Tremendous progress has been made since cementum analysis first applications in the 1950s. Today, with a better understanding of cementum biology, robust, replicable protocols support promising innovative research. Now, cementum should be considered within a broader evolutionary framework and cementogenesis tested from chronobiology theoretical assumptions to identify genetic or environmental variables affecting its circannual growth. With the rise of image analysis automation and optimization of species-specific standardized protocols, cementochronology is mature for site-level experiments. Also, the groundbreaking evolution of noninvasive, 3D cementochronology opens opportunities to study the fossil record, from stem-mammals to our Homo lineage. The breadth of applications across disciplines is a testament to cementochronology as a unique tool to investigate age and season at death, mobility patterns, life-history events, or mammalian evolutionwhich should be deployed broadly in anthropology. The goal of this volume is to promote collaborative efforts and stimulate interdisciplinary opportunities to renew diverse anthropology themes using cementum in anthropology.

Seasonal variations directly impacted the social and economic activities of past human populations. Cementochronology is one of the methods available to address seasonality questions. It relies on the cyclic deposition rate of dental cementum observed microscopically on petrographic thin‐sections of animal teeth from archaeological contexts. However, no protocol exists to select a Region of Interest (ROI) or to identify the last cementum increment. This chapter proposes consensual biological and optical criteria for the selection of optimal ROIs and their analysis. Interobserver tests were performed to assess the criteria, as well as age and season of death, on thirty thin‐sections of modern documented reindeer teeth. Results demonstrate the accuracy, and replicability of this protocol, and emphasize the influence of training and experience for the proper implementation of cementochronology.

For human dental cementum research, sample preparation protocol is now widely tested, validated, and standardized, thanks to the low variability in teeth morphology. For non-human mammals, posterior teeth are typically preferred. However, the taxa diversity implies a significant variation in morphology or specific characteristics for certain species (equids, suids), leading to multiple unstandardized protocols. This work aims to improve protocols for producing a thin section by optimizing the parameters, minimizing the risk of errors, and offering an easily reproducible quality of thin-sections. The result of 26 experiments and 124 analyses during stages of consolidation (embedding), cutting, gluing, and finishing (grinding) allowed the co-authors' combined experience from multiple laboratories to propose standardized humans and ungulates (large teeth) protocols for the systematic analysis of dental research collections.

The activities’ spatial organization of Neanderthal’s territory is often explored by studying stone tool production and use, and its economy, but not their hunting behavior. Consequently, the hypothesis that Neanderthals lacked planning potential or complex land-use strategies during the Mousterian, such as collaborative hunting and food storage, has been questioned. A cementochronology analysis of reindeer in Quina and Discoidal Denticulate in four neanderthal sites in southwestern France suggests a repeated use of specific sites at a precise time of the year for similar hunting purposes scheduled according to a year-round pattern. The development of landmark sites during the late Middle Paleolithic used every year, at the same moment, indicates that the predation system began to structure the activity’s organization within the territory in time and space and that the preys’ behavior directly impacted the social organization of the hunting groups.

Acellular cementum anchors the root to the alveolar socket via the periodontal ligament and grows in layers continuously throughout life, unlike enamel and dentin. Increments are deposited in a biannual light-dark pattern correlated to age and season at death in transmitted light microscopy. This study investigates the still debated structure of individual acellular increments using x-ray fluorescence and x-ray diffraction mapping with synchrotron radiation microbeams on reindeer, red deer, cattle, and human samples. Results show that Ca or Zn x-ray fluorescent intensities and cAp diffracted intensity reveal cementum band structure. Average crystallographic texture (of cAp nanoplatelets’ orientation and collagen fibril orientations) is constant for each specimen. Microtextural variation is also present across individual bands, demonstrating that the overall collagen fibril orientation undergoes subtle changes with season. Patterns of “feast or famine” and concomitant changes in amount and intensity of PDL loading might produce altered collagen (and cAp) orientations between the “good” and the “bad” seasons for ungulates but maybe not for modern human populations.