Distraction osteogenesis is a surgical technique: its main purpose is to induce a mechanically stimulated bone tissue augmentation. A controlled tension, developed by a slow and gradual separation of the corticotomized/osteotomized bone segments, induces new bone formation and related soft tissue augmentation. In this way, we can observe a more harmonious tissue augmentation, better than with traditional techniques as osteotomies with grafts. This procedure, initially applied in orthopedic field for limb lengthening, is now also applied in the cranio-facial field. The most important features of distraction osteogenesis consist in the simplicity of execution, the lack of donor site morbidity and the simultaneous expansion of bone and related soft tissue. Besides, the technique is still at the beginning and requires further acknowledgements, before being widespread used to treat cranio-facial malformations. Disadvantages in bone distraction are related to the external device and consist in esthetic discomfort during treatment, and cutaneous scars. Recently, to solve these problems an intraoral distraction device was proposed. Distraction osteogenesis has now an expanding role in cranio-facial surgery.