Isotopic and dental evidence for infant and young child feeding practices in an imperial Roman skeletal sample.

This study integrates isotopic, palaeopathological, and historical evidence to investigate infant and young child feeding practices in a Roman period (1st to 3rd centuries AD) skeletal sample from the Isola Sacra necropolis (Rome, Italy). Stable isotope analysis of bone collagen from 37 rib samples indicates that transitional feeding began by the end of the first year and weaning occurred by 2-2.5 years of age. Both delta(15)N and delta(13)C data clearly show the trophic level effect associated with breastfeeding. Childhood diet is investigated using dental pathology data in the deciduous dentitions of 78 individuals aged between 1 and 12 years. The presence of calculus, caries, and tooth wear in young children suggests that individuals were provided complementary foods and other items that impacted their dental health at an early age. The isotopic and dental data are generally consistent with the historical evidence from the Roman period with respect to the general timetable of weaning and the character of complementary foods. This is the first study to integrate isotopic and deciduous dental pathology data to explore infant and young child feeding practices in the Roman world.

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.

Sexual dimorphism of the dental tissues in human permanent mandibular canines and third premolars.

Methods of measuring tissue area from images of longitudinal thin tooth sections have been used to assess sexual dimorphism in the permanent dentition. The aim of this study was to demonstrate the extent of sexual dimorphism within the coronal tissue proportions of permanent mandibular canines and premolars, using area measurements of the enamel and dentine-pulp core. The sample consisted of embedded "half-tooth" sections from 45 individuals, all of known age-at-death and sex, collected from the St. Thomas' Anglican Church historic (1821-1874) cemetery site in Belleville, ON, Canada. The relative dentine-pulp area of the third premolars and canines displayed high levels of sexual dimorphism, as well as statistically significant mean differences between the sexes. The male canines and premolars have significantly more dentine than their female counterparts, as well as relatively more dentine with respect to overall crown size. The female canines and premolars have significantly more enamel relative to overall crown area than those of the males. These results suggest that relative area measures of crown tissues are more predictable measures of sexual dimorphism than absolute measures, and tissue proportions may remain constant despite intrasex variation in overall tooth crown size.

Histological identification of syphilis in pre-Columbian England.

Microscopic analyses served to complement the macroscopic identification of venereal syphilis in two of four pre-Columbian skeletons from the site Hull Magistrates Court in England. Diagnosis was based on parameters presented by Schultz ([1994] Origin of Syphilis in Europe, Toulon: Centre Archaeologique du Var, p. 63-67; [2001] Yrbk. Phys. Anthropol. 44:106-147; [2003] Identification of Pathological Conditions in Human Remains, New York: Academic Press, p. 73-109), which characterized venereal syphilis at a histological level. Observation of the microarchitecture of these samples allowed a more comprehensive approach to identification of the disease (processes). In most samples, Polsters and Grenzstreifen (or remnants of such structures) could be identified, suggesting the presence of a chronic, inflammatory disease such as venereal syphilis. Sinous lacunae were also observed in all histological samples, pointing to lytic activity (osteitis). The combination of both proliferative and destructive processes is pathognomonic for syphilis, and histological analyses provided a more accurate diagnosis of this infectious disease in these four individuals. As a result, the histological evidence suggests that venereal syphilis was present in England prior to 1492. This secondary form of evidence supports the macroscopic identification of the disease, and shows the power of a multimethodological approach to paleopathological diagnoses.

Isotopic evidence for age-related variation in diet from Isola Sacra, Italy.

This study examines collagen (N=105) and apatite (N=65) data from an Imperial Roman skeletal sample from the necropolis of Isola Sacra (Rome, Italy). This paper explores correlations between the isotopic composition of bone samples and the inferred age and sex of these individuals (aged 5--45+ years). The collagen of males, and older individuals in general, was significantly enriched in (15)N but not (13)C. Bone carbonate was somewhat depleted in (13)C in some older individuals, suggesting increased consumption of olive oil and possibly wine. Subadults (>5 years) in the sample appear to have consumed an almost exclusively terrestrial diet. This study demonstrates a clear trend in dietary patterns between adult age groups, as well as between adults and children within a population.

