Forensic Dental Age Estimation by Measuring Root Dentin Translucency Area Using a New Digital Technique

Dentin translucency measurement is an easy yet relatively accurate approach to postmortem age estimation. Translucency area represents a two‐dimensional change and may reflect age variations better than length. Manually measuring area is challenging and this paper proposes a new digital method using commercially available computer hardware and software. Area and length were measured on 100 tooth sections (age range, 19–82 years) of 250 μm thickness. Regression analysis revealed lower standard error of estimate and higher correlation with age for length than for area (R = 0.62 vs. 0.60). However, test of regression formulae on a control sample (n = 33, 21–85 years) showed smaller mean absolute difference (8.3 vs. 8.8 years) and greater frequency of smaller errors (73% vs. 67% age estimates ≤ ±10 years) for area than for length. These suggest that digital area measurements of root translucency may be used as an alternative to length in forensic age estimation.     

Quantification of Pubic Symphysis Metamorphosis Based on the Analysis of Clinical MDCT Scans in a Contemporary Malaysian Population

Forensic age estimation methods are biased to sex and population; in general, accuracy is reduced when applied to foreign populations. This study assessed the accuracy of the Suchey–Brooks method in contemporary Malaysian individuals and aimed to formulate population‐specific standards. Multi‐detector computed tomography scans of 355 individuals (165 male; 190 female) of 15–83 years of age were reconstructed using 3D‐volumetric rendering in RadiAnt. Pubic symphyseal phase, bias, inaccuracy, and percentage correct age classifications are examined. Transition analysis was used to develop age estimation standards. High observer agreement (κ = 0.763–0.832) and a positive relationship between age and pubic symphyseal phase (r = 0.884–0.90) were demonstrated. Mean inaccuracies were 8.62 and 8.95 years for males and females, respectively; overall correct classification was 97.8%. Transition ages between phases in males were 18.79, 23.29, 28.85, 43.64, and 61.15 years; in females, the corresponding data were 19.77, 22.53, 32.62, 41.85, and 57.39 years.     

The Reliability of the Greulich and Pyle Atlas When Applied to a Modern Scottish Population

This study examines the reliability of age estimation utilizing the Greulich and Pyle atlas in relation to a modern Scottish population. A total of 406 left‐hand/wrist radiographs (157 females and 249 males) were age‐assessed using the Greulich and Pyle atlas. Analysis showed that there was a strong correlation between chronological age and estimated age (females R² = 0.939, males R² = 0.940). When age groups were broken down into year cohorts, the atlas over‐aged females from birth until 13 years of age. The pattern for males showed that the atlas under‐estimated age until 13 years of age after which point it consistently over‐aged boys between 13 and 17 years of age. This study showed that the Greulich and Pyle atlas can be applied to a modern population but would recommend that any analysis takes into account the potential for over‐ and under‐aging shown in this study.     

Introducing Computed Tomography Standards for Age Estimation of Modern Australian Subadults Using Postnatal Ossification Timings of Select Cranial and Cervical Sites,

Contemporary, population‐specific ossification timings of the cranium are lacking in current literature due to challenges in obtaining large repositories of documented subadult material, forcing Australian practitioners to rely on North American, arguably antiquated reference standards for age estimation. This study assessed the temporal pattern of ossification of the cranium and provides recalibrated probabilistic information for age estimation of modern Australian children. Fusion status of the occipital and frontal bones, atlas, and axis was scored using a modified two‐ to four‐tier system from cranial/cervical DICOM datasets of 585 children aged birth to 10 years. Transition analysis was applied to elucidate maximum‐likelihood estimates between consecutive fusion stages, in conjunction with Bayesian statistics to calculate credible intervals for age estimation. Results demonstrate significant sex differences in skeletal maturation (p < 0.05) and earlier timings in comparison with major literary sources, underscoring the requisite of updated standards for age estimation of modern individuals.     

Ontogeny of Size and Shape Sexual Dimorphism in the Pubis: A Multislice Computed Tomography Study by Geometric Morphometry

Few studies have been conducted to determine sex differences in the immature coxal bone and the results were often contradictory. The authors studied sexual dimorphic differences of the pubis using geometric morphometric analysis of five osteometric landmarks recorded by multislice computed tomography (MSCT), based on three‐dimensional reconstructions of 188 children (95 boys, 93 girls) living in the region of Toulouse, southwestern France, ranging in age from 1 to 18 years old. They used geometric morphometric methodology first to test sexual dimorphism in size (centroid size) and shape (Procrustes residuals) and second to examine patterns of shape change with age (development) and size change with age (growth). Based on statistical significance test results, the pubic shape became sexually dimorphic at 13 years old, although visible shape differences were observed as early as 9 years old. This work showed that the trajectories of pubis shape (development) and size (growth) differed throughout ontogeny and between sexes.     

