Age and Morbidity at the beginning of Life An evaluation of three ageing methods and assessment of infant mortality in a nineteenth century Dutch skeletal collection

Skeletal and dental growth and development is investigated in 39 perinate and infant skeletons aged between 32 weeks gestation to 42 weeks after birth in order to determine the accuracy of three ageing methods and to assess possible periods of increased stress in the sample. The skeletal remains belong to a recently excavated, partly documented cemetery, from Middenbeemster, a rural village in the Netherlands, dating mainly to the nineteenth century. Three ageing methods were chosen to be evaluated, the accuracy of which had not been systematically investigated: 1) the deciduous Demirjian stages by Liversidge and Molleson (2004); 2) the dental height regression equations by Liversidge and colleagues (1993), and; 3) skeletal age estimation using 26 measurements form 18 different bones utilising six different standards (Black and Scheuer 1996; Fazekas and Kósa 1978; Maresh 1955; Molleson and Cox 1993; Saunders et al. 1993; Scheuer and McLaughlin-Black 1994). Accuracy of the methods...Show moreSkeletal and dental growth and development is investigated in 39 perinate and infant skeletons aged between 32 weeks gestation to 42 weeks after birth in order to determine the accuracy of three ageing methods and to assess possible periods of increased stress in the sample. The skeletal remains belong to a recently excavated, partly documented cemetery, from Middenbeemster, a rural village in the Netherlands, dating mainly to the nineteenth century. Three ageing methods were chosen to be evaluated, the accuracy of which had not been systematically investigated: 1) the deciduous Demirjian stages by Liversidge and Molleson (2004); 2) the dental height regression equations by Liversidge and colleagues (1993), and; 3) skeletal age estimation using 26 measurements form 18 different bones utilising six different standards (Black and Scheuer 1996; Fazekas and Kósa 1978; Maresh 1955; Molleson and Cox 1993; Saunders et al. 1993; Scheuer and McLaughlin-Black 1994). Accuracy of the methods is tested on a subsample of ten individuals for whom age at death is known from the Beemster district archives, and the results are further evaluated using the entire sample. Results from individuals of known age indicate high levels of accuracy for skeletal age and dental height with mean difference to chronological age of only -0.4 and +0.6 weeks, respectively. The deciduous developmental stages significantly overestimate chronological age by +5.5 weeks. These observed trends are confirmed in the entire sample were age was compared to the sample mean. In neonatal remains, skeletal age is most accurate regardless the standards used, but for post-neonates only the Maresh (1955) standard provides accurate results (+1.9 weeks). Dental developmental stages are more accurate in individuals less than two months (+2.4 weeks), increasing in older individuals to +5.2 weeks. Dental height gave an outstanding performance with consistent high levels of accuracy in neonatal (+1.6 weeks) and post-neonatal remains (+0.15 weeks), making it the preferred method for age estimation in the infant category. The mortality pattern followed a normal declining curve with the greatest percentage of individuals dying during the neonatal period. Skeletal development lagged behind dental development by about one month in almost 70% of the individuals, showing a trend of an increasing amount of delay with age. But differences in age between skeletal and dental development were not unambiguously pointing to a stress induced delay and more research is needed to clarify the observed trends. This thesis provides new information on the accuracy of dental and skeletal ageing methods of infant remains and should guide our application of these methods in future research of north-west European skeletal samples.Show less

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Age and Morbidity at the beginning of Life An evaluation of three ageing methods and assessment of infant mortality in a nineteenth century Dutch skeletal collection