Determination of sex from the clavicle and scapula in a Guatemalan contemporary rural indigenous population

The clavicle has been described as a useful bone for the metric determination of sex of human skeletal remains in a contemporary, predominantly white, North American forensic sample. In this article, measurements of clavicle and scapula are provided for a contemporary Guatemalan rural indigenous sample of forensic origin. Maximum length and circumference at midshaft of the clavicle, and height and width of the glenoid fossa of the scapula, were measured in 35 female and 62 male clavicles, and in 38 female and 65 male scapulae. Discriminant function analysis was used to study sexual dimorphism in this population with a classification purpose. Leave-one-out method (jackknife) matrices produced classification success rates ranging from 85.6% to 94.8%. A comparison with the North American forensic sample showed low percentages of correctly sexed Guatemalan male clavicles, ranging from 29.4% to 54.9%. The choice of an appropriate standard for the metric determination of sex is a crucial step in forensic anthropology.     

西南地区成人面颅骨的性别判定

目的建立适合西南地区成人的颅骨性别判定函数。方法性别明确的颅骨67个,测量颅骨最大长、颅骨最大宽、颅高等16项指标,所得数据进行统计学分析,建立单一变量及多变量性别判定方程,并对5个无名颅骨进行回带检验。结果 16项指标中有13项存在显著的性别差异,男性大于女性,单变量函数推断性别以鼻高(男78.4%,女83.3%)、颅骨最大长(男83.8%,女73.3%)准确率较高。多变量性别判定函数以颅周长、鼻高贡献最大,判定准确率男89.2%,女90.0%。结论单变量推断颅骨性别以鼻高或颅骨最大长较为理想,但以颅周长、鼻高联合推断性别准确率更高。     

The rhomboid fossa of the clavicle as a sex and age estimator

The costoclavicular (rhomboid) ligament connects the first rib to the clavicle, stabilizing the pectoral girdle. It produces skeletal traits that may be tubercles, roughened impressions, shallow groove-like fossae, deep fossae, or leave no trace. A pit or depression at this site is often called a "rhomboid fossa." While these markings may appear pathological, they are normal variants of the clavicle. Using a large contemporary sample (N = 344:113 females, 231 males), we evaluated the presence of a rhomboid fossa as a sex and age indicator for unidentified skeletal remains. Logistic regression found significant relationships between the presence of a rhomboid fossa and sex and between presence of a rhomboid fossa and age. Fossae were more common in males (36% left, 31% right) than in females (3% left, 8% right). Posterior probabilities suggest that a fossa on the right clavicle is indicative of a male with 81.7% probability; a fossa on the left is indicative of a male with 92.2% probability. Younger individuals more commonly exhibited rhomboid fossae than older individuals, and the largest fossae were most common in males 20-30 years of age. However, the age effect was not conclusive and must be corroborated by other methods. A test of the sex estimation method on an independent sample (26 males, 23 females) found nine males and only one female with fossae present on the left clavicle. When the costoclavicular attachment exhibits an impression, a tubercle, or leaves no trace, this method cannot be used for sex estimation. When a clavicle exhibits a rhomboid fossa, it is likely from a male. The greater difference in fossa expression between the sexes on the left clavicle makes use of the left bone preferable. This technique can corroborate other sex estimates or provide an estimate for unknown individuals in the absence of other skeletal indicators.     

