George J. R. Maat

The caries-attrition competition

Contradictory reports on the interreation of caries and attrition concerning their destructive activity at the occlusal surface of teeth required more investigation. Some suggested that the abrasive action of attrition worked against the progress of decay. Others proposed that attrition facilitated the development of caries in dentine exposed due to the dental wear. A comparison of the condition of teeth in western societies from an intermediate stage, with the preceding period characterized by excessive attrition, and with the following period of ongoing reduction of dental wear, might elucidate the mutual relationship. For this reason the almost complete dental assemblage of fifty men, whalers buried during their short sojourn in the Arctic in the 17th and 18th centuries at a Dutch whaling station, and the data of their contemporaries, were evaluated. The results confirmed the proposition that the rise in caries incidence from (pre-) medieval times on, was associated with an ongoing fall of dental attrition. Within this sample of an intermediate phase, one sees that the percentage of carious molars decreases considerably when the degree of dental wear increases. Besides, at the occlusal surface the decay was almost exclusively located in the natural fissures and pits of teeth, not in the exposed dentine due to wear. These findings strongly suggest a competitive relationship between progress of caries and attrition. The best impression of the attrition rate is gained by linkage of degree of dental attrition (i.e. functional age) to age at death. The wide age ranges fitting to the degrees of molar wear make it hazardous to use attrition for age determination.

On the reliability of non‐metrical morphological sex determination of the skull compared with that of the pelvis in The Low Countries

In order to study the suitability of the skull for sex determination, a sample of 202 adult human skeletons with pelves was analysed according to the recommendations of the Workshop of European Anthropologists (1980). The remains originated from citizens of the medieval city of Dordrecht in The Netherlands (AD 1275–1572). Sex was determined by means of non-metrical morphological sex-descriminant features of the skull (cranium plus mandible) and of the separate cranium and separate mandible, and compared against determination made using the pelvis. The reliability of the pelvic sex determination was verified by evaluating the position of the lowest intermediate frequency of the bimodal distribution of the degrees of sexualization of the pelvis. n n n nContingency diagrams and tables were drawn with respect to the sex diagnosis and the degree of sexualization of (i) the skull (cranium plus mandible) and related pelvis, (ii) the cranium and related pelvis, and (iii) the mandible and related pelvis. n n n nIt was concluded that sex diagnosis using the skull, cranium and mandible corresponded to that using the pelvis in 96.2 per cent (N=106), 95.7 per cent (N=140) and 69.5 per cent (N=118) of the cases, respectively. Notably, in the case of female pelves (N=64), 51.6 per cent of the related mandibles were diagnosed as ‘male’. Therefore a caveat must be entered in the use of the mandible for the determination of sex, because in the Low Countries it was found to lack reliability.

Avulsion injuries of vertebral endplates

Bone changes resulting from avulsions involving vertebral endplates have had little, if any, systematic attention in palaeopathological literature. To gain insight into their occurrence and into their variety, two archaeological skeletal collections covering the period AD 1455–1824 were examined. Additional skeletal material was used to illustrate typical examples. A quarter of the 44 adults who had adequate numbers of vertebrae at all spinal levels showed minor to major vertebral endplate changes as a result of avulsion injuries. The male/female ratio was 7:4. The ratio of individuals with injuries contracted during their youth and during their adulthood was 3:8 (n=11). Approximately half of the affected individuals showed such changes in multiple vertebrae. In about one third of the cases, concomitant vertebral fractures, which did not involve the endplates, were recorded. Since the existing classifications of endplate changes from avulsion injuries were developed on the basis of clinical diagnoses made by means of X-ray or by autopsy, an adapted and extended outline for palaeopathological use is proposed. A series of differential diagnoses is discussed. Although, in general, the poor preservation of archaeological spines hampers epidemiology, the diagnosis of spinal avulsion injuries offers interesting information at the individual level. Copyright

Practising methods of age determination. Comments on methods combining multiple age indicators

For some time, trends in age determination of skeletons have tended to shift from methods using single age indicators to methods combining multiple age indicators. Evidently the latter are expected to offer more balanced age assessments. If one decides to apply a method using multiple age indicators, a choice can be made between two «current» methods, both based on non-metrical age indicators: the socalled Complex Method of Acsádi and Nemeskéri, statistically elaborated by Sjøvold (WEA, 1980), and the so-called Multifactorial Method of Lovejoy et al., 1985a. Comments are given on practical applicability and supposed confidence.

Exploring the effect of the occurrence of sound on force applied by the ear when listening at a surface

In this article, we explore the effect of the occurrence of a target sound on the force that is applied by the ear when listening at a surface because differences in applied force induce variation in carprints of a single ear. Forty two subjects each listened four times at a surface. During two of these listening efforts there was silence. While the subjects were listening, we measured the amount of force that was applied to the surface. To explore the effect of the occurrence of a target sound upon applied force, we applied a mixed model analysis of variance. The force applied by the ear appeared to be uncorrelated to presence or absence of a target sound. This lack of association appeared not to be the result of potential confounders. Only repetition (i.e., the position of a listening effort in the series of four), appeared to significantly affect applied force; this force being generally lower during a first listening effort.

DNA identification of human remains in Disaster Victim Identification (DVI): An efficient sampling method for muscle, bone, bone marrow and teeth

In disaster victim identification (DVI), DNA profiling is considered to be one of the most reliable and efficient means to identify bodies or separated body parts. This requires a post mortem DNA sample, and an ante mortem DNA sample of the presumed victim or their biological relative(s). Usually the collection of an adequate ante mortem sample is technically simple, but the acquisition of a good quality post mortem sample under unfavourable DVI circumstances is complicated due to the variable degree of preservation of the human remains and the high risk of DNA (cross) contamination. This paper provides the community with an efficient method to collect post-mortem DNA samples from muscle, bone, bone marrow and teeth, with a minimal risk of contamination. Our method has been applied in a recent, challenging DVI operation (i.e. the identification of the 298 victims of the MH17 airplane crash in 2014). 98,2% of the collected PM samples provided the DVI team with highly informative DNA genotyping results without the risk of contamination and consequent mistyping the victims DNA. Moreover, the method is easy, cheap and quick. This paper provides the DVI community with a step-wise instructions with recommendations for the type of tissue to be sampled and the site of excision (preferably the upper leg). Although initially designed for DVI purposes, the method is also suited for the identification of individual victims.