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Age Estimation (age + estimation)
Selected AbstractsA Bayesian Approach to Age Estimation in Modern Americans from the Clavicle,JOURNAL OF FORENSIC SCIENCES, Issue 3 2010Natalie Langley-Shirley Ph.D. Abstract:, Clavicles from 1289 individuals from cohorts spanning the 20th century were scored with two scoring systems. Transition analysis and Bayesian statistics were used to obtain robust age ranges that are less sensitive to the effects of age mimicry and developmental outliers than age ranges obtained using a percentile approach. Observer error tests showed that a simple three-phase scoring system proved the least subjective, while retaining accuracy levels. Additionally, significant sexual dimorphism was detected in the onset of fusion, with women commencing fusion at least a year earlier than men (women transition to fusion at approximately 15 years of age and men at 16 years). Significant secular trends were apparent in the onset of skeletal maturation, with modern Americans transitioning to fusion approximately 4 years earlier than early 20th century Americans and 3.5 years earlier than Korean War era Americans. These results underscore the importance of using modern standards to estimate age in modern individuals. [source] Age Estimation Using Thoracic and First Two Lumbar Vertebral Ring Epiphyseal UnionJOURNAL OF FORENSIC SCIENCES, Issue 2 2010Midori Albert Ph.D. Abstract:, Union of the vertebral centra or "ring" epiphyses occurs during adolescence and early adulthood, providing valuable age at death information. We present a system for estimating age based on the timing and pattern of vertebral ring union. Data from 57 known individuals aged 14,27 years were used to establish age ranges for various patterns of union in females and males. Female age ranges were more well defined with less overlap in patterns of union than male age ranges. The age ranges are accompanied by descriptions of the stages of union observed that aid in applying this method. A test of interobserver error in scoring stages of union demonstrated strong consistency among three observers (r = 0.91,0.97). Estimating age by observing all stages documented resulted in 78%, 88%, and 100% accuracies using vertebral data alone. We encourage the continued use of this method, in conjunction with other age indicators. [source] Microscopic Age Estimation from the Anterior Cortex of the Femur in Korean Adults,JOURNAL OF FORENSIC SCIENCES, Issue 3 2009Ph.D., Seung-Ho Han M.D. Abstract:, The purpose of this study was to develop age-predicting equations from the anterior cortex of the femur of Korean adults. Seventy-two femoral samples (44 male and 28 female) were obtained from Korean cadavers and used to develop the equations. The thin sections (<100-,m thick) were prepared by manual grinding; the sections were not decalcified and were stained with Villanueva bone stain reagent. Analysis of covariance showed no significant differences in age-adjusted histomorphological variables between sexes. In stepwise regression analysis, osteon population density, average osteon area, and the most anterior cortical width were selected for an age-predicting equation which produced a high regression correlation (R2 = 0.789). The average Haversian canal area was not significantly related to age for any specimen. [source] Application of Three Dental Methods of Adult Age Estimation from Intact Single Rooted Teeth to a Peruvian SampleJOURNAL OF FORENSIC SCIENCES, Issue 3 2008Douglas H. Ubelaker Ph.D. Abstract:, Methods of estimating adult age at death from such dental features as root translucency, root length, and the extent of periodontosis in intact single rooted teeth have proven useful in studies of modern individuals, especially in estimating age in older adults. Questions remain however, concerning the impact of regional and population variation on accuracy. To examine this issue, three approaches to age estimation were applied to a diverse sample of 100 individuals from Peru. Mean errors of estimation for all three approaches were similar to those originally reported, suggesting minimal impact of population variation of the features measured. A new regression equation, specifically for Peruvian samples, is provided. [source] Assessment of Histomorphological Features of the Sternal End of the Fourth Rib for Age Estimation in Koreans,JOURNAL OF FORENSIC SCIENCES, Issue 6 2007M.S., Yi-Suk Kim M.D. Abstract:, The aim of this study was to assess the histomorphological features of the fourth rib and to develop age-predicting equations for Koreans. Sixty-four rib samples (36 males and 28 females) obtained from forensic cases were used for developing equations. Two thin sections (<100-,m thick) per sample were prepared by manual grinding. Multivariate analysis of covariance revealed statistically significant differences in age-adjusted histomorphological variables between sexes. Using stepwise regression analysis, osteon population density and average osteon area were correlated with unknown sex (r2 = 0.826), and sex plus two histomorphological variables provided the best results for an age-predicting equation