Tissue expansion is a procedure that allows the body to grow extra skin. It is done by inserting a silicone balloon expander under the skin near the area to be repaired (such as scars happening after burns) and then gradually filling the balloon with salt water over time causing the skin to stretch and grow (keeping the skin under tension causes new cells to form).
Tissue expansion is used in conditions such as breast reconstruction surgery, repairing burns, scars, large birth marks, hairy areas such as the scalp (the extra skin is still able to grow hair).
After the skin stretches the scaring is surgically removed and the expanded skin is extended to meet healthy un-scarred skin.