Test of histological methods of determining chronology of accentuated striae in deciduous teeth.

One of the difficulties that has prevented Wilson bands, internal defects of enamel growth, from achieving maximum usefulness as indicators of stress in bioarchaeological studies is the inaccuracy of the methods for determining ages of defect occurrence. This study tests a technique that uses microstructural growth markers of enamel to establish the chronology of Wilson bands in deciduous teeth. A sample of 274 teeth from 127 subadults from an Imperial Roman necropolis was sectioned and examined under a microscope. The sample ranged in age at death from birth to 13 years. Sixty-four teeth from 50 individuals were found to have 447 Wilson bands in total. Of those contributing multiple teeth to the sample, 13 individuals had at least one Wilson band in each of two teeth that could be identified as having been formed coevally. These provided the basis for testing the methodology. Paired t-tests found no significant differences between the chronologies of matched pairs in the two teeth, with mean ages from each differing by less than 1 day. The authors propose a hypothesis that explains the development of Wilson bands, and classifies them within the context of other features of enamel. The most important implications arising from this paper are: 1) aging methods using microstructural growth markers can be applied to deciduous teeth; 2) physiological stressors leave different traces in enamel, depending on severity and time of occurrence relative to total crown development; 3) no threshold level exists; all physiological stress will leave a record; 4) therefore, no minimal definition of a Wilson band can be delineated that recognizes all such events; 5) implying that studies using them will only identify minimum rates of occurrence.

Hypersensitive PCR, ancient human mtDNA, and contamination.

When highly efficient polymerase was used with high cycle numbers (50-60), strong amplifications were observed, but negative controls were also unexpectedly amplified in a study of ancient human mtDNA from 2000-year-old skeletons. The results of a series of tests revealed that the hypersensitive polymerase chain reaction (PCR) generated by higher cycles and the presence of contaminant DNA (though at extremely low levels) should be responsible for the amplification of negative controls. We suggest that PCR sensitivity be optimized to take advantage of highly efficient polymerase and at the same time prevent "background DNA" from becoming "contaminant DNA" and obscuring the analysis of authentic ancient DNA. We propose the use of multiple positive controls when amplifying ancient human mtDNA samples to indicate the sensitivity of individual PCR amplifications and to monitor the contamination levels of modern human DNA. This study provides some suggestions as to how to amplify and analyze ancient human mtDNA when unavoidable and extremely tiny amounts of modern human DNA exist.

Enamel hypoplasia in a Canadian historic sample.

Analyses of historical skeletal samples provide useful comparisons of the prevalence of skeletal indicators of stress to documentary information on health, diet, and socioeconomic status. A sample of the permanent dentitions of 253 adults from the St. Thomas' Anglican Church 19th-century skeletal sample in Belleville, Ontario, was examined macroscopically for the prevalence of enamel defects on the six anterior maxillary and mandibular teeth. The maximum frequency of hypoplasias on the left mandibular canine is 36.1%. The prevalence of enamel defects is low to moderate compared to almost all other reported frequencies in historical samples, which is consistent with historical descriptions of this developing community of middle to high socioeconomic status Canadians. Hypoplasias are significantly more frequent in males but there are no significant differences in the mean age at death between individuals with hypoplasia and those without. Calculations of the peak ages of occurrence of hypoplasias fall within the commonly observed 2-4-year range. This is not consistent with separate studies, demographic, isotopic and historical, of the introduction of complementary foods to 19th-century Belleville infants and of the weaning process. These results do not support the view that peak ages of occurrence of hypoplastic defects are associated with the cessation of breast-feeding or the weaning process in general. Am. J. Hum. Biol. 11:513-524, 1999. Copyright 1999 Wiley-Liss, Inc.