given the assumption of knowing the sex of a specimen (r2 = 0.839). Average Haversian canal area had little influence on age estimation for male or female samples, and relative cortical area was not significantly related to age for any specimen. [source] Age Estimation of Korean Adults by Occlusal Tooth WearJOURNAL OF FORENSIC SCIENCES, Issue 3 2007Jong-Il Yun M.S.D. ABSTRACT: The aim of the present study was to evaluate the validity of the modified Kim's scoring system as a practical method of recording occlusal tooth wear and estimating age. For this purpose, 1092 pairs of maxillary and mandibular full-arch casts were randomly selected, scored, and analyzed. The results showed that the modified Kim's scoring system had excellent reliability, and that occlusal tooth wear had a positive correlation with age. Tooth wear scores of all teeth except the two lower central incisors were higher in males than in females. Calculating tables for age estimation were designed by multiple linear regression analysis. Estimated ages were within ±5 years of actual ages in 63.5% of male subjects, and 64.0% of female subjects. The accuracy of age estimation was increased when the subjects were divided into two age groups and data were re-analyzed. Collectively, it was shown that the modified Kim's scoring system is a reliable and accurate method for age estimation, and that the data from these 1092 individuals can be used as a standard for age estimation of Korean adults. [source] Age Estimation by Pulp/Tooth Ratio in Canines by Peri-Apical X-RaysJOURNAL OF FORENSIC SCIENCES, Issue 1 2007Roberto Cameriere Ph.D. ABSTRACT: Estimation of age in individuals has received considerable attention in forensic science, in which it is a widely used method for individual identification, together with paleo-demographic analyses to establish mortality patterns in past populations. The present investigation, which is a continuation of a previously published pilot study, was conducted to examine the possible application of the pulp/tooth area ratio by peri-apical images as an indicator of age at death. A total of 200 peri-apical X-rays of upper and lower canines were assembled from 57 male and 43 female skeletons of Caucasian origin, aged between 20 and 79 years. They belong to the Frassetto osteological collection of Sassari (Sardinia) and are housed in the Museum of Anthropology, Department of Experimental and Evolutionistic Biology, University of Bologna. For each skeleton, dental maturity was evaluated by measuring the pulp/tooth area ratio on upper (x1) and lower (x2) canines. Very good agreement was found between intraobserver measurements. Statistical analysis was performed in order to obtain multiple regression formulae for dental age calculation, with chronological age as dependent variable, and gender, and upper and lower canines as independent variables. Stepwise regression analysis showed that gender did not contribute significantly to the fit (p=0.881) whereas variables x1 and x2 and the first-order interaction between them did. These two variables explained 92.5% of variations in estimated chronological age and the residual standard error was 4.06 years. Lastly, two simple linear regression equations were obtained for age estimation using canines from the maxilla and mandible separately. Both models explained 86% of variations in estimated chronological age and allowed an age-at-death estimate with a residual standard error of about 5.4 years. [source] 146 Methodological Problems of Marine Macroalgae Age EstimationJOURNAL OF PHYCOLOGY, Issue 2003O. N. Selivanova To know the birthdate of any organism is the best way to estimate its age. Unfortunately direct chronometric method, being the most reliable, can't be generally applied. In these cases indirect methods are used. One of them , morphobiometric , is used to estimate age of trees by the number of year rings in the stem or fucoid algae by the number of dichotomic branching. Both methods are widely used however the data obtained may deviate considerably from the true age of the plants. In this study I compared chronometric data on algal age to those obtained by calculation of the number of dichotomic branching in Fucus evenescens growing in Kamchatka, Russia. Field experiments were carried out from 1999 to 2002. No marked with plastic lables plants survived for 3 years. The comparison showed that morphobiometric data exceeded true age of algae at least in 2,3, sometimes even in 5 times. The first year plants can produce up to 5 dichotomous branching per season and can become fertile in the first months of their life. There is information in Russian literature that Kamchatka's F. evenescens age can reach 12,15 years. I consider these data erroneous and suppose underestimation of the number of branches in the early stages of Fucus development to be the cause of overestimation of its true age. In my opinion it is not more than 4,5 years. Application of morphobiometric method is more problematic in case of polytomy. Besides that this method usually causes damage or death of the plant. So I consider that only chronometric method can give the researcher exact information on