Hugo F.V. Cardoso

Age estimation of adolescent and young adult male and female skeletons II, epiphyseal union at the upper limb and scapular girdle in a modern Portuguese skeletal sample

This study completes previously reported ages for timing of epiphyseal union in the postcranial skeleton in a recent sample, with data from the scapula, clavicle, humerus, radius, and ulna. A sample of 121 individuals between the ages of 9 and 29 (females = 65, males = 56) was derived from the Lisbon documented skeletal collection. Epiphyseal union was scored at 16 anatomical locations, using a three-stage scheme: 1) no union; 2) partial union; and 3) completed union, all traces of fusion having disappeared. In the upper limb, the epiphyses of the elbow are the first to fuse at around 11 to 15 years of age, followed by those of the shoulder and wrist. In the scapular girdle, the coracoid area is the first to fuse, followed by the glenoid surface and remaining epiphyses, with the medial clavicle fusing last, by the age of 25-27. There is a sex difference in maturation, with females showing an advance relative to males of about 2 years in the upper limb. Sex differences in maturation are less noticeable in the scapular girdle, but data suggest that females are also ahead of males. Results suggest overall similar age ranges for stages of union as previous dry bone observations, but some studies show significant divergences which seem to derive from methodological issues. Although some radiographic reference standards provide comparable age ranges, they should probably be avoided when aging skeletal remains.

Two arch criteria of the ilium for sex determination of immature skeletal remains: a test of their accuracy and an assessment of intra- and inter-observer error.

Although the assignment of sex to immature skeletal remains is considered problematic, some traits have been considered useful for both forensic and bioarchaeological applications. One such trait is the arch criterion found in subadult ilia, which is defined relative to the greater sciatic notch-auricular surface area. In adults, the composite arch has also been described in relation to this area and has proven relatively successful in sex determination. This study offers an examination of the accuracy of the arch criterion and the composite arch in determining the sex of subadult skeletal remains, and an assessment of intra- and inter-observer scoring error. A sample of 97 skeletons of known sex and age (<15 years) from the Lisbon collection (Portugal) were selected and the traits were scored by three observers on orthogonal photos of each ilium. In general the agreement within (67.7-88.5%) and between (50.5-76.3%) examiners was poor and overall accuracy (26.7-52.6%) did not meet the expectations of that reported in previous studies. The authors suggest that this derives from great variation in morphology, difficulties in interpreting criteria and possibly a lack of association between the expression of the traits and sex. Careful examination of sex-related morphology in the immature skeleton and additional blind tests of so-called useful traits should continue to be carried out.

On the reliability of a geometric morphometric approach to sex determination: A blind test of six criteria of the juvenile ilium

Despite the attention of many studies, researchers still struggle to identify criteria with which to sex juvenile remains at levels of accuracy and reproducibility comparable with those documented for adults. This study uses a sample of 82 juvenile ilia from an identified Portuguese population (Lisbon collection) to test the cross-applicability of a new approach by Wilson et al. [23] that uses geometric morphometric methods to sex the subadult ilium. Further, we evaluate the wider applicability of these methods for forensic casework, extending the age range of the original study by examining an additional 19 juvenile ilia from the St. Brides and Spitalfields collections, housed in London. Levels of accuracy for the Portuguese sample (62.2-89.0%) indicate that the methods can be used to document dimorphism in another sample. Discriminant functions are sample-specific, indicated by not better than average classification using cross-validation. We propose a methodological update, whereby we recommend disuse of the auricular surface morphology criterion, based upon reduced success rates and inadequate accuracy of female identification. We show, in addition to population differences, differences in the ontogeny of dimorphism may lead to differing degrees of success for female identification using some criteria. The success rates are highest between the ages of 11.00 and 14.99 years (93.3% males, 80.0% females).

