Vertical bone defects of the atrophic alveolar ridge have a negative impact on function and aesthetics. Horizontal ridge atrophy makes difficult to place dental implants that can be appropriately restored. Guided bone regeneration, bone grafting and distraction osteogenesis are well-accepted options for alveolar ridge augmentation. The purpose of this article is to discuss techniques developed for vertical, horizontal and transport distraction of the alveolar ridge and their indications. Distraction forces applied to bone also create tension in the surrounding soft tissue, initiating a sequence of adaptive changes turned distraction histogenesis. Therefore, this method is considered a type of tissue engineering by which the surrounding soft tissue is simultaneously increased. Indications for Alveolar Distraction Osteogenesis: * Partial defects of the alveolar ridge * Atrophic bone segments in the mandible and maxilla * Simultaneous Sinus lift and vertical distraction for maxillary augmentation * Vertical correction or replacement of edentulous segments * Local open bite (Dentulous Segment Distraction) * Assisted eruption of ankylosed impacted tooth (Dentulous Segment Distraction) Repositioning of malpositioned implants Limitations of Alveolar Distraction Osteogenesis: * Contraindicated in patients with osteoporosis * Maximum transport segment width is limited in accord with size of distraction device. * Minimum transport segment height is approximately 5 mm * Inadequate bone volume in cases of severe mandibular atrophy due to the risk of fracture * Patient cooperation Alveolar distraction osteogenesis offers an alternative treatment for three-dimensional ridge augmentation avoiding donor site morbidity. Its indications may be expanded if combined with standard bone grafting techniques.