In vivo facial tissue depth study of Chinese-American adults in New York City

This study examines facial tissue depth in adult Chinese-Americans. Using ultrasound, measurements were taken at 19 landmarks across the faces of 101 individuals aged from 18 to 87 years. Summary statistics are reported for a sample of 67 individuals of normal weight (as determined by a body mass index [BMI] of 19-25). Statistical analyses were used to assess relationships between tissue thickness, age, and BMI. Results indicate that no significant relationship exists between tissue thickness and age for males, and for only 3/19 points in females. Also, only four points showed significant relationships between tissue thickness and sex. However, significant relationships exist between BMI and tissue thickness at multiple points for both males and females. Compared to other American and Asian populations in the literature, Chinese-Americans generally had thinner facial tissue; though, this difference was not assessed statistically. Finally, data generated in this study will add to the body of knowledge concerning facial tissue depth variation in modern humans.     

An Investigation into the Relationship between Human Cranial and Pelvic Sexual Dimorphism

When faced with commingled remains, it might be assumed that a more “masculine” pelvis is associated with a more “masculine” cranium, but this relationship has not been specifically tested. This study uses geometric morphometric analyses of pelvic and cranial landmarks to assess whether there is an intra‐individual relationship between the degrees of sexual expression in these two skeletal regions. Principal component and discriminant function scores were used to assess sexual dimorphism in 113 U.S. Black individuals. Correlation values and partial least squares regression (PLS) were used to evaluate intra‐individual relationships. Results indicate that the os coxae is more sexually dimorphic than the cranium, with element shape being more sexually dimorphic than size. PLS and correlation results suggest no significant intra‐individual relationship between pelvic and cranial sexual size or shape expression. Thus, in commingled situations, associations between these skeletal elements cannot be inferred based on degree of “masculinity.”     

An Analysis on the Choice of Alpha Level in the Osteometric Pair‐matching of the Os Coxa,Scapula, and Clavicle

This study compares the use of 0.05 and 0.10 alpha levels with the updated osteometric pair‐matching model on two samples of the os coxa, scapula, and clavicle. The samples include the Forensic Data Bank, and the osteometric sorting reference used within the Defense POW/MIA Accounting Agency. Mixed‐effects two‐way analyses of variance were used to analyze bilateral asymmetry in the standard measurements. In total, 3,793,566 t‐tests were conducted for osteometric pair‐matching analysis. The results indicate high levels of exclusion power, and accuracy can be obtained with the os coxa and scapula. The clavicle standard measurements capture too much asymmetry causing a lower exclusion to accuracy ratio for osteometric pair‐matching relative to other elements. Both 0.05 and 0.10 alpha levels provide acceptable levels of performance. A lower alpha level will result in higher accuracy with less exclusion, and a higher alpha level will result in lower accuracy with more exclusions.     

The Use of Vertebral Osteoarthritis and Osteophytosis in Age Estimation*

Abstract: Previous research on age and vertebral degenerative change has focused on osteophytosis. The present study expands this research by examining the association between osteoarthritis and osteophytosis and by assessing their relationship to age. Researchers scored the bodies and facets in 104 individuals. Statistical analyses assessed relationships between age and degenerative change for the bodies and facets, both separately and combined, for all vertebrae collectively, and for subcategories of vertebral types. Separate analyses were conducted which included only regions that experience heavier stress loads. Results indicate that osteophytosis and osteoarthritis are not associated with each other for all subcategories of vertebrae. Also, the inclusion of osteoarthritis does not enhance the relationship between age and degenerative change, nor does limiting analyses to areas of heaver stress. Finally, although both conditions are significantly correlated with age, the relationship is not strong enough to yield predictive power for establishing age beyond a general estimate.     

A Reliable Regression‐Based Approach for Reassociating Human Skeletal Elements of the Lower Limbs from Commingled Assemblages

Accurate sorting of commingled human remains comprises a fundamental requirement for all further anthropological analyses. The lower limb bones are particularly important for reconstructing biological profiles. This study introduces a metric technique for sorting these elements using eight standard anthropological measurements and 222 adult individuals from Greece. The bones utilized were the os coxae, the femora, the tibiae and the tali. Simple regression analyses were used to develop functions for reassociating articulating bones, providing strong correlations (r = 0.74–0.95, p‐value <0.05) and high coefficients of determination (r²=0.54–0.91). Blind tests demonstrated that combining metric and morphoscopic techniques provides an excellent sorting accuracy for the hip and knee joints (ten of ten individuals), allowing for a reliable reassociation between a sex and age indicator (os coxae) and a body size indicator (femur). Overall, these results indicate the high value of metric methods in sorting commingled human remains.     

