In mammals, teeth develop as distinct organs. Some organs such as hair and some glands share similarities with tooth organogenesis in their morphological and molecular developmental characteristics, but not in their regenerative capabilities. Dentition, by definition, refers to the characteristics of a set of teeth including type, arrangement, shape, and number. Over the course of their evolutionary path, mammals have developed a reduced capacity for tooth regeneration, but on the other hand, mammalian teeth have developed many variations in size and shape. The dentition of mammals can be divided into four types of teeth; incisors, canines, premolars (premolars), and molars. Molar teeth specifically are the most differently shaped teeth of the four types. Although teeth can develop from either endoderm or mesoderm, in mammals the neural crest and ectodermal tissues produce ectodermal appendages, which subsequently grow as teeth (Smith, 2003; Soukup et al., 2008). Cell-cell signaling and cell differentiation between the ectoderm and mesenchyme cells regulate tooth morphogenesis. Many paracrine signaling molecules that we know are involved in and mediate communication during tooth development. Most of these signals come from the conserved signaling groups Hedgehog (Hh), Ectodysplasin (Eda), transforming growth factor ß (TGFß), Wnt, bone morphogenic protein (Bmp), and fibroblast growth factor (FGF) (Jernvall and Thesleff, 2000). . These conserved signaling families also play a significant role in regulating many other aspects of embryonic development. They not only regulate communication between germ layers, but also within each germ layer. Variation in mammalian dentition relies on these cellular signals to regulate differentiation, so they are present from start to finish even... half of article......Even after reprogramming cells for tooth development , the techniques used in this process will need to take into account the natural environment of the cells. Based on the current understanding of tooth development that we have seen above, it is clear that the techniques used in dental bioengineering will be of significantly higher complexity than that of reprogramming pancreatic cells, and this would need to be done within the oral cavity . To develop methods of programming tooth regeneration in humans requires a clear understanding of the mechanisms involved in normal tooth development. Stem cells in mammalian teeth may not be a good source for bioengineering due to their limited availability and problematic collection methods. Non-dental stem cells such as iPSCs have so far proven to be one of the most promising dental bioengineering avenues to explore.