/COPPE), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    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)

  7. 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)

  8. 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...

  9. 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.

  10. Microleakage of composite resin restoration in cavities prepared by Er,Cr:YSGG laser irradiation and etched bur cavities in primary teeth.

    Science.gov (United States)

    Hossain, Mozammal; Nakamura, Yukio; Yamada, Yoshishige; Murakami, Yoshiko; Matsumoto, Koukichi

    2002-01-01

    In this in vitro study, the surface alterations of enamel and dentin in cavities prepared by Er,Cr:YSGG laser irradiation was investigated by scanning electron microscopy and compared to the microleakage degree after composite resin restoration with etched bur cavities in human primary teeth. The results confirmed that laser cavity surface facilitated a good adhesion with the restorative materials; the acid etch step can be easily avoided with the laser treatment.

  11. 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

    Directory of Open Access Journals (Sweden)

    Giampaolo Piga

    2016-01-01

    Full Text Available 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 (β-TCP phase, otherwise known as whitlockite, clearly ascertained by the X-ray diffraction (XRD patterns collected on the same powdered specimens investigated by ATR-IR. These results point to the need of combining more than one physicochemical technique even if apparently well suitable, in order to verify whether the assumed conditions assessed by spectroscopy are fully maintained in the specimens after temperature and/or mechanical processing.

  12. 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 ...

  13. 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.

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

    Science.gov (United States)

    Khalap, Neha Deepak; Hegde, Vibha; Kokate, Sharad

    2015-01-01

    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. PMID:26752838

  15. 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...

  16. 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)

  17. 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.

  18. 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

  19. 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.

  20. 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

  1. Dentinogenesis imperfecta - hardness and Young's modulus of teeth.

    Science.gov (United States)

    Wieczorek, Aneta; Loster, Jolanta; Ryniewicz, Wojciech; Ryniewicz, Anna M

    2013-01-01

    Dentinogenesis imperfecta type II (DI-II) is the most common dental genetic disease with reported incidence 1 in 8000. Elasticity and hardness of the enamel of teeth are important values which are connected with their resistance to attrition. It is hypothesized that values of physical properties for healthy teeth and teeth with DI-II are different. The aim of the study was to investigate some physical properties of teeth extracted from patients with DI-II in comparison with normal teeth. The material of the study was six teeth: three lower molars, with clinical signs of DI-II, which were extracted due to complications of pulp inflammation and three other lower molars which were extracted for orthodontic reasons - well formed, without any signs of pathology. The surfaces of DI-II and normal teeth were tested on the CSM Instruments Scratch Tester machine (producer CSEM Switzerland) by Oliver and Pharr method. The indenter used was Vicker's VG-73 diamond indenter. Additionally, the Scanning Electron Microscopy (SEM) analysis of the surface of the teeth with DI-II was made. Vickers hardness of the teeth with dental pathology (DI-II) was seven times smaller, and Young's modulus six times smaller than those of healthy teeth. The parameters of hardness and elasticity of enamel of teeth with clinical diagnosis of DI-II were very much smaller than in normal teeth and because of that can be responsible for attrition.

  2. 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.

  3. Fluvial transport potential of shed and root-bearing dinosaur teeth from the late Jurassic Morrison Formation

    Directory of Open Access Journals (Sweden)

    Joseph E. Peterson

    2014-04-01

    Full Text Available Shed dinosaur teeth are commonly collected microvertebrate remains that have been used for interpretations of dinosaur feeding behaviors, paleoecology, and population studies. However, such interpretations may be biased by taphonomic processes such as fluvial sorting influenced by tooth shape: shed teeth, removed from the skull during life, and teeth possessing roots, removed from the skull after death. As such, teeth may behave differently in fluvial systems due to their differences in shape. In order to determine the influence of fluvial processes on the preservation and distribution of shed and root-bearing dinosaur teeth, the hydrodynamic behaviors of high-density urethane resin casts of shed and root-bearing Allosaurus and Camarasaurus teeth were experimentally tested for relative transport distances at increasing flow velocities in an artificial fluviatile environment. Results show that tooth cast specimens exhibited comparable patterns of transport at lower velocities, though the shed Camarasaurus teeth transported considerably farther in medium to higher flow velocities. Two-Way ANOVA tests indicate significant differences in the mean transport distances of tooth casts oriented perpendicular to flow (p < 0.05 with varying tooth morphologies and flow velocities. The differences exhibited in the transportability of shed and root-bearing teeth has important implications for taphonomic reconstructions, as well as future studies on dinosaur population dynamics, paleoecology, and feeding behaviors.

  4. 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

  5. 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.

  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. Replacement of Missing Anterior Teeth in a Patient with Chronic Mouth Breathing and Tongue Thrusting

    Directory of Open Access Journals (Sweden)

    Satheesh B. Haralur

    2013-01-01

    Full Text Available The loss of anterior teeth has serious functional, esthetic disabilities, in addition to compromising the patients' quality of life. Various etiologies can be attributed to the anterior tooth loss, including trauma, caries, and periodontal diseases. The chronic mouth breathing due to nasal adenoids is known to enhance the gingival and periodontal diseases. The dental literature proves the association of nasal breathing, tongue thrusting, and anterior open bite. Arch shape and tooth position are primarily determined by the equilibrium of the forces from tongue and perioral musculature. Increased force from tongue musculature in the tongue thrusting patient leads to flaring of anterior teeth, making them susceptible for periodontal and traumatic tooth loss. Replacement of the anterior teeth in this patient will also help in restoration of anterior guidance, which is critical for the health of temporomandibular joint, posterior teeth, and musculature.

  9. Replacement of missing anterior teeth in a patient with chronic mouth breathing and tongue thrusting.

    Science.gov (United States)

    Haralur, Satheesh B; Al-Qahtani, Ali Saad

    2013-01-01

    The loss of anterior teeth has serious functional, esthetic disabilities, in addition to compromising the patients' quality of life. Various etiologies can be attributed to the anterior tooth loss, including trauma, caries, and periodontal diseases. The chronic mouth breathing due to nasal adenoids is known to enhance the gingival and periodontal diseases. The dental literature proves the association of nasal breathing, tongue thrusting, and anterior open bite. Arch shape and tooth position are primarily determined by the equilibrium of the forces from tongue and perioral musculature. Increased force from tongue musculature in the tongue thrusting patient leads to flaring of anterior teeth, making them susceptible for periodontal and traumatic tooth loss. Replacement of the anterior teeth in this patient will also help in restoration of anterior guidance, which is critical for the health of temporomandibular joint, posterior teeth, and musculature.

  10. 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.

  11. 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...... of a missing tooth based on the best match with our shape model on the known data, and we superior improved reconstructions of our full system....

  12. 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 ...

  13. 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.

  14. 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.

  15. Prevalence of prematurely lost primary teeth in 5–10-year-old children in Thamar city, Yemen: A cross-sectional study

    Science.gov (United States)

    Murshid, Sakhr A.; Al-Labani, Mohammed A.; Aldhorae, Khalid A.; Rodis, Omar M. M.

    2016-01-01

    Objectives: The premature loss of primary teeth is a potential risk factor for poor arch length development. Adequate arch length is important to the progression of the permanent teeth. Poor arch length can lead to crowding, ectopic eruption, or impaction of these teeth. This study is designed to assess the prevalence of premature loss of primary teeth in the 5-10-year-old age group. Materials and Methods: The study group included 185 children, that is, 91 boys and 94 girls. The dental examination was conducted by an experienced examiner under sufficient artificial light. Data including patient age and missing teeth were collected. Descriptive statistics were applied for data analysis, and from the results, Chi-square tests were used at a level of significance of 5% (P < 0.05). Results: We observed a 40.54% prevalence of premature loss of primary teeth with no statistically significant difference between genders. The lower left primary second molar was the most commonly absent tooth in the dental arch (13.5%). Conclusion: The status of premature loss of primary teeth was high in the study group. Implementation of efficient educational and preventive programs to promote oral health would help children maintain a healthy primary dentition and eventually prevent the disturbances in the future development of normal occlusion. Early detection and management of the space problems associated with the early loss of primary teeth would help in reducing malocclusion problems. PMID:27652244

  16. Survey of the caries of deciduous teeth in autistic children of 3-6 years of age in Harbin%哈尔滨市3~6岁孤独症儿童乳牙患龋状况调查

    Institute of Scientific and Technical Information of China (English)

    刘英群; 朱颐馨

    2011-01-01

    目的 探讨3~6岁孤独症儿童乳牙患龋状况及其相关因素,以期为孤独症儿童的龋病防治提供参考.方法 采用整群抽样的方法抽取哈尔滨市3个城区3~6岁孤独症儿童进行问卷调查和口腔检查,问卷调查包括一般人口学特征、饮食习惯、口腔保健意识和行为等方面内容,问卷由儿童家长填写,专人发放与回收;口腔检查采用儿童龋补牙数作为评价儿童乳牙龋病的指标.对检查结果进行统计学分析.结果 共调查孤独症儿童93例(男81例,女12例),患龋率为59%( 55/93),龋均为3.245.随年龄增长,儿童患龋率增加.分析结果显示:母亲龋齿、每天喝甜饮料量、吃甜食频率、睡前吃零食是孤独症儿童龋齿的危险因素;饭后漱口、谁给孩子刷牙、每日刷牙次数、父母文化程度是孤独症儿童龋齿的保护因素.结论 遗传因素、不良饮食习惯及口腔卫生习惯对龋病的发生发展有一定影响,孤独症儿童乳牙龋病及口腔卫生状况的改善有待于家长及医护人员的配合和努力.%Objective To investigate the caries of deciduous teeth in autistic children aged of 3-6 years and its related factors.Methods The 3-6 years-old autistic children from 3 urban areas of Harbin City was investigated by using the cluster sampling method.The investigation included questionnaire and oral examination.Results The data from 93 autistic children (81 boys,12 girls)were analyzed.The caries prevalence rate of 3-6 years old autistic children was 59% (55/93),and the mean decayed and filled teeth was 3.245.The caries prevalence rate increased with age.The results showed that the risk factors for deciduous teeth caries included parental caries,the drinking volume of sweet-drinks each day,frequency of sugar consumption and eating snacks before sleep.The protective factors for the caries included gargling after meals,who brushed teeth for children,daily frequency of brushing teeth and

  17. Are bovine teeth a suitable substitute for human teeth in in vitro studies to assess endotoxin load in root canals?

    Directory of Open Access Journals (Sweden)

    Tiago André Fontoura de MELO

    2015-01-01

    Full Text Available The present study aimed to determine the feasibility of using bovine teeth as a suitable alternative for human teeth, in experiments involving in vitro endotoxin contamination. Twenty bovine central incisors and 20 human single-root premolars had their dental crowns removed and root lengths set at 16 mm. Root canals were prepared up to #60 K-file size and sterilized with cobalt-60 gamma irradiation (20 kGy, 6 h. The teeth were randomly divided into four groups: G1-bovine teeth (bovine negative control, n = 10, G2-human teeth (human negative control, n = 10, G3-bovine teeth, inoculated withEscherichia coli (055:B55 LPS, and G4-human teeth inoculated with E. coli LPS. The G1 and G2 groups were exposed to apyrogenic water. After the teeth had been incubated at 37 °C and atmospheric humidity for 24 h, the samples of solutions in the main canals were collected with apyrogenic absorbent paper tips. LPS levels were quantified using Limulus Amebocyte Lysate assay. The data obtained were statistically analyzed using one-way ANOVA, with a significance level of 5%. A high amount of endotoxin was detected in the inoculated human teeth (G4 when compared to the sterilized teeth (G2, as well as in the inoculated bovine teeth (G3 when compared to the inoculated human teeth (G4. However, there was no statistical difference between bovine teeth before and after the E. coli endotoxin inoculation. Therefore, under the mentioned experimental conditions, the use of bovine teeth should not be a choice for laboratory research on endotoxin contamination.

  18. 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 ...

  19. Long-term survival rate of teeth receiving multidisciplinary endodontic, periodontal and prosthodontic treatments.

    Science.gov (United States)

    Moghaddam, A S; Radafshar, G; Taramsari, M; Darabi, F

    2014-03-01

    Deciding whether to replace or preserve a compromised tooth, even with emerging trends in implant dentistry, is still a common dilemma for practitioners. This study sought to determine the 3- to more than 10-year survival rate of teeth that had undergone endodontic, periodontal and prosthodontic treatments. A total of 245 teeth in 87 patients were clinically and radiographically evaluated. All the teeth had received crown lengthening surgery by a single periodontist. Root canal therapy and prosthodontic procedures were rendered either by specialists or by experienced general dentists. Numbers of lost teeth were recorded and the criteria for hopeless teeth were defined. Survival rate was determined using the Kaplan-Meier estimator. Clinical indices including pocket depth (PD), bleeding index (BI), C/R ratio, position of the restoration margin relative to the gingival margin (RM-GM) and the presence of intra-canal post were compared between different survival groups (10 years) using one-way analysis of variance (anova). Potential predictors of failure were determined using the Cox regression model. The mean ± s.d. of 3-, 5-, 10- and 13-year survival rates was 98 ± 1%, 96 ± 1·6%, 83·1 ± 4·5% and 51·9 ± 14·5%, respectively. The mean PD (P 10-year-survived teeth. Bleeding index and RM-GM showed no significant differences between the groups. C/R ratio and RM-GM position appeared to be the major determinants of tooth loss. The long-term survival rate of multidisciplinary-treated teeth was 83-98% in this specific sample.

  20. 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

  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. The Vikings bare their filed teeth.

    Science.gov (United States)

    Arcini, Caroline

    2005-12-01

    Finds of deliberate dental modification have for the first time been found in archaeological human skeletal material from Europe. The type of modification is a horizontally filed furrow on the frontal upper part of the tooth crown. The furrows are single or, more usually, multiple, and are found on the front teeth in the maxilla. The affected individuals are 24 men from the Viking Age (ca. 800-1050 AD), found in present day Sweden and Denmark. The marks are so well-made that it is most likely they were filed by a person of great skill. The reason for, and importance of, the furrows are obscure. The affected individuals may have belonged to a certain occupational group (such as tradesmen), or the furrows could have been pure decoration.

  3. 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.

  4. 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...... network of social relations provides protection against disability by reducing risk of developing disability....

  5. 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...

  6. 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

  7. Perinatal Complications and Aging Indicators by Midlife

    Science.gov (United States)

    Caspi, Avshalom; Ambler, Antony; Belsky, Daniel W.; Chapple, Simon; Cohen, Harvey Jay; Israel, Salomon; Poulton, Richie; Ramrakha, Sandhya; Rivera, Christine D.; Sugden, Karen; Williams, Benjamin; Wolke, Dieter; Moffitt, Terrie E.

    2014-01-01

    BACKGROUND: Perinatal complications predict increased risk for morbidity and early mortality. Evidence of perinatal programming of adult mortality raises the question of what mechanisms embed this long-term effect. We tested a hypothesis related to the theory of developmental origins of health and disease: that perinatal complications assessed at birth predict indicators of accelerated aging by midlife. METHODS: Perinatal complications, including both maternal and neonatal complications, were assessed in the Dunedin Multidisciplinary Health and Development Study cohort (N = 1037), a 38-year, prospective longitudinal study of a representative birth cohort. Two aging indicators were assessed at age 38 years, objectively by leukocyte telomere length (TL) and subjectively by perceived facial age. RESULTS: Perinatal complications predicted both leukocyte TL (β = −0.101; 95% confidence interval, −0.169 to −0.033; P = .004) and perceived age (β = 0.097; 95% confidence interval, 0.029 to 0.165; P = .005) by midlife. We repeated analyses with controls for measures of family history and social risk that could predispose to perinatal complications and accelerated aging, and for measures of poor health taken in between birth and the age-38 follow-up. These covariates attenuated, but did not fully explain the associations observed between perinatal complications and aging indicators. CONCLUSIONS: Our findings provide support for early-life developmental programming by linking newborns’ perinatal complications to accelerated aging at midlife. We observed indications of accelerated aging “inside,” as measured by leukocyte TL, an indicator of cellular aging, and “outside,” as measured by perceived age, an indicator of declining tissue integrity. A better understanding of mechanisms underlying perinatal programming of adult aging is needed. PMID:25349321

  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. Ultrasound Determination of Gestational Age Using Placental Thickness in Female Dogs: An Experimental Study

    Directory of Open Access Journals (Sweden)

    André Luiz Louzada Maldonado

    2012-01-01

    Full Text Available Objective. To verify if the placental thickness allows determining the gestational age, evaluating the correlation between the referred gestational age with the studied one, and the accuracy of the placental thickness measurement (biometry with fetal morphologic parameters in bitches. Methods. The placental thickness of 336 bitches of diverse breeds was evaluated. Bitches were divided in three groups by body weight: small, medium, and big large size. The gestations pregnancies were evaluated by ultrasound from the third week of gestation. An analysis was performed between the mean values of the gestational age obtained of placental thickness by adjustment of curves and the reported gestational age. Student's t-test was applied to compare the mean of reported and placental thickness gestational age. Significance was defined as P<0.05. Results. A positive and statistically significant correlation exists between the placental thickness and gestational age. The expression that presents the best correlation coefficient and explanation was thickness of placenta = 0.021x gestational age −0.314. Conclusion. It is possible to determine the gestational age in relation to the placental thickness measured by ultrasound in bitches with a satisfactory accuracy in relation to fetal morphologic parameters as gestational vesicle, ribs, or kidneys.

  11. Ultrasound determination of gestational age using placental thickness in female dogs: an experimental study.

    Science.gov (United States)

    Maldonado, André Luiz Louzada; Araujo Júnior, Edward; Mendonça, Débora Sartori; Nardozza, Luciano Marcondes Machado; Moron, Antonio Fernandes; Ajzen, Sérgio Aron

    2012-01-01

    Objective. To verify if the placental thickness allows determining the gestational age, evaluating the correlation between the referred gestational age with the studied one, and the accuracy of the placental thickness measurement (biometry) with fetal morphologic parameters in bitches. Methods. The placental thickness of 336 bitches of diverse breeds was evaluated. Bitches were divided in three groups by body weight: small, medium, and big large size. The gestations pregnancies were evaluated by ultrasound from the third week of gestation. An analysis was performed between the mean values of the gestational age obtained of placental thickness by adjustment of curves and the reported gestational age. Student's t-test was applied to compare the mean of reported and placental thickness gestational age. Significance was defined as P < 0.05. Results. A positive and statistically significant correlation exists between the placental thickness and gestational age. The expression that presents the best correlation coefficient and explanation was thickness of placenta = 0.021x gestational age -0.314. Conclusion. It is possible to determine the gestational age in relation to the placental thickness measured by ultrasound in bitches with a satisfactory accuracy in relation to fetal morphologic parameters as gestational vesicle, ribs, or kidneys. PMID:22848867

  12. Accuracy and precision of estimating age of gray wolves by tooth wear

    Science.gov (United States)

    Gipson, P.S.; Ballard, W.B.; Nowak, R.M.; Mech, L.D.

    2000-01-01

    We evaluated the accuracy and precision of tooth wear for aging gray wolves (Canis lupus) from Alaska, Minnesota, and Ontario based on 47 known-age or known-minimum-age skulls. Estimates of age using tooth wear and a commercial cementum annuli-aging service were useful for wolves up to 14 years old. The precision of estimates from cementum annuli was greater than estimates from tooth wear, but tooth wear estimates are more applicable in the field. We tended to overestimate age by 1-2 years and occasionally by 3 or 4 years. The commercial service aged young wolves with cementum annuli to within ?? 1 year of actual age, but under estimated ages of wolves ???9 years old by 1-3 years. No differences were detected in tooth wear patterns for wild wolves from Alaska, Minnesota, and Ontario, nor between captive and wild wolves. Tooth wear was not appropriate for aging wolves with an underbite that prevented normal wear or severely broken and missing teeth.

