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.     

Validation of the Acetabulum As a Skeletal Indicator of Age at Death in Modern European‐Americans,

Progressive changes in the acetabulum have been used in modern skeletal age estimation, but they have not been completely understood. If their age correlations are weakened by the influence of factors like physical activity and obesity, acetabular changes should not be used for age estimation. To investigate their utility for aging, the acetabular variables of Rissech et al. (2006) were analyzed in 409 modern European‐Americans (Bass Collection, Tennessee). Correlation tests assessed potential associations between acetabular data, osteoarthritis scores (collected per Jurmain, 1990), and documented demographic information (age, body mass index [BMI], metabolic intensity of physical activities). Acetabular changes had statistically significant, positive correlations with osteoarthritis (p < 0.001 in most joints/regions) and age (p < 0.001), indicating their degenerative nature and relevance for age estimation. Acetabular changes showed no associations with BMI or metabolic values, suggesting resistance to obesity and activity effects. These results suggest that acetabular degeneration is a valid skeletal age‐at‐death indicator.     

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.     

Internal Morphological Analysis for Age Estimation of Blow Fly Pupae (Diptera: Calliphoridae) in Postmortem Interval Estimation*

Abstract: Larvae and pupae of blow fly species are frequently used in postmortem interval estimation, their age indicating minimum time since death. Most studies have considered age estimation of larvae, neglecting study of pupae. Relative development of external pupal features is useful, but there are also internal changes during metamorphosis that may be indicators of age, utilizing histological techniques. This study aimed to optimize preservation and histological analysis of blow fly pupae, specifically Calliphora vicina Robineau‐Desvoidy and Lucilia sericata (Meigen), and to examine internal features with potential for age estimation. Effect of hot‐water‐killing and different preservatives were examined. It was determined that blow fly pupae should be pierced through the three tagma, hot‐water‐killed, and preserved in 80% ethanol as the optimal preservation for subsequent analyses. Hematoxylin and eosin stained pupal sections revealed differences in brain and thoracic muscle development throughout the pupal stage with potential for age estimation.     

Thyroid Cartilage Ossification and Multislice Computed Tomography Examination: A Useful Tool for Age Assessment?

Abstract: Many authors have studied the thyroid cartilage ossification process using radiographic features for age estimation of individuals. Their results were various: Sugiyama reported excellent correlation coefficients between ossification rates and civil age, unlike most other authors. We hypothesized that recent advances in imaging techniques would enable more precise evaluation of the ossification of the thyroid cartilage. We retrospectively analyzed the CT scans of 312 French patients using postprocessing software to examine the pattern of thyroid cartilage ossification, calculating the ossified volume of the cartilage on 3D reconstructions. Pearson’s correlation coefficients for volume were 0.73 for men and 0.75 for women (standard error 18.02 and 17.06), indicating considerable inter‐individual variability. Although a correlation between civil age and morphological changes was found, these methods based on thyroid cartilage ossification were not accurate enough for the assessment of individual age.     

A Test of Hartnett's Revisions to the Pubic Symphysis and Fourth Rib Methods on a Modern Sample

Estimating age at death is one of the most important aspects of creating a biological profile. Most adult age estimation methods were developed on North American skeletal collections from the early to mid‐20th century, and their applicability to modern populations has been questioned. In 2010, Hartnett used a modern skeletal collection from the Maricopia County Forensic Science Centre to revise the Suchey‐Brooks pubic symphysis method and the ??can et al. fourth rib methods. The current study tests Hartnett's revised methods as well as the original Suchey‐Brooks and ??can et al. methods on a modern sample from the William Bass Skeletal Collection (N = 313, mean age = 58.5, range 19–92). Results show that the Suchey‐Brooks and ??can et al. methods assign individuals to the correct phase 70.8% and 57.5% of the time compared with Hartnett's revised methods at 58.1% and 29.7%, respectively, with correctness scores based on one standard deviation of the mean rather than the entire age range. Accuracy and bias scores are significantly improved for Hartnett's revised pubic symphysis method and marginally better for Hartnett's revised fourth rib method, suggesting that the revised mean ages at death of Hartnett's phases better reflect this modern population. Overall, both Hartnett's revised methods are reliable age estimation methods. For the pubic symphysis, there are significant improvements in accuracy and bias scores, especially for older individuals; however, for the fourth rib, the results are comparable to the original ??can et al. methods, with some improvement for older individuals.     

Modeling Bone Surface Morphology: A Fully Quantitative Method for Age‐at‐Death Estimation Using the Pubic Symphysis

The pubic symphysis is widely used in age estimation for the adult skeleton. Standard practice requires the visual comparison of surface morphology against criteria representing predefined phases and the estimation of case‐specific age from an age range associated with the chosen phase. Known problems of method and observer error necessitate alternative tools to quantify age‐related change in pubic morphology. This paper presents an objective, fully quantitative method for estimating age‐at‐death from the skeleton, which exploits a variance‐based score of surface complexity computed from vertices obtained from a scanner sampling the pubic symphysis. For laser scans from 41 modern American male skeletons, this method produces results that are significantly associated with known age‐at‐death (RMSE = 17.15 years). Chronological age is predicted, therefore, equally well, if not, better, with this robust, objective, and fully quantitative method than with prevailing phase‐aging systems. This method contributes to forensic casework by responding to medico‐legal expectations for evidence standards.     

