... in the adult skeleton are still largely absent before the advent of pu-berty enabling a less ... more ... in the adult skeleton are still largely absent before the advent of pu-berty enabling a less definitivedetermination of sex in immature ... is also argued that the genetic characteristics associated with ancestry cannot be determined with great accuracy in juvenile remains because ...
Average facial soft-tissue thickness (FSTT) databanks are continuously developed and applied with... more Average facial soft-tissue thickness (FSTT) databanks are continuously developed and applied within craniofacial identification. This study considered and tested a subject-specific regression model alternative for estimating the FSTT values for oral midline landmarks using skeletal projection measurements. Measurements were taken from cone-beam computed tomography scans of 100 South African individuals (60 male, 40 female; Mage = 35 years). Regression equations incorporating sex categories were generated. This significantly improved the goodness-of-fit ( r2-value). Validation tests compared the constructed regression models with mean FSTT data collected from this study, existing South African FSTT data, a universal total weighted mean approach with pooled demographic data and collection techniques and a regression model approach that uses bizygomatic width and maximum cranial breadth dimensions. The generated regression equations demonstrated individualised results, presenting a tot...
We report further details on four partial human skeletons from KwaZulu-Natal previously selected ... more We report further details on four partial human skeletons from KwaZulu-Natal previously selected for genetic analysis. Dating and genetic results indicate that they derived from agriculturist communities of the mid-second millennium AD. Morphological and genetic analysis shows that three individuals were female; identification of the fourth as female comes from genetic analysis only. All four were adults at death, three older adults and one younger. Genetically, all four individuals cluster strongly with Bantu-speaking populations with West African roots, a result supported by craniometric data for the one individual with a complete and well-preserved cranium. All nevertheless display some admixture with Khoe-San populations. We show that three of the women, and probably the fourth, carried genetic resistance to the Plasmodium vivax malaria parasite, while two had some protection against Trypanosoma brucei gambiense-induced sleeping sickness. The unusual rock-shelter burial location...
SANPAD and the Maxi Foundation (Switzerland) for funding parts of the project. The research of M.... more SANPAD and the Maxi Foundation (Switzerland) for funding parts of the project. The research of M.S. is funded by the National Research Foundation (NRF) of South Africa.
The reported incidence of neoplasia in the extinct human lineage is rare, with only a few confirm... more The reported incidence of neoplasia in the extinct human lineage is rare, with only a few confirmed cases of Middle or Later Pleistocene dates reported. It has generally been assumed that pre-modern incidence of neoplastic disease of any kind is rare and limited to benign conditions, but new fossil evidence suggests otherwise. We here present the earliest identifiable case of malignant neoplastic disease from an early human ancestor dated to 1.8–1.6 million years old. The diagnosis has been made possible only by advances in 3D imaging methods as diagnostic aids. We present a case report based on re-analysis of a hominin metatarsal specimen (SK 7923) from the cave site of Swartkrans in the Cradle of Humankind, South Africa. The expression of malignant osteosarcoma in the Swartkrans specimen indicates that whilst the upsurge in malignancy incidence is correlated with modern lifestyles, there is no reason to suspect that primary bone tumours would have been any less frequent in ancient...
Standards for estimating mouth width and Cupid’s bow width in craniofacial approximation and supe... more Standards for estimating mouth width and Cupid’s bow width in craniofacial approximation and superimposition are limited. Currently, the only guideline for mouth width, using direct skeletal references, is a general rule indicating a 75% inter‐canine to mouth width ratio. The philtrum, which closely corresponds to the Cupid’s bow, is said to be equal to the inter‐superior prominences of the maxillary central incisors. This study tested these guidelines against newly generated regression models and mean values. Cone‐beam CT scans of 120 black and 39 white southern African adults were used. Comparative hard and soft tissue measurements were taken using a 3D DICOM viewer. Regression equations accounting population, sex, and approximate age variables (20–39 and 40+ years), utilizing maxillary inter‐canine width to estimate mouth width and maxillary central–lateral incisor junction width to estimate Cupid’s bow width, performed statistically best. The regression models were more reliable than existing standards in validation tests.
Although guidelines for facial approximations, including those for the eye, are in use in South A... more Although guidelines for facial approximations, including those for the eye, are in use in South Africa, limited data on African populations exist to confirm its validity. As precise placement of the eyes in facial approximations is of importance for facial recognition, this study tested established guidelines by measuring specific instrumental dimensions. Forty-nine cadavers from the Sefako Makgatho Health Sciences University and the University of Pretoria were dissected to determine the position of the canthi and the size and position of the eyeball in the orbit. Thirty cone beam computer tomography scans and 30 computer tomography scans from the Oral and Dental and Steve Biko Hospitals respectively were used to determine the size of the eyeball. Results from this study were compared to the published guidelines. The most prominent discrepancies included a more rectangular shape of the orbit, an oval shaped eyeball and a different position of the canthi. In African faces, the medial...
Burial of remains is an important factor when one attempts to establish the post-mortem interval ... more Burial of remains is an important factor when one attempts to establish the post-mortem interval as it reduces, and in extreme cases, excludes oviposition by Diptera species. This in turn leads to modification of the decomposition process. The aim of this study was to record decomposition patterns of buried remains using a pig model. The pattern of decomposition was evaluated at different intervals and recorded according to existing guidelines. In order to contribute to our knowledge on decomposition in different settings, a quantifiable approach was followed. Results indicated that early stages of decomposition occurred rapidly for buried remains within 7–33 days. Between 14 and 33 days, buried pigs displayed common features associated with the early to middle stages of decomposition, such as discoloration and bloating. From 33 to 90 days advanced decomposition manifested on the remains, and pigs then reached a stage of advanced decomposition where little change was observed in the...
