Original published work submitted to the Faculty of Health Sciences, University of the
Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of
Philosophy, August 2019 / Age-at-death estimates in skeletal remains are hampered by observer bias and error, as
well as individual and population variation. This study aimed at improving accuracy and
reliability of age estimates obtained from applying methods involving the assessment of
histomorphometric variables of bone and bone mineral density (BMD).
The assessment of osteon population density (OPD) and size (length, surface area and
volume) of Haversian systems were investigated in three populations by means of
stereology. Bone slides prepared from South African black (n = 99), South African white
(n = 94) and Danish white (n = 30) individuals were analysed using MicroBrightField’s
StereoInvestigator software. ANCOVA results revealed a statistically significant
difference (p < 0.001) between the three groups in terms of OPD. No statistically
significant difference was seen in the size of secondary osteons between the groups.
Linear regression analysis was used to construct population-specific formulae for age-atdeath
estimation in South African white and black individuals. The Danish sample was
used as a comparative group for white South African standards established. Age
mimicry appeared to play a role in the over-estimation of age in the Danish individuals,
after which the problem was corrected by combining the two samples in order to achieve
normal age distribution within the larger sample.
Secondly, DXA scans of the proximal femur were done for a subgroup of South African
black (n = 64) and white (n = 59) individuals for estimation of age-at-death from bone
mineral density. Results displayed a significant difference between white and black
groups for total and neck BMD. White males and females differed in total and neck
BMD, although black males and females differed only in terms of neck BMD. Age could
be significantly correlated with BMD in the white population, but not in the black
population. Regression analysis was also done for the complete sample (white and black
individuals pooled), as ancestry is unknown in some cases. A significant correlation was
seen for age versus neck BMD in the total sample and in sex-specific groups.
The outcome of this study suggested that the three population samples are somewhat
dissimilar in bone microstructure, with differences related to OPD and BMD present
between the groups. Based on this outcome, it should be emphasized that age estimation
standards should be adapted to accommodate combined groups and create to more
generally applicable standards. Further research involving various disciplines is needed to
better understand the underlying reason(s) for these differences between these populations. / PH2020
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/29812 |
| Date | 08 1900 |
| Creators | Botha, Deona |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | Online resource (132 leaves), application/pdf |
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