New identification criteria for the Chilean population: Estimation of sex and stature

In the analysis of human skeletal or otherwise unidentifiable remains the assessment of sex is an initial vital element when rendering a biological profile. As such other aspects of the biological profile are sex-specific (e.g. stature and age) and cannot be successfully determined without this preliminary assessment. In addition, the estimation of stature is an essential parameter of the biological profile, which is often used to confirm or exclude presumptive identifications.The purpose of this study is to present newly developed local identification criteria for the estimation of sex from the postcrania and stature for Chileans. Linear discriminant functions were derived for the humerus and femur. Sexing accuracies of 87%, 86%, and 82% were achieved. Furthermore, new univariate predictive stature equations are presented using a Bayesian approach for the humerus, femur and tibia.     

男性上肢长骨的测量及其最大长推算

目的探讨用上肢长骨的残骨某一项指标建立肱骨、尺骨和桡骨最大长的回规方程,然后可根据所得值间接推算人体身高。方法选男性肱骨、尺骨和桡骨50例,左、右共100侧肢体。用人体测量仪器,按体质人类学测量方法进行各项指标测量,所得值经统计学分析后,分别与肱骨、尺骨和桡骨最大长建立直线回规方程。结果经相关分析建立了肱骨最大长回规方程17个,尺骨最大长回规方程8个,桡骨最大长回规方程11个。结论若能测得上肢长骨残骨的某一项指标,就可用所建立的回规方程推算该骨的最大长,这在法医学上具有一定的参考价值。     

法医骨组织学研究

在实际检案中 ,当现场发现的骨骼残片体积较小时 ,用解剖学观察无法进行骨骼残片的法医鉴定 ,需使用骨组织学的方法进行骨骼残片的个体识别。目前 ,这是法医人类学中一门较活跃的领域 ,即法医骨组织学。法医骨组织学的内容主要包括两个方面 :(1)骨骼残片是否属于人类骨骼 ,或属于何种动物骨骼。这方面的研究包括人类骨骼的组织学特征研究及不同动物的组织学特征研究。 (2 )人类骨骼个体识别的组织学研究。这方面的研究主要包括 ,人类骨骼的组织学特征的年龄判断 ,例如股骨、胫骨、肱骨、锁骨等 ,以及使用骨组织学方法 ,进行人类骨骼的年龄评价的准确性研究。本文对上述内容进行了综述。     

中国汉族成人肱骨近端CR片特征与年龄的相关性

目的探讨中国汉族成人肱骨近端CR片的特征随年龄变化的规律,以推断年龄。方法 210例中国汉族成人肩关节CR片,其中男性124例,年龄范围18~83周岁,女性86例,年龄范围18~60周岁,选取与年龄变化关系密切的肱骨骨髓腔高度、肱骨近端骨骺骨小梁变化、肱骨大结节内骨小梁变化、锁骨骨髓腔肩峰侧骨小梁变化4项指标,观察不同年龄各指标的变化进行统计分析。结果四项指标均是影响年龄变化的重要因素。肱骨近端骨骺骨小梁变化、锁骨骨髓腔肩峰侧骨小梁变化对年龄的预测影响较大,肱骨骨髓腔高度、肱骨大结节内骨小梁变化稍小。利用以上指标建立的回归方程能很好的反映成人肱骨的增龄性变化,预测骨龄较为准确。结论利用成人肱骨骨髓腔高度、肱骨近端骨骺骨小梁变化、肱骨大结节内骨小梁变化、锁骨骨髓腔肩峰侧骨小梁变化可推断年龄。     

Bidimensional Data Allow for Better Age Estimation on Immature Specimens than Unidimensional Data: A Preliminary Study on the Ilium

Most biometric age estimation methods used in anthropological and forensic science for juveniles are based on unidimensional measurements (length or width). Here, a new method using bidimensional data was tested. A 3D morphometric analysis was performed on 108 CT scans of ilium bone of juveniles (from 20 gestational weeks to 12 years old). The sample was divided into training and validation groups. Best predictors were determined by comparing the efficiency of each variable (length, width, area, and module: a product of length and width). We established linear and polynomial regressions for each parameter for both sides. Applying the equations to the validation sample showed no significant difference between real and predicted ages. For age estimation, the area and module parameters yielded better results than unidimensional measurements. The results from this preliminary study were highly conclusive, and it would be interesting to extend the work, covering larger samples, and other bones.     