the age of macroalgae. [source] Age estimation of archaeological remains using amino acid racemization in dental enamel: A comparison of morphological, biochemical, and known ages-at-deathAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2009R.C. Griffin Abstract The poor accuracy of most current methods for estimating age-at-death in adult human skeletal remains is among the key problems facing palaeodemography. In forensic science, this problem has been solved for unburnt remains by the development of a chemical method for age estimation, using amino acid racemization in collagen extracted from dentine. Previous application of racemization methods to archaeological material has proven problematic. This study presents the application to archaeological human remains of a new age estimation method utilizing amino acid racemization in a potentially closed system,the dental enamel. The amino acid composition and extent of racemization in enamel from two Medieval cemeteries (Newcastle Blackgate and Grantham, England) and from a documented age-at-death sample from a 19th century cemetery (Spitalfriedhof St Johann, Switzerland) were determined. Alterations in the amino acid composition were detected in all populations, indicating that diagenetic change had taken place. However, in the Medieval populations, these changes did not appear to have substantially affected the relationship between racemization and age-at-death, with a strong relationship being retained between aspartic acid racemization and the morphological age estimates. In contrast, there was a poor relationship between racemization and age in the post-medieval documented age-at-death population from Switzerland. This appears to be due to leaching of amino acids post-mortem, indicating that enamel is not functioning as a perfectly closed system. Isolation of amino acids from a fraction of enamel which is less susceptible to leaching may improve the success of amino acid racemization for archaeological age estimation. Am J Phys Anthropol, 2009. © 2009 Wiley-Liss, Inc. [source] Age estimation from stages of union of the vertebral epiphyses of the ribsAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2009Luis Ríos Abstract This study attempts to fill a persistent gap in the literature by documenting the timing of epiphyseal union at the vertebral end of the ribs in a sample of modern Portuguese skeletons. The skeletal remains of 53 females and 45 males, between the ages of 11 and 30, were taken from the Lisbon documented skeletal collection. Individuals in the sample have been previously described as being representative of a middle-to-low socioeconomic segment of the early 20th century Lisbon population. Three anatomical locations were examined for epiphyseal union: the head, the articular tubercle and the nonarticular tubercle. The first epiphysis to show partial union is that of the nonarticular tubercle (females, 11,19 years; males, 11,19 years), followed by the epiphysis of the articular tubercle (females, 11,20 years; males, 16,20 years), and finally by the head epiphysis (females, 15,24 years; males, 16,22 years), which can still show incomplete epiphyseal closure at 25 and 24 years for females and males, respectively. A trend for earlier female maturation was observed, but the statistical tests only confirmed this result for some ribs and age groups. No directional asymmetry was found, but a significant fluctuating asymmetry was observed in all three epiphyses. A preliminary analysis showed that the asymmetric group of individuals in the study sample includes all the rural-to-urban migrants, relative to the symmetric group. Am J Phys Anthropol, 2009. © 2009 Wiley-Liss, Inc. [source] Age estimation of faces: a review,APPLIED COGNITIVE PSYCHOLOGY, Issue 1 2009Matthew G. Rhodes Accurate age estimation is important in a variety of settings, particularly those in which age is a condition for access to a product such as alcohol or tobacco. The current paper reviews data on the estimation of age, focusing on changes that occur to the ageing face, methodology and findings. The accumulated data suggest that age estimation of unfamiliar faces can be quite accurate, is sensitive to cues at the local and global level and may vary on the basis of group membership. Potential directions for future research are highlighted and findings are discussed with respect to their implications for policies regarding the solicitation of age identification. Copyright © 2008 John Wiley & Sons, Ltd. [source] Age changes in bone microstructure: do they occur uniformly?INTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 6 2005G. A. Macho Abstract Age estimations based on conventional multifactorial methods were compared with trends observed in the internal morphology of bones obtained from high-resolution µCT. Specifically, average trabecular thickness and number of trabeculae/mm transect were determined in the non-load-bearing capitate (hand) and the load-bearing navicular (foot). The µCT findings reveal age-related trends but,surprisingly,these correspond only loosely with the ages assigned by conventional ageing methods, and are also not in accordance with what