The main objective of this book is to identify the effect of stem cells of human dental pulp of deciduous teeth (SHD) alone and when seeded in microporous biphasic calcium phosphate (MBCP) scaffold, transplanted during mandibular distraction osteogenesis (DO) on a new bone formation. The first study is concentrated on the possibility to synthesize a scaffold with desired properties. The in vitro work concentrated on discussing the techniques of primary cell culture. Thirdly testing whether MBCP exert cytotoxic effect or biocompatible, using an in vitro cytotoxicity test. The forth experiment is the in vivo study to evaluate the performance of SHD alone, SHD in combination with the carrier MBCP transplanted in DO gap. This experimental studies will give a good solution to decrease consolidation time of DO which is the major disadvantage of this process, this concept may be useful for patient with compromised bone healing due to osteoporosis, radiotherapy and others, as well it will give important information for synthesis and characterization of ideal bone graft and its in vitro cytotoxicity,additionally discus the art of isolation and expansion of stem cells.