Identification from Chest X‐Rays: Reliability of Bone Density Patterns of the Humerus*

Abstract: A critical review of Kahana and Hiss’ study on identification from bone trabecular pattern and a test of their method conducted on the humerus are presented. Bone trabecular pattern was studied through the generation of a numerical file representing the gray scale. Using the correlation coefficient, several pairwise comparisons between numerical files were performed. The test gave nearly 30% of incorrect exclusions (the method did not recognize couples of radiographs belonging to the same subject) and 50% of misidentifications (the method recognized couples of radiographs belonging to different subjects, as belonging to the same subject); therefore, this research shows that at the present time, it is not possible to safely quantify identification through bone density patterns, of the proximal humerus taken from thoracic X‐rays. Thus, an “easy”—but dangerous—use of trabecular density patterns on this specific type of radiogram as an identification method should be currently avoided.     

Stature estimation from radiographically determined long bone length in a Spanish population sample

The estimation of stature from of a variety of bones is an important aspect of forensic work. In order to obtain reliable results, it is important to have comparative data obtained from the same population group as the skeletal remains. However, lack of up to date information on the population groups of Southern Europe makes the estimation of stature from bones in this area subject to possible error. In this study, the stature of 104 healthy adults from Spain was measured, and an anteroposterior teleradiograph of the right lower and the right upper limb of every subject in the study was made in order to measure the lengths of the femur, tibia, fibula, humerus, cubitus and ulna. Pearson's regression formulae were obtained for both limbs. In males, we found the femur to be the most accurate predictor of stature (R = 0.851), whereas in females best results were obtained with the tibia (R = 0.876).     

Morphometric diagnostics of the age of encapsulated subdural hematomas

The present morphometric investigation was carried out using dura matter preparations, capsules, and contents of 94 encapsulated subdural hematomas obtained from the corpses of subjects with a non-penetrating craniocerebral injury and the duration of the post-traumatic period ranging from 8 days to 2.5 years. The correlation analysis confirmed the necessity of differentiation between resorbed and unresorbed encapsulated subdural hematomas. The data obtained were used to construct 5 regression models for the estimation of the age of unresorbed encapsulated subdural hematomas and 1 regression model for the identification of the age of resorbed encapsulated subdural hematomas. The regression models included different combinations of three morphometric characteristics of the hematoma capsule as the independent variables, viz. maximum thickness, relative extent of hemosiderosis, and relative amount of macrophages in the cellular infiltrate. The amount of variability in the age of encapsulated subdural hematomas accounted for by the regression models is 62%. It is concluded that the results of the study can be used in the practical work of forensic medical experts.     

Estimation of Age Using Alveolar Bone Loss: Forensic and Anthropological Applications

The objective of this study was to utilize a new odontological methodological approach based on radiographic for age estimation. The study was comprised of 397 participants aged between 9 and 87 years. A clinical examination and a radiographic assessment of alveolar bone loss were performed. Direct measures of alveolar bone level were recorded using CT scans. A medical examination report was attached to the investigation file. Because of the link between alveolar bone loss and age, a model was proposed to enable simple, reliable, and quick age estimation. This work added new arguments for age estimation. This study aimed to develop a simple, standardized, and reproducible technique for age estimation of adults of actual populations in forensic medicine and ancient populations in funeral anthropology.     