  13. Evaluation of enamel damages following orthodontic bracket debonding in fluorosed teeth bonded with adhesion promoter

    Science.gov (United States)

    Baherimoghadam, Tahreh; Akbarian, Sahar; Rasouli, Reza; Naseri, Navid

    2016-01-01

    Objective: To evaluate shear bond strength (SBS) of the orthodontic brackets bonded to fluorosed and nonfluorosed teeth using Light Bond with and without adhesion promoters and compare their enamel damages following debonding. Materials and Methods: In this study, 30 fluorosed (Thylstrup and Fejerskov Index = 4–5) and 30 nonfluorosed teeth were randomly distributed between two subgroups according to the bonding materials: Group 1, fluorosed teeth bonded with Light Bond; Group 2, fluorosed teeth bonded with adhesion promoters and Light Bond; Group 3, nonfluorosed teeth bonded with Light Bond; Group 4, nonfluorosed bonded with adhesion promoters and Light Bond. After bonding, the SBS of the brackets was tested with a universal testing machine. Stereomicroscopic evaluation was performed by unbiased stereology in all teeth to determine the amount of adhesive remnants and the number and length of enamel cracks before bonding and after debonding. The data were analyzed using two-way analysis of variance, Kruskal–Wallis, Wilcoxon Signed Rank, and Mann–Whitney test. Results: While fluorosis reduced the SBS of orthodontic bracket (P = 0.017), Enhance Locus Ceruleus LC significantly increased the SBS of the orthodontic bracket in fluorosed and nonfluorosed teeth (P = 0.039). Significant increasing in the number and length of enamel crack after debonding was found in all four groups. There were no significant differences in the length of enamel crack increased after debonding among four groups (P = 0.768) while increasing in the number of enamel cracks after debonding was significantly different among the four groups (P = 0.023). Teeth in Group 2 showed the highest enamel damages among four groups following debonding. Conclusion: Adhesion promoters could improve the bond strength of orthodontic brackets, but conservative debonding methods for decreasing enamel damages would be necessary. PMID:27095895

  14. 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

  15. 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.

  16. 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.

  17. Root resorption after orthodontic treatment : a study of age factor and prevalence in anterior teeth%正畸前牙牙根吸收的年龄因素及好发牙位的探讨

    Institute of Scientific and Technical Information of China (English)

    田玉楼; 王坤; 王晶; 刘芳; 朴美玲

    2013-01-01

    PURPOSE: To investigate the impact of age factor on root resorption and the prevalence in anterior teeth during orthodontic treatment. METHODS: Sixty extraction cases treated with straight wire appliance were divided into adult group and child group, with 30 cases in each group.The panoramic radiographs pre-treatment and post梩reatment were examined to measure the degrees of root resorption. A total of 360 anterior teeth in each group were evaluated- SPSS 13.0 software package was applied to perform statistical analysis. RESULTS: There was significant difference in root resorption index before and after treatment(P<0.01). The incidence of root resorption increased remarkably after orthodontic treatment There was significant difference in the degree of root resorption in two groups (P<0.01). The prevalence of root resorption in anterior teeth was: upper central incisors, upper lateral incisors, lower central incisors, lower lateral incisors, upper canines and lower canines. CONCLUSIONS: The root resorption in adult patients are more obvious than child patients. The prevalence of root resorption in anterior teeth is different. Moderate or severe root resorption is prone to happen in upper central incisors or lateral incisors in adult patients.%目的:探讨年龄因素对正畸治疗引起牙根吸收的影响及在前牙中的好发牙位,以供临床参考.方法:选择60例拔牙后经直丝弓矫治完成的病例,分为成人组与儿童组,每组各30例.以上、下颌前牙作为研究对象,每组各360颗牙.应用全颌曲面体层片,研究正畸治疗后牙根吸收情况,采用SPSS 13.0软件包对结果进行统计学分析.结果:60例患者正畸治疗前、后牙根吸收指数改变均有统计学意义(P<0.01),正畸治疗后牙根吸收发生率明显升高;成人组与儿童组牙根吸收等级比较有显著差异(P<0.01).上、下前牙各牙位牙根吸收好发顺序是上颌中切牙、上颌侧切牙、下颌中切牙、下颌侧切

  18. Radiographic Follow-Up during Orthodontic Treatment for Early Diagnosis of Sequential Supernumerary Teeth

    Science.gov (United States)

    Suga, Uhana Seifert Guimarães; Terada, Raquel Sano Suga

    2016-01-01

    Most supernumerary teeth are impacted and asymptomatic. Objective. The aim of this paper is to describe two cases of sequential development of supernumerary teeth in the mandibular premolar region, identified during orthodontic treatment. Reports. The first case describes the radiographic follow-up of a female patient that presented a supernumerary tooth at the age of 9 years and 10 months in the right mandibular premolar region, followed by a further supernumerary tooth in the left mandibular premolar region identified at the age of 11 years and 3 months. In the second case, the radiographic follow-up of a male patient demonstrated 3 supernumerary teeth in the premolar region at the age of 16 years. During orthognathic surgery planning at the age of 20 years and 5 months, a supplemental supernumerary tooth was found in the left mandibular region. Conclusion. Considering the late developing of supernumerary premolars, appropriate follow-up with panoramic radiographs of patients with previous experience of supernumerary teeth is essential for early diagnosis of supplemental premolars to prevent possible complications. PMID:27313911

  19. 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...

  20. Fluvial transport potential of shed and root-bearing dinosaur teeth from the late Jurassic Morrison Formation.

    Science.gov (United States)

    Peterson, Joseph E; Coenen, Jason J; Noto, Christopher R

    2014-01-01

    Shed dinosaur teeth are commonly collected microvertebrate remains that have been used for interpretations of dinosaur feeding behaviors, paleoecology, and population studies. However, such interpretations may be biased by taphonomic processes such as fluvial sorting influenced by tooth shape: shed teeth, removed from the skull during life, and teeth possessing roots, removed from the skull after death. As such, teeth may behave differently in fluvial systems due to their differences in shape. In order to determine the influence of fluvial processes on the preservation and distribution of shed and root-bearing dinosaur teeth, the hydrodynamic behaviors of high-density urethane resin casts of shed and root-bearing Allosaurus and Camarasaurus teeth were experimentally tested for relative transport distances at increasing flow velocities in an artificial fluviatile environment. Results show that tooth cast specimens exhibited comparable patterns of transport at lower velocities, though the shed Camarasaurus teeth transported considerably farther in medium to higher flow velocities. Two-Way ANOVA tests indicate significant differences in the mean transport distances of tooth casts oriented perpendicular to flow (p dinosaur population dynamics, paleoecology, and feeding behaviors.

  1. Supernumerary teeth vary depending on gender.

    Science.gov (United States)

    Küchler, Erika Calvano; Costa, Adriana Gomes da; Costa, Marcelo de Castro; Vieira, Alexandre Rezende; Granjeiro, José Mauro

    2011-01-01

    The presence of supernumerary teeth (ST) is a dental developmental anomaly of patterning and morphogenesis. Its variability of morphology, location and developmental timing can shed light on its etiology. In this work we report ST patterns. Orthopantomograms of 1,166 pediatric subjects were examined and the morphology, location and timing of the formation of ST were determined. The frequency of supernumerary teeth in the studied population was 2.3% (n = 27). Twenty-five subjects presented one ST. Maxilla midline was the most commonly affected region (nine cases). We noted high incidence of conical morphology in the midline region. Only teeth with tuberculate morphology presented delayed formation. ST in the midline region occurred more often in males whereas ST in the incisor region were more common in females. In conclusion, ST patterns vary depending on gender. PMID:21359454

  2. Supernumerary teeth vary depending on gender

    Directory of Open Access Journals (Sweden)

    Erika Calvano Küchler

    2011-02-01

    Full Text Available The presence of supernumerary teeth (ST is a dental developmental anomaly of patterning and morphogenesis. Its variability of morphology, location and developmental timing can shed light on its etiology. In this work we report ST patterns. Orthopantomograms of 1,166 pediatric subjects were examined and the morphology, location and timing of the formation of ST were determined. The frequency of supernumerary teeth in the studied population was 2.3% (n = 27. Twenty-five subjects presented one ST. Maxilla midline was the most commonly affected region (nine cases. We noted high incidence of conical morphology in the midline region. Only teeth with tuberculate morphology presented delayed formation. ST in the midline region occurred more often in males whereas ST in the incisor region were more common in females. In conclusion, ST patterns vary depending on gender.

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

    Energy Technology Data Exchange (ETDEWEB)

    Haskell, E.; Kenner, G.; Hayes, R. [Univ. of Utah, Salt Lake City, UT (United States). Center for Applied Dosimetry; Chumak, V.; Shalom, S. [Scientific Center for Radiation Medicine, Kiev (Ukraine)

    1997-03-01

    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, Cheliabinsk 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Haskell, E.; Kenner, G.; Hayes, R. [Center for Applied Dosimetry, Salt Lake City, UT (United States); Chumak, V.; Shalom, S.

    1996-12-31

    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)

  5. 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...

  6. 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.

  7. Interrelationships in the Variability of Root Canal Anatomy among the Permanent Teeth: A Full-Mouth Approach by Cone-Beam CT

    Science.gov (United States)

    Peters, Ove A.; Maury, Elisabeth; Telmon, Norbert; Georgelin-Gurgel, Marie; Maret, Delphine

    2016-01-01

    Objectives In endodontic practice, clinicians should be aware of possible root canal anatomic variations. The aim of this study was to assess using CBCT acquisitions regarding whether one root canal anatomy of a tooth is associated with a specific anatomy of another tooth. Methods A total of 106 CBCT acquisitions were obtained using a CBCT scanner with 200μm voxel size. Numbers of roots and canals of the entire dentition were described. Bivariate analyses and logistic regressions were conducted to explore root canal anatomy on one tooth according to age, gender, jaw, side and the others teeth. Multiple correspondence analysis (MCA) was performed to correlate the different numbers of canals profiles. Results A total of 2424 teeth were analyzed. Independently from the other variables, the presence of an additional root canal on a mandibular incisor increases the risk of having an additional root canal on a mandibular premolar (OR [95%] 3.7 [1.0;13.2]). The mandibular molar variability increases in women compared to men (OR [95%] 0.4 [0.1; 0.9]). MCA showed correspondence between 2-canals maxillary incisor and canines and 5-canals maxillary molars, and some correlation between additional canal on maxillary and mandibular premolars. Conclusions Although CBCT examinations are conducted in the first intention of making a diagnosis or prognostic evaluation, medium FOV acquisitions could be used as an initial database thus furnishing preliminary evaluations and information. In endodontic practice, clinicians should be aware of possible root canal anatomic variations. The visualization of all canals is considered essential in endodontic therapy. The use of multi-correspondence analysis for statistics in endodontic research is a new approach as a prognostic tool. PMID:27764246

  8. 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.

  9. 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...

  10. 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...

  11. 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

  12. Eruption of teeth into crowded position, loss of attachment, and downgrowth of subgingival plaque.

    Science.gov (United States)

    Waerhaug, J

    1980-10-01

    The role of crowded teeth in the etiology of attachment loss was studied in thirty teeth extracted for orthodontic reasons from eight children 12 to 13 years of age. Following extraction, the teeth were stained in a 1 percent solution of water blue and examined under the stereomicroscope. In one third of the thirty teeth, a 0.9, 2.0, and 3.5 mm. loss of attachment was observed on surfaces adjacent to which another tooth had erupted into an extremely crowded environment. On the same surfaces, subgingival plaque had grown down to the area of the cementoenamel junction. The premature loss of attachment was assumed to be mediated by collagenase derived from the regressing dental organ or from the junctional epithelium surrounding the erupting teeth. The premature downgrowth of subgingival plaque to the area of the cementoenamel junction was facilitated by the development of an irregular contact line within the interdental papilla, rather than a contact point above the papilla.

  13. 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)

  14. 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...... diversity in social relations and high social participation were important factors for maintaining functional ability among the 75-year-old men and women, while social support was a risk factor for functional decline among the 80-year-old men. The present study suggests that being "embedded" in a strong...

  15. Determination of age and its correlation with biometric variables and seasonal reproductive indices of Leporinus obtusidens

    Directory of Open Access Journals (Sweden)

    Viviane de Oliveira Felizardo

    2015-07-01

    Full Text Available This study determined the age and its correlation with biometric variables and reproductive indices of piapara Leporinus obtusidens caught at the Funil Reservoir. We caught 133 specimens between September 2006 and August 2007. Weight, total length, standard length, depth, height, head length and radius of the scales were measured. The sex was determined by macroscopic examination of gonads. The age of each fish was determined by analyzing the growth rings on the scales. Seasonal differences in biometric variables were tested using the NK test at 5%. The correlation of age and radius of the scales with the biometric variables and reproductive indices were analyzed using the SAEG software. Fish individuals ranging from 3 to 14 years of age were caught. In the spring and summer, smaller fish were captured compared to those caught during the fall and winter. Females tended to have higher weight and morphometric values when compared to males. Age and radius of the scales were correlated with biometric variables in L. obtusidens. It can be concluded that the biometric variables of this species can be used as an indicator of age.

  16. 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.

  17. 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...

  18. 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

  19. Determination of fetal thymic morphometric dimensions in relation to gestational age.

    Directory of Open Access Journals (Sweden)

    Carmen Niurka Piña Loyola

    2010-07-01

    Full Text Available Background: the appropriate relationship between gestational age and fetal weight are variables that reflect the intrauterine development and fetal welfare. There are studies that have attempted to establish morphological patterns of the thymus in relation to gestational age and who report dissimilar values. Objective: To determine the morphometric dimensions of the thymus in relation to gestational age. Methods: A descriptive, observational case series conducted in the period May 2003 to May 2008 in General Hospital Universitario "Dr. Gustavo Lima Aldereguía "of Cienfuegos. The sample consisted of 147 scams dead fetuses from 17 weeks gestational age until the end, who met the inclusion criteria. Body measurements were made such as: weight, height, width, thickness and volume. Results: We observed a progressive increase of all the morphometric dimensions of the thymus in relation to higher gestational age, marked in the late fetal stage where the values are doubled. The weight, height and volume were lower thymic 80% of the sample. For 90% of cases the thickness of the organ was below 5 mm and width, regardless of gestational age was less than 20 mm by 50%, and the remaining 50% of 20-50 mm. Conclusions: determined morphometric dimensions of the thymus and showed a gradual increase of these in relation to gestational age and fetal weight.

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

    Science.gov (United States)

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

    2016-02-26

    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 and 1 = at least one lost primary tooth. The prevalence of at least one missing tooth was 24.7% (n = 206) (95% CI = 21.8-27.7). The variables that were associated with the prevalence of tooth loss (p teeth (OR = 1.11), the largest number of filled teeth (OR = 1.23), the worst oral hygiene (OR = 3.24), a lower frequency of brushing (OR = 1.60), an increased consumption of soda (OR = 1.89) and use of dental care (curative: OR = 2.83, preventive: OR = 1.93). This study suggests that the premature loss of teeth in the primary dentition is associated with oral hygiene, consumption of soft drinks, dental care and previous caries experience in Mexican schoolchildren. These data provide relevant information for the design of preventive dentistry programs.

  1. 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

  2. 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

  3. 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.

  4. Age estimation by dental developmental stages in children and adolescents in Iceland.

    Science.gov (United States)

    Vidisdottir, Sigridur Rosa; Richter, Svend

    2015-12-01

    Studies have shown that it is necessary to create a database for dental maturity for every population and compare it to others. The present study is the first one for dental development in the Icelandic population the age range being 4-24 years. It will help in forensic dental age estimation and will also help dentists, physicians, anthropologists, archaeologists and other professionals who rely on developmental age assessment in children and adolescents. In this present retrospective cross-sectional study, dental maturity was determined in 1100 Icelandic children and adolescents from orthopantomograms (OPGs). The first 100 were used for a pilot study and the remaining 1000 for the main study. A total of 23 subjects were excluded. The sample consisted of 508 girls and 469 boys from the age of 4-24 years and a dental developmental scoring system was used as a standard for determination of dental maturity stages. A total of 200 OPGs were studied both on the left and right side and the remaining on the right side. Dental maturity was established for all teeth and both genders, when the sample permitted, from the beginning of crown formation to the root apex closure. The Cronbach's Alpha reliability test showed high reliability, R=0.982. Girls in Iceland reach dental maturity root completed (stage 10, Rc) at 17.81 years of age for the maxillary and at 18.47 years for the mandibular teeth. Boys reach dental maturity root completed (stage 10, Rc) at 18.00 years of age in the maxilla and 17.63 in the mandible. There was no significant difference between left and right side (r=0.95-1.00) and there was no gender difference, except in root formation in maxillary and mandibular canines where girls reached root completed earlier than boys. A reliable database has been established in Iceland for tooth development in the age range of 4-24 years, which is compatible with international studies. These results will help forensic odontologists and other professionals to estimate with

  5. 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

  6. 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

  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. 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. Midlife Determinants Associated with Sedentary Behavior in Old Age

    DEFF Research Database (Denmark)

    van der Berg, Julianne D; Bosma, Hans; Caserotti, Paolo;

    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...

  10. 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

  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. 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.

  13. 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....

  14. Aging related changes in determinants of muscle force generating capacity: a comparison of muscle aging in men and male rodents.

    Science.gov (United States)

    Ballak, Sam B; Degens, Hans; de Haan, Arnold; Jaspers, Richard T

    2014-03-01

    Human aging is associated with a progressive decline in skeletal muscle mass and force generating capacity, however the exact mechanisms underlying these changes are not fully understood. Rodents models have often been used to enhance our understanding of mechanisms of age-related changes in human skeletal muscle. However, to what extent age-related alterations in determinants of muscle force generating capacity observed in rodents resemble those in humans has not been considered thoroughly. This review compares the effect of aging on muscle force generating determinants (muscle mass, fiber size, fiber number, fiber type distribution and muscle specific tension), in men and male rodents at similar relative age. It appears that muscle aging in male F344*BN rat resembles that in men most; 32-35-month-old rats exhibit similar signs of muscle weakness to those of 70-80-yr-old men, and the decline in 36-38-month-old rats is similar to that in men aged over 80 yrs. For male C57BL/6 mice, age-related decline in muscle force generating capacity seems to occur only at higher relative age than in men. We conclude that the effects on determinants of muscle force differ between species as well as within species, but qualitatively show the same pattern as that observed in men.

  15. 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)

  16. Determining Ages of APOGEE Giants with Known Distances

    CERN Document Server

    Feuillet, Diane K; Holtzman, Jon; Girardi, Leo; MacDonald, Nick; Majewski, Steven R; Nidever, David L

    2015-01-01

    We present a sample of local red giant stars observed using the New Mexico State University 1 m telescope with the APOGEE spectrograph, for which we estimate stellar ages and the age distribution from the high-resolution spectroscopic stellar parameters and accurate distance measurements from Hipparcos. The high-resolution (R ~ 23,000), near infrared (H-band, 1.5-1.7 micron) APOGEE spectra provide measurements of the stellar atmospheric parameters (temperature, surface gravity, [M/H], and [alpha/M]). Due to the smaller uncertainties in surface gravity possible with high-resolution spectra and accurate Hipparcos distance measurements, we are able to calculate the stellar masses to within 40%. For red giants, the relatively rapid evolution of stars up the red giant branch allows the age to be constrained based on the mass. We examine methods of estimating age using both the mass-age relation directly and a Bayesian isochrone matching of measured parameters, assuming a constant star formation history (SFH). To i...

  17. 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.

  18. 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 ...

  19. 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.

  20. Aging process on spectrally determined spontaneous baroreflex sensitivity: a 5-year prospective study.

    Science.gov (United States)

    Fauvel, Jean-Pierre; Cerutti, Catherine; Mpio, Ignace; Ducher, Michel

    2007-09-01

    The interindividual age-related decrease in baroreflex sensitivity (BRS) was reported in many cross-sectional studies. However, the long-term intraindividual decrease in BRS has never been confirmed by longitudinal studies. Data obtained from a 5-year prospective study designed to assess the 5-year stress effects on blood pressure (BP) provided the opportunity to assess longitudinal aging process on spectrally determined BRS (S-BRS) using the cross spectral analysis. This analysis was carried out in 205 men aged between 18 and 50 years who had 2 valid beat to beat BP recordings (Finapress) at a mean 5-year interval. At inclusion and at end of follow-up, S-BRS was significantly correlated with age (r=-0.50, P<0.001, r=-0.33, P<0.001 respectively). Interestingly, the slopes and the intercepts were not significantly different at a 5-year interval. This result is in favor of the good reproducibility of S-BRS. The attenuation with age of S-BRS was calculated at 3.6% a year. This decrease was slightly higher than the one obtained with the baseline data (2.3% per year). This longitudinal study provided, for the first time, an estimate of the slope of the age-related physiological S-BRS decrease in a mid-aged healthy male population. Our findings reinforce the interest of evaluating spontaneous BRS reported to predict hypertension and cardiovascular events in various populations.