... in the adult skeleton are still largely absent before the advent of pu-berty enabling a less ... more ... in the adult skeleton are still largely absent before the advent of pu-berty enabling a less definitivedetermination of sex in immature ... is also argued that the genetic characteristics associated with ancestry cannot be determined with great accuracy in juvenile remains because ...
Average facial soft-tissue thickness (FSTT) databanks are continuously developed and applied with... more Average facial soft-tissue thickness (FSTT) databanks are continuously developed and applied within craniofacial identification. This study considered and tested a subject-specific regression model alternative for estimating the FSTT values for oral midline landmarks using skeletal projection measurements. Measurements were taken from cone-beam computed tomography scans of 100 South African individuals (60 male, 40 female; Mage = 35 years). Regression equations incorporating sex categories were generated. This significantly improved the goodness-of-fit ( r2-value). Validation tests compared the constructed regression models with mean FSTT data collected from this study, existing South African FSTT data, a universal total weighted mean approach with pooled demographic data and collection techniques and a regression model approach that uses bizygomatic width and maximum cranial breadth dimensions. The generated regression equations demonstrated individualised results, presenting a tot...
We report further details on four partial human skeletons from KwaZulu-Natal previously selected ... more We report further details on four partial human skeletons from KwaZulu-Natal previously selected for genetic analysis. Dating and genetic results indicate that they derived from agriculturist communities of the mid-second millennium AD. Morphological and genetic analysis shows that three individuals were female; identification of the fourth as female comes from genetic analysis only. All four were adults at death, three older adults and one younger. Genetically, all four individuals cluster strongly with Bantu-speaking populations with West African roots, a result supported by craniometric data for the one individual with a complete and well-preserved cranium. All nevertheless display some admixture with Khoe-San populations. We show that three of the women, and probably the fourth, carried genetic resistance to the Plasmodium vivax malaria parasite, while two had some protection against Trypanosoma brucei gambiense-induced sleeping sickness. The unusual rock-shelter burial location...
SANPAD and the Maxi Foundation (Switzerland) for funding parts of the project. The research of M.... more SANPAD and the Maxi Foundation (Switzerland) for funding parts of the project. The research of M.S. is funded by the National Research Foundation (NRF) of South Africa.
The reported incidence of neoplasia in the extinct human lineage is rare, with only a few confirm... more The reported incidence of neoplasia in the extinct human lineage is rare, with only a few confirmed cases of Middle or Later Pleistocene dates reported. It has generally been assumed that pre-modern incidence of neoplastic disease of any kind is rare and limited to benign conditions, but new fossil evidence suggests otherwise. We here present the earliest identifiable case of malignant neoplastic disease from an early human ancestor dated to 1.8–1.6 million years old. The diagnosis has been made possible only by advances in 3D imaging methods as diagnostic aids. We present a case report based on re-analysis of a hominin metatarsal specimen (SK 7923) from the cave site of Swartkrans in the Cradle of Humankind, South Africa. The expression of malignant osteosarcoma in the Swartkrans specimen indicates that whilst the upsurge in malignancy incidence is correlated with modern lifestyles, there is no reason to suspect that primary bone tumours would have been any less frequent in ancient...
Standards for estimating mouth width and Cupid’s bow width in craniofacial approximation and supe... more Standards for estimating mouth width and Cupid’s bow width in craniofacial approximation and superimposition are limited. Currently, the only guideline for mouth width, using direct skeletal references, is a general rule indicating a 75% inter‐canine to mouth width ratio. The philtrum, which closely corresponds to the Cupid’s bow, is said to be equal to the inter‐superior prominences of the maxillary central incisors. This study tested these guidelines against newly generated regression models and mean values. Cone‐beam CT scans of 120 black and 39 white southern African adults were used. Comparative hard and soft tissue measurements were taken using a 3D DICOM viewer. Regression equations accounting population, sex, and approximate age variables (20–39 and 40+ years), utilizing maxillary inter‐canine width to estimate mouth width and maxillary central–lateral incisor junction width to estimate Cupid’s bow width, performed statistically best. The regression models were more reliable than existing standards in validation tests.
Although guidelines for facial approximations, including those for the eye, are in use in South A... more Although guidelines for facial approximations, including those for the eye, are in use in South Africa, limited data on African populations exist to confirm its validity. As precise placement of the eyes in facial approximations is of importance for facial recognition, this study tested established guidelines by measuring specific instrumental dimensions. Forty-nine cadavers from the Sefako Makgatho Health Sciences University and the University of Pretoria were dissected to determine the position of the canthi and the size and position of the eyeball in the orbit. Thirty cone beam computer tomography scans and 30 computer tomography scans from the Oral and Dental and Steve Biko Hospitals respectively were used to determine the size of the eyeball. Results from this study were compared to the published guidelines. The most prominent discrepancies included a more rectangular shape of the orbit, an oval shaped eyeball and a different position of the canthi. In African faces, the medial...
Burial of remains is an important factor when one attempts to establish the post-mortem interval ... more Burial of remains is an important factor when one attempts to establish the post-mortem interval as it reduces, and in extreme cases, excludes oviposition by Diptera species. This in turn leads to modification of the decomposition process. The aim of this study was to record decomposition patterns of buried remains using a pig model. The pattern of decomposition was evaluated at different intervals and recorded according to existing guidelines. In order to contribute to our knowledge on decomposition in different settings, a quantifiable approach was followed. Results indicated that early stages of decomposition occurred rapidly for buried remains within 7–33 days. Between 14 and 33 days, buried pigs displayed common features associated with the early to middle stages of decomposition, such as discoloration and bloating. From 33 to 90 days advanced decomposition manifested on the remains, and pigs then reached a stage of advanced decomposition where little change was observed in the...
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Papers by Maryna Steyn