Forensic age estimation on digital X-ray images: Medial epiphyses of the clavicle and first rib ossification in relation to chronological age

In recent years, there has been a renewed interest in forensic sciences about forensic age estimation in living subjects by means of radiological methods. This research was conducted on digital thorax X-rays to test the usefulness of some radiological changes in the clavicle and first rib. The sample consisted in a total of 123 subjects of Spanish origin (61 men and 62 women; age range: 5-75 years). From all subjects, a thorax posterior-anterior radiograph was obtained in digital format. Scoring for fusion of medial epiphyses of the clavicle was carried out by Schmeling's system and ossification of the costal cartilage of the first rib by Michelson's system. Degree of ossification and epiphyseal fusion were analyzed in relation with known age and sex of these subjects. The results give a minimum age of >20 years for full fusion of the medial epiphysis of the clavicle (Stages 4 and 5). Concerning the first rib, all subjects with the final Stage 3 of ossification were above 25 years of age. These results suggest that the first rib ossification might become an additional method to the ones so far recommended for forensic age estimation in subjects around 21. New research would be desirable to confirm this suggestion.     

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.     

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.     

Accuracy of Dental Age in Nonadults: A Comparison of Two Methods for Age Estimation Using Radiographs of Developing Teeth

This research tests the accuracy of two methods for age estimation, Cameriere's European formula and AlQahtani's London Atlas, on a multi‐population American sample. Digitized radiographs of 360 European American, Hispanic, and American Indian children aged 6–17 years were analyzed. The accuracy of these methods was assessed using the mean and absolute mean difference of the residuals. Results indicate that Cameriere's European formula underestimated age for both sexes, with a mean difference of ?1.19 years for girls and ?1.32 years for boys, prompting the first author to create an American‐specific formula. The London Atlas underestimated age with a mean difference of ?0.18 years for girls and ?0.16 years for boys. Sex and ancestry had no significant affect on accuracy. The results indicate that both methods can be used for age estimation in an American population.     

Age Estimation in Living Adults using 3D Volume Rendered CT Images of the Sternal Plastron and Lower Chest

Age estimation is commonly of interest in a judicial context. In adults, it is less documented than in children. The aim of this study was to evaluate age estimation in adults using CT images of the sternal plastron with volume rendering technique (VRT). The evaluation criteria are derived from known methods used for age estimation and are applicable in living or dead subjects. The VRT images of 456 patients were analyzed. Two radiologists performed age estimation independently from an anterior view of the plastron. Interobserver agreement and correlation coefficients between each reader's classification and real age were calculated. The interobserver agreement was 0.86, and the correlation coefficients between readers classifications and real age classes were 0.60 and 0.65. Spearman correlation coefficients were, respectively, 0.89, 0.67, and 0.71. Analysis of the plastron using VRT allows age estimation in vivo quickly and with results similar than methods such as Iscan, Suchey–Brooks, and radiographs used to estimate the age of death.     

Ossification Degrees of Cranial Sutures Determined with Flat‐Panel Computed Tomography: Narrowing the Age Estimate with Extrema

Abstract: Since Broca’s time (1824–1880), ossification of the neurocranial sutures has been used as a characteristic of age. Current approaches include the visual macroscopic examination of ecto and endocranial sutures. The evaluation of the cross‐section of sutures usually necessitates the destruction of the neurocranium. In a nondestructive alternative approach that was tested within the context of the “Digital Forensic Osteology” project that ran in cooperation with the Virtopsy^®‐Project, it emerged that the resolution of conventional multi‐slice computed tomography data sets was not high enough to image sutures. Thus for the experiments presented here, the eXplore Locus Ultra flat‐panel computed tomography scanner from GE Healthcare was used. Calottes were scanned during autopsy and then immediately returned to the corpse. So far, the skullcaps of 221 individuals have been scanned. The cross‐sections of 14 suture segments could be assessed for seven previously defined stages of ossification. In a converse step, the 14 highest and lowest age estimate values corresponding to the individual stages of suture closure found were estimated for each calotte. The obtained ranges narrowing down the age estimate were evaluated with statistics. A mean value of 43.31 years for the range of narrowed age estimates shows that this method can be a useful aid in estimating age. The results of intra‐ and inter‐observer tests showed good overall agreement between the findings of three observers. This method is suitable for a nondestructive age estimation and can be used for the entire calotte.     

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.     

A Test of the Revised Auricular Surface Aging Method on a Modern European Population

The accurate age estimation of adults is an important step in the construction of the biological profile of skeletonized remains. The auricular surface of the ilium as it was developed in 1985 by Lovejoy et al., is one of the methods employed for age estimation. This study presents the results of a blind test of the revised auricular surface aging method developed by Buckberry and Chamberlain. A sample of 120 individuals from the Athens Collection was used to test this revised aging technique. Almost all features and composite score were positively correlated with known age‐at‐death. The calculation of bias demonstrated no obvious trend for either overestimation or underestimation of age when all individuals were pooled together. Inaccuracy showed that absolute errors of estimated ages against known ages are substantial. The data generated from this study suggest that the revised method can be reliable for age estimation on a modern European population.