Dental cell type atlas reveals new stem and differentiated cell types in mouse and human teeth

Reconstruction and engineering of human teeth are the tasks of utmost importance. Here we introduce detailed cellular atlas of the growing and non-growing mouse and human teeth including a condition with caries, which will enhance the field of dental engineering and lead to a better understanding of stem cell niche dynamics enabling tooth growth. We report previously unappreciated cellular complexity of the mouse incisor, including new spatially-restricted stem, progenitor and differentiated populations and compare this model system with the human adult, growing and caries-lesioned teeth. This comparison revealed specific parallelisms in mechanisms of dental growth in humans and mice. Beyond the main mesenchymal and epithelial compartments, we demonstrate a surprising role of the immune system as a mediator of the epithelial-mesenchymal interactions required for proper development. Finally, our results brought new insights into the differentiation of cell lineages producing enamel and dentin, which should be of utmost importance for dental reconstructive engineering.