Sex Determination by Discriminant Function Analysis of Lumbar Vertebrae

Sex determination is critical for developing the biological profile of unidentified skeletal remains. When more commonly used elements (os coxa, cranium) for sexing are not available, methods utilizing other skeletal elements are needed. This study aims to assess the degree of sexual dimorphism of the lumbar vertebrae and develop discriminant functions for sex determination from them, using a sample of South African blacks from the Raymond A. Dart Collection (47 males, 51 females). Eleven variables at each lumbar level were subjected to univariate and multivariate discriminant function analyses. Univariate equations produced classification rates ranging from 57.7% to 83.5%, with the highest accuracies associated with dimensions of the vertebral body. Multivariate stepwise analysis generated classification rates ranging from 75.9% to 88.7%. These results are comparable to other methods for sexing the skeleton and indicate that measures of the lumbar vertebrae can be used as an effective tool for sex determination.     

利用中国汉族成人股骨上端CR片特征判定年龄

目的探讨中国汉族成人股骨上端CR片的特征随年龄变化的规律,以推断年龄。方法 277例中国汉族成人骨盆正位CR片,其中男性139例,年龄范围18-83岁,女性138例,年龄范围18-85岁,选取股骨上端的股骨头、股骨颈、大转子内的骨小梁及股骨上端髓腔高度四项指标,观察不同年龄各指标的变化进行统计分析。结果成人股骨头、股骨颈骨小梁变化和股骨上端髓腔高度是影响45岁以下年龄变化的重要因素,股骨大转子影响较小。四项指标对45岁以上年龄组均是影响年龄变化的重要因素。利用以上指标建立的回归方程能很好的反映成人股骨上端的增龄性变化,预测骨龄较为准确。结论利用成人股骨头、股骨颈、股骨大转子内骨小梁的改变及股骨上端髓腔高度变化可推断年龄。     

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.     

A Geometric Morphometric Approach to Sex Determination of the Human Adult Os Coxa

Abstract: Sex determination of the human skeleton is best assessed from the os coxa. The present study explored the possibility of using three‐dimensional landmark coordinate data collected from various landmarks located over the entire bone to determine whether there were significant sex differences local to the landmarks. Thirty‐six landmarks were digitized on 200 African American and European American male and female adult human os coxae. MANCOVA results show that sex and size have a significant effect on shape for both European Americans (Sex, F = 17.50, d.f. = 36, 63, p > F = 0.0001; Size, F = 2.56, d.f. = 36, 63, p > F = 0.0022) and African Americans (Sex, F = 21.18, d.f. = 36, 63, p > F = 0.0001; Size, F = 2.59, d.f. = 36, 63, p > F = 0.0005). The discriminant analysis shows that sexing accuracy for European Americans is 98% for both males and females, 98% for African American females, and 100% for African American males.     

An Analysis of Hounsfield Unit Values and Volumetrics from Computerized Tomography of the Proximal Femur for Sex and Age Estimation

Sex and age are two elements in the establishment of a biological profile for forensic identification. While the pelvic bones are the most ideal structures for sex estimation, the condition of a body is not always ideal due to the nature of death, such as in mass disasters, or postmortem processes. This study utilized CT scans and resultant 3D models of 100 male and 100 female adults of known ages ranging from 18 to 98 years old to collect volumetric and Hounsfield unit measurements of the proximal femur. Equations were created to establish logistic regression models for sex estimation and linear regression models for age estimation. The resultant sex estimation method had an accuracy of 93.5% and utilized the volume of the proximal femur. This study provides three linear regression models for age with an accuracy range of 86%–92% ±12 years. As imaging technologies are increasingly adopted for forensic purposes, the power of 3D data will provide the opportunity for more quantitative and reproducible analyses. The proposed method for sex and age estimation provides a reliable tool that can be utilized in both day-to-day casework and disaster victim identification.     

Investigations Into Age‐related Changes in the Human Mandible,

While changes in mandibular shape over time are not widely recognized by skeletal biologists, mandibular remodeling and associated changes in gross morphology may result from a number of causes related to mechanical stress such as antemortem tooth loss, changes in bite force, or alterations of masticatory performance. This study investigated the relationship between age‐related changes and antemortem tooth loss in adult humans via dry bone measurements. This study examined 10 standard mandibular measurements as well as individual antemortem tooth loss scores using the Eichner Index from a total of 319 female and male individuals with ages ranging from 16 to 99 years. Results indicate that few mandibular measurements exhibited age‐related changes, and most were affected by antemortem tooth loss.     

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.     

The Impact of Racial Metric Variation in the Os Coxae on the Morphological Assessment of Sex*

Abstract: This study examines whether sex determination based on morphological traits in the os coxae is impacted by racial quantitative variation. Nineteen traits were evaluated independently by two observers in 876 os coxae. Chi‐square test was used on a random sample of 400 individuals to assess whether the distribution of correct sex assessment varied for white and black individuals based on each trait individually and all 19 traits collectively, as well as on inter‐observer agreement in correct sex assessment. Results indicate that accuracy of sex assessment varied between white and black individuals in certain individual traits; however, accuracy was not impacted when all traits were considered together. Furthermore, traits that showed significant variation in correct sex assessment between races generally were not related to size, but instead were “discrete.” Finally, analyses of inter‐observer variation suggest that disparities in sex assessment for some traits may be related to differences in trait interpretation between observers rather than morphological dissimilarities between races.     