would be predicted from biomechanical considerations: trabeculae tend to be thinner in the (habitually) load-bearing navicular than in the (habitually) non-load-bearing capitate. While the statistically significant correlation between trabecular thickness and number of trabeculae would suggest a compensatory mechanism between these two aspects of microanatomy, they are not correlated with the assigned ages and, importantly, may differ between sexes. Only in females is there an unequivocal trend towards trabecular thickness increase with age. These findings, although unexpected, can be reconciled with recent histological evidence and assumed average activity levels in historical populations. Conversely, changes in trabecular number are less clear-cut and may be due to the lack of very old individuals in the sample. Nevertheless, the trends observed for trabecular thickness, as well as for trabecular number, seem to imply that the higher incidence of osteoporosis in women could be explained from a structural point of view alone. Copyright © 2005 John Wiley & Sons, Ltd. [source] Robust gender and age estimation under varying facial poseELECTRONICS & COMMUNICATIONS IN JAPAN, Issue 7 2008Hironori Takimoto Abstract This paper presents a method for gender and age estimation which is robust to changing facial pose. We propose a feature point detection method, called the adapted retinal sampling method (ARSM), and a feature extraction method. A basic concept of the ARSM is to add knowledge about the facial structure to the retinal sampling method. In this method, feature points are detected on the basis of seven points corresponding to facial organs from a facial image. The reason why we used seven points as the basis of feature point detection is that facial organs are conspicuous in the facial region, and are comparatively easy to extract. As features robust to changing facial pose, skin texture, hue, and the Gabor jet are used for gender and age estimation. For classification of gender and estimation of age, we use a multilayered neural network. We also examine the left, right symmetry of faces in connection with gender and age estimation by the proposed method. © 2008 Wiley Periodicals, Inc. Electron Comm Jpn, 91(7): 32, 40, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10125 [source] Haplotype analysis and age estimation of the 113insR CDKN2A founder mutation in Swedish melanoma familiesGENES, CHROMOSOMES AND CANCER, Issue 2 2001Jamileh Hashemi Germline mutations in the CDKN2A tumor suppressor gene located on 9p21 have been linked to development of melanomas in some families. A germline 3-bp insertion in exon 2 of CDKN2A, leading to an extra arginine at codon 113 (113insR), has been identified in 17 Swedish melanoma families. Analysis of 10 microsatellite markers, spanning approximately 1 Mbp in the 9p21 region, showed that all families share a common allele for at least one of the markers closest to the CDKN2A gene, suggesting that the 113insR mutation is an ancestral founder mutation. Differences in the segregating haplotypes, due to meiotic recombinations and/or mutations in the short-tandem-repeat markers, were analyzed further to estimate the age of the mutation. Statistical analysis using a maximum likelihood approach indicated that the mutation arose 98 generations (90% confidence interval: 52,167 generations), or approximately 2,000 years, ago. Thus, 113insR would be expected to have a more widespread geographic distribution in European and North American regions with ancestral connections to Sweden. Alternatively, CDKN2A may lie in a recombination hot spot region, as suggested by the many meiotic recombinations in this narrow ,1-cM region on 9p21. © 2001 Wiley-Liss, Inc. [source] Estimating age by tooth wear of prehistoric human remains in Brazilian archaeological sitesINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 5 2006R. N. Oliveira Abstract The occlusal surfaces of 298 permanent maxillary and mandibular molar teeth of prehistoric shellfish-gatherer subjects from the Piaçaguera and Tenorio sites (4930 to 1875 BP), near the central-northern coastline of São Paulo, Brazil, were examined for classification of macro-wear stages. Molar tooth wear is an indication of masticatory activity and can be used in the estimation of age at death. The examination of visual and schematic aspects of occlusal macro-wear used a visual chart proposed by Brothwell, which includes the three superior and inferior, left and right, permanent molars. Three examiners performed the macroscopic observations twice under the same conditions. The resulting age estimates were compared with previous information of age estimated by skeletal examination. A reduced intra- and inter-observer variation was observed; all re-examinations indicated discrepancies of less than two years for the upper and lower limit of the age range estimates. The procedure was also considered consistent with the skeletal method used for age estimation of human remains excavated in Brazilian archaeological shell mounds, with a discrepancy of less than 8.22 years between the upper and lower limits of estimates by both methods. Age classification