This chemical is responsible for the hair loss on the tops of men's heads when they have male pattern baldness. However, it does not affect the back and sides of their hair in most cases. These areas have healthy hair follicles and make excellent donor sites for hair transplant surgery. These are called stable sites because they remain unchanged over time rather than shrinking like the hair follicles affected by DHT do. He remembers the way it was just a few short years ago and wants to duplicate the image. A good hair transplant surgeon will discourage a low hairline. Instead, he will campaign for a higher hairline. There are several advantages to this. One is that, with less top hair to cover, more donor hair will be saved. Many doctors still use grafts that contain up to eight hairs. These do not look as conspicuous as the hair plugs of earlier decades, but they do not look as natural as they can, either. Try to find a doctor that uses grafts that contain one to four hair follicles. These smaller grafts, also called follicular unit grafts, are ideal in restoring a receding hairline. One drawback to eyebrow hair transplant surgery is that eyebrow hair, which usually does not grow, will grow and need to be cut because it is actually scalp hair. Also, when the wounds heal, the lay of the eyebrows may change and not be so natural. However, if you need hair transplant surgery to replace your eyebrows, it is usually a much better alternative than other choices you have. Based on the fact that the average Caucasian male has a density of 2 hairs per millimeter, it can be assumed that the average density of hair is 1250 hairs per square inch. Figuring at an average of 2 hairs per follicular unit, it would take 625 follicular units per square inch. To get 25% of that, you would need 156 follicular units per square inch. It certainly does not seem like a relaxing experience. Yet some feel that there is that degree of pain involved. The injections of the local anesthetic into the scalp before hair transplant procedures are definitely painful to some degree. Anyone who has had a tooth pulled knows that, if the tooth is deadened properly, it is not the tooth-pulling that hurts.