广东东莞市男性青少年肩关节正位DR片骨龄研究

目的利用肩关节正位数字化X线片（DR片）上诸骨发育特点建立男性青少年骨龄评测数学模型。方法对广东东莞市310名15~22岁男性青少年拍摄肩关节正位DR片,根据锁骨肩峰端（X1）、肩胛骨肩峰端（X2）、喙突（X3）、肱骨近端（X4）及锁骨胸骨端（X5）骨骺发育分级评分,利用SPSS统计进行各骨骼发育评分与年龄间的相关分析、Fisher＇s线性两类判别分析及多元逐步回归分析。结果 X1~X5与生活年龄间的Pearson相关系数分别为0.496、0.571、0.559、0.702、0.807（P〈0.01）;16、17、18周岁判别分析综合判别率为87.2%~91.4%,年龄推断多元逐步回归方程准确率（±1岁）约79.8%。结论本研究建立的年龄判别分析方程及多元逐步回归方程,可为法医活体年龄鉴定提供了新的地区性标准和方法。     

Progress in forensic anthropology: the 20th century

Anthropological contribution to forensic sciences has been multifaceted and the progress has been remarkable in the last quarter of this century. The field has brought together scientists from all around the world. The purpose of this paper is to present a special issue on forensic anthropological research. Some of the papers cover age estimation from the ankle and knee epiphyses (India), basioccipital synchondrosis (also India), sternal end rib metamorphosis in Turks, and histomorphometry of the Japanese. Sex determination from the South African cranium and Mongoloid humerus are the subject of two papers. Factors of individualization include a comparison of photographic images using neural network, bone trabecular radiography, determination of handedness from the humerus, time since death using 210Po to 210Pb ratio, and changes in the mineral content of bone after burial. From the papers in this special issue it can be concluded that there will be integration of many areas of forensic sciences to deal with anthropological issues in the 21st century. Estimation of time since death will be based on new and more precise techniques. Further research is needed to develop population specific osteological standards for populations of Africa, central and southeast Asia and Pacific region. In addition, there will be an increased interest in the study of living people.     

Quantitative Assessment of the Sternal Rib End Morphology and Implications for Its Application in Aging Human Remains

Intercostal and age differences in the sternal rib end morphology of documented female skeletons from Spitalfields and St. Bride's are examined. The morphology was captured using three‐dimensional morphometrics and the statistical analyses employed included parametric and nonparametric MANOVA, discriminant analysis, and multilinear regressions. It was found that the quantified morphology of the sternal rib end was statistically significantly different between rib four and all other ribs except for the third one and that the morphological characteristics of all ribs varied with age. However, due to the inherent variability in sternal rib end morphology, nonstatistically significant results were obtained among the various age groups and neither disciminant nor multilinear regression analysis could be used for the estimation of the age of an individual based on digitized coordinates of the sternal rib end of individuals of known age, raising some concern as to the rigorousness of the fourth rib aging method.     

Morphometric analysis of third molar root development by an experimental method using digital orthopantomographs

Abstract:  The aim of the study was to conduct a morphometric analysis of the root development of the third molar, with the purpose of overcoming the limits of an exclusively morphological analysis. The study was divided in two phases. The first one was the verification of the existence of a constant crown-root (C/R) ratio on a sample of 100 third molars, characterized by a complete root development. The value obtained was used in the second phase to predict the final root's length, knowing the crown height. So we have calculated, on a sample of 322 third molars with developing roots, the final ratios between incomplete roots and complete roots. Statistical analysis was then made with 90%, 95%, and 99% confidence intervals. The results showed a significant difference according to the age of the subject and the limit values, lower and upper, for subjects aged 16 and 17 years versus those aged 18 and 19. For each analysis, the width of the class of tolerance and other statistical indicators were calculated. The results we obtained support the advantage of a morphometric study as opposed to an exclusively morphological study, but all the techniques used to determine the age of a living subject can provide only indications of the biological age, but no certainties as regards chronological age.     

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).     

