Two Stem-Cell Pathways Could Enable Real Tooth and Jawbone Regrowth

Researchers identified two distinct mesenchymal stem cell lineages that drive tooth root and surrounding bone formation in developing teeth. One lineage from the apical papilla uses CXCL12 and Wnt signaling to become odontoblasts, cementoblasts, or osteoblasts; the other lineage in the dental follicle (PTHrP-expressing) forms alveolar bone via a Hedgehog–Foxf–signaling interaction that must be suppressed to activate bone fate. Mapping these pathways provides a mechanistic framework for tooth-root development and could inform stem-cell–based therapies to regenerate teeth and periodontal bone.