BMP2 and dentinogenesis imperfecta: Teeth with Bmp2 cKO mice display the similar phenotype of dentin defects to that of dentinogenesis imperfecta (DGI) in humans and mice, the most common dentin genetic diseases, showing retardation of tooth growth, abnormal dentin structure with wide predentin, and thin dentin (Zhang et al., 2001; Lu et al., 2007; Lee et al., 2009).