A Computational Framework for Age‐at‐Death Estimation from the Skeleton: Surface and Outline Analysis of 3D Laser Scans of the Adult Pubic Symphysis

In forensic anthropology, age‐at‐death estimation typically requires the macroscopic assessment of the skeletal indicator and its association with a phase or score. High subjectivity and error are the recognized disadvantages of this approach, creating a need for alternative tools that enable the objective and mathematically robust assessment of true chronological age. We describe, here, three fully computational, quantitative shape analysis methods and a combinatory approach that make use of three‐dimensional laser scans of the pubic symphysis. We report a novel age‐related shape measure, focusing on the changes observed in the ventral margin curvature, and refine two former methods, whose measures capture the flatness of the symphyseal surface. We show how we can decrease age‐estimation error and improve prior results by combining these outline and surface measures in two multivariate regression models. The presented models produce objective age‐estimates that are comparable to current practices with root‐mean‐square‐errors between 13.7 and 16.5 years.     

Age estimation by pulp/tooth ratio in canines by mesial and vestibular peri-apical X-rays

Changes in the size of the pulp canal, caused by apposition of secondary dentine, are the best morphometric parameters for estimating age by X-rays. The apposition of secondary dentine is the most frequently used method for age estimation in adult subjects. In two previous papers, we studied the application of the pulp/tooth area ratio by peri-apical X-rays as an indicator of age at death. The aim of the present study was to test the accuracy of age evaluation by combined analysis of labio-lingual and mesial peri-apical X-rays of lower and upper canines. A total of 200 such X-rays were assembled from 57 male and 43 female skeletons of Caucasian origin, aged between 20 and 79 years. For each skeleton, dental maturity was evaluated by measuring the pulp/tooth area ratio according to labio-lingual and mesial X-rays on upper (x(1), x(2)) and lower (x(3), x(4)) canines. Very good agreement was found between intra-observer measurements. Statistical analysis showed that all variables x(1), x(2), x(3), and x(4) and the first-order interaction between x(1) and x(3) contributed significantly to the fit, so that they were included in the regression model, yielding the following regression formula: Age = 120.737 - 337.112x(1) - 79.709x(2) - 364.534x(3) - 65.655x(4) + 1531.918x(1)x(3) . The residual standard error of estimated ages was 3.62 years, with 94 degrees of freedom, and the median of the residuals was -0.155 years, with an interquartile range of 4.96 years. The accuracy of the method was ME = 2.8 years, where ME is the mean prediction error. The model also explained 94% of total variance (R(2) = 0.94).     

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.     

The extent of aspartic acid racemization in dentin: a possible method for a more accurate determination of age at death?

In the current study the objective was to find to what extent a reliable determination of age at death is made possible by establishing the degree of aspartic acid racemization in the dentin of teeth. The results of the investigation of 46 teeth are in agreement with the values found by other authors. The method presented makes a reproducible and accurate estimation of age possible. We intend to elaborate and improve this promising method for determination of age at death. The relevant points are presented here.     

Sex determination by discriminant analysis: an evaluation of the reliability of patella measurements

Recently, a method which estimates the sex of unknown skeletal remains by discriminant function analysis of the patella has received much recognition. With seven simple measurements and a sexing accuracy of almost 84% this morphometric approach would be very suitable both in the forensic and anthropological context. In order to put this method to the test, 52 unfractured and non-pathological left and right patellae (26 males, 26 females) from a prehistoric skeletal sample were analyzed. In addition, 30 patellae were randomly selected which were not part of the original reference series. The first 15 (4 males, 11 females) had the same sample origin as the 30 target specimen but were of mediocre preservational state. The second 15 belonged to an archaeological sample of different provenience (8 males, 7 females). The results of the current study indicate that the morphometric assessment of this sesamoid is indeed well-suited as the results of the previous study could be duplicated, when sample size was not taken into consideration (85%). However, when the issue of small sample size was systematically addressed via a jack-knife procedure or the calculation of Delta-value, the resultant accuracies dropped to 78 and 74%, respectively. It is suggested that two confounding factors--age and sex of the individual--may be held accountable. There are slight, whilst not statistically significant tendencies to misclassify female and older specimen.