  1. 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)

  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. 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

  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. 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. 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

  8. 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.

  9. 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.

  10. 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

  11. 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...

  12. 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 ...

  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. 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.

  15. 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.

  16. 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...

  17. 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...

  18. 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.

  19. 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…

  20. 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.

  1. Age as a determinant of reproductive success among captive female rhesus macaques (Macaca mulatta).

    Science.gov (United States)

    Gagliardi, Christine; Liukkonen, John R; Phillippi-Falkenstein, Kathrine M; Harrison, Richard M; Kubisch, H Michael

    2007-04-01

    A retrospective analysis was performed on fertility outcomes among a colony of captive Indian rhesus monkeys. The analysis covered over 30 years and was based on 1443 females with a total of 11,453 pregnancies. Various determinants of fertility were assessed including birth rates, pregnancy loss, infant survival, interbirth intervals, and interval from last birth to death. Binary variables were analyzed with generalized linear models with random intercepts, while linear mixed models were used for analysis of continuous variables. Age of the dam was a significant factor in determining whether a pregnancy resulted in a birth and whether an infant survived the first 30 days with primiparous or older mothers being less likely to produce an infant surviving to that age. In contrast, sex proved to be the only significant factor in determining whether an infant lived to 1 year, with females being more likely to survive. The interval between births proved to be affected primarily by dam age, while the late death of an infant depressed the likelihood of an extended time interval between her last birth and her death. Overall, these results demonstrate that maternal age contributes significantly to a decline in fertility and older females can live relatively long periods following birth of their last infant. PMID:17504925

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Application of electrical test in diagnosis of ambiguous teeth involved by cyst of jaws%牙髓活力电测仪检测法在颌骨囊肿受累牙诊断中的应用

    Institute of Scientific and Technical Information of China (English)

    王敬旭; 高平; 刘海潮

    2011-01-01

    术前用牙髓活力电测仪对颌骨囊肿可疑受累牙进行活力测试,记录牙髓活力状态,并对无活力或活力显著下降牙行一次性根管治疗;术中记录可疑受累牙实际受累情况.结果发现牙髓活力电测仪诊断颌骨囊肿可疑受累牙的准确率为93.2%.提示牙髓活力电测仪在颌骨囊肿可疑受累牙诊断中具有参考价值.%178 jaw cyst involved teeth were diagnosed by roentgenogram. Dental pulp vitality of the teeth was examined by Neosono Co-pilot Pulp Tester and the teeth were treated by root canal thearapy before surgical removal of the cysts. During operation 121 teeth were observed to be involved in the cysts and 113 out off the 121 (93.2%) had been found without or with decreased pulp vitality before treatment.

  7. Age determinations in the Precambrian basement of the Wadi Araba area, southwest Jordan

    Energy Technology Data Exchange (ETDEWEB)

    Jarrar, G. (Jordan Univ., Amman. Dept of Geology); Baumann, A. (Muenster Univ. (Germany, F.R.). Inst. fuer Mineralogie, Mineralogisches Museum); Wachendorf, H. (Technische Univ. Braunschweig (Germany, F.R.). Inst. fuer Geologie und Palaeontologie)

    1983-05-01

    The Precambrian basement of Jordan belongs to the northern margin of the Arabian-Nubian Shield. Age determinations by U-Pb isotopic analyses on sized and magnetic zircon fractions, a monazite and an apatite sample and by Rb-Sr isotopic studies on whole-rocks and minerals of metasedimentary rocks, granodiorites, granites and dykes have elucidated the following events: (1) A major regional high-grade metamorphism accompanied by magmatization and synkinematic plutonism occurred at about 800 Ma according to U-Pb zircon ages of metasediments and granites. (2) During a postkinematic plutonic event between 615 and 600 Ma extensive masses of granodioritic to granitic composition and dykes were emplaced. The U-Pb data of zircons of the rocks yielded upper intercept ages with the concordia consistent with RbSr biotite ages. The Rb-Sr mineral ages of the older metasedimentary rocks document the resetting of the Rb-Sr system due to the thermal pulse at this time. (3) A younger plutonic event produced diorites and dykes at about 570 Ma. The plutonic events are related to the Pan-African orogenic phase. The low initial /sup 87/Sr//sup 86/Sr ratios of the plutonic rocks (0.7032-0.7046) correspond to values reported from equivalent rocks throughout the Arabian-Nubian Shield and suggest that no significant portions of ancient sialic crustal material contributed to the generation of the granitic to granodioritic magmas.

  8. Age determinations in the Precambrian basement of the Wadi Araba area, southwest Jordan

    Science.gov (United States)

    Jarrar, Ghaleb; Baumann, Albrecht; Wachendorf, Horst

    1983-05-01

    The Precambrian basement of Jordan belongs to the northern margin of the Arabian-Nubian Shield. Age determinations by U-Pb isotopic analyses on sized and magnetic zircon fractions, a monazite and an apatite sample and by Rb-Sr isotopic studies on whole-rocks and minerals of metasedimentary rocks, granodiorites, granites and dykes have elucidated the following events: (1)A major regional high-grade metamorphism accompanied by migmatization and synkinematic plutonism occurred at about 800 Ma according to U-Pb zircon ages of metasediments and granites. (2)During a postkinematic plutonic event between 615 and 600 Ma extensive masses of granodioritic to granitic composition and dykes were emplaced. The U-Pb data of zircons of the rocks yielded upper intercept ages with the concordia consistent with Rb-Sr biotite ages. The Rb-Sr mineral ages of the older metasedimentary rocks document the resetting of the Rb-Sr system due to the thermal pulse at this time. (3)A younger plutonic event produced diorites and dykes at about 570 Ma. The plutonic events are related to the Pan-African orogenic phase. The low initial 87Sr/ 86Sr ratios of the plutonic rocks (0.7032-0.7046) correspond to values reported from equivalent rocks throughout the Arabian-Nubian Shield and suggest that no significant portions of ancient sialic crustal material contributed to the generation of the granitic to granodioritic magmas.

  9. 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

  10. 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...

  11. Determination of the age of the earth from Kamland measurement of geo-neutrinos

    OpenAIRE

    Mohanty, Subhendra

    2003-01-01

    The low energy component of the antineutrino spectrum observed in the recent Kamland experiment has significant contribution from the radioactive decay of $^{238}U$ and $^{232}Th$ in the crust and mantle of the earth. By taking the ratio of the antineutrino events obeserved in two different energy ranges we can determine the present value $[Th/U]$ independent of the U,Th distribution in the earth. Comparing with the r-process initial value of $[Th/U]_0$ we determine the age of the earth as a ...

  12. 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...

  13. 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...

  14. 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.

  15. 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.

  16. Lateral incisor agenesis, canine impaction and characteristics of supernumerary teeth in a South European male population

    OpenAIRE

    Livas, Christos; Bornstein, Michael; Delli, Konstantina

    2013-01-01

    Objective: To assess the prevalence of lateral incisor agenesis impacted canines and supernumerary teeth in a young adult male population. Materials and Methods: The panoramic radiographs of 1745 military students (mean age: 18.6 ± 0.52 years) who attended the Center of Aviation Medicine of the Armed Forces of Greece during the period 1997-2011 were initially analyzed for lateral incisor agenesis by two observers. After exclusion of the known orthodontic cases, a subgroup of 1636 examinees (m...

  17. 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; Bohlen, Stefan; Bonelli, Raphael M.; Bos, Reineke; Bourne, Colin; Bradbury, Alyson; Brockie, Peter; Brown, Felicity; Bruno, Stefania; Bryl, Anna; Buck, Andrea; Burg, Sabrina; Burgunder, Jean-Marc; Burns, Peter; Burrows, Liz; Busquets, Nuria; Busse, Monica; Calopa, Matilde; Carruesco, Gemma T.; Casado, Ana Gonzalez; Catena, Judit López; Chu, Carol; Ciesielska, Anna; Clapton, Jackie; Clayton, Carole; Clenaghan, Catherine; Coelho, Miguel; Connemann, Julia; Craufurd, David; Crooks, Jenny; Cubillo, Patricia Trigo; Cubo, Esther; Curtis, Adrienne; De Michele, Giuseppe; De Nicola, A.; de Souza, Jenny; de Weert, A. Marit; de Yébenes, Justo Garcia; Dekker, M.; Descals, A. Martínez; Di Maio, Luigi; Di Pietro, Anna; Dipple, Heather; Dose, Matthias; Dumas, Eve M.; Dunnett, Stephen; Ecker, Daniel; Elifani, F.; Ellison-Rose, Lynda; Elorza, Marina D.; Eschenbach, Carolin; Evans, Carole; Fairtlough, Helen; Fannemel, Madelein; Fasano, Alfonso; Fenollar, Maria; Ferrandes, Giovanna; Ferreira, Jaoquim J.; Fillingham, Kay; Finisterra, Ana Maria; Fisher, K.; Fletcher, Amy; Foster, Jillian; Foustanos, Isabella; Frech, Fernando A.; Fullam, Robert; Fullham, Ruth; Gago, Miguel; García, RocioGarcía-Ramos; García, Socorro S.; Garrett, Carolina; Gellera, Cinzia; Gill, Paul; Ginestroni, Andrea; Golding, Charlotte; Goodman, Anna; Gørvell, Per; Grant, Janet; Griguoli, A.; Gross, Diana; Guedes, Leonor; BascuñanaGuerra, Monica; Guerra, Maria Rosalia; Guerrero, Rosa; Guia, Dolores B.; Guidubaldi, Arianna; Hallam, Caroline; Hamer, Stephanie; Hammer, Kathrin; Handley, Olivia J.; Harding, Alison; Hasholt, Lis; Hedge, Reikha; Heiberg, Arvid; Heinicke, Walburgis; Held, Christine; Hernanz, Laura Casas; Herranhof, Briggitte; Herrera, Carmen Durán; Hidding, Ute; Hiivola, Heli; Hill, Susan; Hjermind, Lena. E.; Hobson, Emma; Hoffmann, Rainer; Holl, Anna Hödl; Howard, Liz; Hunt, Sarah; Huson, Susan; Ialongo, Tamara; Idiago, Jesus Miguel R.; Illmann, Torsten; Jachinska, Katarzyna; Jacopini, Gioia; Jakobsen, Oda; Jamieson, Stuart; Jamrozik, Zygmunt; Janik, Piotr; Johns, Nicola; Jones, Lesley; Jones, Una; Jurgens, Caroline K.; Kaelin, Alain; Kalbarczyk, Anna; Kershaw, Ann; Khalil, Hanan; Kieni, Janina; Klimberg, Aneta; Koivisto, Susana P.; Koppers, Kerstin; Kosinski, Christoph Michael; Krawczyk, Malgorzata; Kremer, Berry; Krysa, Wioletta; Kwiecinski, Hubert; Lahiri, Nayana; Lambeck, Johann; Lange, Herwig; Laver, Fiona; Leenders, K.L.; Levey, Jamie; Leythaeuser, Gabriele; Lezius, Franziska; Llesoy, Joan Roig; Löhle, Matthias; López, Cristobal Diez-Aja; Lorenza, Fortuna; Loria, Giovanna; Magnet, Markus; Mandich, Paola; Marchese, Roberta; Marcinkowski, Jerzy; Mariotti, Caterina; Mariscal, Natividad; Markova, Ivana; Marquard, Ralf; Martikainen, Kirsti; Martínez, Isabel Haro; Martínez-Descals, Asuncion; Martino, T.; Mason, Sarah; McKenzie, Sue; Mechi, Claudia; Mendes, Tiago; Mestre, Tiago; Middleton, Julia; Milkereit, Eva; Miller, Joanne; Miller, Julie; Minster, Sara; Möller, Jens Carsten; Monza, Daniela; Morales, Blas; Moreau, Laura V.; Moreno, Jose L. López-Sendón; Münchau, Alexander; Murch, Ann; Nielsen, Jørgen E.; Niess, Anke; Nørremølle, Anne; Novak, Marianne; O'Donovan, Kristy; Orth, Michael; Otti, Daniela; Owen, Michael; Padieu, Helene; Paganini, Marco; Painold, Annamaria; Päivärinta, Markku; Partington-Jones, Lucy; Paterski, Laurent; Paterson, Nicole; Patino, Dawn; Patton, Michael; Peinemann, Alexander; Peppa, Nadia; Perea, Maria Fuensanta Noguera; Peterson, Maria; Piacentini, Silvia; Piano, Carla; Càrdenas, Regina Pons i; Prehn, Christian; Price, Kathleen; Probst, Daniela; Quarrell, Oliver; Quiroga, Purificacion Pin; Raab, Tina; Rakowicz, Maryla; Raman, Ashok; Raymond, Lucy; Reilmann, Ralf; Reinante, Gema; Reisinger, Karin; Retterstol, Lars; Ribaï, Pascale; Riballo, Antonio V.; Ribas, Guillermo G.; Richter, Sven; Rickards, Hugh; Rinaldi, Carlo; Rissling, Ida; Ritchie, Stuart; Rivera, Susana Vázquez; Robert, Misericordia Floriach; Roca, Elvira; Romano, Silvia; Romoli, Anna Maria; Roos, Raymond A.C.; Røren, Niini; Rose, Sarah; Rosser, Elisabeth; Rosser, Anne; Rossi, Fabiana; Rothery, Jean; Rudzinska, Monika; Ruíz, Pedro J. García; Ruíz, Belan Garzon; Russo, Cinzia Valeria; Ryglewicz, Danuta; Saft, Carston; Salvatore, Elena; Sánchez, Vicenta; Sando, Sigrid Botne; Šašinková, Pavla; Sass, Christian; Scheibl, Monika; Schiefer, Johannes; Schlangen, Christiane; Schmidt, Simone; Schöggl, Helmut; Schrenk, Caroline; Schüpbach, Michael; Schuierer, Michele; Sebastián, Ana Rojo; Selimbegovic-Turkovic, Amina; Sempolowicz, Justyna; Silva, Mark; Sitek, Emilia; Slawek, Jaroslaw; Snowden, Julie; Soleti, Francesco; Soliveri, Paola; Sollom, Andrea; Soltan, Witold; Sorbi, Sandro; Sorensen, Sven Asger; Spadaro, Maria; Städtler, Michael; Stamm, Christiane; Steiner, Tanja; Stokholm, Jette; Stokke, Bodil; Stopford, Cheryl; Storch, Alexander; Straßburger, Katrin; Stubbe, Lars; Sulek, Anna; Szczudlik, Andrzej; Tabrizi, Sarah; Taylor, Rachel; Terol, Santiago Duran-Sindreu; Thomas, Gareth; Thompson, Jennifer; Thomson, Aileen; Tidswell, Katherine; Torres, Maria M. Antequera; Toscano, Jean; Townhill, Jenny; Trautmann, Sonja; Tucci, Tecla; Tuuha, Katri; Uhrova, Tereza; Valadas, Anabela; van Hout, Monique S.E.; van Oostrom, J.C.H.; van Vugt, Jeroen P.P.; vanm, Walsem Marleen R.; Vandenberghe, Wim; Verellen-Dumoulin, Christine; Vergara, Mar Ruiz; Verstappen, C.C.P.; Verstraelen, Nichola; Viladrich, Celia Mareca; Villanueva, Clara; Wahlström, Jan; Warner, Thomas; Wehus, Raghild; Weindl, Adolf; Werner, Cornelius J.; Westmoreland, Leann; Weydt, Patrick; Wiedemann, Alexandra; Wild, Edward; Wild, Sue; Witjes-Ané, Marie-Noelle; Witkowski, Grzegorz; Wójcik, Magdalena; Wolz, Martin; Wolz, Annett; Wright, Jan; Yardumian, Pam; Yates, Shona; Yudina, Elizaveta; Zaremba, Jacek; Zaugg, Sabine W.; Zdzienicka, Elzbieta; Zielonka, Daniel; Zielonka, Euginiusz; Zinzi, Paola; Zittel, Simone; Zucker, Birgrit; Adams, John; Agarwal, Pinky; Antonijevic, Irina; Beck, Christopher; Chiu, Edmond; Churchyard, Andrew; Colcher, Amy; Corey-Bloom, Jody; Dorsey, Ray; Drazinic, Carolyn; Dubinsky, Richard; Duff, Kevin; Factor, Stewart; Foroud, Tatiana; Furtado, Sarah; Giuliano, Joe; Greenamyre, Timothy; Higgins, Don; Jankovic, Joseph; Jennings, Dana; Kang, Un Jung; Kostyk, Sandra; Kumar, Rajeev; Leavitt, Blair; LeDoux, Mark; Mallonee, William; Marshall, Frederick; Mohlo, Eric; Morgan, John; Oakes, David; Panegyres, Peter; Panisset, Michel; Perlman, Susan; Perlmutter, Joel; Quaid, Kimberly; Raymond, Lynn; Revilla, Fredy; Robertson, Suzanne; Robottom, Bradley; Sanchez-Ramos, Juan; Scott, Burton; Shannon, Kathleen; Shoulson, Ira; Singer, Carlos; Tabbal, Samer; Testa, Claudia; van, Kammen Dan; Vetter, Louise; Walker, Francis; Warner, John; Weiner, illiam; Wheelock, Vicki; Yastrubetskaya, Olga; Barton, Stacey; Broyles, Janice; Clouse, Ronda; Coleman, Allison; Davis, Robert; Decolongon, Joji; DeLaRosa, Jeanene; Deuel, Lisa; Dietrich, Susan; Dubinsky, Hilary; Eaton, Ken; Erickson, Diane; Fitzpatrick, Mary Jane; Frucht, Steven; Gartner, Maureen; Goldstein, Jody; Griffith, Jane; Hickey, Charlyne; Hunt, Victoria; Jaglin, Jeana; Klimek, Mary Lou; Lindsay, Pat; Louis, Elan; Loy, Clemet; Lucarelli, Nancy; Malarick, Keith; Martin, Amanda; McInnis, Robert; Moskowitz, Carol; Muratori, Lisa; Nucifora, Frederick; O'Neill, Christine; Palao, Alicia; Peavy, Guerry; Quesada, Monica; Schmidt, Amy; Segro, Vicki; Sperin, Elaine; Suter, Greg; Tanev, Kalo; Tempkin, Teresa; Thiede, Curtis; Wasserman, Paula; Welsh, Claire; Wesson, Melissa; Zauber, Elizabeth

    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

  18. Teeth of the red fox Vulpes vulpes (L., 1758) as a bioindicator in studies on fluoride pollution.

    Science.gov (United States)

    Kalisińska, Elżbieta; Palczewska-Komsa, Mirona

    2011-10-01

    An examination was made of fluoride content in the mandibular first molars of the permanent teeth of the red fox Vulpes vulpes living in north-west (NW) Poland. The teeth were first dried to a constant weight at 105°C and then ashed. Fluorides were determined potentiometrically, and their concentrations were expressed in dry weight (DW) and ash. The results were used to perform an indirect estimation of fluoride pollution in the examined region of Poland. The collected specimens (n = 35) were classified into one of the three age categories: immature (im, 6-12 months), subadult (subad, from 12 to 20 months) and adult (ad, >20 months). The mean concentrations (geometric mean) of fluoride were similar in the im and subad groups (230 and 296 mg/kg DW and 297 and 385 mg/kg ash, respectively), and significantly smaller than in the ad group (504 and 654 mg/kg, respectively, in DW and ash). Basing on other reports that the ∼400 mg/kg DW concentration of fluoride in bones in the long-lived wild mammals generally reflects the geochemical background, it was found that 57% of the foxes in NW Poland exceeded this value by 9% to 170%. This indirectly reflects a moderate fluoride contamination in the tested region. PMID:21957316

  19. 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...

  20. 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.

  1. 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).

  2. 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)

  3. An observational study of the frequency of supernumerary teeth in a population of 2000 patients

    OpenAIRE

    Leco Berrocal, María Isabel; Martín Morales, José F.; Martínez González, José María

    2007-01-01

    An evaluation is made of the epidemiological characteristics of supernumerary teeth, with an analysis of the associated clinical-eruptive complications. A longitudinal observational study was made of 2000 patients, with the documentation of demographic data, the presence of supernumerary teeth, their location, mechanical accidents and the presence of associated pathology. The presence of supernumerary teeth was recorded in 1.05% of the study subjects (mean age 20.2 years), with a greater freq...