Sexual dimorphism of the scapula and the clavicle in a contemporary Greek population: applications in forensic identification

Sex estimation is the grounds for an accurate identification of unknown human skeletal elements. The need for reliable methods distinguishing males from females based upon various skeletal elements is evident in cases of commingled, eroded and/or missing remains. The aim of this work lays on establishing criteria for sex estimation from the scapula and the clavicle in modern Greeks. A total of 147 left scapulae and 147 clavicles (66 females and 81 males) were used in the study. Eight and six measurements were taken on the scapula and clavicle respectively and data were subjected to principal components analysis (PCA) and discriminant function analysis (DFA). Posterior probabilities for the classification of each individual are also calculated. Statistical analysis was carried out using the software PAST (Paleontological Statistics) and SPSS (Statistical Package for Social Sciences) 18. The results supported the existence of pronounced sexual dimorphism, which was mainly attributed to size differences among the two groups. Univariate and multivariate methods of statistical classification showed high accuracy for all scapular and most clavicular measurements, verifying their value as sex indicators in the under study population. We recommend the use of this method for sex assessment from the scapula and the clavicle in cases exhibiting over 95% probability of correct classification. This is regardless of the overall high degree of accuracy reported here, as the method of choice in forensic contexts should always be case-driven.     

中国豫北地区17～78岁人群锁骨骨骺愈合情况及年龄推断

目的通过观察分析锁骨内侧骨骺的愈合情况,评价其在年龄推断中的作用。方法收集343对已知年龄和性别的尸体锁骨,以1岁为组,观察分析锁骨内侧端骨骺愈合亭台变化,根据软骨细胞失去增值能力,骺软骨骨板被骨组织所代替情况进行分级分析,对所得数据进行统计学分析,按17～30岁和31岁以上年龄分组进行比较。结果男性和女性的锁骨最早于18岁开始愈合,22岁愈合完全。完全愈合时间在男性最迟为32岁,而女性为31岁。不同性别的骨骺愈合情况在两个年龄组中存在显著差异(P<0.01)。结论锁骨骨骺愈合情况随年龄的增长呈规律性变化,特别是17～32岁年龄段,根据锁骨骨骺愈合情况推断年龄,在法医学实践中有应用价值。     

Estimating sex of the human skeleton based on metrics of the sternum

Estimating the sex of skeletal remains is critical in creating the biological profile of an adult individual. Previous research has shown that analyzing the sternum may lead to an accurate estimation of sex based on studies performed on various populations around the globe, such as Indian, European, African, Canadian and North American. The motivation of the current study is to develop classification functions and sectioning points for use in forensic investigations in the United States. The majority of previously published methods are population specific, meaning the data would not prove useful in the United States. For this study, sternal measurements were collected from the William M. Bass Donated Skeletal Collection located at The University of Tennessee, Knoxville following the metric definitions provided by Schwartz and Bass. This collection consists of recent skeletal remains with known age at death, ancestry and sex. Material for the present study consisted of 410 human sterna: 285 male (256 American White/29 American Black) and 125 female (120 American White/5 American Black). Previous studies analyze the applicability of Hyrtl's law in the estimation of sex. This law follows that the mesosternum is greater than twice the length of the manubrium in males and in females the length of the manubrium is greater than half the length of the mesosternum. In this study, comparisons of the proportion of the length of the manubrium to the length of the mesosternum were performed to determine if Hrytl's law is applicable in an American population. Comparisons of these measurements between individuals identified as American Black and American White were analyzed to determine whether this method could be used on both population groups. Further, discriminant function analysis was used to estimate sex and provide a population specific classification function for use in the United States. The discriminate function analysis produced an overall cross-validation classification rate of 84.12% for sex estimation. The cross-validation classification rate for males and females was 80.00% and 88.24%, respectively.     

Index and ring finger ratio--a new sex determinant in south Indian population

Identification of human remains is an imperative element of any medicolegal investigation, and a challenging task for forensic experts and physical anthropologists worldwide. Three hundred adult hands (150 males and 150 females) belonging to south Indian population were studied to investigate sexual dimorphism of the index and ring finger ratio. The index and ring finger ratio is derived by dividing the index finger length by ring finger length. The index and ring finger ratio is found to be higher in females. Index and ring finger ratio < or =0.9700 identified 80% of males for both hands, and ratio >0.9700 identified 74% females for the right hand and 78% for the left hand accurately. This study may prove useful to determine the sex of an isolated hand when it is subjected for medicolegal examination.     