Using PMCT of Individuals of Known Age to Test the Suchey–Brooks Method of Aging in Victoria,Australia

The estimation of an individual's age at death plays a critical role in the investigation of unidentified human remains. The Suchey–Brooks method, which involves the analysis of degenerative morphological changes in the pubic symphysis, is currently widely used to estimate age in adults. This study tested the applicability of the Suchey–Brooks method on a contemporary adult Australian (Victorian) subpopulation by observing three‐dimensional volume‐rendered postmortem computed tomographic (PMCT) reconstructions of the pubic symphysis of 204 individuals aged 15–100 years. Results showed the method was reliable for females (85% correct allocations) but not for males (67% correct allocations). It is therefore recommended that extreme caution be used when applying the Suchey–Brooks method for estimating age at death of an individual in this subpopulation from PMCT images. The results suggest further investigation into alternate age estimation methods is required.     

The Use of CT Scans in Estimating Age at Death by Examining the Extent of Ectocranial Suture Closure

We examined the utility of CT scans in the evaluation of degree of ectocranial suture closure. Five cranial points (left and right midcoronal positions, left and right midlambdoidal positions, and the lambda) were evaluated in 231 CT scans using a three‐point scoring system (open, partial closed, and closed). The slice increment and thickness varied between three groups of the scans. The results showed a good correlation between degree of suture closure and increasing age in each group. Young individuals (<40 years) and old individuals (>60 years) could be clearly distinguished from the middle‐aged individuals. ANOVA test revealed no difference between two groups of scans and between left and right sides (p > 0.05). Interobserver agreement was good, especially considering the score by sides. The results of this study create the base for developing a robust and simple method to estimate the age at death using CT scans.     

Sexual Dimorphism of the Fetal Ilium: A 3D Geometric Morphometric Approach with Multislice Computed Tomography

Adult sexual dimorphism is well established. However, data regarding fetuses are sparse with contradictory results. Our study aimed to look for fetal sexual dimorphism. Multislice computed tomography (MSCT) examinations and three‐dimensional (3D) reconstructions were recorded on 93 fetal iliac bones aged between 21 and 40 weeks of amenorrhea (WA). The collection was divided into two age groups, with a cutoff at 30 WA. The 3D geometric morphometric analysis was based on outline analysis. We used elliptic Fourier analysis (EFA) because of the difficulty of landmark positioning. Step‐by‐step reconstructions allowed a better comprehension of the fine shape details. Principal component analysis (PCA) and linear discriminant analysis (LDA) were performed on the two age groups. Results did not show any difference between male and female shapes, in both age groups. We demonstrate the feasibility of outline analysis for immature shapes, but sexual dimorphism has not been established in our collection.     

The Utility of the Proximal Epiphysis of the Fifth Metatarsal in Age Estimation

Radiographs of 277 living individuals were assessed via a numerical scoring system to determine the timing of appearance and degree of fusion between the proximal epiphysis of the fifth metatarsal and its diaphysis. The epiphysis was observed to first appear in females at 8 years and 10 years in males and fuse by 14 years in females and 15 years in males. When assessing the level of agreement of category assignment, inter‐observer agreement was 78% for females and 64% for males whereas intra‐observer agreement was 77% for females and 86.1% for males. These results suggest that the maturation of the proximal epiphysis of the fifth metatarsal may be of value in age estimation in the child and that the scoring system is sufficiently robust to merit continued investigation. Previously this epiphysis has been considered an inconstant feature, but this research confirmed its presence in all individuals studied.     

