Fetal Age Assessment From Primary Teeth and Long Bones.

ABSTRACT: This study evaluated traditional and expedited methods for assessing the age of fetal remains. Because of their rare occurrence, the discovery of fresh, decomposing, disfigured, or skeletal fetuses engenders heightened awareness by forensic pathologists primarily tasked with age estimation in relation to viability. With decomposed complete or isolated fetal remains, dentists focus on primary molar mineralization, whereas anthropologists perform long bone measurements along with discernment of other indicators of skeletal maturity to obtain an age estimation.The results of this study are 4-fold: (1) The "best" technique for harvesting fetal tooth buds and long bones is the dissection of the developing tooth buds with maceration for the long bones. (2) Metric analysis was applied to the tooth buds and long bones for age estimation, and the findings were correlated. (3) There is a statistically significant difference between known age and dental age and between dental age and long bone age. The difference between known age and long bone age is not statistically significant, but a type II error exists because of the small sample size. (4) A central incisor staging technique for fetuses younger than 26 weeks was developed as a supplement to the molar staging system of Kraus and Jordan (1965).

Investigation of salivary biomarkers as indicators of skeletal and dental maturity in children.

OBJECTIVE: Estimation of patient's skeletal maturity in orthodontics is essential for the diagnosis and treatment planning. The aim of the study was to investigate the potential use of metabolic fingerprint of saliva for bone growth and tooth development estimation. MATERIALS AND METHODS: Saliva samples from 54 young patients were analysed by an untargeted gas chromatography-mass spectrometry metabolomics-based method. The skeletal maturity was calculated with the cervical vertebrae maturation method, and the dental age was estimated with the Demirjian method. Multivariate analysis and univariate analysis were performed to investigate differences within skeletal, dental and chronological age groups. RESULTS: Metabolomic analysis identified 61 endogenous compounds. Mannose, glucose, glycerol, glyceric acid and pyroglutamic acid levels differentiated significantly with skeletal age (P = .02 to .043), while mannose, lactic acid, glycolic acid, proline, norleucine, 3-aminoisobutyric acid, threonine, cadaverine and hydrocinnamic acid levels differed within the dental age groups (P = .018 to .04); according to the chronological age, only the levels of mannose and 3-hydroxyphenylacetic acid showed variation (P = .029 and .048). The principal component analysis did not manage to highlight differences between the groups of the studied parameters. CONCLUSION: Differentiated levels of mannose, glucose, glycerol, glyceric acid and pyroglutamic acid related to skeletal maturation were identified. According to dental development, the levels of mannose, lactic acid, glycolic acid, proline, norleucine, 3-aminoisobutyric acid, threonine, cadaverine and hydrocinnamic acid differed within the groups, while regarding chronological age, only the levels of mannose and 3-hydroxyphenylacetic acid showed variations. Further studies are required to prove their relation to skeletal and dental development pathway by applying complementary analytical techniques to wider cover the metabolome.

Molecular clocks in ancient proteins: Do they reflect the age at death even after millennia?

Age at death estimation in cases of human skeletal finds is an important task in forensic medicine as well as in anthropology. In forensic medicine, methods based on "molecular clocks" in dental tissues and bone play an increasing role. The question, whether these methods are applicable also in cases with post-depositional intervals far beyond the forensically relevant period, was investigated for two "protein clocks", the accumulation of D-aspartic acid (D-Asp) and the accumulation of pentosidine (Pen) in dentine. Eight teeth of skeletons from different burial sites in Austria and with post-depositional intervals between c. 1216 and c. 8775 years were analysed. The results of age at death estimation based on D-Asp and Pen in dentine were compared to that derived from a classical morphological examination. Age at death estimation based on D-Asp resulted consistently in false high values. This finding can be explained by a post-mortem accumulation of D-Asp that may be enhanced by protein degradation. In contrast, the Pen-based age estimates fitted well with the morphological age diagnoses. The described effect of post-mortem protein degradation is negligible in forensically relevant time horizons, but not for post-depositional intervals of thousands of years. That means that the "D-Asp clock" loses its functionality with increasing post-depositional intervals, whereas Pen seems to be very stable. The "Pen-clock" may have the potential to become an interesting supplement to the existing repertoire of methods even in cases with extremely long post-depositional intervals. Further investigations have to test this hypothesis.

Paleodemographic analysis of age at death for a population of Black Sea Scythians: An exploration by using Bayesian methods.

