Sometimes the appearance of a scar is improved by changing its direction. A z-plasty is a basic technique of plastic surgery in which two triangular pieces of skin, called flaps, are transposed and their positions are exchanged. The final scar has the appearance of a letter Z.
The Z-plasty has two main functions. First, it lengthens the scar. This is an advantage when the scar is contracted because it relaxes the scar. Second, it changes the direction of the scar so that it lies in the natural skin lines or creases.