Determination of male age at death in Chinese Han population: using quantitative variables statistical analysis from pubic bones

Determination of age at death by skeletal features is difficult, but important, both in forensic and physical anthropology. Pubic symphysis is a widely accepted morphological indicator, which provides the best result for personal age identification. Age prediction in this study used nine indicators of morphological changes, viz: ridges and furrows on the symphysial surface, ridge of pubic tubercle, lower extremity, ventral beveling, ossific nodules, dorsal margin, ventral rampart, general macroscopic changes of symphysial surface, and bone density of the symphysial surface. Samples were drawn from 262 male individuals. The study procedures are as follows: Firstly, we examined the morphological features of pubic symphysis using criteria similar to Hanihara's and Suchey-Brooks (SB). Secondly, we evaluated each stage with an appropriate score. Thirdly, we deduced four equations of male age assessment of morphological features by statistic analysis. The results were compared with Hanihara's and Suchey-Brooks method; the similarities and differences among them were discussed objectively. The method produced consistent results as well as developing the criteria of Hanihara's and Suchey-Brooks'.     

骨骼CT三维重建图像性别判定和年龄推断研究

目的通过计算骨骼计算机断层扫描(Computed Tomography,CT)三维重建图像判定性别和推断年龄的准确率,评价利用骨骼CT三维重建图像判定性别和推断年龄的可行性。方法将法医人类学教材中性别判定和年龄推断的方法应用于539例骨骼CT三维重建图像样本,判定245例骨盆的性别,推断100例男性耻骨联合、100例男性胸骨和94例男性锁骨的年龄,计算准确率。结果骨盆性别判定准确率为98.4%,耻骨下角和坐骨大切迹是区分性别最好的两项指标。男性耻骨联合、胸骨、锁骨的年龄推断准确率在45%以上,其中锁骨双侧方程准确率最高为77%。结论利用骨骼CT三维重建图像判定性别和推断年龄具有可行性。使用大体标本建立的骨盆形态学性别判定方法可直接应用于骨骼CT三维重建图像。使用大体标本建立的男性耻骨联合、胸骨、锁骨形态学年龄推断指标、分级和评分标准以及方程需要修改和补充。     

重建耻骨联合三维结构用于活体年龄推断的技术方法

目的建立基于MRI成像的快速耻骨联合三维结构重建技术方法。方法利用3.0 T超导磁共振仪对成年男性志愿者骨盆进行T1小角度快速激发3D梯度回波序列扫描,进行二值化阈值分割、区域增长提取骨盆软组织图像;运算获得耻骨联合三维结构模型雏形,经逆向工程软件降噪处理建立耻骨联合三维结构模型,并与耻骨CT扫描三维结构重建模型进行比较。结果耻骨联合面沟嵴、下端、腹侧缘(斜面)、背侧缘(斜面)、耻骨结节等结构显示完整,无明显噪点,与CT扫描三维重建模型吻合较好。结论 MRI扫描成像可实现快速有效的耻骨联合三维结构重建,可为法医活体年龄推断提供安全无辐射作用的三维可视化影像学技术方法。     

Age Estimation of Adult Living Donor by Pubic MSCT Three-dimensional ReconstructionCSCD

Objective: To establish a method for the age estimation of adult living donor based on pubic MSCT three-dimensional reconstruction and verify its accuracy and reliability. Methods: The volume rendering (VR)image data of pubic symphysis surface were collected from 300 volunteers aged over 17 years old. According to different age groups, the age estimation of these volunteers was performed by the method and formula of pubic symphysis surface. Results: In the 300 volunteers, the difference between biological age and actual age was <1 year in 117 cases, >1-2 years in 178 cases, >2 years in 5 cases. Conclusion: MSCT three-dimensional reconstruction technology of pubic symphysis surface can be used to estimate the age of adult living donor, which can provide a high accurate and reliable result. © 2018 by the Editorial Department of Journal of Forensic Medicine.     