应用锁骨薄层CT容积重建影像推算四川汉族身高

目的探讨锁骨薄层CT三维容积重建影像(CT-VRT)在身高推算中的应用价值,以期更新我国西南地区身高推算数据,为鉴定实践提供技术支撑。方法应用300例锁骨薄层CT-VRT影像,测量并计算左侧锁骨长(LCL)、右侧锁骨长(RCL)、双侧锁骨均长(ACL),分析身高与LCL、RCL、ACL相关性及性别差异,建立身高推算线性回归方程,并对所建模型进行回代检验。结果男性、女性ACL和身高的相关系数分别为0.534、0.707;LCL和身高的相关系数分别为0.484、0.680;RCL和身高的相关系数分别为0.523、0.695。分别建立ACL、LCL、RCL男女性身高推算线性回归模型。回代检验示ACL方程男性身高推算平均绝对误差(MAD)为4.48cm,女性MAD为3.51cm;LCL方程男性身高推算MAD为4.60cm,女性MAD为3.64cm;RCL方程男性身高推算MAD为4.49cm,女性MAD为3.59cm。结论建立的推算身高的回归方程具有统计学意义,模型预测精度较高,表明利用薄层CT-VRT影像测量的锁骨可运用于四川汉族人群身高推算研究。但模型R2较小,因此在应用ACL进行身高推算时最好结合其他指标。     

Age and sex related measurement of craniofacial soft tissue thickness and nasal profile in the Chinese population

The purpose of this study was to acquire accurate data of craniofacial soft tissue thickness (CFSTT) and nasal profile in Chinese people of Han population. A total of 31 anatomical landmarks and 4 nasal profile parameters were determined using magnetic resonance imaging (MRI) in 425 subjects (233 males and 192 females). In the present study, the mean CFSTT values of male subjects exceeded those of female subjects at most anatomical landmarks except at seven (22.58%) and 6 out of the 7 landmarks were bilateral anatomical landmark points. The age-related and sex × age interactions were found to be statistically significant at all landmarks. Significant differences were found in the nasal profile data of males and females, and 15 out of 20 different groups had significant differences between sexes, and the mean values of nasal length, nasal height, nasal depth and nasal breadth in males were all greater than those in females. Furthermore, both CFSTT and nasal profile showed good correlation with age. The thickest CFSTT of male and female were found at the respective ages of 45-59 and 35-44, and the nasal profile becomes more constant after 24 years of age. CFSTT of the lower part of the face shows greater variation compared to the upper part, so special care needs to be applied when reconstructing the lower portion of the face. Our data on CFSTT and nasal profile for the Chinese Xi'an Han population is important in understanding craniofacial characteristics of the Chinese population and might be potentially helpful in forensic identification.     

Sex estimation in a modern American osteological sample using a discriminant function analysis from the calcaneus

Reliable methods for sex estimation during the development of a biological profile are important to the forensic community in instances when the common skeletal elements used to assess sex are absent or damaged. Sex estimation from the calcaneus has potentially significant importance for the forensic community. Specifically, measurements of the calcaneus provide an additional reliable method for sex estimation via discriminant function analysis based on a North American forensic population. Research on a modern American sample was chosen in order to develop up-to-date population specific discriminant functions for sex estimation. The current study addresses this matter, building upon previous research and introduces a new measurement, posterior circumference that promises to advance the accuracy of use of this single, highly resistant bone in future instances of sex determination from partial skeletal remains. Data were collected from The William Bass Skeletal Collection, housed at The University of Tennessee. Sample size includes 320 adult individuals born between the years 1900 and 1985. The sample was comprised of 136 females and 184 males. Skeletons used for measurements were confined to those with fused diaphyses showing no signs of pathology or damage that may have altered measurements, and that also had accompanying records that included information on ancestry, age, and sex. Measurements collected and analyzed include maximum length, load-arm length, load-arm width, and posterior circumference. The sample was used to compute a discriminant function, based on all four variables, and was performed in SAS 9.1.3. The discriminant function obtained an overall cross-validated classification rate of 86.69%. Females were classified correctly in 88.64% of the cases and males were correctly classified in 84.75% of the cases. Due to the increasing heterogeneity of current populations further discussion on this topic will include the importance that the re-evaluation of past studies has on modern forensic populations. Due to secular and micro evolutionary changes among populations, the near future must include additional methods being updated, and new methods being examined, both which should cover a wide population spectrum.     