Bone Mineral Density Adult Age Estimation in Forensic Anthropology: A Test of the DXAGE Application

Estimating age‐at‐death of individuals represented only by skeletonized human remains is a fundamental aspect of forensic anthropological casework. Recently, several researchers have proposed that bone mineral density (BMD) is a useful predictor of age‐at‐death in forensic contexts. Navega et al. (JFS 63(2):497–503) developed an online application called DXAGE for calculating age‐at‐death from BMD parameters. This study tests the utility of DXAGE by utilizing data from the National Health and Nutrition Examination Survey (NHANES). BMD data from a female subsample (n = 470) of the NHANES 2007–2008 dataset were analyzed, and the relationship between predicted age and real age was examined. Inaccuracy was 14.25 years, and bias was ?7.20 years. Results show that there is a weak correlation between predicted and actual age (r = 0.47) using the DXAGE application. While BMD data are potentially useful for predicting age age‐at‐death, the DXAGE application should be used cautiously in forensic anthropological contexts.     

Age Estimation from Radiographic Images of the Knee

This study examines the reliability of age estimation utilizing the Pyle and Hoerr atlas in relation to a modern Scottish population. The knee radiographs of 442 individuals (168 females, 274 males) were age assessed using the Pyle and Hoerr atlas. Analysis showed that there was a strong correlation between chronological age and estimated age (females R² = 0.968, males R² = 0.952). For females, the atlas method was most accurate between the ages of 9 and 15 years of age with an underage of 2.27 months and an overage of 2.38 months. For males, the atlas consistently overestimated age from the age of 9 years to the age of 16 years from between 0.14 and 8.81 months. The standard deviation for females was 9.86 months and for males was 10.75 months. This study showed that the Pyle and Hoerr atlas can be applied to a modern population with small modifications.     

Age at Death Estimation Using Multislice Computed Tomography Reconstructions of the Posterior Pelvis*

Abstract: Thanks to recent advances, computed tomography is now seen as a tool of great value in the field of physical anthropology. In this study, we focused on the posterior pelvis and the auricular surface and evaluated the accuracy of 3D reconstructions of the auricular surface, using a methodology derived from a previous study by Lovejoy et al. We also looked for trabecular bone criteria expressing age‐related changes. Forty‐six coxal bones were scanned, and scoring of macroscopic criteria showed a good agreement between 3D reconstructions and photographs, especially for transverse organization (k = 0.90). The changes occurring in the posterior part of the sacropubic trabecular bundle were evaluated on CT reconstructions via three new criteria, which exhibited a good intra‐ and inter‐observer agreement (k = 0.77–0.89), and were particularly useful in identifying older subjects. We concluded that these CT‐evaluated trabecular bone criteria are promising and yield useful information about age at death.     

A Comparative Assessment of the Chen et al. and Suchey‐Brooks Pubic Aging Methods on a North American Sample, ,

Accurately estimating the age‐at‐death of adult human skeletons is fundamental in forensic anthropology. This study evaluates the accuracy of two pubic bone age estimation methods—Chen et al. and Suchey‐Brooks. Specimens were obtained from a known collection of modern pubic bones curated at the Maricopa County Forensic Science Center in Phoenix, Arizona. A sample of 296 left male pubic bones of European ancestry was statistically evaluated via bias, absolute mean error, and intra‐ and inter‐observer error. Results indicate that the two methods are similar; the Suchey‐Brooks method is the most accurate for aging young adults (error c. 7 years), while the Revised Chen et al. method is most accurate for aging middle‐age adults (error c. 6 years). Thus, the Chen et al. method is an important contribution to forensic anthropology for aging older adult skeletal remains. There are, however, some limitations such as subjectivity and the intricate scoring system of Chen et al. method.     

Epiphyseal Union of the Cervical Vertebral Centra: Its Relationship to Skeletal Age and Maturation of Thoracic Vertebral Centra

Epiphyseal union stages for cervical vertebral centra (ring epiphyses) were documented for 55 individuals (females and males, ages 14–27 years) from the Terry Collection, using the Albert and Maples method 1, to examine both its relationship to age at death and to thoracic data collected from the same individuals using the same method. Results showed a moderate correlation between cervical ring union and age (r = 0.63, p = 0.000), and a fairly low correlation between cervical and thoracic ring union (r = 0.41, p = 0.002). Paired samples t‐tests yielded a statistically significant difference between cervical and thoracic union mean values (p = 0.01). Union progressed earlier in cervical vertebrae and in females. Results indicated fairly substantial variation in both sexes. Findings may serve as a basic guideline for estimating a general age range at death for unknown skeletal remains and to corroborate findings from other skeletal age indicators.     