  4. 不同年生西洋参中20种有机氯农药的气相色谱分析%Determination of Organochlorine Pesticides in Panax quinquefolium L. with Different Ages by Gas Chromatography

    Institute of Scientific and Technical Information of China (English)

    秦公伟; 曹小勇; 耿敬章; 张静; 陈玉芳; 陈富东

    2012-01-01

    a high performance gas chromatography method has been developed for determining 20 kinds of organochlorine pesticides including α-BHC and 4,4'-DDT in American ginseng(Panax quinquefolium L.) grown in different areas of GAP plantation base from Liuba county,shaanxi province.The accumulation of organochlorine pesticides in American ginseng with different ages was also explored.Organochlorine pesticides in samples were extracted by hexane-ethyl acetate(1:1) solution,and then purified by a column packed with Florisil using hexane-ethyl acetate(1:1) as elution solvent.Chromatographic analysis was performed on a DB-17 capillary column supplemented with electron capture detector(ECD).A total of 19 organochlorine pesticides except for endrin were detected.The contents of organochlorine pesticides in samples from different areas revealed an obvious difference.Moreover,the residues of organochlorine pesticides in four-year-old American ginseng were higher than those in three-year-old or five-year-old American ginseng.Therefore,this developed method is effective,fast and accurate,which can be used for determining 20 kinds of organochlorine pesticides in American ginseng.%建立西洋参中α-六六六(α-BHC)、4,4'-滴滴涕(4,4'-DDT)等20种有机氯农药残留量的一种简便有效的气相色谱分析方法,对陕西留坝县西洋参GAP生产基地不同种植地块、不同生长年限西洋参中有机氯农药的种类和含量进行测定,并探讨不同生长年限西洋参中有机氯农药富集规律。样品有机氯农药残留用正己烷-乙酸乙酯(1:1)溶液提取,通过弗罗里硅土小柱净化,正己烷-乙酸乙酯(1:1)溶液洗脱后浓缩定容,采用DB-17毛细管柱分离,气相色谱-电子捕获检测器(gas chromatography-electron capture detector,GC-ECD)检测,以保留时间定性,外标法定量。结果表明:10个西洋参样品中除异狄氏剂未检出外,标准溶液中的其他19

  5. Determination of the lactate threshold and maximal blood lactate steady state intensity in aged rats.

    Science.gov (United States)

    Cunha, Rafael Rodrigues; Cunha, Verusca Najara de Carvalho; Segundo, Paulo Russo; Moreira, Sérgio Rodrigues; Kokubun, Eduardo; Campbell, Carmen Sílvia Grubert; de Oliveira, Ricardo Jacó; Simões, Herbert Gustavo

    2009-08-01

    The reliability of the lactate threshold (LT) determined in aged rats and its validity to identify an exercise intensity corresponding to the maximal blood lactate steady state (MLSS) were analyzed. Eighteen male aged Wistar rats (approximately 365 days) were submitted to two incremental swimming tests until exhaustion, consisting of an initial load corresponding to 1% of body mass (BM) and increments of 1% BM at each 3-min with blood lactate ([lac]) measurements. The LT was determined by visual inspection (LT(V)) as well by applying a polynomial function on the [lac]/workload ratio (LT(P)) by considering the vertices of the curve. For the MLSS, twelve animals were submitted, on different days, to 3-4 exercise sessions of 30-min with workload corresponding to 4, 5 or 6% BM. The MLSS was considered the highest exercise intensity at which the [lac] variation was not higher than 0.07 mM.min(-1) during the last 20-min. No differences were observed for the test-retest results (4.9 +/- 0.7 and 5.0 +/- 0.8 %BM for LTv; and 6.0 +/- 0.6 and 5.8 +/- 0.6 %BM for LTp) that did not differ from the MLSS (5.4 +/- 0.5 %BM). The LT identified for aged rats in swimming, both by visual inspection and polynomial function, was reliable and did not differ from the MLSS. PMID:19585487

  6. [Determination of amanitatoxins by HPLC].

    Science.gov (United States)

    Nishizawa, Chiemi; Yamaura, Yoshio

    2003-10-01

    High-performance liquid chromatographic (HPLC) assay has been developed for the simultaneous determination of alpha-amanitin, beta-amanitin and phalloidin in serum. Three toxins were extracted by reflux in a water bath at 80 degrees C for one hour and purified by Sep-Pak Plus tC18 cartridges. The HPLC assay was performed under gradient conditions using Develosil RP AQUEOUS column. The moble phase consisted with a mixture of acetonitorile containing 0.01 M ammonium acetate(pH 5.0). The column effluence was monitored at 295 nm, 302 nm and 230 nm for 35 min. Detection limit of three toxins in serum were 0.2 microgram/ml respectively. High recovery yields in the range of 81.5-88.1% for toxins were obtained by using this method. PMID:14740566

  7. 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.

  8. Age-related energy values of bakery meal for broiler chickens determined using the regression method.

    Science.gov (United States)

    Stefanello, C; Vieira, S L; Xue, P; Ajuwon, K M; Adeola, O

    2016-07-01

    A study was conducted to determine the ileal digestible energy (IDE), ME, and MEn contents of bakery meal using the regression method and to evaluate whether the energy values are age-dependent in broiler chickens from zero to 21 d post hatching. Seven hundred and eighty male Ross 708 chicks were fed 3 experimental diets in which bakery meal was incorporated into a corn-soybean meal-based reference diet at zero, 100, or 200 g/kg by replacing the energy-yielding ingredients. A 3 × 3 factorial arrangement of 3 ages (1, 2, or 3 wk) and 3 dietary bakery meal levels were used. Birds were fed the same experimental diets in these 3 evaluated ages. Birds were grouped by weight into 10 replicates per treatment in a randomized complete block design. Apparent ileal digestibility and total tract retention of DM, N, and energy were calculated. Expression of mucin (MUC2), sodium-dependent phosphate transporter (NaPi-IIb), solute carrier family 7 (cationic amino acid transporter, Y(+) system, SLC7A2), glucose (GLUT2), and sodium-glucose linked transporter (SGLT1) genes were measured at each age in the jejunum by real-time PCR. Addition of bakery meal to the reference diet resulted in a linear decrease in retention of DM, N, and energy, and a quadratic reduction (P energy as birds' ages increased from 1 to 3 wk. Dietary bakery meal did not affect jejunal gene expression. Expression of genes encoding MUC2, NaPi-IIb, and SLC7A2 linearly increased (P energy and nitrogen in the basal diet decreased when bakery meal was included and increased with age of broiler chickens.

  9. 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...

  10. Deformation and stiffness of spur gear teeth and their influence on gear noise

    Directory of Open Access Journals (Sweden)

    Silvia MEDVECKÁ-BEŇOVÁ

    2015-12-01

    Full Text Available Gear teeth are deformed due to the load. The deformation of gear teeth is causing some negative as well as positive effects. A tooth has a complex shape and due to the complex shape of the teeth, a theoretical determination of the deformation is difficult. The existing experimental techniques are based on static deflection measurements gearing loaded of constant force or seismic measurement deviations at slow rotation. Recently, at ever faster evolving computer technology and the available literature, we can encounter modern numerical methods, such as finite element method (FEM, which can serve as methods for the determination of teeth of gearing. The article is devoted to the problems of gearing stiffness analysis. The problem is solved for spur gears. Deformation analysis solved by FEM is used for calculations of the gearing stiffness. There are many influences that cause vibrations in the gearbox and that have to be taken into account already in the phase of design, manufacture, installation and operation. Detailed analysis of gearboxes manufacturers have shown that improving of the gear accuracy cannot reduce the transmission unit noise to the desired level. Only fundamental changes to the shape of the tooth and changes in production technology can achieve stronger noise reduction of gear mechanism.

  11. 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

  12. Objective criteria for determination of functional-reserve potentials of secondary school age pupils

    Directory of Open Access Journals (Sweden)

    Bodnar I.R.

    2015-11-01

    Full Text Available Purpose: to substantiate criteria for determination of functional-reserve potentials of secondary school age pupils. Material: 1017 pupils of 5-9 forms from 16 schools were questioned. Besides, 200 physical culture teachers from 75 schools of 25 Ukrainian cities were questioned. 154 schoolchildren were tested/ Physical fitness and health levels were tested by index. Pupils fulfilled 4 simple test exercises. Results: we determined indicators of physical condition, psychic state, scopes of motor functioning. We substantiated criteria for determination of schoolchildren’s functional-reserve potentials as well as values of boundary physical condition and physical fitness indicators, which guarantee strong health and optimal functional-reserve potentials of pupil’s organism. Conclusions: Deviation of these indicators’ complex from boundary values informs about pupils’ potential belonging to group of risk. It requires correction of pupil’s way of life and his (her motor functioning.

  13. [Efficiency of teeth local anesthesia by articaine-containing formulation with adrenaline and clonidine in pediatric dentistry].

    Science.gov (United States)

    Mel'nikova, A V; Shugaĭlov, I A; Garus, Ia N

    2014-01-01

    The study evaluated duration and depth of the local infiltration anesthesia by articaine with different combinations of epinephrine and clonidine : articaine (4%) + epinephrine (1: 200 000), articaine (4%) + clonidine (1:100 000), articaine (4%) + epinephrine (1:200 000) + clonidine (1:100 000), articaine (4%) + epinephrine (1: 400 000) + clonidine (1:100, 000) in pediatric dental practice. It was revealed that the replacement of the vasoconstrictor epinephrine on clonidine associated with reduced depth and duration of analgesia. This increased efficiency is provided by inclusion of epinephrine (1:200 000), and clonidine (1:100 000) into anesthetic solution, which provided statistically significant increase in depth and duration of anesthesia.

  14. Absolute ages from crater statistics: Using radiometric ages of Martian samples for determining the Martian cratering chronology

    Science.gov (United States)

    Neukum, G.

    1988-01-01

    In the absence of dates derived from rock samples, impact crater frequencies are commonly used to date Martian surface units. All models for absolute dating rely on the lunar cratering chronology and on the validity of its extrapolation to Martian conditions. Starting from somewhat different lunar chronologies, rather different Martian cratering chronologies are found in the literature. Currently favored models are compared. The differences at old ages are significant, the differences at younger ages are considerable and give absolute ages for the same crater frequencies as different as a factor of 3. The total uncertainty could be much higher, though, since the ratio of lunar to Martian cratering rate which is of basic importance in the models is believed to be known no better than within a factor of 2. Thus, it is of crucial importance for understanding the the evolution of Mars and determining the sequence of events to establish an unambiguous Martian cratering chronology from crater statistics in combination with clean radiometric ages of returned Martian samples. For the dating goal, rocks should be as pristine as possible from a geologically simple area with a one-stage emplacement history of the local formation. A minimum of at least one highland site for old ages, two intermediate-aged sites, and one very young site is needed.

  15. 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...

  16. 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.

  17. Indirect porcelain veneer technique for restoring intrinsically stained teeth.

    Science.gov (United States)

    Cutbirth, S T

    1992-01-01

    Indirect porcelain veneers are often the ideal restoration for intrinsically stained teeth. This article details a step-by-step procedure for esthetically restoring discolored teeth. Porcelain laminate veneers are often indicated when teeth bleaching or direct composite bonding procedures cannot provide the desired esthetic result. Veneers are more appealing to many patients than full coverage crowns because of the more conservative tooth preparation required. If technique details are followed meticulously and cases are appropriately selected, porcelain veneers are not only durable but also promote marvelous gingival health and may be the most esthetic anterior dental restoration.

  18. Uranium age determination: Separation and analysis of 230Th and 231Pa

    International Nuclear Information System (INIS)

    In this work we focused on the age determination of uranium materials of different uranium enrichment. The radioactive decay of the uranium isotopes provides a chronometer that is inherent to the material, in particular the mother/daughter pairs 234U/230Th and 235U/231Pa can be advantageously used. Due to the relatively long half-lives of 234U (2.46 · 105 years) and 235U (7.04 · 108 years) only minute amounts of daughter nuclides are growing in, therefore both separation of Th and Pa from uranium must be of high chemical recovery and must afford large decontamination factors. Analytical methods for the age determination of uranium samples using the parent/daughter relations 234U/230Th and 235U/231Pa is demonstrated. Thorium is separated from bulk uranium using extraction chromatography and subsequently quantified using square-spectrometry, thermal ionisation mass spectrometry (TIMS) and inductively coupled mass spectrometry (ICP-MS). Protactinium is separated by highly selective sorption of protactinium to silica gel followed by square-spectrometric quantification. The methods were tested and validated using uranium reference materials of different uranium enrichment and of known ages. The experimental results obtained with both methods were found to agree with the assumed ages of the reference materials within the combined uncertainty of the measurement. The analysis exploiting the parent/daughter pair 235U/231Pa exhibits a slightly larger combined uncertainty and bias than the thorium method but is found valuable in validating the experimental results by means of a second, independent analysis

  19. Determinants of vitamin D status in fair-skinned women of childbearing age at northern latitudes.

    Directory of Open Access Journals (Sweden)

    Linnea Hedlund

    Full Text Available BACKGROUND AND OBJECTIVE: Poor vitamin D status during pregnancy has been associated with unfavorable outcomes for mother and child. Thus, adequate vitamin D status in women of childbearing age may be important. The aim of this study is to investigate the determinants of 25-hydroxyvitamin D (25(OHD serum concentrations in women of childbearing age living in Sweden, at latitude 57-58° north. METHOD: Eighty four non-pregnant, non-lactating, healthy, fair-skinned women aged between 25-40 years were included. All subjects provided blood samples, four day food records and answered questionnaires about sun exposure and lifestyle. Total serum 25(OHD was analyzed using Roche Cobas® electrochemoluminiescent immunoassay. RESULTS: Mean 25(OHD was 65.8±19.9 nmol/l and 23% of the subjects had concentrations <50 nmol/l. Only 1% had concentrations <25 nmol/l. Determinants of 25(OHD concentrations were recent sunbed use, recent travel to southern latitude, season, estrogen contraceptive use and use of supplementary vitamin D (R(2 = 0.27. CONCLUSION: Every fifth woman had 25(OHD concentrations <50 nmol/l. About 30% of the variation in vitamin D status was explained by sun exposure, use of vitamin D supplements and use of estrogen contraceptives. Cutaneous vitamin D synthesis seems to be a major contributor to vitamin D status, even at northern latitudes. Thus, recommendations on safe UV-B exposure could be beneficial for vitamin D status.

  20. [Biologic age as a criterion for work evaluation (exemplified by titanium alloys production)].

    Science.gov (United States)

    Afanas'eva, R F; Prokopenko, L V

    2009-01-01

    The article deals with results of studies concerning biologic age of workers (males) under occupational hazards of titanium alloys (jeopardy classes 3.3, 3.4.4) in Verkhne-Saldinsky metallurgic production association. Based on mathematic statistic analysis, the authors worked out an equation of multiple regression for ageing pace to forecast the ageing with consideration of age, length of service, occupation. The authors determined occupational groups characterized by premature ageing and increased risk of health disorders.

  1. Study of jojoba oil aging by FTIR.

    Science.gov (United States)

    Le Dréau, Y; Dupuy, N; Gaydou, V; Joachim, J; Kister, J

    2009-05-29

    As the jojoba oil was used in cosmetic, pharmaceutical, dietetic food, animal feeding, lubrication, polishing and bio-diesel fields, it was important to study its aging at high temperature by oxidative process. In this work a FT-MIR methodology was developed for monitoring accelerate oxidative degradation of jojoba oils. Principal component analysis (PCA) was used to differentiate various samples according to their origin and obtaining process, and to differentiate oxidative conditions applied on oils. Two spectroscopic indices were calculated to report simply the oxidation phenomenon. Results were confirmed and deepened by multivariate curve resolution-alternative least square method (MCR-ALS). It allowed identifying chemical species produced or degraded during the thermal treatment according to a SIMPLISMA pretreatment.

  2. Alteration of Heterogeneous Ice Nucleation Properties Induced by Particle Aging

    Science.gov (United States)

    Sullivan, R. C.; Polen, M.; Beydoun, H.; Lawlis, E.; Ahern, A.; Jahn, L.; Hill, T. C. J.

    2015-12-01

    Aerosol particles that can serve as ice nuclei frequently experience rapid and extensive chemical aging during atmospheric transport. This is known to significantly alter some ice nucleation modes of the few types of ice nucleation particle systems where aging effects have been simulated, such as for mineral dust. Yet much of our understanding of atmospheric particle freezing properties is derived from measurements of fresh or unaged particles. We know almost nothing regarding how atmospheric aging might alter the freezing properties of biomass burning aerosol or biological particle nucleants. We have investigated the effects of simulated aging using a chamber reactor on the heterogeneous ice nucleation properties of biomass burning aerosol (BBA) and ice-active bacteria particles. Some types of aging were found to enhance the freezing ability of BBA, exhibited as a shift in a portion of the droplet freezing curve to warmer temperatures by a few °C. Ice-active bacteria were found to consistently loose their most ice-active nucleants after repeated aging cycles. The bacterial systems always retained significantly efficient ice active sites that still allowed them to induce freezing at mild/warm temperatures, despite this decrease in freezing ability. A comprehensive series of online single-particle mass spectrometry and offline spectromicroscopic analysis of individual particles was used to determine how the aging altered the aerosol's composition, and gain mechanistic insights into how this in turn altered the freezing properties. Our new ice nucleation framework that uses a continuous distribution of ice active site ability (contact angle) was used to interpret the droplet freezing spectra and understand how aging alters the internal and external variability, and rigidity, of the ice active sites.

  3. Determination of Lead by Electrochemistry

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Lead is one of the poisonous trace element for human body. It is important to find a way for measuring content of lead. Deternination of lead by electrochemistry is one of a method[1]. In this paper, lead is determined by single-sweep polarography. The absorption behavior of meso-tetra (4-sulfonylphenyl) porphyrin (H2TPPS4) complex with lead ion has also been studied.In Na2B4O7-NaOH solution with pH=l 0.5, the reduction peaks of the ligand are P1 (Ep1=-0.38V), P2 (Ep2=-1.04V), which potentials are obtained vs. S.C.E. When lead ion has been added into above solution. The peak current of P1 and P2 decrease, and a new reduction peak P3 (Ep3=-1.10 V) appears. It shows that the TPPS4-Pb(Ⅱ) complex forms,and this method can be applied to study the complex.

  4. Determination of Lead by Electrochemistry

    Institute of Scientific and Technical Information of China (English)

    HE; YuFeng

    2001-01-01

    Lead is one of the poisonous trace element for human body. It is important to find a way for measuring content of lead. Deternination of lead by electrochemistry is one of a method[1]. In this paper, lead is determined by single-sweep polarography. The absorption behavior of meso-tetra (4-sulfonylphenyl) porphyrin (H2TPPS4) complex with lead ion has also been studied.In Na2B4O7-NaOH solution with pH=l 0.5, the reduction peaks of the ligand are P1 (Ep1=-0.38V), P2 (Ep2=-1.04V), which potentials are obtained vs. S.C.E. When lead ion has been added into above solution. The peak current of P1 and P2 decrease, and a new reduction peak P3 (Ep3=-1.10 V) appears. It shows that the TPPS4-Pb(Ⅱ) complex forms,and this method can be applied to study the complex.……

  5. Re-examination of 'Einige Beitrage zur Theorie der Zahnregulierung' (Some contributions to the theory of the regulation of teeth) published in 1904-1905 by Carl Sandstedt.

    Science.gov (United States)

    Bister, Dirk; Meikle, Murray C

    2013-04-01

    The original histological investigation that forms the basis of our present understanding of tooth movement was carried out on dogs by the Swedish dentist Carl Sandstedt at the Karolinska Institute, Stockholm. His findings were published in 1901 as a monograph in Swedish, and shortly after his death in 1904, as three articles in German entitled 'Einige Beiträge zur Theorie der Zahnregulierung'. Sandstedt observed that the bone was deposited on the alveolar wall of the tension side with both heavy and light forces, new bone spicules following the orientation of the periodontal fibres. On the pressure side, with light forces, osteoclasts resorbed the surface of the alveolar bone, but heavy forces compressed the periodontal ligament resulting in hyalinization--the formation of localized cell-free areas. At these sites, bone removal resulted from undermining resorption by osteoclasts from adjacent marrow spaces. He also observed root resorption and commented on the centre of rotation of the teeth. No English version of Sandstedt's research has ever been published, and in view of its importance, one of us (DB) has translated his three articles from the original German. The aim was to persuade an orthodontic journal to publish the articles in full--however, weighing-in at 21,000 words, the impracticality of this plan soon became clear. We concluded that excerpts from the text plus commentary would be the most practical solution. Where possible and without materially changing the intended meaning, we have translated the German text into something resembling contemporary English, accompanied by the original 16 figures. PMID:22450601

  6. U-Pb systematics of the unique achondrite Ibitira: Precise age determination and petrogenetic implications

    Science.gov (United States)

    Iizuka, Tsuyoshi; Amelin, Yuri; Kaltenbach, Angela; Koefoed, Piers; Stirling, Claudine H.