by the occlusal molar wear may be a useful tool for the classification of archaeological findings, mainly when only fragmentary skeletal remains are excavated. The current results indicate that the application of the Brothwell chart for Brazilian archaeological series presented satisfactory results of consistency, and its expanded use may represent a relevant adjunct for research. Copyright © 2006 John Wiley & Sons, Ltd. [source] Age of closure of the foramen of Huschke: an osteological studyINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 1 2006L. T. Humphrey Abstract The foramen of Huschke is a dehiscence in the antero-inferior surface of the tympanic plate, which forms during the normal post-natal development of the temporal bone. Closure of the foramen is generally reported to take place by 5 years of age, although a persistent foramen has been observed in 0,67% of adult crania depending on the population. A persistent foramen of Huschke in adult life may be involved in abnormalities of the external auditory canal and related structures, which can lead to otological complications. This paper examines age-related changes in the development of the tympanic plate from the perinatal to the adult condition using two osteological samples from Britain, and is the first systematic evaluation beyond the age of six years. The results suggest that the widely cited chronology for the closure of the foramen of Huschke is erroneous. Earlier stages of formation may be used for narrowing age estimation in fragmentary remains of juveniles in a skeletal collection of unknown age or in a forensic or clinical context. Copyright © 2005 John Wiley & Sons, Ltd. [source] Use of the first rib for adult age estimation: a test of one methodINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 5 2005H. Kurki Abstract The human first rib is relatively easy to identify and is often preserved, in comparison with elements such as the fourth rib and pubic symphysis. Therefore it is potentially a valuable skeletal element for estimating age in forensic and archaeological contexts. A method of adult age estimation using the first rib (Kunos et al., 1999) is tested on a sample of known age skeletons from the J.C.B. Grant Collection (n,=,29, mean age,=,55.7 years). The high correlation coefficient (r,=,0.69) and moderate coefficient of determination (r2,=,0.47) demonstrate agreement between the known and estimated ages, suggesting that the first rib demonstates morphological changes with age. The inaccuracy and bias are high (all ages inaccuracy,=,10.4 years, bias,=,4.7 years) but comparable to several other age estimation methods in common use. Although the results are not as good for younger age categories (<,50 years: inaccuracy and bias rank ninth of nine age estimation methods), the inaccuracy and bias for the older age categories are relatively low (60,+ years inaccuracy,=,8.9 years, ranks third out of nine; bias,=,,,5.8 years, ranks first out of nine) compared with other age estimation methods. The first rib method is reasonably precise (93% of individuals fall within the limits of agreement of the mean difference between two trials). The first rib method is therefore a useful addition to the methods available for biological profile reconstructions from skeletal remains, especially if it is suspected that the remains represent an older individual. Copyright © 2005 John Wiley & Sons, Ltd. [source] Otolith microstructure analysis with OTC validation confirms age overestimation in Atlantic thread herring Opisthonema oglinum from north-eastern BrazilJOURNAL OF FISH BIOLOGY, Issue 7 2008R. Lessa The daily periodicity of micro-increments in the otoliths of Atlantic thread herring Opisthonema oglinum was demonstrated from juveniles injected with oxytetracycline and reared for up to 62 days. Micro-increments ranged from 26 to 358 in the overall sample. Von Bertalanffy growth function (VBGF) using micro-increment counts were: L,= 337 mm fork length (LF) (s.e. = 31 mm); K = 1·2 (s.e. = 0·2) and t0= 0·04 years (s.e. = 0·01 years). The otolith-based growth was corroborated using the LF frequency analysis. Observed lengths of increments were considered unsuitable for VBGF derivation, as no increase in size was obtained from them. Furthermore, the high percentage of unreadable otoliths suggests that increment analysis is unreliable for age estimation. Most growth occurs within the first year, differing from previous longevity estimates of 4,8 years. In contrast with published information, O. oglinum is a fast-growing and short-lived species. [source] Analysis of Age-at-Death Estimation Using Data from a New, Modern Autopsy Sample,Part I: Pubic Bone,JOURNAL OF FORENSIC SCIENCES, Issue 5 2010Kristen M. Hartnett Ph.D. Abstract:, This research tests the accuracy of age estimation from the pubic bone. Specimens were collected from decedents of known age, sex, and race at the Forensic Science Center (FSC) in Phoenix, Arizona. The collection consists of pubic bones and fourth rib ends from 419 males and 211 females, ranging in age from 18 to 99. Age-at-death was estimated by three observers using the Suchey,Brooks method. The correlation results