Age Estimation Based on DNA Methylation Using Blood Samples From Deceased Individuals

Age estimation using DNA methylation levels has been widely investigated in recent years because of its potential application in forensic genetics. The main aim of this study was to develop an age predictor model (APM) for blood samples of deceased individuals based in five age-correlated genes. Fifty-one samples were analyzed through the bisulfite polymerase chain reaction (PCR) sequencing method for DNA methylation evaluation in genes ELOVL2, FHL2, EDARADD, PDE4C, and C1orf132. Linear regression was used to analyze relationships between methylation levels and age. The model using the highest age-correlated CpG from each locus revealed a correlation coefficient of 0.888, explaining 76.3% of age variation, with a mean absolute deviation from the chronological age (MAD) of 6.08 years. The model was validated in an independent test set of 19 samples producing a MAD of 8.84 years. The developed APM seems to be informative and could have potential application in forensic analysis.     

Ontogeny of femur subtrochanteric shape in Native Americans and American Blacks and Whites

Femur subtrochanteric size and shape can be used to differentiate between adult Native Americans and American Blacks and Whites, but little is known about when shape differences are established during growth and development. Ontological changes in subtrochanteric shape were examined using 74 Native American and 61 American Black/White subadult femora. At birth, the proximal femur diaphysis is relatively circular in both groups. Between birth and 5 years, the diaphysis becomes more mediolaterally broad, especially in Native Americans, due to differential growth between the mediolateral and anteroposterior planes. This change may be due to biomechanical stresses associated with developing a mature gait pattern. After the age of 5, growth occurs more equally in the two planes and shape does not change significantly. The adult shape of the proximal femur is established by c. 5 years of age and can be used to discriminate between Native American and American Black/White femora in older subadults.     

应用膝关节MRI T_2加权脂肪抑制像推断活体年龄

目的探索膝关节MRI T2加权脂肪抑制像(T2-FS)在法医年龄推断中的应用价值,建立安全可靠的四川汉族年龄推断方法。方法收集膝关节MRI 324例(男性170例,女性154例),年龄范围为10~30岁。采用西门子1.5T磁共振仪摄片,MRI参数:T2-FS TSE序列,矢状位。将股骨远端、胫骨近端骨骺发育分为6个等级并赋分,分析各指标性别差异及年龄相关性,建立年龄推断回归模型。结果男女性股骨远端、胫骨近端MRI等级与年龄呈正相关性,股骨远端与年龄的相关性男性0.687,女性0.661;胫骨近端与年龄的相关性男性0.684,女性0.488。股骨远端骨骺完全闭合,骺线消失的最小年龄男性18.42岁,女性19.36岁;胫骨近端男性骺线消失的最小年龄为16.93岁,女性为14.68岁。股骨远端等级1~3、5、6和胫骨近端等级1~3、5年龄分布性别差异不显著。分别建立男女年龄推断模型,男性年龄推断平均绝对误差(MAD)=2.90岁;女性年龄推断MAD=3.30岁。结论膝关节MRI T2-FS影像可作为活体年龄推断的指标之一,股骨远端等级6可作为判断18岁的指标之一。     

In Vivo Facial Tissue Depth for Canadian Aboriginal Children: A Case Study from Nova Scotia,Canada

This study examines facial tissue depth in Canadian Aboriginal children. Using ultrasound, measurements were taken at 19 points on the faces of 392 individuals aged 3–18 years old. The relationships between tissue thickness, age, and sex were investigated. A positive linear trend may exist between tissue thickness and age for Aboriginal females and males at multiple points. No points show significant differences in facial tissue depth between males and females aged 3–8 years old; seven points show significant differences in facial tissue depth between males and females aged 9–13 years old; and five points show significant differences in facial tissue depth between males and females aged 14–18 years old. Comparisons were made with White Americans and African Nova Scotians. These data can assist in 3‐D facial reconstructions and aid in establishing an individual's identity. Previously, no data existed for facial tissue thickness in Canadian Aboriginal populations.     

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.     

Using the acetabulum to estimate age at death of adult males

The acetabular region is often present and adequately preserved in adult human skeletal remains. Close morphological examination of the 242 left male os coxae from the identified collection of Coimbra (Portugal) has enabled the recognition of seven variables that can be used to estimate age at death. This paper describes these variables and argues their appropriateness by analyzing the correlation between these criteria and the age, the intra- and interobserver consistence, and the accuracy in age prediction using Bayesian inference to estimate age of identified specimens. Results show significant close correlation between the acetabular criteria and age, nonsignificant differences in intra- and interobserver test, and 89% accuracy in Bayes prediction. Obtained estimated age of the specimens had similar accuracy in all ages. These results indicate that these seven variables, based on the acetabular area, are potentially useful to estimate age at death for adult specimens.