Secular trends in social class differences of height, weight and BMI of boys from two schools in Lisbon, Portugal (1910–2000)

Data on the physical growth of children can provide useful information about the temporal changes in the economic conditions of the society in which they live and the extent of social inequalities within that society as well. Several studies have documented secular changes in the physical growth of children or of adult height, but seldom have the socioeconomic differences in secular trend been reported. The aim of this study is to examine differences in the secular trend of height, weight and BMI of 10-16-year-old boys enrolled in two schools of opposite socioeconomic makeup in Lisbon, Portugal, in the early and late 20th century. The samples from the upper-middle class come from the Colégio Militar, a military boarding school, and the lower-class samples come from the Casa Pia de Lisboa, a residential school for underprivileged boys. While boys from both schools show an approximate increase of 13.6cm in height, 13.5kg in weight and 2.4kg/m(2) in BMI, the Casa Pia students were shorter and lighter than their Colégio Militar counterparts throughout the 90-year period. Social class differences in mean height, weight and BMI tend to be greater in 1910 than in 2000, but results are statistically significant for height alone. When the two periods are taken together, Colégio Militar boys differ from their Casa Pia counterparts by approximately 6.4cm in height, 4.8kg in weight and 0.4kg/m(2) in BMI. Both samples show a considerable increase in height, weight and BMI but class differences in height, weight and BMI decreased slightly if at all, throughout the 90-year period. This suggests that socioeconomic disparities are persistent, having diminished only slightly since the early 20th century.

Is the length of the sternum reliable for estimating adult stature? A pilot study using fresh sterna and a test of two methods using dry sterna.

Stature estimation is one of the four attributes of the biological profile obtained from human skeletal remains. The length of the long bones has been consistently used to estimate stature from regression equations, but these may be useless when dealing with fresh or decomposed mutilated remains. Until recently, there was no consistent assessment of the reliability of measurements of the sternum for stature estimation. The purpose of this paper is to test previously developed regression formulae for stature based on measurements of the dry sternum and to assess the reliability of measurements of the fresh sternum in estimating stature. The formulae developed by Menezes et al. and Singh et al. were applied to a sample of 5 known stature skeletons from the identified human skeletal collection curated at the National Museum of Natural History, in Lisbon, Portugal. Testing of these formulae showed that estimated stature confidence intervals do not allow discrimination between individuals with similar stature. The length of the fresh sternum was measured on a sample of 45 male individuals autopsied at the National Institute of Legal Medicine - North Delegation (Porto, Portugal). Cadaver length was regressed on sternum length and a simple linear regression formula was obtained. The regression model provided a 95% confidence interval of 13.32 cm and a correlation coefficient of only 0.329. Compared to other studies, regression formulae based on the length of the sternum provided considerably larger standard errors than that based on long bone lengths. These results suggest that the length of the sternum has limited forensic value and relatively low reliability in estimating stature from mutilated human skeletal remains, either skeletonized or fresh.

Environmental effects on skeletal versus dental development II: Further testing of a basic assumption in human osteological research

This study further tests the general assumption that skeletal development is more sensitive to socioeconomic factors than dental development in a sample of modern immature Portuguese skeletons (N = 41) of known sex, age, and socioeconomic background. Skeletal development was assessed from skeletal maturation of the knee and dental development was assessed from schedules of tooth formation. Discrepancies between physiological age (skeletal and dental age) and chronological age were used as a measure of developmental status. A positive score indicates that physiological age is in advance of chronological age, whereas a negative score indicates the reverse. Two socioeconomic groups, one of low and the other of high socioeconomic status, were created based on the occupation of the father and on the place of residence, and developmental status was compared between the two socioeconomic groups. Results confirm previous studies by showing that dental development is less affected by environmental insults than skeletal maturation. While socioeconomic differences in skeletal maturation range from 1.20 to 1.22 years (15-18% of chronological age), socioeconomic differences in dental maturation range from 0.51 to 0.53 years (4-9% of chronological age). Compared to a previous study, results also suggest that skeletal maturation is more affected than skeletal growth. Additionally, an adaptation of the radiographic atlas of skeletal development of the knee is proposed for use with dry skeletal material.

