A dark and shiny hair is a never fading scenery given by God to human beings. Hair not only plays a role in decorating the beauty, but also has a role in keeping the body warm, shielding it from wind and cold, and preventing ultraviolet radiation. In daily life, there are many reasons that can lead to baldness, including: 1. various skin diseases, such as seborrheic alopecia, flat warts on the head, baldness, abnormal hormone secretion, etc. 2. Traumatic baldness, such as trauma, avulsion injury, after head tumor removal, after local radiation therapy, and other causes. Commonly used treatments include treatment of the primary disease, local wearing of wigs, hair transplantation, and expander treatment. For scar baldness or post-traumatic surgery baldness, the success rate of hair transplantation is low because of poor blood flow to the skin in the affected area. We can apply scalp dilation to repair baldness. Scalp dilation involves the placement of a silicone bladder expander under the skin of the normal scalp around the balding area, and the bladder is periodically filled with water and expanded after the surgery. This method adds no new scarring and there is no significant change in hair density. However, this procedure is not suitable for children under 5 years of age.