Sex assessment using measurements of the first lumbar vertebra

Sex determination is a vital part of the medico-legal system but can be difficult in cases where the integrity of the body has been compromised. The purpose of this study was to develop a technique for sex assessment from measurements of the first lumber vertebrate. Twenty-nine linear measurements and five ratios were collected from 113 Chinese adult males and 97 Chinese adult females using digital three-dimensional anthropometry methods. By using discriminant analysis, we found that 23 linear measurements and two ratios identified sexual dimorphism (P<0.01), with predictive accuracy ranging from 57.1% to 86.6%. Using a stepwise method of discriminant function analysis, we found three dimensions predicted sex with 88.6% accuracy: (a) upper end-plate width (EPWu), (b) left pedicle height (PHl), and (c) middle end-plate depth (EPDm). This study shows that a single first lumber vertebra can be used for this purpose, and that the discriminant equation will help forensic determination of sex in the Chinese population.     

Estimation of sex on the basis of radiographs of the calcaneus

Lateral and anteroposterior radiographs of the ankles of 800 Central Europeans aged 20 to 79 were analyzed with regard to sexual dimorphism. All the distances, but not the angles, of the calcaneus were much larger in males than in females. Approximately 80% of the study sample could be sexed correctly by classifying all specimens greater than 86.0 mm in length as male and those less than 86.0 mm as female. The prevalence of os tibiale externum was 8.0 and 2.6% and the prevalence of plantar heel spur was 16.3 and 6.5% (increasing with age) for males and females, respectively, being significantly more frequent in females. On the other hand, the bone island frequencies were 9.1% in males and 4.8% in females. Our study suggests that radiographs of the ankle are a convenient, rapid, cheap and non-invasive means for estimating sex.     

Sex determination from the head of the femur of South African whites and blacks

The current practice whereby criminals dismember the remains of their victims in an attempt to make their identification difficult requires that simple methods of sex determination from fragmented skeletal remains are available to forensic anthropologists and skeletal biologists. The head of the femur is an example of such bone fragments. Identification and demarking points have been derived from the diameters of the head of the femur and used to determine the sex of individuals. It has been shown, however, that the numerical values of these parameters that permit sex identification vary between races. The objectives of the present study were therefore to establish the standard numerical values of the identification and demarking points for sex determination in South African whites and blacks and to see if these standards are different in the two races. A total of 520 femurs of white (160 males and 100 females) and black (160 males and 100 females) South Africans were obtained from the Raymond Dart Skeletal Collection in the Department of Anatomical Sciences of the University of the Witwatersrand, Johannesburg, South Africa. The vertical and transverse diameters of the heads of the femurs were measured by means of a stainless steel vernier caliper. Identification and demarking points were derived from the values of these diameters. The head diameter identification point and demarking point were found to be sexually dimorphic in both white and black South Africans. The mean head diameter of the male femur was significantly greater than the mean head diameter of the female femur in both population groups (significant at P<0.001). These values were correspondingly greater in the white than the black population. The numerical values of the male identification and demarking points were higher than the corresponding female values in the two population. In both sexes, these values were greater in the whites than the blacks South Africans. It is concluded that the diameters of the head of the femur and the identification and demarking points that are derived from them are sexually dimorphic in South African white and black populations. However, the numerical values of these sex-determining bone parameters defer between the two population groups. Therefore, it is necessary to determine race-specific standards of these parameters.     

