Bone regeneration during distraction osteogenesis

Bone has the capacity to regenerate in response to injury. During distraction osteogenesis, the renewal of bone is enhanced by gradual stretching of the soft connec- tive tissues in the gap area between two separated bone segments. This procedure has received much clinical atten- tion as a way to correct congenital growth retardation of bone tissue or to generate bone to fill skeletal defects. The process of bone regeneration involves a complex system of biological changes whereby mechanical stress is converted into a cascade of signals that activate cellular behavior resulting in (enhanced) formation of bone. Over the last decade, significant progress has been made in understand- ing the bone regeneration process during distraction osteo- genesis. The mechanical and biological factors that are important for the success of the distraction treatment have been partially characterized and are discussed in this review.