Secular changes in body height and weight of Portuguese boys over one century

This study examines secular changes in attained height and weight in student boys from a military boarding school (Colégio Militar) in Lisbon, Portugal. Data for 1899–1906, 1929–1936, 1961–1966, and 1999–2006 obtained from the archives and medical files of the Colégio Militar were used in this study. In a century Portuguese boys increased in height by 10.5 cm at age 10 to 19.1 cm at age 14, at a mean increase of 1.54 cm per decade. The gain in weight was between 8.7 and 18.9 kg for 10‐ and 14‐year‐old boys, respectively, at a mean increase of 1.54 kg per decade. In the same period, age at peak height and weight velocity advanced ∼2 years, showing an acceleration of developmental tempo. However, most of the real gain in height and weight and the decrease in pubertal age occurred after 1961–1966. This mirrors major improvements in social and economic conditions that initiated in Portugal in the 1960s, and then by political events in the 1970s that promoted further progress. Am. J. Hum. Biol., 2008.

Shape, size, and maturity trajectories of the human ilium

Morphological traits of the ilium have consistently been more successful for juvenile sex determination than have techniques applied to other skeletal elements, however relatively little is known about the ontogeny and maturation of size and shape dimorphism in the ilium. We use a geometric morphometric approach to quantitatively separate the ontogeny of size and shape of the ilium, and analyze interpopulation differences in the onset, rate and patterning of sexual dimorphism. We captured the shape of three traits for a total of 191 ilia from Lisbon (Portugal) and London (UK) samples of known age and sex (0-17 years). Our results indicate that a) there is a clear dissociation between the ontogeny of size and shape in males and females, b) the ontogeny of size and shape are each defined by non-linear trajectories that differ between the sexes, c) there are interpopulation differences in ontogenetic shape trajectories, which point to population-specific patterning in the attainment of sexual dimorphism, and d) the rate of shape maturation and size maturation is typically higher for females than males. Male and female shape differences in the ilium are brought about by trajectory divergence. Differences in size and shape maturation between the sexes suggest that maturity may confound our ability to discriminate between the sexes by introducing variation not accounted for in age-based groupings. The accuracy of sex determination methods using the ilium may be improved by the use of different traits for particular age groups, to capture the ontogenetic development of shape in both sexes.

Secular change in the timing of dental root maturation in Portuguese boys and girls

Although secular changes in human growth are frequently reported in the literature, a secular trend in dental maturation has not been consistently shown to date.

Age Estimation From Stages of Union of the Vertebral Epiphyses of the Ribs

This study attempts to fill a persistent gap in the literature by documenting the timing of epiphyseal union at the vertebral end of the ribs in a sample of modern Portuguese skeletons. The skeletal remains of 53 females and 45 males, between the ages of 11 and 30, were taken from the Lisbon documented skeletal collection. Individuals in the sample have been previously described as being representative of a middle-to-low socioeconomic segment of the early 20th century Lisbon population. Three anatomical locations were examined for epiphyseal union: the head, the articular tubercle and the nonarticular tubercle. The first epiphysis to show partial union is that of the nonarticular tubercle (females, 11-19 years; males, 11-19 years), followed by the epiphysis of the articular tubercle (females, 11-20 years; males, 16-20 years), and finally by the head epiphysis (females, 15-24 years; males, 16-22 years), which can still show incomplete epiphyseal closure at 25 and 24 years for females and males, respectively. A trend for earlier female maturation was observed, but the statistical tests only confirmed this result for some ribs and age groups. No directional asymmetry was found, but a significant fluctuating asymmetry was observed in all three epiphyses. A preliminary analysis showed that the asymmetric group of individuals in the study sample includes all the rural-to-urban migrants, relative to the symmetric group.