Time burnt away: The impact of heat-induced changes on skeletal age-at-death diagnostic features

This paper investigates the established notion that bone calcination has a major impact on age estimation while low-intensity burns have a mere negligible impact. Few systematic researches have been carried out so far about this topic so the true impact of heat-induced changes on diagnostic age features is mostly unknown.The agreement between pre-burning and post-burning observations of age features was investigated on 51 human skeletons (22 males and 29 females with ages-at-death ranging from 61 to 93 years old) subjected to experimental burns. These skeletons belong to the 21st Century Identified Skeletal Collection housed at the Laboratory of Forensic Anthropology of the Department of Life Sciences, University of Coimbra, Portugal. The Suchey-Brooks method based on the pubic symphysis and the method developed on the auricular surface by Buckberry and Chamberlain (2002) were scrutinized.The Suchey-Brooks method provided better agreement between pre- and post-burn observations than the method from Buckberry and Chamberlain (2002). However, it became clear that heat-induced changes affected both methods regardless of heat intensity since both calcined bones and bones burnt at lower intensities often showed less than perfect agreement. Therefore, this research demonstrates that the analysis of age-at-death can be impaired in burnt bones, even those not subjected to calcination, with clear impact for forensic and archaeological investigations.     

Evaluation of cast methods for estimating age from the os pubis.

Age-related changes of the pubic symphysis have gained wide acceptance among physical anthropologists as one basis for estimating adult skeletal age. However, these methods have not been tested by independent observers on large samples with known ages at death that represent contemporary populations. In this study 202 female and 116 male pairs of pubes collected at autopsy were blindly evaluated for age using the McKern-Stewart or Gilbert-McKern and Suchey-Brooks methods. Performance of the methods was measured by mean absolute deviation of true age from scored interval means and frequencies of true age falling within +/- 1 and +/- 2 standard deviations from the mean. The results suggest that the Suchey-Brooks methods are superior in forensic applications and that the racially specific refinement for males should be used. Age estimates should include +/- 2 standard deviations, and chances of error should be considered, especially when advanced age or debilitation is suspected.     

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.     

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.     

Application of the Iscan method to two- and three-dimensional imaging of the sternal end of the right fourth rib

Age determination is a major field of interest in physical and forensic anthropology. Among the different methods based on macroscopic skeletal study, the Iscan method, which analyzes the sternal end of the right fourth rib, is one of the most reliable. We applied the Iscan method to two- and three-dimensional multislice computed tomography (MSCT) reconstructions of the sternal end of the right fourth rib on 39 ribs. The intra-observer variability on MSCT reconstructions was good (gamma coefficient equal to 0.86; value of the Krippendorff's alpha reliability equal to 0.79); inter-observer variability on MSCT reconstructions was also good (gamma coefficient ranging from 0.82 to 0.88; value of the Krippendorff's alpha reliability ranging from 0.78 to 0.86). We demonstrated excellent agreement between the results of analysis of bone samples and those of the two- and three-dimensional images, in particular regarding bone projections, morphology of the pit and of its rim. The accuracy of age estimation did not significantly differ between the Iscan method applied to dry bones and the same method applied to MSCT images. Determination of the Krippendorff's alpha reliability coefficient for the inter-error method confirmed the agreement between phase estimations obtained with the two methods (ranging from 0.55 to 0.71). The real civil age was comprised in 21 cases out of 36 for assessment performed on dry bones and in 23 cases out of 36 on MSCT reconstructions, which represented 58.3% and 63.9%, respectively. Use of MSCT reconstructions in forensic anthropology offers many advantages: no bone preparation, no damage to bone material, and the possibility of application to living individuals.     

Pubic bone age estimation in adult women

In recent years, numerous physical anthropologists have pointed out the need for regional standards for estimating age in various world populations. While investigating aging methods for East European populations, dramatic changes were noted in the pubic symphyseal morphology and structure of older adult female individuals. These changes were not captured in the typically used pubic symphysis aging methods. This paper defines and tests the need for a new phase, phase VII, that follows the Suchey-Brooks phase VI. In addition, Suchey-Brooks phases V and VI are redefined. Phase definitions, decision-making rules, and comparison graphics for the new method are presented. Balkan (n = 85) and Eastern Tennessee (n = 104) samples, totaling 189 individuals, were used in the analysis. Pearson correlation coefficients between four observers and a control seriation were strong, indicating ease of replicability between investigators. No statistically significant intra-observer error was detected. Summary statistics show that individuals in phase V were on average in the early 50s, while individuals in phase VI were in their mid 50s to mid 60s, and individuals in phase VII were in their mid 70s. Since linear regression models tend to under-age the elderly and over-age the young, transition analysis, using an unrestricted cumulative probit model, was undertaken to evaluate the phases and to produce point estimates for the ages-at-transition for the Balkan sample. The highest posterior density region point estimates with their associated upper and lower bounds can be used for predicting age for unknown forensic cases related to the Balkan sample. Further, the mean ages and standard deviations for phases V-VII for the Tennessee sample are presented for use in American forensic cases.     