    2014-05-01

    Ibitira is an unbrecciated, equilibrated vesicular basaltic achondrite that is considered to have originated on a parent body distinct from all other known meteorites. We present the first combined high-precision U and Pb isotopic data for this unique meteorite. The 238U/235U value of 137.777 ± 0.013 determined for the whole rock is comparable to values determined for bulk chondrites and other basaltic achondrites. This value results in corrections of -1.1 Ma for Pb-Pb dates calculated using the previously assumed invariant 238U/235U value of 137.88. Using the determined 238U/235U value, the 7 most radiogenic Pb isotopic analyses for acid-leached pyroxene-rich and whole rock fractions yield an isochron Pb-Pb age of 4556.75 ± 0.57 Ma, in excellent agreement with the results of Mn-Cr chronology which give the ages of 4557.4 ± 2.5 Ma and 4555.9 ± 3.2 Ma using the U-corrected Pb-Pb age of D'Orbigny as a time anchor. Along with the previously proposed thermal history of Ibitira and our closure temperature estimates for Pb diffusion, the Pb-Pb age is interpreted as the timing of the last chemical equilibration and coarse pyroxene exsolution that occurred during high temperature metamorphism. The metamorphism may have been caused by burial of Ibitira lava under successive lava flows and, if so, the Pb-Pb age should post-date the crystallization by a short time interval. The Pb isotopic data for acid leachates suggest partial re-equilibration of Pb between plagioclase and phosphate, perhaps during an impact event at 4.49 Ga, as recorded by K-Ar systematics. The whole rock 238U/204Pb indicates that compared to CI chondrites, Ibitira is less depleted in Pb than in some alkali elements despite a lower condensation temperature of Pb than the alkali elements. The restricted Pb depletion may reflect preferential concentration of metals with high fluid/melt partition coefficients including Pb and Zn as a result of fluid exsolution and migration within the parent magma. We

  7. Is pathological gambling moderated by age?

    Science.gov (United States)

    Granero, Roser; Penelo, Eva; Stinchfield, Randy; Fernandez-Aranda, Fernando; Savvidou, Lamprini G; Fröberg, Frida; Aymamí, Neus; Gómez-Peña, Mónica; Pérez-Serrano, Miriam; del Pino-Gutiérrez, Amparo; Menchón, José M; Jiménez-Murcia, Susana

    2014-06-01

    The age of a patient is a strong moderator of both the course and the evolution of disorders/diseases. However, the effects of current age in pathological gambling (PG) have rarely been examined. The aim of this study is to explore the moderating effects of the patients' current age in relation to personality traits and clinical outcomes of PG. A total sample of 2,309 treatment-seeking patients for PG, diagnosed according to DSM-IV criteria, participated in this study and were assessed with the Diagnostic Questionnaire for Pathological Gambling according to DSM-IV criteria, the South Oaks Gambling Screen, the Symptom Checklist, the Temperament and Character Inventory-R, and other clinical and psychopathological measures. Orthogonal polynomial contrasts showed linear trends in the relationship between age and PG: the older the patient, the more comorbid health problems were visible. The presence of additional quadratic trends also suggests that age plays a significant role in moderating the possibility of existing PG problems and general psychopathology. No interaction term was found between age and sex, but it was present for age and some personality traits: self-transcendence and reward dependence (these two traits were only relevant to the level of impairment due to PG at specific ages). This study suggests that the patients' age influences psychopathological and clinical aspects associated to PG. Intervention in the earliest manifestations of this complex problem is essential in order to better address the need of successful treatment planning.

  8. 76 FR 60112 - Culturally Significant Objects Imported for Exhibition Determinations: “Byzantium and Islam: Age...

    Science.gov (United States)

    2011-09-28

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE Culturally Significant Objects Imported for Exhibition Determinations: ``Byzantium and Islam: Age of... Islam: Age of Transition (7th-9th Century),'' imported from abroad for temporary exhibition within...

  9. Geomagnetic paleointensity and direct age determination of the ISEA (M0r?) chron

    Science.gov (United States)

    Zhu, Rixiang; Hoffman, Kenneth A.; Nomade, Sébastien; Renne, Paul R.; Shi, Ruiping; Pan, Yongxin; Shi, Guanghai

    2004-01-01

    A combined paleomagnetic and geochronologic study has been conducted on an andesite lava sequence at Jianguo (Liaoning province, northeastern China). Thermal demagnetization and thermomagnetic analysis revealed that natural remanent magnetization is carried by both magnetite and hematite. Stepwise thermal demagnetization up to 675°C isolated well-defined reverse characteristic remanent magnetization (ChRM) in three time-independent lava flows with a mean direction of D/ I=179.2°/-59.7° with α95=3.0°. It also showed that a high-temperature component (>585°C) has the same ChRM direction as that of the low- to medium-temperature (ca. 170/300-585°C) components. A modified version of the Thellier-Thellier paleointensity method [Coe, J. Geophys. Res. 72 (1967) 3247-3262] with systematic partial thermoremanent magnetization checks was used for paleointensity determinations. Twelve out of 39 samples yielded reliable results in the temperature interval of 170-550°C. Virtual dipole moment values range from 3.9 to 4.7×10 22 Am 2 with an average of 4.2±0.1×10 22 Am 2. 40Ar/ 39Ar age determination on one lava flow is 116.8±3.0 Myr (2σ error, relative to Fish Canyon sanidine: 28.02±0.28 Myr). The magnetic reversed polarity with well-defined age could correspond to the 'ISEA' within the older part of the Cretaceous normal superchron (CNS), but we cannot rule out the possibility that this reversal interval could also correspond to the M0r due to many ambiguities on previous published ages on ISEA and M0r intervals as well as the new monitor age correction we applied. It also suggests that a weak magnetic field nature already documented before the CNS extended at least into the very beginning of the CNS.

  10. Evidence of authentic DNA from Danish Viking Age skeletons untouched by humans for 1,000 years.

    Directory of Open Access Journals (Sweden)

    Linea Melchior

    Full Text Available BACKGROUND: Given the relative abundance of modern human DNA and the inherent impossibility for incontestable proof of authenticity, results obtained on ancient human DNA have often been questioned. The widely accepted rules regarding ancient DNA work mainly affect laboratory procedures, however, pre-laboratory contamination occurring during excavation and archaeological-/anthropological handling of human remains as well as rapid degradation of authentic DNA after excavation are major obstacles. METHODOLOGY/PRINCIPAL FINDINGS: We avoided some of these obstacles by analyzing DNA from ten Viking Age subjects that at the time of sampling were untouched by humans for 1,000 years. We removed teeth from the subjects prior to handling by archaeologists and anthropologists using protective equipment. An additional tooth was removed after standard archaeological and anthropological handling. All pre-PCR work was carried out in a "clean- laboratory" dedicated solely to ancient DNA work. Mitochondrial DNA was extracted and overlapping fragments spanning the HVR-1 region as well as diagnostic sites in the coding region were PCR amplified, cloned and sequenced. Consistent results were obtained with the "unhandled" teeth and there was no indication of contamination, while the latter was the case with half of the "handled" teeth. The results allowed the unequivocal assignment of a specific haplotype to each of the subjects, all haplotypes being compatible in their character states with a phylogenetic tree drawn from present day European populations. Several of the haplotypes are either infrequent or have not been observed in modern Scandinavians. The observation of haplogroup I in the present study (<2% in modern Scandinavians supports our previous findings of a pronounced frequency of this haplogroup in Viking and Iron Age Danes. CONCLUSION: The present work provides further evidence that retrieval of ancient human DNA is a possible task provided adequate

  11. Digital approach for measuring dentin translucency in forensic age estimation

    Directory of Open Access Journals (Sweden)

    Simranjit Singh

    2013-01-01

    Full Text Available Background: Dentin translucency is best suited for age estimation not only in terms of accuracy but also in terms of simplicity. Conventionally, translucency has been measured using calipers. Computer-based methods have been proposed for the same, although these required the use of custom-built software programs. Objectives: The objectives of the study were to use a simple digital method to measure dentinal translucency on sectioned teeth and to compare digital measurements to conventionally obtained translucency measurements. Materials and Methods: Fifty extracted permanent teeth were collected and were sectioned to 250 μm. Translucency measurements were obtained using the digital method and compared with those obtained using a caliper. Results: Correlation coefficients of translucency measurements to age were statistically significant for both methods (P < 0.001, and marginally higher for the conventional approach (r = 0.4671. Application of derived linear regression equations on an independent sample (n = 10 revealed a similar ability of both the methods to assess age to within ±5 years of the actual age. Conclusion: The translucency measurements obtained by the two methods were very similar, with no clear superiority of one method over the other. Hence, further studies on a large scale are warranted to determine which method is more reliable to estimate the age.

  12. Electron Spin Resonance Dating of Some Animal Teeth Enamel and Shell Fossils

    International Nuclear Information System (INIS)

    Full text: Electron spin resonance (ESR) dating was conducted for some ungulate tooth enamel samples and shell fossils of the the Tham Lod rock shelter Area I (S23W10) located in Highland Archaeology Project in Pang Mapha District, Mae Hong Son Province, Thailand. Age estimation for wave-induced breaching of the cavity and initial sand deposition (Level 19-29) was 33,200 - 18,700 years and 32,300 years for teeth enamel and the shell fossils of Nodularia scobinata sp. (Carditidae) respectively. ESR spectra showed g-factor g1 (gll, gcenter) = 2.0030 - 2.0036, g2 = 2.0040 - 2.0041 and g3 (g?) = 1.997 - 1.9988 formed by CO2- orthorhombic free radical for teeth enamel and g-factor (gcenter) = 2.0042 + 0.0003 formed by SO3- free radical for fresh shell fossils

  13. Multiple teeth fractures in dentinogenesis imperfecta: a case report.

    Science.gov (United States)

    Min, Boram; Song, Je Seon; Lee, Jae-Ho; Choi, Byung-Jai; Kim, Kwang-Mahn; Kim, Seong-Oh

    2014-01-01

    Dentinogenesis imperfecta (DGI) is a hereditary defect consisting of opalescent teeth composed of irregularly formed and hypomineralized dentin. This paper presents the multiple fractures of DGI-affected teeth and suggests the reason of low fracture resistance by observing the dentin microstructures directly using scanning electron microscope (SEM) and by measuring its surface hardness using the Vickers hardness test. SEM revealed that while the enamel microstructure was similar in the DGI-affected and normal teeth, the microstructure of the DGI-affected dentin was poorly woven and more loosely packed than that of the normal dentin. The Vickers hardness of the DGI-affected dentin was 4.89 times softer than the normal dentin. The low fracture resistance of DGI-affected teeth can be attributed to the poorly woven microstructure of their dentin, which leads to a reduction in hardness.

  14. Computerized 3-D reconstruction of two "double teeth".

    Science.gov (United States)

    Lyroudia, K; Mikrogeorgis, G; Nikopoulos, N; Samakovitis, G; Molyvdas, I; Pitas, I

    1997-10-01

    "Double teeth" is a root malformation in the dentition and the purpose of this study was to reconstruct three-dimensionally the external and internal morphology of two "double teeth". The first set of "double teeth" was formed by the conjunction of a mandibular molar and a premolar, and the second by a conjunction of a maxillary molar and a supernumerary tooth. The process of 3-D reconstruction included serial cross-sectioning, photographs of the sections, digitization of the photographs, extraction of the boundaries of interest for each section, surface representation using triangulation and, finally, surface rendering using photorealistic effects. The resulting three-dimensional representations of the two teeth helped us visualize their external and internal anatomy. The results showed: a) in the first case, fusion of the radical and coronal dentin, as well as fusion of the pulp chambers; and b) in the second case, fusion only of the radical dentin and the pulp chambers. PMID:9550051

  15. Preservative Therapy of the Posterior Teeth with Longitudinal Fracture by Plastic Crown Temporary Fixation%塑料冠暂时固定纵折后牙的保存治疗

    Institute of Scientific and Technical Information of China (English)

    符起亚

    2001-01-01

    To study the curative effect of the posterior teeth with longitudinal fracture by temporary fixation of plastic crown,the posterior teeth with longitudinal fracture was fixed with instant crown of selfcuring crylic resin, following root canal treatment and then replaced with cast crown.All of cases were followed up 1~3 years. 24 of 28 cases(85.71%) treated by this method were satisfactary.The results showed that the curative effect of the posterior teeth with longitudinal fracture fixed by the plastic crown was better than that by the tiny steel wire,and the method is simple.%为探讨塑料冠暂时固定纵折后牙的疗效,采用自凝塑料冠固定纵折后牙,牙合面钻孔行根管治疗后铸造金属全冠修复.结果表明:28颗患牙中有26颗经治疗后铸造全冠修复,成功24例,成功率达85.71%.塑料冠固定纵折后牙比单纯金属丝固定效果好,且制作简便.

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

    Science.gov (United States)

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

    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 and 1 = at least one lost primary tooth. The prevalence of at least one missing tooth was 24.7% (n = 206) (95% CI = 21.8-27.7). The variables that were associated with the prevalence of tooth loss (p soft drinks, dental care and previous caries experience in Mexican schoolchildren. These data provide relevant information for the design of preventive dentistry programs. PMID:26916132

  17. [Risk factors for teeth aplasia and hypoplasia in cleft lip and palate children].

    Science.gov (United States)

    Korolenkova, M V; Starikova, N V; Ageeva, L V

    2016-01-01

    The aim of the study was to assess the significance of environmental risk factors for teeth aplasia and hypoplasia in cleft lip and palate children. Two hundred and forty-seven cleft lip and palate (CLP) children were enrolled in the study including 105 (42.5%) with bilateral CLP and 57.5% with unilateral CLP. The mean age was 11.2±4.9 years. Teeth condition was assessed clinically and radiologically. The impact of risk factors for teeth anomalies was analyzed by retrospective data obtained from computer database (absence of preoperative orthopedic treatment, palatal defects after primary palatoplasty and type of primary procedures). Surgical trauma by early periosteoplasty (at the age of 3-4 months), excessive scarring and tissue traction due to absence of early orthopedic treatment and palatal defect were associated with significantly higher incidence of incisors hypoplasia (both developmental enamel defects and microdentia) and aplasia of central incisors not seen in the other study subgroups. Incisors aplasia and hypoplasia in CLP patients do not always have disembryogenic origin but may depend on external environmental factors, including surgical trauma.

  18. Determinants of Anemia among School-Aged Children in Mexico, the United States and Colombia

    Directory of Open Access Journals (Sweden)

    Sana Syed

    2016-06-01

    Full Text Available Anemia affects approximately 25% of school-aged children (SAC—aged 5.00–14.99 years globally. We determined in three countries the prevalence and determinants of anemia in SAC. Data on sociodemographics, inflammation and nutrition status were obtained from the 2006 Mexican National Nutrition Survey, the 2003-6 US National Health and Nutrition Examination Surveys, and the 2010 Encuesta Nacional de Nutrición Situación Colombia. In the US, vitamin A and iron deficiency (ID were available only for girls aged 12.00–14.99 years to which our analysis was limited. Associations were evaluated by country using multivariable logistic regression adjusting for confounders and complex survey design. The prevalence of anemia and ID were: Mexico 12% (ID 18%, n = 3660; US 4% (ID 10%, n = 733; and Colombia 4% (ID 9%, n = 8573. The percentage of anemia associated with ID was 22.4% in Mexico, 38.9% in the US and 16.7% in Colombia. In Mexico, anemia was associated with ID (adjusted OR: 1.5, p = 0.02 and overweight (aOR 0.4, p = 0.007. In the US, anemia was associated with black race/ethnicity (aOR: 14.1, p < 0.0001 and ID (aOR: 8.0, p < 0.0001. In Colombia, anemia was associated with black race/ethnicity (aOR: 1.6, p = 0.005, lowest socio-economic status quintile (aOR: 1.8, p = 0.0005, ID (aOR: 2.7, p < 0.0001, and being stunted (aOR: 1.6, p = 0.02. While anemia was uniformly associated with iron deficiency in Mexico, Columbia, and the United States, other measured factors showed inconsistent associations with anemia. Additional data on anemia determinants in SAC are needed to guide interventions.

  19. Wy10快速牙齿美白术在口腔临床中的应用%Application of Wy10 Fast Teeth Whitening Technique in Clinical Stomatology

    Institute of Scientific and Technical Information of China (English)

    姜茜; 李洁云; 余优成

    2014-01-01

    目的:研究Wy10快速牙齿美白术对各类着色牙的疗效及敏感度的影响。方法:将门诊中要求牙齿美白的20例患者的着色牙,按病因分为増龄性黄牙180颗,外源性染色牙120颗,轻、中度四环素牙60颗,轻、中度氟斑牙40颗。采用Wy10快速牙齿美白术对患牙进行美白治疗,用比色板观察术后即刻及1个月后牙面色泽的改变,探诊和冷诊检测术后即刻及1个月后牙面的敏感度。结果:Wy10快速牙齿美白术对増龄性黄牙和外源性染色牙即刻有效率100%,1个月后的有效率分别为97.2%和97.5%;对四环素牙和氟斑牙即刻有效率为96.6%和97.5%,1个月后有效率分别为93.3%和95%。术后绝大多数治疗牙无明显不适,仅极少数有即刻轻度不适,1个月后均恢复正常。结论:采用Wy10快速牙齿美白术治疗牙齿着色安全高效,其对増龄性黄牙和外源性染色牙的治疗效果较四环素牙和氟斑牙好。%Objective:To study the clinical efficacy and sensitivity of Wy10 fast teeth whitening technique to all kinds of discolored teeth in stomatology clinic .Methods :Twenty cases of outpatients were randomly selected ,whose discolored teath were divided according to their pathogenesis .There were 180 age-related discolorationteeth ,120 extrinsic staining teeth ,60 tetracycline stained teeth and 40 teeth of dental fluorosis which were treated by Wy10 fast teeth whitening technology .The changes of teeth color were examined by Vita shade guide while probing and cold air were used to detect the degree of dental sensitivity ,immeddiately after the operation and a month later .Results:The effective ratios was 100% immediataly after the operation and up to 97 .2% and 97 .5% respectively after a month on the age-related discolored teeth and extrinsic staining teeth .The effective ratios were 96 .6% and 97 .5% respectively immediately after the operation and up to 93 .3% and

  20. Uranium age determination - Separation and analysis of 230Th and 231Pa

    International Nuclear Information System (INIS)

    be of high chemical recovery and must afford large decontamination factors. In general, the age obtained from parent/daughter ratios refers to the last separation of the parent nuclide from its daughters, i.e. the last purification of the material. The accuracy of the obtained age therefore depends on the quality of the purification process and assumes that the material subsequently has not been contaminated. Obviously the availability of two analytical methods relying on both, independent parent/daughter pairs will therefore significantly increase the confidence in the experimental results. In this work we demonstrate analytical methods for the age determination of uranium samples using the parent/daughter relations 234U/230Th and 235U/231Pa. Thorium is separated from bulk uranium using extraction chromatography and subsequently quantified using □-spectrometry, thermal ionisation mass spectrometry (TIMS) and inductively coupled mass spectrometry (ICP-MS). Protactinium is separated by highly selective sorption of protactinium to silica gel followed by □-spectrometric quantification. The methods were tested and validated using uranium reference materials of different uranium enrichment and of known ages. The experimental results obtained with both methods were found to agree with the assumed ages of the reference materials within the combined uncertainty of the measurement. The analysis exploiting the parent/daughter pair 235U/231Pa exhibits a slightly larger combined uncertainty and bias than the thorium method but is found valuable in validating the experimental results by means of a second, independent analysis. (author)

  1. Teeth Grinding: Is Emotional Stability related to Bruxism?

    OpenAIRE

    Sutin, Angelina R.; Terracciano, Antonio; Ferrucci, Luigi; Costa, Paul T.

    2010-01-01

    This study examines the association between personality traits and bruxism, the repetitive grinding or clenching of teeth. Community-dwelling participants (N = 470) had a comprehensive oral examination by a dentist and completed a dental history and personality questionnaires. Consistent with the literature on state anxiety and depression as antecedents of bruxism, Neuroticism-related traits were associated with self-reported teeth grinding. These traits were also associated with other oral c...