Use of 2D:4D Digit Ratios to Determine Sex

Second to fourth digit ratios (2D:4D) are sexually dimorphic in human hands and established by the 13th gestational week. Application of 2D:4D for determining sex in living individuals by Kanchan et al. (Forensic Sci Int, 181, 2008, 53.e1) produced classification rates of 80% for males and 74–78% for females. Few studies have explored the use of 2D:4D for sexing skeletal remains. We test estimated finger lengths, phalanx lengths, and 2D:4D derived from hand bones for determining sex. Maximum phalanx length was collected using a mini‐osteometric board from 451 individuals of known age, sex, and ancestry in four skeletal collections. Logistic regression of 2nd and 4th digit finger and phalanx lengths produced classification rates greater than 80%. Digit ratios, however, failed to reach classification rates greater than 59%. Our results support those of Voracek (Forensic Sci Int, 185, 2009, e29) and suggest that 2D:4D may be population‐specific and thus inappropriate for universal application as a means of determining sex.     

利用髋骨进行性别判别的的新方法

通过已知性别的干燥成人髋骨190副（男123副，女67副）进行研究，发现髋骨上界线的弧长、界线的弦长和孤高，以及髋臼的直径等值均存在着显著的性别差异。四项指标的单一性别判别准确率分别为78．42％、73．68％、74．74％及72．63％。分别利用前三项指标与髋臼直径的比值作为性别判别公式，判别准确率可达91．58％、8．95％、85．26％。利用筋骨进行性别判别建立新的方法。     

Does sexual dimorphism in facial soft tissue depths justify sex distinction in craniofacial identification?

Separation of male and female soft tissue depths into discrete groups for craniofacial identification implies that males and females differ enough from each other, with respect to this application, for this distinction to be useful. In this study, previously published soft tissue depth data were analyzed for sex separation. It was found that the variation within each sex was large while the variation between the sexes was small. Often the value of two standard deviations of the measurement for either sex was larger than the difference displayed between the means of each sex. Furthermore, opposite sex overlap in regions defined to be close to the male or female mean were found to be large and the amount of variance explained by sex was small (less than 6% on average). These results indicate that while male and female means at single craniofacial landmarks may differ slightly, and even at statistically significant levels, individual male and female soft tissue depths are often the same or very similar. On average, soft tissue depths of the face do display some sexual dimorphism but it is not marked and of little practical meaning for craniofacial identification where a single individual must be independently considered. Thus, there is little use in separate reporting of data for males and females and data should be combined to increase sample sizes.     

Quantification of the subpubic angle in South Africans

Due to the high crime rate in South Africa, forensic anthropologists are increasingly approached to aid in the identification of skeletonized remains, with sex and population affinity assignment being some of the most critical tasks they face. For over a century, the pelvis has been known to be one of the most sexually dimorphic bones of the human body and the subpubic angle is one of the most accurate, albeit scarcely quantified, features thereof. Hence, the aim of this study was to quantify the size of the subpubic angle and compare it between male and female South Africans of African (black) and European (white) descent. One hundred and forty five (145) pelves were selected, consisting of 68 white (43 male and 25 female) and 77 black South Africans (44 male and 33 female), from the Raymond A. Dart Collection of Human Skeletons housed at the University of the Witwatersrand, Johannesburg, South Africa. Each of the pelves were articulated and placed into a custom built stand for photographing. Measures of the subpubic angle from these digital images were subjected to numerous statistical analyses. Results indicated that significant differences exist between the sexes, as well as between the two population groups. For black individuals it was found that males generally possessed a subpubic angle of 74.9° or less, with larger values being indicative of the female sex. For white individuals, subpubic angles of 81.4° and less indicated males whilst larger values indicated females, with an average accuracy of 86% for both population groups. These results illustrate the advantages of using the subpubic angle to assist in the estimation of sex and population affinity and also reinforce the need for population specific parameters to be applied.     

