Virtual histology of archaeological human deciduous prenatal enamel through synchrotron X-ray computed microtomography images

Abstract

Virtual histology is increasingly utilized to reconstruct the cell mechanisms underlying dental morphology for fragile fossils when physical thin sections are not permitted. Yet, the comparability of data derived from virtual and physical thin sections is rarely tested. Here, the results from archaeological human deciduous incisor physical sections are compared with virtual ones obtained by phase-contrast synchrotron radiation computed microtomography (SRµCT) of intact specimens using a multi-scale approach. Moreover, virtual prenatal daily enamel secretion rates are compared with those calculated from physical thin sections of the same tooth class from the same archaeological skeletal series. Results showed overall good visibility of the enamel microstructures in the virtual sections which are comparable to that of physical ones. The highest spatial resolution SRµCT setting (effective pixel size = 0.9 µm) produced daily secretion rates that matched those calculated from physical sections. Rates obtained using the lowest spatial resolution setup (effective pixel size = 2.0 µm) were higher than those obtained from physical sections. The results demonstrate that virtual histology can be applied to the investigated samples to obtain reliable and quantitative measurements of prenatal daily enamel secretion rates.

Understanding the maternal-infant nexus from dental histology and high-resolution compositional biogeochemistry: implications for bioarchaeological research

“…A possible attenuation of destructive and microdestructive sampling is the ability to perform virtual non-destructive histological analysis using synchrotron-based X-ray microtomography. The now well-established use of this technique (Tafforeau and Smith, 2008;Tafforeau et al, 2012;Le Cabec et al, 2015;Le Cabec et al, 2017;Nava et al, 2017b;Mahoney et al, 2021;Cerrito et al, 2022;Nava et al, 2022) allows analyses of incremental dental growth microstructures to be extended to ancient specimens, albeit without the biogeochemical data. It is worth noting that synchrotron-based X-ray fluorescence imaging, which is applied to analyse elemental distributions in mineralised dental tissues (Dean et al, 2019;Dean et al, 2020), requires dental thin sections.…”

Synchrotron X-ray Studies of the Structural and Functional Hierarchies in Mineralised Human Dental Enamel: A State-of-the-Art Review

“…Similarly, X-ray tomography was also used to investigate post-endodontic restorations, to assess the bonding of composite resin cement, and identified gaps and voids with a pixel size of 650 nm [ 344 , 345 ] ( Figure 8 a), as well as remineralisation [ 314 ]. Virtual slices from tomography (referred to as virtual histology) were also recently compared with histological descriptions visualised using optical microscopy, with a higher resolution from the synchrotron data (effective pixel size of 0.9 µm instead of 2 µm) showing that optical images were sufficient to characterise the daily secretion rate of enamel [ 309 ]. In terms of structure and tissue, additional details of application research which has been done are summarised in Table 1 .…”

“…The data were extracted from Endnote software in ‘.txt’ format and manually edited to arrange the studies by techniques. In total, 31 terms were considered based on these studies [ 11 , 31 , 39 , 56 , 57 , 77 , 78 , 89 , 90 , 121 , 169 , 170 , 171 , 172 , 173 , 175 , 193 , 195 , 247 , 266 , 286 , 294 , 299 , 303 , 304 , 305 , 306 , 307 , 308 , 309 , 310 , 311 , 312 , 313 , 314 , 315 , 316 , 317 , 318 , 319 , 320 , 321 , 322 , 323 , 324 , 325 , 326 , 327 , 328 , 329 , 330 , ...…”

“…The data were extracted from Endnote software (Clarivate) in ‘.txt’ format and manually edited to match the reading format and correlation of words; for example, British spelling was applied when translating non-English titles and acronyms were generally written in full length. The minimum number of occurrences of a term was set to four, and in total 140 terms were used based on these studies [ 11 , 31 , 39 , 56 , 57 , 77 , 78 , 89 , 90 , 121 , 169 , 170 , 171 , 172 , 173 , 175 , 193 , 195 , 247 , 266 , 286 , 294 , 299 , 303 , 304 , 305 , 306 , 307 , 308 , 309 , 310 , 311 , 312 , 313 , 314 , 315 , 316 , 317 , 318 , 319 , 320 , 321 , 322 , 323 , 324 , 325 , 326 , 327 ,…”

XRM imaging for non-destructive age at death estimation of the incinerated teeth from the Motya Tophet

“…Although in recent years the use of synchrotron radiation microtomography imaging (SR-μCT), considered a structurally non-destructive technique, enabled high-resolution virtual histology [14][15][16], its application in routine and extensive analyses is undermined by the limited access to facilities and the expensive cost.…”