  2. Odontomas and Supernumerary Teeth: Is There a Common Origin?

    OpenAIRE

    Pippi, Roberto

    2014-01-01

    The aim of the present work is to analyze all scientific evidence to verify whether similarities supporting a unified explanation for odontomas and supernumerary teeth exist. A literature search was first conducted for epidemiologic studies indexed by PubMed, to verify their worldwide incidence. The analysis of the literature data shows some interesting similarities between odontomas and supernumerary teeth concerning their topographic distribution and pathologic manifestations. There is also...

  3. 正畸牙移入牙槽突裂患者植骨区的牙CT评价%Evaluation of orthodontic teeth moving in bone graft area by dental CT

    Institute of Scientific and Technical Information of China (English)

    吴军; 王国民

    2012-01-01

    Objective To evaluate alveolar bone shape changing after orthodontic teeth moving in the alveolar bone graft area by dental CT. Methods Three unilateral complete alveolar cleft patients were chosen in this study. Patients were examined before and after alveolar bone grafting, after orthodontic treatment by dental CT. The alveolar bone shape changing after orthodontic teeth moving in bone graft area was evaluated. Results The orthodontic teeth could move in the bony graft area, and graft alveolar bone could reshape the morphology followed the teeth move in. Conclusion Alveolar bone grafting and orthodontic treatment are good for reconstruct dental arch integrity.%目的 应用牙CT评价正畸牙移入牙槽突裂患者植骨区后牙槽骨的形态变化.方法 对3位牙槽突裂患者在植骨前后和正畸治疗后行牙槽突裂裂隙区的三维牙CT检查,分析正畸牙移入植骨区域后,正畸牙位置及牙槽骨的形态变化.结果 牙槽突裂植骨术后,正畸牙可以顺利移入植入骨区域,正畸牙的牙根尖位置发生明显的位移,牙槽骨会随正畸牙的移动发生塑形改变,而不仅仅是牙齿在牙槽骨内的移动.结论 牙槽突裂植骨及正畸治疗有益于重建牙弓的完整性.

  4. Chediak-Higashi syndrome and premature exfoliation of primary teeth.

    Science.gov (United States)

    Rezende, Karla Mayra; Canela, Alfredo Hiram Carrillo; Ortega, Adriana Oliveira Lira; Tintel, Claudia; Bönecker, Marcelo

    2013-01-01

    The Chediak-Higashi syndrome (CHS) is a rare hereditary fatal disease, if not treated. These changes are associated with various diseases and syndromes that mainly cause periodontal disease and thus the premature loss of teeth. This paper describes the monitoring of premature loss of primary teeth that began when the child was 5 years old. On presentation his teeth were mobile and there was a history of gingival bleeding. Panoramic radiography revealed generalized and severe bone loss, and the teeth showed no bony support enough for their stability. Blood test was ordered to assess the overall health of the child and giant cells with cytoplasmic granules were found, confirming the diagnosis of CHS. The management of periodontal disease focused on the control of infection and bacterial plaque by mechanical and chemical methods.

  5. Premature exfoliation of teeth in childhood and adolescence.

    Science.gov (United States)

    Hartsfield, J K

    1994-01-01

    Although the premature loss of primary teeth in conjunction with early eruption may be of no clinical significance, the loss of primary or permanent teeth in the absence of trauma should not be overlooked by the clinician. Premature loss of teeth associated with systemic disease usually results from some change in the immune system or connective tissue. This chapter presented some conditions associated with loosening and/or premature loss of teeth that may be encountered in children and adolescents. The most common of these conditions appear to be hypophosphatasia and early-onset periodontitis. Other less common conditions were described to aid in forming a differential diagnosis. Other diseases that may manifest with severe oral infection, such as Wiskott-Aldrich syndrome, diabetes mellitus, or herpes zoster, could result in early tooth loss.

  6. Isotopic composition of recent shark teeth as a proxy for environmental conditions

    Science.gov (United States)

    Vennemann, T. W.; Hegner, E.; Cliff, G.; Benz, G. W.

    2001-05-01

    The O, C, and Sr isotope compositions of teeth from ten species, belonging to five families, and three orders of sharks were measured to determine the influence of habitat, diet, and possible species-specific fractionation effects on the isotopic composition of biogenic phosphate from fish. The sharks were recently caught in subtropical waters off the KwaZulu-Natal (KZN) coast of South Africa, as well as from cold waters in Prince William Sound (PWS), Alaska, and Victor Bay (VB), Nunavut, Canada. δ 18O values of tooth phosphate (δ 18O P) range from 20.9 to 23.5‰ for the KZN sharks. For most species the range in measured δ 18O P values is about 0.6‰, but it may be as high as 1.1‰ for different teeth from a single shark. Dentine and enameloid within individual teeth have no apparent differences in δ 18O P values. The δ 18O P values of the KZN shark teeth reflect the typical habitat of the studied species, primarily the thermal structure of the water column off KZN at depths between 20 and 280 m. The δ 18O P values of teeth from different Greenland sharks from VB and Pacific sleeper sharks from PWS are very homogeneous, averaging 25.8 and 24.7‰, respectively. These values appear to be in equilibrium with deep (>500 m) ocean waters in each case at temperatures of about -0.3°C or less. There is little discernable evidence for species-specific fractionation effects for the oxygen isotope composition of phosphate in the studied marine fish. The oxygen isotope composition of carbonate in apatite averages about 9.1‰ higher than corresponding δ 18O P values, in agreement with equilibrium fractionation between carbonate and phosphate, but with a large variance (1σ = ±1.5‰). δ 18O C values also vary by up to 1‰ between enameloid and dentine within single teeth, but in a non-systematic way. Differences in δ 13C values between carbonate in enameloid and dentine is also large (up to 8‰) but the δ 13C values vary systematically. Enameloid is always

  7. [Diagnostics and planning of orthodontic treatment of patients with crowded teeth position with the use of elastomeric correcting splints].

    Science.gov (United States)

    Arsenina, O I; Riakhovskiĭ, A N; Safarova, N M

    2011-01-01

    3D scanning of plaster jaw models and further processing of the received data in editing program for three dimensional models Rapid Form 2006 Basis is one of the used methods of diagnostics of patients with crowded teeth position (measurement of anthropometric parameters of jaw models, dental arches symmetry, sizes and forms of dentitions). On 3D jaw models with crowded teeth position there were planned trajectories of gradual single tooth displacement in such a way that to move them in new correct position. Prescribing determined step with which the tooth would be moved there was made a series of individual plastic jaw models corresponding to each stage of treatment by stereolithographic method. On the received models there was made a series of elastomeric correcting splints producing some pressure upon teeth and making for their displacement. PMID:21512472

  8. [Diagnostics and planning of orthodontic treatment of patients with crowded teeth position with the use of elastomeric correcting splints].

    Science.gov (United States)

    Arsenina, O I; Riakhovskiĭ, A N; Safarova, N M

    2011-01-01

    3D scanning of plaster jaw models and further processing of the received data in editing program for three dimensional models Rapid Form 2006 Basis is one of the used methods of diagnostics of patients with crowded teeth position (measurement of anthropometric parameters of jaw models, dental arches symmetry, sizes and forms of dentitions). On 3D jaw models with crowded teeth position there were planned trajectories of gradual single tooth displacement in such a way that to move them in new correct position. Prescribing determined step with which the tooth would be moved there was made a series of individual plastic jaw models corresponding to each stage of treatment by stereolithographic method. On the received models there was made a series of elastomeric correcting splints producing some pressure upon teeth and making for their displacement.

  9. Teeth and physical fitness in a community-dwelling 40 to 79-year-old Japanese population

    Science.gov (United States)

    Inui, Akinari; Takahashi, Ippei; Sawada, Kaori; Naoki, Akimoto; Oyama, Toshirou; Tamura, Yoshihiro; Osanai, Toshiyuki; Satake, Anna; Nakaji, Shigeyuki; Kobayashi, Wataru

    2016-01-01

    Purpose Decline in the number of teeth and physical fitness begins from 40 years of age; however, several epidemiological studies have identified relationships between oral conditions and physical performance parameters in community-dwelling elderly population. The aim of this study was to validate the relationship between the muscle mass and its function and oral conditions (number of teeth and dental occlusion) after 40 years of age in a community-dwelling population in Japan. Materials and methods The subjects comprised of 552 volunteers (198 males and 354 females, 40–79 years) who participated in the Iwaki Health Promotion Project in 2013. Multiple linear regression analyses were performed with the measures of the muscle mass and its function as objective variables and the measures of the number of teeth, age, body mass index, medical history, serum albumin concentration, smoking status, habitual alcohol intake, marital status, education levels, and exercising habits as explanatory variables. The relationships between the Eichner index and the muscle mass and its function were analyzed using analysis of covariance, with adjustment for confounding factors. Results After adjusting for confounding factors, the number of teeth was shown to be an independent risk factor for the timed 10 m walk test (in females) and the skeletal muscle mass of the whole body (in males). The results also revealed that the timed 10 m walk test was significantly correlated with the Eichner index (Classes A and C in females were correlated). Conclusion This cross-sectional study on a Japanese community-dwelling population revealed relationships between oral conditions and the muscle mass and its function. However, the interpretation of our results was hampered by a lack of data, including those on socioeconomic status and longitudinal observations. Future research exploring teeth loss and the muscle mass and its function is warranted. PMID:27418813

  10. Natal Teeth: A Case Report and Reappraisal

    OpenAIRE

    Malki,Ghadah A.; Al-Badawi, Emad A.; Dahlan, Mohammad A.

    2015-01-01

    The presence of teeth at birth (natal teeth) or within a month after delivery (neonatal teeth) is a rare condition. Natal and neonatal teeth are conditions of significant importance to pediatric dentists and pediatricians. This report discusses a case in which a five-day-old infant required extraction of a mobile mandibular natal tooth to avoid the risk of aspiration and interference with feeding. Also, a review of the literature was conducted to discuss the etiology, clinical features, compl...

  11. Corrected Age for Preemies

    Science.gov (United States)

    ... Prenatal Baby Bathing & Skin Care Breastfeeding Crying & Colic Diapers & Clothing Feeding & Nutrition Preemie Sleep Teething & Tooth Care Toddler Preschool Gradeschool Teen Young Adult Healthy Children > Ages & Stages > Baby > Preemie > Corrected Age ...

  12. 8 Areas of Age-Related Change

    Science.gov (United States)

    ... age. 6. Dental: gingivitis, periodontitis, loss of teeth Tooth decay is not just a problem for children. It ... as you have natural teeth in your mouth. Tooth decay ruins the enamel that covers and protects your ...

  13. Clinical evaluation of the cross-action and between teeth toothbrushes effects on the bacterial plaque and gingival status

    Directory of Open Access Journals (Sweden)

    Sayar Ferena

    2015-05-01

    Full Text Available Background and Aims: The routine mechanical plaque control is done by toothbrush. With regard to different designs of tooth head brushes in order to better plaque removal, the aim of this study was to evaluate the effect of between teeth and cross-action tooth brush on the plaque and gingival status among dental students of dental branch-Islamic Azad University during 2012-13 academic years.   Materials and Methods: This single-blind, cross over, clinical trial was conducted on 30 subjects with mean age (23±0.9 in two groups of 15 persons . They had at least 20 teeth and had gingivitis with no history of antibiotic use in the last 3 months. Those who were undergoing orthodontic treatment, using drugs affecting the gums and having crown and bridge were excluded from the study. The first group used the cross action toothbrush and the second group used between teeth toothbrush and the subjects were asked to brush their teeth for two minutes twice a day in modified bass method and not to floss during the execution of this study. After 14 days plaque index (Turesky, Approximal plaque index and gingival bleeding index were recorded on all teeth except third molars. After a week wash out period, second stage of the study was conducted the same as the first stage with the other kind of brush for each group. Data were analyzed using Generalized Linear Model (GLM test.   Results: There was no statistical significant difference between two toothbrushes based on plaque index, gingival bleeding index and approximal plaque index, respectively (P = 0.29, P = 0.47, P = 0.33. In all measured indices, the treatment sequence showed no significant difference (P = 0.23.   Conclusion: There was no statistical difference between cross-action and between teeth toothbrush in reducing plaque and gingival bleeding.

  14. Take Care of Your Teeth and Gums

    Science.gov (United States)

    ... Teeth and Gums Print This Topic En español Take Care of Your Teeth and Gums Browse Sections The ... The Basics The Basics: Overview It’s important to take care of your teeth and gums. You can prevent ...

  15. Cracked Teeth: A Review of the Literature

    OpenAIRE

    Lubisich, Erinne B.; Hilton, Thomas J.; Ferracane, Jack

    2010-01-01

    Although cracked teeth are a common problem for patients and dentists, there is a dearth of evidence-based guidelines on how to prevent, diagnose, and treat cracks in teeth. The purpose of this article is to review the literature to establish what evidence exists regarding the risk factors for cracked teeth and their prevention, diagnosis, and treatment.

  16. Is biologic width of anterior and posterior teeth similar?

    Directory of Open Access Journals (Sweden)

    Amir Alireza Rasouli Ghahroudi

    2014-09-01

    Full Text Available The biologic width (BW includes attached epithelial cells and connective tissue attachment complex being very important in the periodontal health during prosthetic treatments as invading this zone can cause bone resorption and gingival recession. The present study investigated biologic width values in the normal periodontium in anterior and posterior teeth. 30 patients that referred from restorative department to periodontics department of Tehran University of medical sciences who need crown lengthening procedure on their teeth with no history of orthodontic, prosthodontic and periodontal treatment were randomly enrolled in this cross-sectional trial. Sulcus depths (SD as well as the distance between free gingival margin and the bone crest (FB of anterior and posterior teeth were measured by UNC-15 probe and compared. periodontium thickness was also assessed. The data were subjected to Student t test. Mean BW in the 43 anterior and 47 posterior teeth was measured and not significantly different (1.4651±0.39 mm vs. 1.6312±0.49 mm was observed; however, BW was significantly more in the teeth with thick periodontium compared to those with thin periodontium (1.703±0.5 vs. 1.408±0.35; P=0.002. BW not only is different in individuals but also could be dissimilar in different teeth and should be calculated independently prior to restorative treatments.

  17. Comparative analysis of human and bovine teeth: radiographic density

    Directory of Open Access Journals (Sweden)

    Jefferson Luis Oshiro Tanaka

    2008-12-01

    Full Text Available Since bovine teeth have been used as substitutes for human teeth in in vitro dental studies, the aim of this study was to compare the radiographic density of bovine teeth with that of human teeth to evaluate their usability for radiographic studies. Thirty bovine and twenty human teeth were cut transversally in 1 millimeter-thick slices. The slices were X-rayed using a digital radiographic system and an intraoral X-ray machine at 65 kVp and 7 mA. The exposure time (0.08 s and the target-sensor distance (40 cm were standardized for all the radiographs. The radiographic densities of the enamel, coronal dentin and radicular dentin of each slice were obtained separately using the "histogram" tool of Adobe Photoshop 7.0 software. The mean radiographic densities of the enamel, coronal dentin and radicular dentin were calculated by the arithmetic mean of the slices of each tooth. One-way ANOVA demonstrated statistically significant differences for the densities of bovine and human enamel (p 0.05. Based on the results, the authors concluded that: a the radiographic density of bovine enamel is significantly higher than that of human enamel; b the radiodensity of bovine coronal dentin is statistically lower than the radiodensity of human coronal dentin; bovine radicular dentin is also less radiodense than human radicular dentin, although this difference was not statistically significant; c bovine teeth should be used with care in radiographic in vitro studies.

  18. Age, introduction of solid feed and weaning are more important determinants of gut bacterial succession in piglets than breed and nursing mother as revealed by a reciprocal cross-fostering model.

    Science.gov (United States)

    Bian, Gaorui; Ma, Shouqing; Zhu, Zhigang; Su, Yong; Zoetendal, Erwin G; Mackie, Roderick; Liu, Junhua; Mu, Chunlong; Huang, Ruihua; Smidt, Hauke; Zhu, Weiyun

    2016-05-01

    A reciprocal cross-fostering model with an obese typical Chinese piglet breed and a lean Western breed was used to identify genetic and maternal effects on the acquisition and development gut bacteria from birth until after weaning. Pyrosequencing of 16S rRNA genes results revealed an age- and diet-dependent bacterial succession process in piglets. During the first 3 days after birth, the bacterial community was relatively simple and dominated by Firmicutes with 79% and 65% relative abundance for Meishan and Yorkshire piglets, respectively. During the suckling period until day 14, the piglet breed and the nursing mother lead to increasing differentiation of the fecal bacterial community, with specific bacteria taxa associated with breed, and others with the nursing sow most likely due to its milk composition. Although the effect of nursing mother and the breed were evident through the suckling period, the introduction of solid feed and subsequent weaning were the major events occurring that dominated succession of the gut microbiota in the early life of piglets. This piglet cross-fostering model is a useful tool for studying the effects of diet, host genetics and the environment on the development and acquisition of the gut microbiota and over longer studies the subsequent impact on growth, health and performance of pigs.

  19. Current conditions and influence factors analysis of deciduous teeth caries disease among 200 children aged 3~7%3~7岁儿童患龋相关风险因素分析

    Institute of Scientific and Technical Information of China (English)

    高茜; 杨宁燕; 时清

    2014-01-01

    目的:分析儿童患龋相关风险因素,提出有针对性的口腔卫生指导。方法随机抽取北京口腔医院儿童口腔科就诊的3~7岁儿童200例,记录乳牙患龋情况,并对其看护人进行问卷调查,分析儿童龋病相关因素。结果200例受检儿童患龋率为92.5%,男女之间患龋率差异没有显著性(P>0.05)。乳牙龋均7.58,男童龋均6.95,女童龋均8.40,男女童龋均差异有显著性(P0. 05). The index of dmft(decayed,missed and filled teeth) for the whole observed population was 7. 58,with a significant divergence between boys(6. 95) and girls(8. 40)(P<0. 05). Time of begin-ning to brush teeth and amount of sugar intake showed significant relation to the incidence of deciduous caries. Con-clusion Educationon oral health should be promoted during treatment. More work should be done to emphasize and regulate the propagandaon caries prevention. Developing good oral health habit is very important.

  20. Determination of uranium content in dental porcelains by means of the fission track method and estimation of radiation dose to oral mucosa by radioactive elements

    International Nuclear Information System (INIS)

    Porcelain teeth, some of which contained uranium compounds for aesthetic purpose, have been widely used in dental clinics. Recently, the hazardous effects by uranium radiation were suggested. In the present study, the authors carried out the determination of uranium concentrations of four major brands of porcelain teeth marketed in Japan using the fission track method, and the absorbed doses of oral tissues were calculated by the authors' introduced formula for calculation of alpha radiation. Average uranium concentrations of the brands studied were determined 3.6 ppm (0.33 - 10 ppm, Japan), 18 ppm (0.69 - 81 ppm, Japan), 9.4 ppm (2.5 - 14 ppm, Japan) and 82 ppm (11 - 205 ppm, U.S.A.), respectively. The corresponding dose equivalents at the surface of oral mucosal membrane were 2.9 rem y-1, 14 rem y-1, 7.6 rem y-1 and 66 rem y-1. (author)

  1. The utility of ultrasonographic bone age determination in detecting growth disturbances; a comparative study with the conventional radiographic technique

    International Nuclear Information System (INIS)

    To test whether the conventional radiographic technique in determining bone age abnormalities can be replaced by ultrasonography. A total of 54 Caucasian subjects up to 7 years of age with clinically suspected growth problems underwent left hand and wrist radiographic and ultrasonographic bone age estimations with the use of the Greulich-Pyle atlas. The ultrasonographic scans targeted the ossification centers in the radius and ulna distal epiphysis, carpal bones, epiphyses of the first and third metacarpals, and epiphysis of the middle phalanx, as described in previous reports. The degree of agreement between the two sets of data, as well as the accuracy of the ultrasonographic method in detecting radiographically suggested bone age abnormities, was examined. The mean chronological age, radiographic bone age, and ultrasonographic bone age (all in months) were 41.96 ± 22.25, 26.68 ± 14.08, and 26.71 ± 13.50 in 28 boys and 43.62 ± 24.63, 30.12 ± 17.69, and 31.27 ± 18.06 in 26 girls, respectively. According to the Bland-Altman plot there was high agreement between the results of the two methods with only three outliers. The deviations in bone age from the chronological age taken by the two techniques had the same sign in all patients. Supposing radiography to be the method of reference, the sensitivity, specificity, positive predictive value, and negative predictive value of sonography in detecting growth abnormalities were all 100 % in males and 90.9, 100, 100, and 93.8 %, respectively, in females. The conventional radiographic technique for determining bone age abnormalities could be replaced by ultrasonography. (orig.)

