A commonly used skin dilator is a controllable dilator, which consists of an expansion sac, an injection pot and a catheter. When in use, the dilator is implanted under the skin or muscle by surgery, and sterile isotonic saline is injected into the injection pot regularly through the skin, and the latter flows into the expansion sac along the catheter to expand the tissue.

Another method of skin expansion is a self-expanding dilator. The dilator is filled with hypertonic saturated sodium chloride solution in sealed silicone rubber. By using the osmotic pressure difference between inside and outside, the tissue fluid permeates into the expansion capsule through the artificial semi-permeable membrane on the capsule wall, so that the volume of the capsule expands gradually, and the purpose of expanding the tissue is achieved.

Skin expansion is mainly suitable for face, neck, head, chest, trunk, limbs and other parts that need normal skin for cosmetic plastic repair. The advantage is that the "redundant" skin tissue provided by this tissue expansion is similar or consistent with the skin around the defect area in terms of color, texture, thickness, hair distribution and aesthetic degree, and it also has the characteristics of good blood supply and feeling, unlike skin grafting, which will produce new scars in the donor area, and the operation is simple and easy.