Extended-field synchrotron microtomography for non-destructive analysis of incremental lines in human teeth cementum: example data

Abstract

Tooth cementum annulation (TCA) is used for determining age-at-death and stress periods based on yearly
deposited layers in the root cementum of human teeth. Traditionally, TCA analysis employs optical microscopy,
which requires cutting sections of the root and provides only sparse sampling in the third dimension. Ancient
teeth are often unique specimens that should not be damaged. In this imaging study, we show that extended-field
synchrotron radiation-based microtomography can be used to provide true micrometer resolution and full
coverage of the tooth for non-destructively surveying ancient teeth for incremental layers. To rapidly review the
root cementum layer of four teeth from an early 19th century cemetery with historical records of life events, we
developed a method for automatically enhancing incremental lines on virtual slices and for detecting regions with
strong incremental line appearances. Surveying large regions of the root cementum avoids missing high-contrast
incremental lines and hence improves TCA analysis as an alternative to irreversible slicing of the unique teeth.

Data

The repository contains the microtomography data from four teeth to enable reproducing Figures 6a,c,e,f in the associated publication, Tanner et al., "Extended-field synchrotron microtomography for non-destructive analysis of incremental lines in archeological human teeth cementum". Proceedings of SPIE 11840 (2021) 1184019. DOI: 10.1117/12.2595180. Each dataset contains 57 tif slices around the selected slice selZ, i.e. selZ-28:selZ+28, as stated below.

Processing

Incremental teeth lines can be enhanced via the MATLAB programs available in the github repository unibas-bmc/enhanceIncrementalTeethLines.

Please extract the data from name.tar.gz via unix command "tar -xzvf name.tar.gz" . Place the .tif files called reco_????.tif  in directory "dataDir1" or "dataDir2" (see last column in table) using subdirectories based on the tooth name and heightstep, e.g.  "tooth4_hs04/reco/" for dataset "tooth4_hs04_reco_selZ715.tar.gz". Then set the "sampleIdx" and "hs" parameter in "dataParameterDefinitionTeeth.m" as stated in the table above. Finally run "extractCementumPatchesEnhanceIL.m" to process the data.

Note

We are grateful for beamtime access at the Synchrotron SOLEIL, ANATOMIX beamline (experiment no. 20200712). ANATOMIX is an Equipment of Excellence (EQUIPEX) funded by the Investments for the Future program of the French National Research Agency (ANR), project NanoimagesX, grant no. ANR-11-EQPX-0031. 

We also thank the Citizen Science Project BBS “Bürgerforschungsprojekt Basel-Spitalfriedhof” for their time-consuming voluntary research regarding the historical sources of the samples.