  2. The utility of ultrasonographic bone age determination in detecting growth disturbances; a comparative study with the conventional radiographic technique

    Energy Technology Data Exchange (ETDEWEB)

    Hajalioghli, Parisa; Tarzamni, Mohammad Kazem; Arami, Sara [Tabriz University of Medical Sciences, Department of Radiology, Imam Reza Teaching Hospital, Tabriz (Iran, Islamic Republic of); Fouladi, Daniel Fadaei [Tabriz University of Medical Sciences, Neurosciences Research Center, Tabriz (Iran, Islamic Republic of); Tabriz University of Medical Sciences, Imam Reza Teaching Hospital, Neurosciences Research Center, Tabriz (Iran, Islamic Republic of); Ghojazadeh, Morteza [Tabriz University of Medical Sciences, Department of Physiology, School of Medicine, Tabriz (Iran, Islamic Republic of)

    2015-09-15

    To test whether the conventional radiographic technique in determining bone age abnormalities can be replaced by ultrasonography. A total of 54 Caucasian subjects up to 7 years of age with clinically suspected growth problems underwent left hand and wrist radiographic and ultrasonographic bone age estimations with the use of the Greulich-Pyle atlas. The ultrasonographic scans targeted the ossification centers in the radius and ulna distal epiphysis, carpal bones, epiphyses of the first and third metacarpals, and epiphysis of the middle phalanx, as described in previous reports. The degree of agreement between the two sets of data, as well as the accuracy of the ultrasonographic method in detecting radiographically suggested bone age abnormities, was examined. The mean chronological age, radiographic bone age, and ultrasonographic bone age (all in months) were 41.96 ± 22.25, 26.68 ± 14.08, and 26.71 ± 13.50 in 28 boys and 43.62 ± 24.63, 30.12 ± 17.69, and 31.27 ± 18.06 in 26 girls, respectively. According to the Bland-Altman plot there was high agreement between the results of the two methods with only three outliers. The deviations in bone age from the chronological age taken by the two techniques had the same sign in all patients. Supposing radiography to be the method of reference, the sensitivity, specificity, positive predictive value, and negative predictive value of sonography in detecting growth abnormalities were all 100 % in males and 90.9, 100, 100, and 93.8 %, respectively, in females. The conventional radiographic technique for determining bone age abnormalities could be replaced by ultrasonography. (orig.)

  3. Genotype by sex and genotype by age interactions with sedentary behavior: the Portuguese Healthy Family Study.

    Directory of Open Access Journals (Sweden)

    Daniel M V Santos

    Full Text Available Sedentary behavior (SB expression and its underlying causal factors have been progressively studied, as it is a major determinant of decreased health quality. In the present study we applied Genotype x Age (GxAge and Genotype x Sex (GxSex interaction methods to determine if the phenotypic expression of different SB traits is influenced by an interaction between genetic architecture and both age and sex. A total of 1345 subjects, comprising 249 fathers, 327 mothers, 334 sons and 325 daughters, from 339 families of The Portuguese Healthy Family Study were included in the analysis. SB traits were assessed by means of a 3-d physical activity recall, the Baecke and IPAQ questionnaires. GxAge and GxSex interactions were analyzed using SOLAR 4.0 software. Sedentary behaviour heritability estimates were not always statistically significant (p>0.05 and ranged from 3% to 27%. The GxSex and GxAge interaction models were significantly better than the single polygenic models for TV (min/day, EEsed (kcal/day, personal computer (PC usage and physical activty (PA tertiles. The GxAge model is also significantly better than the polygenic model for Sed (min/day. For EEsed, PA tertiles, PC and Sed, the GxAge interaction was significant because the genetic correlation between SB environments was significantly different from 1. Further, PC and Sed variance heterogeneity among distinct ages were observed. The GxSex interaction was significant for EEsed due to genetic variance heterogeneity between genders and for PC due to a genetic correlation less than 1 across both sexes. Our results suggest that SB expression may be influenced by the interactions between genotype with both sex and age. Further, different sedentary behaviors seem to have distinct genetic architectures and are differentially affected by age and sex.

  4. Determination of radionuclides in samples of middle-aged and older human femurs

    International Nuclear Information System (INIS)

    The paper presents the studies of the presence of gamma isotopes and 90Sr in 19 middle-to old-aged human femur samples. The samples were taken up during routine orthopedic operations in 2012. The aim of the paper was determination of some radionuclides in human bones and estimation of radiation dose created by 90Sr and 90Y (in bones). The 137Cs, 40K, 226Ra, 228Th, 234Th and 210Pb isotopes were determined by gamma spectrometry. The above mentioned radionuclide contents were in the ranges: 137Cs (0.04–1.45); 40K (13–86); 226Ra (1–21.5); 228Th (1.4–40.2); 234Th (0.4–5.7); 210Pb (0.7–8.4) Bq/kg d.w. 90Sr was assayed based on radiometric measurement of ingrown 90Y. The 90Sr content was in the range 0.27–1.85 Bq/kg d.w. Measurements of concentration of 90Sr and 90Y in bones were used to estimation of health risk by calculation of radiation dose. Adsorbed doses ranged from 2.7· 10−7 to 1.9 · 10−6 Gy/y for 90Sr and from 1.2 · 10−6 to 8.3 · 10−7 Gy/y for 90Y. - Highlights: • The paper presents the studies of the presence of gamma isotopes and 90Sr in 19 human femur samples. • The 137Cs, 40K, 226Ra, 228Th, 234Th, 210Pb. isotopes were determined by the gamma spectrometry method. • The 90Sr content was determined by LSC method

  5. Psychosocial Effects of Fractured Anterior Teeth among Rural Children

    Science.gov (United States)

    Naveen, Mohan; Teja, Ravi; Paulindraraj, Shankar; Vallabhaneni, Sai K; Arumugam, Selva B

    2016-01-01

    ABSTRACT Aim: The aim of the study is to determine how rural children view children with visible incisor fracture. Materials and methods: Class 7 (aged 11-12 years) and class 10 (aged 14-15 years) schoolchildren (the participants) were invited to make a social judgment about the color photograph of two children (the subjects). Participants were randomly allocated either (i) pictures of children without incisor fracture or (ii) pictures of the same children whose photographs had been digitally modified to visible incisor fracture. Using a child-centered questionnaire, participants rated subjects using a four-point Likert scale for three negative and six positive attributes. Total attribute scores were tested for significant differences, according to whether the subject had visible incisor fracture or not, using multivariate analysis of variance (p < 0.05). Results: Both class 7 and 10 children rated subjects with visible incisor fracture more negatively than the subjects without incisor fracture. Female participants of class 10 have rated the male subject with incisor fracture significantly negatively (p < 0.01) than male subject without incisor fracture. How to cite this article: Venkatesan R, Naveen M, Teja R, Paulindraraj S, Vallabhaneni SK, Arumugam SB. Psychosocial Effects of Fractured Anterior Teeth among Rural Children. Int J Clin Pediatr Dent 2016;9(2):128-130. PMID:27365933

  6. An analysis of vascular surgery in elderly patients to determine whether age affects treatment strategy.

    LENUS (Irish Health Repository)

    O'Brien, G

    2012-03-01

    The incidence of arterial disease increases with age. Increasing life expectancy in the western world will intensify demands on vascular surgeons with regard to increasing caseload, expanding patient selection criteria, and more complex and minimally-invasive treatment options. We analysed our arterial cases over the past 31 years (n = 6,144) and compared our methods of intervention and complication rates in the elderly population (>75) with the younger cohort, in order to determine whether age should influence our management strategies.

  7. 应用锥形束CT评价前牙唇舌侧牙槽骨高度及厚度的研究%Evaluation of quantitative measurement of labial and lingual alveolar height and thickness in anterior teeth by cone-beam computed tomography

    Institute of Scientific and Technical Information of China (English)

    钟金晟; 柳登高; 欧阳翔英; 谢晓艳

    2012-01-01

    Objective To evaluate the accuracy of in vitro and in vivo measurement of labial and lingual alveolar height and thickness in anterior teeth by cone-beam computed tomography ( CBCT). Methods Anterior teeth sockets in 10 dry mandibles were examined by CBCT, and the alveolar height and thickness were measured and compared with direct measurement. Twenty-two anterior teeth, that had been determined to extract, were examined by CBCT, and the alveolar height and thickness were measured and compared with direct measurement after the extraction. Results In vitro experiments , no significant difference was found between the data obtained by CBCT and direct measurements ( P > 0.05 ) . In vivo experiments, no significant difference was found between the data obtained by CBCT and direct measurements except for the labial alveolar height. The difference might be caused by the trauma from the extraction and patient mobility during the projection. Conclusion CBCT could provide accurate information of labial and lingual alveolar height and thickness in anterior teeth.%目的 评价锥形束CT(CBCT)在体内外定量测量前牙唇舌侧牙槽骨高度及厚度的准确性.方法 体外实验利用CBCT测量10个干下颌骨下前牙牙槽窝的高度和厚度,并与直接测量结果进行比较;体内实验选取待拔除的22颗前牙,拔除前使用CBCT测量牙槽骨的高度和厚度,并与拔除后即刻直接测量的结果进行比较.结果 体外实验CBCT与直接测量结果之间的差异无统计学意义(P>0.05);体内实验CBCT对唇侧牙槽骨厚度测量结果大于CBCT测量结果(P<0.05),而其他3个参数二者之间的差异无统计学意义,造成差异的原因可能与拔牙的损伤和CBCT拍摄过程中患者的移动有关.结论 CBCT可以较好地反映前牙唇舌侧牙槽骨高度和厚度的实际情况.

  8. DETERMINATION OF F-WAVE LATENCY IN INDIVIDUALS AGED 20 YEARS AND OLDER

    Directory of Open Access Journals (Sweden)

    H. R. Hatamian M. R. Imamhadi

    2005-06-01

    Full Text Available Determination of F-wave latency is a simple and valuable method in evaluating proximal part of peripheral nerves. The aim of this study was to determine the mean minimal peroneal F wave (F min in healthy individuals. A total of 282 individuals were studied. The mean age was 45.6 years. The F min (± SD for 564 peroneal nerves was 47.09 ± 4.51 ms. The F min for the age group of 20-45 and height group of 160-180 cm were 47.63 ± 4.50 and 49.77 ± 3.76, respectively. This study demonstrates that the mean F min of our samples was not significantly different from other important similar studies. Age and particularly height had a major role in determination of F min value and these two parameters must be considered in clinical evaluation of patients.

  9. Age and season determine European rabbit habitat use in Mediterranean ecosystems

    Science.gov (United States)

    Rueda, Marta; Rebollo, Salvador; Bravo, Lucía Gálvez

    2008-11-01

    Knowledge about the factors determining habitat use is especially interesting for herbivores living under seasonal climates as they have to deal with food shortage during the drought season. In this context, different-aged individuals are expected to respond differently to seasonal variations because nutritional requirements and predation risk can vary with age. We investigated adult and juvenile European rabbit ( Oryctolagus cuniculus) habitat use in a Mediterranean ecosystem of central Spain, during spring, summer and winter. Relationships between adult and juvenile rabbit pellet abundances and 11 environmental variables related to food availability and refuge density were analysed by means of multiple regression, and evaluated using information theory to identify the set of models best supported by the data. Density of warren entrances was the more constant predictor of habitat use for juvenile rabbits in all the seasons. Herbaceous vegetation volume had a negative influence and was the strongest predictor for adult rabbit habitat use in spring and winter. In summer, green vegetation cover became the strongest positive habitat use predictor. These results suggest that adults prefer to forage in low volume swards ensuring a wide sensory range for the detection of approaching predators. However, the arrival of summer and its associated food depletion forces them to shift toward more open productive areas where green vegetation persists, but at the expense of higher predation risk. Seasonal variation induces minor changes in juvenile habitat use due to their strong dependence on warrens. Thus, our results show that rabbit habitat use is influenced by animal age and seasonal variations in resources.

  10. Temperature dependence of the electrical resistance of sound and carious teeth

    NARCIS (Netherlands)

    Huysmans, MCDNJM; Longbottom, C; Christie, AM; Bruce, PG; Shellis, RP

    2000-01-01

    Temperature variations are expected to influence measurement error in electrical resistance of teeth. It was the aim of this study to determine the changes in electrical behavior of extracted human teeth due to temperature changes in the range of room temperature to intra-oral temperature. Nine extr

  11. Fracture Strength of Endodontically-treated Teeth Restored with Post and Cores and Composite Cores Only

    NARCIS (Netherlands)

    Ozcan, M.; Valandro, L. F.

    2009-01-01

    This study compared the fracture strength of different conditioned metallic posts, fiber-reinforced-composite posts and composite cores only in teeth without coronal tooth structure and determined failure modes after the fracture test. Post spaces were prepared in the root canals, and the teeth were

  12. Validation of adult height prediction based on automated bone age determination in the Paris Longitudinal Study of healthy children

    International Nuclear Information System (INIS)

    An adult height prediction model based on automated determination of bone age was developed and validated in two studies from Zurich, Switzerland. Varied living conditions and genetic backgrounds might make the model less accurate. To validate the adult height prediction model on children from another geographical location. We included 51 boys and 58 girls from the Paris Longitudinal Study of children born 1953 to 1958. Radiographs were obtained once or twice a year in these children from birth to age 18. Bone age was determined using the BoneXpert method. Radiographs in children with bone age greater than 6 years were considered, in total 1,124 images. The root mean square deviation between the predicted and the observed adult height was 2.8 cm for boys in the bone age range 6-15 years and 3.1 cm for girls in the bone age range 6-13 years. The bias (the average signed difference) was zero, except for girls below bone age 12, where the predictions were 0.8 cm too low. The accuracy of the BoneXpert method in terms of root mean square error was as predicted by the model, i.e. in line with what was observed in the Zurich studies. (orig.)

  13. Validation of adult height prediction based on automated bone age determination in the Paris Longitudinal Study of healthy children

    Energy Technology Data Exchange (ETDEWEB)

    Martin, David D. [Tuebingen University Children' s Hospital, Tuebingen (Germany); Filderklinik, Filderstadt (Germany); Schittenhelm, Jan [Tuebingen University Children' s Hospital, Tuebingen (Germany); Thodberg, Hans Henrik [Visiana, Holte (Denmark)

    2016-02-15

    An adult height prediction model based on automated determination of bone age was developed and validated in two studies from Zurich, Switzerland. Varied living conditions and genetic backgrounds might make the model less accurate. To validate the adult height prediction model on children from another geographical location. We included 51 boys and 58 girls from the Paris Longitudinal Study of children born 1953 to 1958. Radiographs were obtained once or twice a year in these children from birth to age 18. Bone age was determined using the BoneXpert method. Radiographs in children with bone age greater than 6 years were considered, in total 1,124 images. The root mean square deviation between the predicted and the observed adult height was 2.8 cm for boys in the bone age range 6-15 years and 3.1 cm for girls in the bone age range 6-13 years. The bias (the average signed difference) was zero, except for girls below bone age 12, where the predictions were 0.8 cm too low. The accuracy of the BoneXpert method in terms of root mean square error was as predicted by the model, i.e. in line with what was observed in the Zurich studies. (orig.)

  14. New Age of Fishes initiated by the Cretaceous−Paleogene mass extinction

    Science.gov (United States)

    Sibert, Elizabeth C.; Norris, Richard D.

    2015-01-01

    Ray-finned fishes (Actinopterygii) comprise nearly half of all modern vertebrate diversity, and are an ecologically and numerically dominant megafauna in most aquatic environments. Crown teleost fishes diversified relatively recently, during the Late Cretaceous and early Paleogene, although the exact timing and cause of their radiation and rise to ecological dominance is poorly constrained. Here we use microfossil teeth and shark dermal scales (ichthyoliths) preserved in deep-sea sediments to study the changes in the pelagic fish community in the latest Cretaceous and early Paleogene. We find that the Cretaceous−Paleogene (K/Pg) extinction event marked a profound change in the structure of ichthyolith communities around the globe: Whereas shark denticles outnumber ray-finned fish teeth in Cretaceous deep-sea sediments around the world, there is a dramatic increase in the proportion of ray-finned fish teeth to shark denticles in the Paleocene. There is also an increase in size and numerical abundance of ray-finned fish teeth at the boundary. These changes are sustained through at least the first 24 million years of the Cenozoic. This new fish community structure began at the K/Pg mass extinction, suggesting the extinction event played an important role in initiating the modern “age of fishes.” PMID:26124114

  15. Effects of Length and Inclination of Implants on Terminal Abutment Teeth and Implants in Mandibular CL1 Removable Partial Denture Assessed by Three-Dimensional Finite Element Analysis

    OpenAIRE

    Amir Fayaz; Alahyar Geramy; Yeganeh Memari; Zahra Rahmani Rahmani

    2016-01-01

    Objectives: This study sought to assess the effects of length and inclination of implants on stress distribution in an implant and terminal abutment teeth in an implant assisted-removable partial denture (RPD) using three-dimensional (3D) finite element analysis (FEA).  Materials and Methods: In this in vitro study, a 3D finite element model of a partially dentate mandible with a distal extension RPD (DERPD) and dental implants was designed to analyze stress distribution in bone around termin...

  16. Age, growth and size interact with stress to determine life span and mortality.

    Science.gov (United States)

    Roach, Deborah Ann

    2012-10-01

    Individuals in a large experimental field population, of the short-lived perennial species Plantago lanceolata, were followed to determine the sources of variation that influence mortality and life span. The design included multiple age groups with initially similar genetic structure, which made it possible to separate age effects from period effects and to identify the genetic component to variation in life span. During a period of stress, individuals of all ages showed parallel increases in mortality but different cohorts experienced this period of high mortality at different ages. This then influenced the distribution of life spans across cohorts. Age and size-age interactions influenced mortality during the period of stress. Smaller individuals died but only if they were old. Additionally, growth and age interacted with stress such that older individuals had negative growth and high mortality whereas younger individuals had positive growth and relatively lower mortality during stress. The results of this study show that it is not simply the environment that can have a major impact on demography in natural populations; rather, age, size and growth can interact with the environment to influence mortality and life span when the environment is stressful. PMID:22664575

  17. Interaction between age and aerobic fitness in determining heart rate dynamics

    International Nuclear Information System (INIS)

    Heart rate variability (HRV) and phase-rectified signal averaging (PRSA) estimates of heart rate dynamics are diminished in older people compared with younger people. However, it is not fully elucidated whether these differences are related to age per se or to the concomitant influence of aerobic fitness. Aerobic fitness (peak oxygen uptake, gas exchange threshold, oxygen uptake kinetics, exercise economy) was assessed in 70 healthy adults (41 male) aged 18–57 years. Participants also underwent a 24 h, ambulatory ECG for the derivation of HRV and PRSA variables. HRV was most sensitive to age and aerobic fitness when measured during the morning period (6 am–12 pm). HRV and PRSA were both diminished with age and were higher in aerobically superior participants. The decline in HRV with age was predominantly attributable to age itself (33%), with aerobic fitness representing an additional modulating factor. The present study also provides tentative evidence that assessment of the influence of aerobic fitness should not rely on .VO2peak alone. These findings demonstrate that age per se is an important factor in determining HRV. However, given the clinical importance of diminished HRV and the immutable nature of aging, the potential significance of physical activity/training to enhance cardiac regulatory function should not be underestimated. (paper)

  18. Shark Teeth Classification

    Science.gov (United States)

    Brown, Tom; Creel, Sally; Lee, Velda

    2009-01-01

    On a recent autumn afternoon at Harmony Leland Elementary in Mableton, Georgia, students in a fifth-grade science class investigated the essential process of classification--the act of putting things into groups according to some common characteristics or attributes. While they may have honed these skills earlier in the week by grouping their own…

  19. Non-masticatory uses of anterior teeth of Sima de los Huesos individuals (Sierra de Atapuerca, Spain)

    OpenAIRE

    Lozano Ruiz, Marina; Bermúdez de Castro, José María; Carbonell i Roura, Eudald; Arsuaga, Juan Luis

    2008-01-01

    In this study we examine the labial and occlusal surfaces of incisors and canines of hominins recovered from the Sima de los Huesos (SH), middle Pleistocene site, in order to establish the possible extramasticatory use of anterior teeth.We have compared the microwear of these fossils with microwear from the anterior teeth of Australian Aborigines, a population characterized by ethnographic evidence of the use of their teeth as a third hand. These two samples of teeth were microsco...