OBJECTIVES: Studies of the demography of past populations involving deterministic life tables can be criticized for ignoring the errors of estimation. Bayesian methods offer an alternative, by focusing on the uncertainty of the estimates, although their results are often sensitive to the choice of prior distributions. The aim of this study is to explore a range of Bayesian methods for estimating age at death for a population of nomadic warriors-Scythians from the Black Sea region. MATERIALS AND METHODS: In total, skeletons of 312 individuals (93 children and 219 adults) from Glinoe (Moldova), dated to the 5th-2nd century BCE, were examined. We unified the age categories corresponding to different aging methods, allowing an application of a probabilistic assessment of the age categorization. A hierarchical Bayesian multinomial-Dirichlet-Dirichlet model was applied, with a hypothetical, subjective reference population, a real reference population, and no reference. RESULTS: Stationary-population life expectancy was estimated as 27.7 years (95% CI: 25.1-30.3) for a newborn (e0 ), and 16.4 years (14.0-19.0) for 20-year-olds (e20 ), although with high uncertainty, and sensitive to the model specification. Slight differences in longevity between different social strata and between the Classical and Late chronological periods were found, although with high estimation errors. A more robust finding, confirming earlier studies, was a high probability of death in young adulthood, which could depend on Scythian lifestyle (conflicts, wars). DISCUSSION: Our study shows a way to overcome some limitations of broad age categorization by using the Bayesian approach with alternative model specifications, allowing to assess the impact of reference populations.

Evaluation of the accuracy of the Nolla method for the estimation of dental age of children between 4-14 years old in Spain: A radiographic study.

The aim of this study was to estimate the age of subjects from their dental age by showing the different stages of tooth development using the Nolla method in a Spanish population sample considering the gender, age group, and the development of the two dental arches. The sample consisted of 604 orthopantomographs corresponding to Spanish children (male: 302 and female: 302) aged from 4 to 14 years old. The resulting chronological and dental ages were compared using Student's t-test. We obtained a good index of agreement between the evaluators and good internal consistency in the evaluation of the ages of the teeth. In general, the dental age estimates were lower than the chronological ages, obtaining an underestimation with the application of the Nolla method. In the male group, the average dental age of the maxillary teeth was 8.36 years and that of the mandibular teeth was 8.40 years, compared to the chronological age of 8.84 years in both cases. In the female group, the average dental age of the maxillary teeth was 7.76 years and that of the mandibular teeth was 7.88 years, compared to the chronological age of 8.70 years in both cases. On applying the Nolla method to our sample, a significant overestimation was observed only in children aged between 4 and 6.9 years. The Nolla method can be used as a complementary tool for estimating age in children of Spanish origin. The application of this method is more favourable in the case of individuals evaluated under the law applied to minors. In general, with this method, age is underestimated, but the calculations involved are reliable, and greater precision has been observed in male than in female. The data from this study can be used as a reference to determine the dental maturity of Spanish children and to estimate their ages.

Three-dimensional analysis of third molar development to estimate age of majority.

Third molars are one of the few biological markers available for age estimation in undocumented juveniles close the legal age of majority, assuming an age of 18years as the most frequent legal demarcation between child and adult status. To obtain more accurate visualization and evaluation of third molar mineralization patterns from computed tomography images, a new software application, DentaVol©, was developed. Third molar mineralization according to qualitative (Demirjian's maturational stage) and quantitative parameters (third molar volume) of dental development was assessed in multi-slice helical computed tomography images of both maxillary arches displayed by DentaVol© from 135 individuals (62 females and 73 males) aged between 14 and 23years. Intra- and inter-observer agreement values were remarkably high for both evaluation procedures and for all third molars. A linear correlation between third molar mineralization and chronological age was found, with third molar maturity occurring earlier in males than in females. Assessment of dental development with both procedures, by using DentaVol© software, can be considered a good indicator of age of majority (18years or older) in all third molars. Our results indicated that virtual computed tomography imaging can be considered a valid alternative to orthopantomography for evaluations of third molar mineralization, and therefore a complementary tool for determining the age of majority.

Relative dental maturity and associated skeletal maturity in prehistoric native Americans of the Ohio valley area.

Estimation of age-at-death of subadults in prehistoric skeletal samples based on modern reference standards rests on a number of assumptions of which many are untestable. If these assumptions are not met error of unknown magnitude and direction will be introduced to the subadult age estimates. This situation suggests that an independent estimate or estimates of age-related features, free of most of the assumptions made when using modern reference standards may be useful supplements in evaluating the age of subadults in prehistoric samples. The present study provides an internally consistent, population-specific measure of maturity for prehistoric Ohio valley Native Americans based on the seriation of dental development that may be used as a supplement to age-estimation. The developing dentition of 581 subadults from eight Ohio valley prehistoric-protohistoric groups was seriated within and among individuals resulting in a sequence of tooth development and a sequence of individuals from least to most mature. Dental maturity stages or sorting categories were then defined based on exclusive, easily observable, and highly repeatable tooth-formation stages. Tooth eruption (into occlusion), bone lengths, and fusion of skeletal elements are summarized by dental maturity stage. This procedure provides maturity estimates for skeletal features ordered by dental maturity stages derived from the same sample thus making explicit the relationship between dental and skeletal maturity.