Sex determination and estimation of stature from the long bones of the arm

The determination of sex and the estimation of stature from bones play an important role in identifying unknown bodies, parts of bodies or skeletal remains. In medico-legal practice statements on the probable sex of a decomposed body or part of a body are often expected even during autopsy. The present study was, therefore, restricted to few easily accessible dimensions from bones which were prepared only by mechanically removing soft tissues, tendons and ligaments. The specimens came from the Anatomical Institutes in Munich and Cologne from the years 1994-1998 including a total of 143 individuals (64 males and 79 females). The mean age was 79 years (46-108), the mean body height 161cm (134-189). The following measurements were taken: maximum humeral length (mean: 33.4cm in males; 30.7cm in females), vertical humeral head diameter (mean: 5.0cm in males, 4.4cm in females), humeral epicondylar width (mean: 6.6cm in males; 5.8cm in females), maximum ulnar length (mean: 26.5cm in males, 23.8cm in females), proximal ulnar width (mean: 3.4cm in males, 2.9cm in females), distal ulnar width (mean: 2.2cm in males; 1.8cm in females), maximum radial length (mean: 24.6cm in males; 22.0cm in females), radial head diameter (mean: 2.6cm in males, 2.2cm in females) and distal radial width (mean: 3.6cm in males; 3.2cm in females). The differences between the means in males and females were significant (P<0.0005). A discriminant analysis was carried out with good results. A percentage of 94.93% of cases were correctly classified when all measures of the radius were applied jointly, followed by humerus (93.15%) and ulna (90.58%). Applied singly, the humeral head diameter allowed the best distinction (90.41% correctly grouped cases), followed by the radial length (89.13%), the radial head diameter (88.57%) and the humeral epicondylar width (88.49%). The linear regression analysis for quantifying the correlation between the bone lengths and the stature led to unsatifactory results with large 95%-confidence intervals for the coefficients and high standard errors of estimate.     

Forensic Age Estimation Using Thin‐Slice Multidetector CT of the Clavicular Epiphyses Among Adolescent Western Chinese

Reaching the age of 18 years is the most significant step for criminal proceedings in China. In this study, a population of 752 individuals was recruited to clarify how strong the chronological age relates to clavicular ossification status revealed by CT scans with 1 mm slice thickness in the West China Han population. Finally, the epiphysis was observed to commence fusion in females at 16.28 years and 16.74 years in males and be fully ossified by 25.97 years in females and 25.81 years in males. These findings suggested that ossification of medial clavicular epiphyseal cartilage can be used in age estimation for West China Han population with the age threshold of 18 years. By comparison with previous German studies, our results suggested that the pace of ossification of medial clavicular epiphyseal cartilage may be potentially affected by socioeconomic status.     

Age-related factors in the relationship between foot measurements and living stature and body weight

The measurements of feet and footprints are especially important in forensic identification, as they have been used to predict the body height and weight of victims or suspects. It can be observed that the subjects of forensic-oriented studies are generally young adults. That is to say, researchers rarely take into consideration the body's proportional changes with age. Hence, the aim of this study is to generate equations which take age and sex into consideration, when stature and body weight are estimated from foot and footprints dimensions. With this aim in mind, we measured the stature, body weight, foot length and breadth, heel breadth, footprint length and breadth, and footprint heel breadth of 516 volunteers (253 males and 263 females) aged between 17.6 and 82.9 years using standard measurement techniques. The sample population was divided randomly into two groups. Group 1, the study group, consisted of 80% of the sample (n = 406); the remaining 20% were assigned to the cross-validation group or Group 2 (n = 110). In the first stage of the study, we produced equations for estimating stature and weight using a stepwise regression technique. Then, their reliability was tested on Group 2 members. Statistical analyses showed that the ratios of foot dimensions to stature and body weight change considerably with age and sex. Consequently, the regression equations which include these variables yielded more reliable results. Our results indicated that age and sex should be taken into consideration when predicting human body height and weight for forensic purposes.