  20. [Effect of smear layer removal on bevelled and retrofilled teeth in vitro].

    Science.gov (United States)

    Carlson, E; Simon, J

    1990-03-01

    The "smear layer" is composed of debris that cover and insert into dentinal tubules. It is not really known if this form of debris may harbon viable bacterias or does form a barrier that enhances endodontic fillings by lining or plugging the tubules. The purpose of this study is to determine the role of the smear layer in leakage by using two groups of teeth in which the smear layer was removed of the root canals, in the first group and left into the roots in the second group. Some samples were beveled and all teeth were retrofilled after Root Canal Preparation, and then filled with India Ink. After examination of leakage under various conditions, it has been found a correlation between leakage and removal of smear layer. PMID:2382045

  1. Births By Age of Mother, 1960-2013

    Data.gov (United States)

    U.S. Department of Health & Human Services — This dataset is for California live births by age of mother, for years 1960-2013. The live birth counts per age bracket represent the live births to California...

  2. Determination of permanent premolars eruption ages among public school children in Lahore, Pakistan

    International Nuclear Information System (INIS)

    Objective: To determine mean eruption age, range and sequence of permanent maxillary and mandibular premolars in public schools of Lahore, Pakistan so as to provide a reference for planning orthodontic treatment and in pediatric dentistry. Methodology: This is a cross sectional study consisting of multistage random sampling and included 4000 children, with ages in between 9-14 years of different public schools in Lahore. Participants were examined and tooth numbering was noted by two-digit system of FDI (Federation Dentaire Internationale). Emergence was divided into three stages depending on eruption level. SPSS version 18 was used for statistical analysis. Results: Out of 4000 children, 1960 were boys and 2031 were girls. In both genders maxillary premolars erupted before mandibular counterparts. All premolars erupted earlier in females than the males. The sequence of emergence for both genders was P1, P2 in upper as well as in lower arch. Conclusion: Eruption of premolar in females was earlier than males but delayed in both genders while compared with Western standard. (author)

  3. Is Greulich–Pyle age estimation applicable for determining maturation in male Africans?

    Directory of Open Access Journals (Sweden)

    Alan G. Morri

    2012-09-01

    Full Text Available Skeletal age estimation as a means of assessing development and skeletal maturation in children and adolescents is of great importance for clinical and forensic purposes. The skeletal age of a test population is estimated by comparison with established standards, the most common standards being those in the Radiographic atlas of skeletal development of the hand and wristpublished by Greulich and Pyle in 1959. These standards are based on the assumption that skeletal maturity in male individuals is attained by the chronological age of 19 years. Although they have been widely tested, the applicability of these standards to contemporary populations has yet to be tested on a population of African biological origin living in South Africa. We therefore estimated the skeletal age of 131 male Africans aged between 13 and 21 years, using the Greulich–Pyle method which we applied to pre-existing hand–wrist radiographs. Estimated skeletal age was compared to the known chronological age for each radiograph. Skeletal age was on average approximately 6 months younger than chronological age. The Greulich–Pyle method underestimated skeletal age for approximately 74%of the sample and overestimated skeletal age for 26%of the sample. Skeletal maturity as characterised by complete epiphyseal fusion occurred approximately 2.1 years later than Greulich and Pyle’s estimate of 19 years. Thus skeletal maturation was still in progress in a large proportion of the 20- and 21-year-old individuals in our study. The Greulich–Pyle method showed high precision but low accuracy and was therefore not directly applicable to African male individuals. Formulation of skeletal age estimation standards specific to South African populations is therefore recommended.

  4. Persuasion Tactics Used by College Age Females on College Age Males.

    Science.gov (United States)

    Hanson, Erika J.; Pollard, Gloria D.; Williams, Christina M.

    This paper researched persuasive tactics used by college age females on college age males. Previous evidence indicates that nonverbal persuasion is more effective than verbal persuasion. The topics explored in previous research on persuasion consisted of physical attractiveness, indirect knowledge of influence, tactics used by children and college…

  5. Radiographic correlation of dental and skeletal age: Third molar, an age indicator

    Directory of Open Access Journals (Sweden)

    G N Suma

    2011-01-01

    Full Text Available Background: Age estimation plays a great role in forensic investigations, orthodontic and surgical treatment planning, and tooth transplantation. Teeth offer an excellent material for age determination by stages of development below the age of 25 years and by secondary changes after the age of 25 years. Third molar is often not included for this purpose due to its notorious developmental patterns. The aim of this study was to evaluate the development of third molar anlage in relation to skeletal maturities and the chronological age. Materials and Methods: One hundred and fifty-six young individuals, 78 males and 78 females, were selected. The stages of development of all the third molars in every individual were determined from panoramic radiographs. The skeletal development was assessed using hand wrist radiographs. Data were analyzed statistically for mean value, standard deviation and the relationship between the recorded characteristics. Results: A strong correlation was found between third molar development and skeletal maturity (in males: r=0.88, P<0.001; in females: r=0.77 for maxillary third molar and 0.89 for mandibular third molar, P<0.001. Conclusion: Hence, it is concluded that a strong correlation exists between chronological age, developmental stages of third molars and maturation of epiphyses of hand. Any of the three parameters could be used for the assessment of other maturities.

  6. Burnup determination and age dating of spent nuclear fuel using noble gas isotopic analysis

    International Nuclear Information System (INIS)

    During the chopping and dissolving phases of reprocessing, gases (such as tritium, krypton, xenon, iodine, carbon dioxide, nitrogen oxide, and steam) are released. These gases are traditionally transferred to a gas-treatment system for treatment, release, and/or recycle. Because of their chemically inert nature, the xenon and krypton noble gases are generally released directly into the loser atmosphere through the facility's stack. These gases (being fission products) contain information about the fuel being reprocessed and may prove a valuable monitor of reprocessing activities. Two properties of the fuel that may prove valuable from a safeguards standpoint are the fuel burnup and the fuel age (or time since discharge from the reactor). Both can be used to aid in confirming declared activities, and the burnup is generally indicative of the usability of the fuel for fabricating nuclear explosives. A study has been ongoing at Los Alamos National Laboratory to develop a methodology to determine spent-fuel parameters from measured xenon and/or krypton isotopic ratios on-stack at reprocessing facilities. This study has resulted in the generation of the NOVA data analysis code, which links to a comprehensive database of reactor physics parameters (calculated using the Monteburns 3.01 code system). NOVA has been satisfactorily tested for burnup determination of weapons-grade fuel from a US production reactor. Less effort has been spent quantifying NOVA's ability to predict burnup and fuel age for power reactor fuel. The authors describe the results predicted by NOVA for xenon and krypton isotopic ratios measured after the dissolution of spent-fuel samples from the Borssele reactor. The Borssele reactor is a 450-MW(electric) pressurized water reactor (PWR) consisting of 15 x 15 KWU assemblies. The spent-fuel samples analyzed were single fuel rods removed from one assembly and dissolved at the La Hague reprocessing facility. The assembly average burnup was estimated at 32

  7. Numerical Simulation Of Cutting Of Gear Teeth

    Science.gov (United States)

    Oswald, Fred B.; Huston, Ronald L.; Mavriplis, Dimitrios

    1994-01-01

    Shapes of gear teeth produced by gear cutters of specified shape simulated computationally, according to approach based on principles of differential geometry. Results of computer simulation displayed as computer graphics and/or used in analyses of design, manufacturing, and performance of gears. Applicable to both standard and non-standard gear-tooth forms. Accelerates and facilitates analysis of alternative designs of gears and cutters. Simulation extended to study generation of surfaces other than gears. Applied to cams, bearings, and surfaces of arbitrary rolling elements as well as to gears. Possible to develop analogous procedures for simulating manufacture of skin surfaces like automobile fenders, airfoils, and ship hulls.

  8. Applicability of Community Periodontal Index Teeth and Random Half-mouth Examination to Gingival Bleeding Assessment in Untreated Adult Population in Beijing

    Institute of Scientific and Technical Information of China (English)

    Jing-hua Zhang

    2012-01-01

    To assess whether Community Periodontal Index (CPI) teeth and random half-mouth methods are representative of full-mouth method in gingival bleeding examination.Methods Data from 1000 untreated adults (age > 18) collected in Beijing from January 2000 to January 2001 were utilized in the analysis.Half of the subjects were examined by Gingival Bleeding Index (GBI) and the other half by Sulcus Bleeding Index (SBI).The data were sorted out and calculated according to CPI teeth and random half-mouth teeth methods.The results of the 2 methods were separately compared with those of full-mouth examination.Results There was a significant difference between CPI teeth method and full-mouth examination (P<0.05) in both GBI and SBI.In contrast,compared with full-mouth examination,significant difference was not observed in diagonal or ipsilateral half-mouth results in SBI (P>0.05),nor in diagonal half-mouth results in GBI (P>0.05)Conclusions The results of CPI teeth method on gingival bleeding could not reflect the full-mouth situation.Ipsilateral and diagonal half-mouth results can serve as a substitute for full-mouth results in SBI,while diagonal half-mouth results in GBI.

  9. Self-Determination among Transition-Age Youth with Autism or Intellectual Disability: Parent Perspectives

    Science.gov (United States)

    Carter, Erik W.; Lane, Kathleen Lynne; Cooney, Molly; Weir, Katherine; Moss, Colleen K.; Machalicek, Wendy

    2013-01-01

    This study examined 68 parents' views of the self-determination skills and capacities of their young adult children with autism spectrum disorders and intellectual disability (ages 19-21 years). Results indicated parents placed a high value on the importance of all seven component skills (i.e., choice-making skills, decision-making skills,…

  10. Gestational age

    Science.gov (United States)

    Fetal age - gestational age; Gestation; Neonatal gestational age; Newborn gestational age ... Gestational age can be determined before or after birth. Before birth, your health care provider will use ...

  11. Prevalence and management of natal/neonatal teeth in cleft lip and palate patients

    Science.gov (United States)

    Yilmaz, R. Burcu Nur; Cakan, Derya Germec; Mesgarzadeh, Nasim

    2016-01-01

    Objective: The aim of this study was to determine the prevalence and distribution of natal/neonatal teeth in infants with cleft lip and palate (CLP) according to gender, involving jaw and side and to show the management of some cases. Materials and Methods: A retrospective study was carried out on medical history and photographic records of 69 infants with CLP, who were treated at the CLP clinic of Yeditepe University between years 2014–2015. The presence of neonatal teeth was determined, and if present the gender, type of cleft, and position were recorded. Statistical analysis was performed. Results: Neonatal teeth were observed in 7% of the study group. No significant differences were found between cleft types and gender (P > 0.05). The prevalence of neonatal teeth in bilateral, unilateral and isolated cleft type was 16.5%, 6.5%, and none, respectively. All neonatal teeth were located in the maxilla and on the cleft-side (100%). Conclusion: The presence of natal/neonatal teeth in infants with CLP was not rare. In all of these cases the teeth were located adjacent to the cleft region. In isolated palatal cleft, where the alveolar region including the teeth buds are away from the cleft, no neonatal teeth were observed. It may be concluded that neonatal teeth in infants with CLP are frequently present and located inside the borders of the presurgical orthopedic treatment (POT) plate. Therefore, if possible, immediate extraction of the neonatal teeth is advised or if not possible because of systemic health reasons, modifications of the plate are required. PMID:27011740

  12. Age determinations and Earth-based multispectral observations of lunar light plains

    Science.gov (United States)

    Koehler, U.; Jaumann, R.; Neukum, G.

    1993-01-01

    The history of light plains still remains doubtful, but there are good arguments - mainly obtained by age determinations and supported by multispectral observations - for an endogenic (magmatic) instead of an (exclusively) impact related origin. Light plains are characterized by smooth areas with an albedo lower than the surrounding highlands (12 - 13 percent), but significantly higher than maria (5 - 6 percent). Before Apollo 16 a volcanic source has been supposed, but analysis of returned samples (highly brecciated and metamorphosed rocks) favored an impact ejecta related origin. Among the currently discussed models are formation by ejecta sedimentation from multi-ringed basins, formation by secondary and tertiary cratering action of ballistically ejected material during the formation of multi-ringed basins, in situ formation by impact melt of large events, and premare (crypto-) volcanism basalts covered by a thin ejecta cover; younger impacts penetrated the ejecta surface to create the dark haloed craters. To find arguments in favor or against these ideas the chronology of light plains is of major importance. Obviously a genetic relationship between the evolution of light plains and the basin forming impacts can be possible only if the events of emplacement features happened simultaneously.

  13. Regeneration of the aged thymus by a single transcription factor

    OpenAIRE

    Bredenkamp, N.; Nowell, C. S.; Blackburn, C C

    2014-01-01

    Thymic involution is central to the decline in immune system function that occurs with age. By regenerating the thymus, it may therefore be possible to improve the ability of the aged immune system to respond to novel antigens. Recently, diminished expression of the thymic epithelial cell (TEC)-specific transcription factor Forkhead box N1 (FOXN1) has been implicated as a component of the mechanism regulating age-related involution. The effects of upregulating FOXN1 function in the aged thymu...

  14. Pulp tissue in sex determination: A fluorescent microscopic study

    Directory of Open Access Journals (Sweden)

    Amit Nayar

    2014-01-01

    Full Text Available Aims: To determine and compare the reliability of pulp tissue in determination of sex and to analyze whether caries have any effect on fluorescent body test. Materials and Methods: This study was carried on 50 maxillary and mandibular teeth (25 male teeth and 25 female teeth, which were indicated for extraction. The teeth are categorized into 5 groups, 10 each (5 from males and 5 from females on the basis of caries progression. The pulp cells are stained with quinacrine hydrochloride and observed with fluorescent microscope for fluorescent body. Gender is determined by identification of Y chromosome fluorescence in dental pulp. Results: Fluorescent bodies were found to be more in sound teeth in males as the caries increase the mean percentage of fluorescent bodies observed decreases in males. We also observed the fluorescent spots in females, and the value of the spot increases in female as the caries progresses, thereby giving false positive results in females. Conclusion: Sex determination by fluorescent staining of the Y chromosome is a reliable technique in teeth with healthy pulps or caries with enamel or up to half way of dentin. Teeth with caries involving pulp cannot be used for sex determination.

  15. PERIAPICAL HEALTH AND CORONARY RESTORATION QUALITY OF ROOT-FILLED TEETH IN THE TURKISH POPULATION

    Directory of Open Access Journals (Sweden)

    E. Bodrumlu

    2012-09-01

    Full Text Available Objective: The purpose of this study was to compare the quality of coronary restorations and root canal fillings with the periapical status of root-filled teeth, in a subpopulation of Turkish individuals. Method: The study included 18,210 randomly selected, 20- to 70-year-old patients referred to the Dental Faculty of Ondokuz Mayis University. A total number of 1,027 root-filled teeth from 780 patients (645 females, 382 males matched these criteria. Additionally, the radiographs were separated according to the age and gender of patients. Panoramic radiographies compared the quality of coronary restorations and root canal fillings with the periapical status of root-filled teeth. Results: The most numerous root-filled teeth were observed in the 20- to 29-year-old group, in both genders. For the maxillary and mandibular incisive teeth, the prevalence of inadequate coronary restoration with apical periodontitis (AP is 29.04% in males and 70.96%, respectively, in females (p<0.05. For the posterior teeth, in both jaws, the prevalence of inadequate coronary restoration with AP is 38.99% in males and 61.02%, respectively, in females. The AP prevalence in inadequate coronary restorations was significantly higher for the posterior than for the anterior teeth. Conclusion: This study concludes that adequate coronary restorations and crowned root-filled teeth significantly reduce AP incidence.

  16. RICHMOND CROWN - FOR RESTORATION OF BADLY MUTILATED POSTERIOR TEETH : A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Yadav

    2015-07-01

    Full Text Available Restoration of badly broken endodontically treated teeth is a common problem in restorative dentistry. Such teeth often require additional support from the root canal by means of a post and core restoration. In cases where tooth structure is significantly lost full coverage restorations for posterior teeth are necessary to achieve proper tooth form and function. Badly broken teeth with minimal or no crown structure require added retention and support. The Richmond crown can be a good treatment alternative for restoration of such teeth. The Richmond crown was introduced in 1878 and incorporated a threaded tube in the canal with a screw retained crown. It was later modified to eliminate the threaded tube and was redesigned as a one piece dowel and crown. This case report shows restoration of badly mutilated posterior teeth with Richmond crown.

  17. Demineralization–remineralization dynamics in teeth and bone

    Science.gov (United States)

    Abou Neel, Ensanya Ali; Aljabo, Anas; Strange, Adam; Ibrahim, Salwa; Coathup, Melanie; Young, Anne M; Bozec, Laurent; Mudera, Vivek

    2016-01-01

    Biomineralization is a dynamic, complex, lifelong process by which living organisms control precipitations of inorganic nanocrystals within organic matrices to form unique hybrid biological tissues, for example, enamel, dentin, cementum, and bone. Understanding the process of mineral deposition is important for the development of treatments for mineralization-related diseases and also for the innovation and development of scaffolds. This review provides a thorough overview of the up-to-date information on the theories describing the possible mechanisms and the factors implicated as agonists and antagonists of mineralization. Then, the role of calcium and phosphate ions in the maintenance of teeth and bone health is described. Throughout the life, teeth and bone are at risk of demineralization, with particular emphasis on teeth, due to their anatomical arrangement and location. Teeth are exposed to food, drink, and the microbiota of the mouth; therefore, they have developed a high resistance to localized demineralization that is unmatched by bone. The mechanisms by which demineralization–remineralization process occurs in both teeth and bone and the new therapies/technologies that reverse demineralization or boost remineralization are also scrupulously discussed. Technologies discussed include composites with nano- and micron-sized inorganic minerals that can mimic mechanical properties of the tooth and bone in addition to promoting more natural repair of surrounding tissues. Turning these new technologies to products and practices would improve health care worldwide.

  18. Anisotropic, gradient and metal-like mechanical behaviors of teeth and their implications on tooth functions

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The anisotropy and gradient of the elastic modulus and the hardness of teeth were investigated by means of instrumented indentation method. Such properties are attributed to the unique microstructures of teeth based on scanning electron microscopic analysis. By comparing the relationship between the ratio of hardness to the reduced elastic modulus and the ratio of elastic unloading work to the total work of teeth in course of indentation to those of other materials, we found that the material behaviors of teeth display metal-like characteristics rather than ceramics as considered traditionally. These material behaviors and relevant functions are discussed briefly.

  19. Kinetics of Amino Acid racemization (epimerisation) in the dentine of fossil and modern bear teeth

    OpenAIRE

    Torres Pérez-Hidalgo, Trinidad José de

    2003-01-01

    The present study examines the question of whether heating experiments on modern bear teeth dentine model the pattern of D/L racemization in fossil teeth. Using samples of modern bear teeth dentine heated at 65°C, 85°C (up to 53 days), and 105°C (up to 71 days), and three independently dated fossil bear teeth, we have compared the modes of racemization induced by temperature in the modern samples and by time on the fossil samples. We have studied seven amino acids (aspartic and...

  20. Correlation between some facial indexes and mesiodistal width of maxillary anterior teeth

    Directory of Open Access Journals (Sweden)

    Leila Ahmadian

    2012-01-01

    Full Text Available Background: Both tooth size and shape of the anterior maxilla play important role in complete denture and facial esthetics. Tooth selection for an edentulous patient with no pre-extraction is very difficult. The purpose of this study was to analyze mesio-distal width of maxillary anterior teeth and to determine the presence of any relationship between them and other facial measurements.Materials and Method: In this cross-sectional study, after enrolment of 100 high school students, full-face standardized digital images of them were taken in frontal view. Bizaygomatic, interpupilary and interalar distance were measured by images. Width of teeth was determined on the casts. T-test and pearson correlation coefficient were performed to analyze the data.Results: Maxillary central incisor is the widest anterior tooth in both male and female. Correlation between bizaygomatic and interpupillay distances and central incisor width were not significant but between interalar and intercanine were significant.Conclusion: Based on this study, interalar distance is a better index to estimate the width of anterior teeth of maxilla in an edentulous patient