The famous Swiss mummy, the "Lady of the Franciscan Church", is located in Basel. Subsequent to discovery in 1975, many investigations on her origin were performed without success. Four decades later, however, the mummy’s origin has been identified: Anna Catharina Gernler-Bischoff (1719-1787), who was a direct ancestor of Boris Johnson, the former Prime Minister of the United Kingdom. Further details about her life have been collected. For this purpose, teeth were removed and physically sliced for imaging using optical microscopy. One single tooth remained and became available for this cementochronology study. We have applied microtomography to visualize the annual deposits in tooth cementum, termed incremental layers, without the need of physical slicing. The applicability of synchrotron radiation-based tomography to cementochronology has previously been investigated and showed promise. It is, however, unclear how far tomography will work for the mummy tooth. Laboratory-based microtomography enabled us to discriminate between enamel, dentin, and cementum, but the annual layers remained invisible. The improved density and spatial resolution of the tomography setup at the beamline ANATOMIX, Synchrotron SOLEIL, France, however, brought the incremental layers to light. We have counted 30 layers on average. Their thickness corresponds to (4.6 ± 1.4) µm. The available tomography data of the entire tooth should be further analyzed to correlate the life history of Anna Catharina Gernler-Bischoff with thickness and contrast of the incremental layers. The pipeline developed and the gained knowledge will be beneficial for cementochronology of humans dead and alive.
Tooth cementum annulation (TCA) is used by anthropologists to decipher age-at-death and stress periods based on
yearly deposited incremental lines (ILs). The destructive aspect of the TCA method, which requires cutting the tooth root
in sections to display the ILs, using transmission light microscopy, can be problematic for archeological teeth, and so a
non-invasive imaging technique is preferred. The purpose of this study is to evaluate conventional micro computed
tomography (μCT) and synchrotron radiation-based X-ray micro computed tomography (SRμCT) as a non-destructive
technique to explore the tooth cementum ultrastructure and to display ILs. Seven archeological teeth from the Basel-
Spitalfriedhof collection (patients died between 1845 and 1868 in the city hospital) were selected for the μCT
experiments. This collection is considered a unique worldwide reference series in the anthropological science
community, due to the high level of documented life history data in the medical files and the additionally collected and
verified birth history by genealogists. The results demonstrate that the conventional μCT is complementary to the
SRμCT allowing to prescreen the teeth using conventional μCT to identify the appropriate specimens and areas for the
SRμCT measurements. SRμCT displayed cementum ring structure corresponding to the ILs in the microscope view in
archeological teeth in a non-invasive fashion with the potential for more accurate assessments of ILs compared to
conventional techniques. The ILs were mainly clearly visible, and it was possible to count them for age-at-death
assessment and identify qualitatively irregular ILs which could constitute stress markers.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.