Potential Factors & Cells Regulating Formation and Regeneration of the Periodontium. Appropriate development of the periodontium requires a balance between formation of soft connective tissues, i.e. PDL, and hard connective tissues, i.e., bone and cementum. (For consistency and clarity we consider periodontal tissue development to include formation of: root/cementogenesis, supporting alveolar bone and PDL.) We predict that key regulatory molecules include: a) amelogenin and/or amelogenin-like molecules secreted by surrounding epithelial cells that promote follicle cells to express genes linked with the cementoblast/osteoblast phenotype, e.g. BSP/OCN, thereby inducing cementogenesis; b) BMPs: BMP3, found in high concentrations within the follicle cell region, functions as a negative regulator of mineralization [4], while BMP2 functions as a positive regulator of mineralization promoting follicle cells to differentiate along the cementoblast/osteoblast pathway [3, 5]and; c) noggin, a regulator of BMP and Cbfa1, putative a master switch, may control these activities.

Abbreviations: DF=dental follicle; ERS=epithelial root sheath