Evaluation of the Suchey-Brooks method for aging skeletons in the Balkans

This study has been carried out to examine whether the Suchey-Brooks (S&B) methods could be successfully applied in age assessment of populations from the Balkans. The known-age sample consists of 33 females and 52 males pairs of pubic bones collected from the autopsy cases. Age estimation by S&B method showed an accuracy of 89.74% in males and 72.0% in females. Statistical analysis showed a positive correlation between the actual age of the investigated individuals and age phases obtained by the S&B method, although the mean values of the sixth age category differed significantly compared with the original model. The most reliable indicators in both sexes were the relief of the symphyseal surface, lipping, symphyseal rim, and dorsal margin. The discriminating power of these indicators was the least reliable in distinguishing S&B phases 2 and 3. Based on these results, the appropriate recommendations for aging Serbian populations are made. There was a good agreement between two observers (kappa=0.726).     

Age estimation from the human os coxa: a test on a documented Italian collection*

Current standards for age at death estimation from the pelvis are based on Americans of European and African ancestry. Our limited understanding of population variability hampers our efforts to apply these techniques to the various skeletal populations around the world, especially in global forensic contexts. However, documented skeletal samples are rare, limiting our ability to test our techniques. This study tested the Suchey-Brooks pubic symphysis aging method and the auricular surface method originally developed by Lovejoy et al. on a large sample (n = 404) of known sex and age from the Sassari Collection, housed at the Museum of Anthropology at the University of Bologna, Italy. The results indicate that for both methods, bias and inaccuracy increased with age and actual age tended to be underestimated over the age of 40. The auricular surface method performed slightly better, exhibiting slightly lower levels of bias and inaccuracy, especially for males.     

Current practices by forensic anthropologists in adult skeletal age estimation

When determining an age estimate from adult skeletal remains, forensic anthropologists face a series of methodological choices. These decisions, such as which skeletal region to evaluate, which methods to apply, what statistical information to use, and how to combine information from multiple methods, ultimately impacts the final reported age estimate. In this study, a questionnaire was administered to 145 forensic anthropologists, documenting current trends in adult age at death estimation procedures used throughout the field. Results indicate that the Suchey-Brooks pubic symphysis method (1990) remains the most highly favored aging technique, with cranial sutures and dental wear being the least preferred, regardless of experience. The majority of respondents stated that they vary their skeletal age estimate process case-by-case and ultimately present to officials both a narrow and broad possible age range. Overall, respondents displayed a very high degree of variation in how they generate their age estimates, and indicated that experience and expertise play a large role in skeletal age estimates.     

Effects of Parturition on Pelvic Age Indicators

This research assessed whether parity has a differential effect on age indicators of the pelvis. The data were collected from the William M. Bass Donated Skeletal Collection. Age indicators of the pubic symphysis and auricular surface were assessed using the Todd, Suchey–Brooks, Lovejoy et al., and Buckberry and Chamberlain scoring systems. A transition analysis was conducted, and scoring systems of the pubic symphysis showed the parous female group transitioning between eight and 14 years earlier than the nulliparous female and male groups, and 1 and 7 years earlier using the auricular surface methods. A likelihood ratio test produced significantly different results between parous and nulliparous females using the pubic symphysis (p < 0.01) but not the auricular surface (p > 0.05). Although parous females were inaccurately assessed more often than nulliparous females, no correction of methods is necessary at this time as current standards take parity into account by utilizing a lumped female sample.     