indicate that there are significant differences in the observed versus actual ages (r = 0.68169, p < 0.001) and that there are significant interobserver differences. No significant differences were found in the intra-observer tests. The FSC pubic bones were sorted based on morphology without knowing age. New descriptions and age ranges were created. A phase seven was described and is comprised of males and females over 70 years of age-at-death. [source] Multislice Computed Tomography of the First Rib: A Useful Technique for Bone Age AssessmentJOURNAL OF FORENSIC SCIENCES, Issue 4 2010Guillaume Moskovitch M.S. Abstract:, Macroscopic study of the first rib has been described by Kunos et al. as an efficient method of age estimation. We retrospectively reviewed a test sample of 160 first right ribs obtained from multislice computed tomography (MSCT) clinical investigations of living individuals aged 15,30 years old. Based on the descriptions of Kunos et al., we analyzed the morphological appearance of the sternal end of the first rib on two- and three-dimensional MSCT reconstructions and defined changes in appearance in stages (from 2 to 5). We also studied the calcification and ossification of the costal cartilage as an independent feature. By statistical analysis (ANOVA), we determined for each gender the correlation between the estimated stage of the costal face, the appearance of the costal cartilage, and the documented age of the subjects. We demonstrated that MSCT of the first rib appears to be an efficient noninvasive modality for bone age estimation. [source] Assessment of Histomorphological Features of the Sternal End of the Fourth Rib for Age Estimation in Koreans,JOURNAL OF FORENSIC SCIENCES, Issue 6 2007M.S., Yi-Suk Kim M.D. Abstract:, The aim of this study was to assess the histomorphological features of the fourth rib and to develop age-predicting equations for Koreans. Sixty-four rib samples (36 males and 28 females) obtained from forensic cases were used for developing equations. Two thin sections (<100-,m thick) per sample were prepared by manual grinding. Multivariate analysis of covariance revealed statistically significant differences in age-adjusted histomorphological variables between sexes. Using stepwise regression analysis, osteon population density and average osteon area were correlated with unknown sex (r2 = 0.826), and sex plus two histomorphological variables provided the best results for an age-predicting equation given the assumption of knowing the sex of a specimen (r2 = 0.839). Average Haversian canal area had little influence on age estimation for male or female samples, and relative cortical area was not significantly related to age for any specimen. [source] Age Estimation of Korean Adults by Occlusal Tooth WearJOURNAL OF FORENSIC SCIENCES, Issue 3 2007Jong-Il Yun M.S.D. ABSTRACT: The aim of the present study was to evaluate the validity of the modified Kim's scoring system as a practical method of recording occlusal tooth wear and estimating age. For this purpose, 1092 pairs of maxillary and mandibular full-arch casts were randomly selected, scored, and analyzed. The results showed that the modified Kim's scoring system had excellent reliability, and that occlusal tooth wear had a positive correlation with age. Tooth wear scores of all teeth except the two lower central incisors were higher in males than in females. Calculating tables for age estimation were designed by multiple linear regression analysis. Estimated ages were within ±5 years of actual ages in 63.5% of male subjects, and 64.0% of female subjects. The accuracy of age estimation was increased when the subjects were divided into two age groups and data were re-analyzed. Collectively, it was shown that the modified Kim's scoring system is a reliable and accurate method for age estimation, and that the data from these 1092 individuals can be used as a standard for age estimation of Korean adults. [source] Age Estimation by Pulp/Tooth Ratio in Canines by Peri-Apical X-RaysJOURNAL OF FORENSIC SCIENCES, Issue 1 2007Roberto Cameriere Ph.D. ABSTRACT: Estimation of age in individuals has received considerable attention in forensic science, in which it is a widely used method for individual identification, together with paleo-demographic analyses to establish mortality patterns in past populations. The present investigation, which is a continuation of a previously published pilot study, was conducted to examine the possible application of the pulp/tooth area ratio by peri-apical images as an indicator of age at death. A total of 200 peri-apical X-rays of upper and lower canines were assembled from 57 male and 43 female skeletons of Caucasian origin, aged between 20 and 79 years. They belong to the Frassetto osteological collection of Sassari (Sardinia) and are housed in the Museum of Anthropology, Department of Experimental and Evolutionistic Biology, University of Bologna. For each skeleton, dental maturity was evaluated by measuring the pulp/tooth area ratio on upper (x1) and lower (x2) canines. Very good agreement was found between intraobserver measurements. Statistical analysis was performed in order to obtain