Pubic Symphyseal Age Estimation from Three‐Dimensional Reconstructions of Pelvic CT Scans of Live Individuals

Skeletal age estimation using the pubic symphysis is a reliable and popular practice among forensic anthropologists. In instances in which accessing the skeleton is impossible, such as in the case of living individuals, three‐dimensional (3D) reconstructions of computed tomography (CT) scans can be created and analyzed for aspects of the biological profile. This study examined 3D reconstructions of pelvic CT scans of a sample of 44 live adults to estimate age using the Suchey–Brooks J Hum Evol 1990;5(3):227‐38 method. Images were created using OsiriX software (Pixmeo, Geneva, Switzerland). Estimated age ranges based on the 3D‐CT images captured the true age of the individual at the time of the CT scan 79.5% of the time with good intra‐observer reliability. The features best visualized on the 3D images included the ossific nodule and the pubic symphyseal rim. This study shows that clinical CT scanning parameters are adequate for creating 3D images to be analyzed for age using the pubic symphysis.     

Estimating Age of Majority on Third Molars Developmental Stages in Young Adults from Thailand Using a Modified Scoring Technique*

Abstract: The aim of this study was to achieve a referral database for dental age estimation of unaccompanied minors of Thai nationality. A total of 1199 orthopantomograms were collected from original Thai women and men equally divided in age categories between 15 and 24 years. On the radiographs, the developmental stage of the third molars was scored applying a modified scoring technique. Inter- and intra-observer reliabilities were tested using kappa statistics. Correlation between the scores of all four wisdom teeth and left–right symmetry were evaluated with Pearson’s correlation coefficient. Student’s t-test on asymmetry was performed and regression formulas were calculated. The present database was the first to assemble third molar developmental scores on radiographs of Thai individuals and provides more appropriate dental age estimation of unaccompanied Thai minors. Future research on similar databases of different nationalities worldwide may expose ethnical influences on dental development.     

Discrete Traits of the Sternum and Ribs: A Useful Contribution to Identification in Forensic Anthropology and Medicine

During forensic anthropological investigation, biological profile is determined by age, sex, ancestry, and stature. However, several individuals may share the same profile. Observation of discrete traits can yield useful information and contribute to identification. This research establishes the frequency of discrete traits of the sternum and ribs in a modern population in southern France, using 500 computer tomography (CT) scans of individuals aged 15–60 years. Only discrete traits with a frequency lower than 10% according to the literature were considered, a total of eight traits. All scans examined were three‐dimensional (3D) volume renderings from DICOM images. In our population, the frequency of all the discrete traits was lower than 5%. None were associated with sex or age, with the exception of a single trait, the end of the xiphoid process. Our findings can usefully be applied for identification purposes in forensic anthropology and medicine.     

Testing Reliability of the Computational Age‐At‐Death Estimation Methods between Five Observers Using Three‐Dimensional Image Data of the Pubic Symphysis,

In an effort to standardize data collection and analysis in age estimation, a series of computational methods utilizing high‐dimensional image data of the age indicator have recently been proposed as an alternative to subjective visual, trait‐to‐phase matching techniques. To systematically quantify the reproducibility of such methods, we investigate the intrascan variability and within‐ and between‐observer reliability in initial scan data capturing and editing using 3D laser scans of the Suchey–Brooks pubic symphysis casts and five shape‐based computational methods. Our results show that (i) five observers with various training background and experience levels edited the scans consistently for all three trials and the derived shape measures and age estimates were in excellent agreement among observers, and (ii) the computational methods are robust to a measured degree of scan trimming error. This study supports the application of computational methods to 3D laser scanned images for reliable age‐at‐death estimation, with reduced subjectivity.     

Age Estimation from the Teeth Using a Modified Demirjian System*

Abstract: The estimation of age at time of death is often an important step in the identification of human remains. The purpose of this study was to test the applicability of the Demirjian system on a sample of the Sydney child population and to develop and test age‐prediction models using a large sample of Sydney children (1624 girls, 1637 boys). The use of the Demirjian standards resulted in consistent overestimates of chronological age in children under the age of 14 by as much as a mean of 0.99 years. Of the alternative predictive models derived from the Sydney sample, those that provided the most accurate age estimates are applicable for the age ranges 2–14 years, with R‐square = 0.94 and a 95% confidence interval of ±1.8 years. The Sydney‐based standards provided significantly different and more accurate estimates of age for that sample when compared to the published standards of Demirjian.