A Comparison of Different Age Estimation Methods of the Adult Pelvis

The adult human pelvis is useful to estimate age because it contains three age indicators—the pubic symphysis, auricular surface, and acetabulum. This study tested the accuracy, inaccuracy, and bias of age estimation from the Suchey‐Brooks pubic symphysis, Osborne auricular surface, Rissech and Calce acetabulum aging methods, and a summary age of these indicators. The study sample consisted of 212 White individuals with known age and sex from the William M. Bass Donated Skeletal Collection. The Rissech method performed the best, was the most accurate method with smallest inaccuracy and bias, followed by the Osborne, Suchey‐Brooks, summary age, and then Calce methods. Though the Pearson correlation showed only the Suchey‐Brooks method to correlate significantly with known age, it is likely the Suchey‐Brooks study sample coincidentally reflected the age distribution of this test sample. Results suggested that Bayesian prediction may improve age estimation and should be applied to other age indicators.     

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.     

The Utility of the Samworth and Gowland Age‐at‐Death “Look‐up” Tables in Forensic Anthropology*

Abstract: Accurate age‐at‐death estimates are crucial to forensic anthropologists when onstructing biological profiles aimed at narrowing a missing‐persons list and to allow for timely and efficient identification of an unknown victim. The present contribution evaluates the utility of three new age‐at‐death estimation techniques recently proposed by Samworth and Gowland (2007). Results indicate that, in the samples under study, the Samworth and Gowland estimates from the pubic symphysis and auricular surface perform similar to alternate phase methods. The combined method does not appear to further enhance either the precision or the accuracy of the single pubic symphysis age‐at‐death estimate. In conclusion, these new methods seem to be more robust to distribution deviations than originally proposed by Samworth and Gowland (2007). They are therefore suitable for immediate and reliable forensic usage in the United States and worthy of further research for their use in North American forensic contexts.     

The age at death assessment in a multi-ethnic sample of pelvic bones using nature-inspired data mining methods

Recently published studies showed that age assessment methods are population specific. Authors analyse the senescence changes in pubic symphysis and sacro-pelvic surface of a pelvic bone using data mining methods. The multi-ethnic data set consists of 956 adult individuals ranging from 19 to 100 years of age derived from 9 different populations with known age and sex. The results show that accurate and reliable age assessment is possible to three age classes (less than 30, 30-60, 60 and more). The study confirms that population specificity of the methods exists and the variable "sex" is not important in age classification.     

Assessing age-related morphology of the pubic symphysis from digital images versus direct observation

The increasingly global role of a forensic anthropologist necessitates a proper means for archiving evidence for re-examination. Large quantities of evidence can be stored and be made readily accessible through digital imaging. This study focuses on age assessment from digital photographs for personal identity reconstructions. A comparison of 52 Suchey-Brooks scores assigned to digital images and actual bone revealed that age assessment from digital images can be completed with accuracy. Coefficients of concordance imply that there significant agreement between osteological assessment of aging criteria from digital images and direct observation-greater than random change alone (p < 0.05). However, assessments from images should be approached with caution since there are inherent limitations of the naked eye in identifying morphological changes in certain skeletal features, especially where older adults are concerned. Although there is no replacement for a hands-on physical assessment, a digital archive may facilitate the global needs of the forensic anthropologist.     

Estimation and evidence in forensic anthropology: age-at-death

A great deal has previously been written about the use of skeletal morphological changes in estimating ages-at-death. This article looks in particular at the pubic symphysis, as it was historically one of the first regions to be described in the literature on age estimation. Despite the lengthy history, the value of the pubic symphysis in estimating ages and in providing evidence for putative identifications remains unclear. This lack of clarity primarily stems from the fact that rather ad hoc statistical methods have been applied in previous studies. This article presents a statistical analysis of a large data set (n = 1766) of pubic symphyseal scores from multiple contexts, including anatomical collections, war dead, and victims of genocide. The emphasis is in finding statistical methods that will have the correct "coverage."Coverage" means that if a method has a stated coverage of 50%, then approximately 50% of the individuals in a particular pubic symphyseal stage should have ages that are between the stated age limits, and that approximately 25% should be below the bottom age limit and 25% above the top age limit. In a number of applications it is shown that if an appropriate prior age-at-death distribution is used, then "transition analysis" will provide accurate "coverages," while percentile methods, range methods, and means (+/-standard deviations) will not. Even in cases where there are significant differences in the mean ages-to-transition between populations, the effects on the stated age limits for particular "coverages" are minimal. As a consequence, more emphasis needs to be placed on collecting data on age changes in large samples, rather than focusing on the possibility of inter-population variation in rates of aging.