DD is known to be associated with a number of molecular abnormalities of cytokine and growth factor over-expression (e.g. transforming growth factor beta (TGF-β), platelet derived growth factor (PDGF) and connective tissue growth factor (CTGF)) [65], [68], [71], [72] and over-expression of a number of ECM-associated proteins (eg Collagen, Fibronectin, Tenascin and α-SMA). This evidence concerns the gene ACTA1 and dentin dysplasia.