multiple regression formulae for dental age calculation, with chronological age as dependent variable, and gender, and upper and lower canines as independent variables. Stepwise regression analysis showed that gender did not contribute significantly to the fit (p=0.881) whereas variables x1 and x2 and the first-order interaction between them did. These two variables explained 92.5% of variations in estimated chronological age and the residual standard error was 4.06 years. Lastly, two simple linear regression equations were obtained for age estimation using canines from the maxilla and mandible separately. Both models explained 86% of variations in estimated chronological age and allowed an age-at-death estimate with a residual standard error of about 5.4 years. [source] An improved sample preparation for an LC method used in the age estimation based on aspartic acid racemization from human dentinJOURNAL OF SEPARATION SCIENCE, JSS, Issue 1 2007Raja Yekkala Abstract The determination of age on the basis of aspartic acid (Asp) racemization in teeth is one of the most reliable and accurate methods to date. In this paper, the usefulness of HPLC coupled with fluorescence detection for determination of Asp racemization was evaluated. A modified sample preparation is proposed for better stability of o -phthaldialdehyde- N -acetyl- L -cysteine derivatives of D/L -Asp (due to the instability below pH 7). To ensure the accuracy of the method, the validation parameters' specificity, precision, linearity, and LOD were determined. Three dentin samples of premolar teeth, extracted from living individuals (bucco-lingual longitudinal sections of 1 mm thickness), were analyzed and quantitative results are discussed. [source] Lines of arrested growth in bone and age estimation in a small primate: Microcebus murinusJOURNAL OF ZOOLOGY, Issue 1 2004J. Castanet Abstract In primates, age determination using lines of arrested growth (LAGs) from bones has rarely been attempted, and the reliability of these structures has never been experimentally validated. In order to test skeletochronology in primates, LAGs were studied mainly in the long bones of known age Microcebus murinus, a small primate, whose potential longevity may reach 12 years. LAGs were extensively studied in 43 males and 23 females ranging from juveniles to 11-year-old adults. All individuals were born and reared in captivity. Some young individuals were injected with fluorescent dyes to quantify bone growth rates. LAGs in the diaphysis of the tibia are well correlated with age and this skeletal element appears to be the best for assessing skeletochronology in Microcebus murinus. There is strong evidence that the seasonal cycle of photoperiodicity is more important than age alone in producing LAGs. [source] Assessment of weight changes during and after pregnancy: practical approachesMATERNAL & CHILD NUTRITION, Issue 1 2008Amanda R. Amorim Abstract The usefulness of routine prenatal weight measurements in predicting pregnancy outcomes is still a controversial issue. Comparisons among studies and the interpretation of research findings are complicated due to the variety of indicators applied to express maternal weight changes during and after pregnancy. A review of literature was conducted to clarify the definitions and examine the strengths and limitations of methods for measuring gestational weight gain (WG) and postpartum weight changes. The reasons for weak correlations or non-significant associations between gestational WG and maternal and neonatal outcomes were probably owing to poor quality of obstetrics records and selection of wrong indicators to compute gestational WG. The choice of an indicator depends on clinical and research purpose, availability and reliability of data and cost. Considering the health implication of gestational WG, it is necessary to take into account the measurements used as initial and final weight, accuracy of gestational age estimation and the inclusion of fetal weight as part of maternal WG. Regardless of the indicators used to compute the weight changes after delivery, attention is drawn to the approach for designating prepregnancy weight, the time frame of postpartum weight measurements and the use of overlapping variables, which results in bias (part,whole correlation). It is necessary to address criticisms on the accuracy of prenatal weight measurements and the way of expressing the maternal weight changes during and after pregnancy in order to have reliable results from research. [source] Gestational age estimation on United States livebirth certificates: a historical overviewPAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 2007Megan L. Wier Summary Gestational age on the birth certificate is the most common source of population-based gestational age data that informs public health policy and practice in the US. Last menstrual period is one of the oldest methods of gestational age estimation and has been on the US Standard Certificate of Live Birth since 1968. The ,clinical estimate of gestation', added to the standard certificate in 1989 to address missing or erroneous last menstrual period data, was replaced by the ,obstetric estimate of gestation' on the 2003 revision, which specifically precludes neonatal assessments. We discuss the strengths and weaknesses of these measures, potential research implications and challenges accompanying the transition to the obstetric estimate. [source] New method for age estimation of developmental defects of enamel formation in living populationsAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 4 2010Rhonda Gillett-Netting Histologically based age of occurrence estimates for developmental defects of enamel (DDE) are raising questions about the continued utility of traditional macroscopic methods; however, the new techniques are not appropriate for use on living populations. This study, using methodology suitable for noninvasive use on living populations, compares assignment of defect timing using a histologically informed macroscopic method (HIMM) versus traditional methodology (TM). For this Southern African population, TM estimates later median age of DDE occurrence than HIMM (Z -score: ,13.565, P < 0.000) and modal age is 1 year earlier. HIMM allows for continued collection of DDE in living populations with the added benefit of more precise timing of enamel development. Accuracy for estimating general stressors during childhood is necessary for construction of diachronic analyses. Am. J. Hum. Biol., 2010. © 2010 Wiley-Liss, Inc. [source] Brief communication: A probabilistic approach to age estimation from infracranial sequences of maturation,AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2010Hélène Coqueugniot Abstract Infracranial sequences of maturation are commonly used to estimate the age at death of nonadult specimens found in archaeological, paleoanthropological, or forensic contexts. Typically, an age assessment is made by comparing the degree of long-bone epiphyseal fusion in the target specimen to the age ranges for different stages of fusion in a reference skeletal collection. While useful as a first approximation, this approach has a number of shortcomings, including the potential for "age mimicry," being highly dependent on the sample size of the reference sample and outliers, not using the entire fusion distribution, and lacking a straightforward quantitative way of combining age estimates from multiple sites of fusion. Here we present an alternative probabilistic approach based on data collected on 137 individuals, ranging in age from 7- to 29-years old, from a documented skeletal collection from Coimbra, Portugal. We then use cross validation to evaluate the accuracy of age estimation from epiphyseal fusion. While point estimates of age can, at least in some circumstances, be both accurate and precise based on the entire skeleton, or many sites of fusion, there will often be substantial error in these estimates when they derive from one or only a few sites. Because a probabilistic approach to age estimation from epiphyseal fusion is computationally intensive, we make available a series of spreadsheets or computer programs that implement the approach presented here. Am J Phys Anthropol 142:655,664, 2010. © 2010 Wiley-Liss, Inc. [source] Age estimation of archaeological remains using amino acid racemization in dental enamel: A comparison of morphological, biochemical, and known ages-at-deathAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2009R.C. Griffin Abstract The poor accuracy of most current methods for estimating age-at-death in adult human skeletal remains is among the key problems facing palaeodemography. In forensic science, this problem has been solved for unburnt remains by the development of a chemical method for age estimation, using amino acid racemization in collagen extracted from dentine. Previous application of racemization methods to archaeological material has proven problematic. This study presents the application to archaeological human remains of a new age estimation method utilizing amino acid racemization in a potentially closed system,the dental enamel. The amino acid composition and extent of racemization in enamel from two Medieval cemeteries (Newcastle Blackgate and Grantham, England) and from a documented age-at-death sample from a 19th century cemetery (Spitalfriedhof St Johann, Switzerland) were determined. Alterations in the amino acid composition were detected in all populations, indicating that diagenetic change had taken place. However, in the Medieval populations, these changes did not appear to have substantially affected the relationship between racemization and age-at-death, with a strong relationship being retained between aspartic acid racemization and the morphological age estimates. In contrast, there was a poor relationship between racemization and age in the post-medieval documented age-at-death population from Switzerland. This appears to be due to leaching of amino acids post-mortem, indicating that enamel is not functioning as a perfectly closed system. Isolation of amino acids from a fraction of enamel which is less susceptible to leaching may improve the success of amino acid racemization for archaeological age estimation. Am J Phys Anthropol, 2009. © 2009 Wiley-Liss, Inc. [source] | |||||||||||||||||||