Hair Transplant-General Forum
Hair Transplant Density

Density is a function of the incision size. There is a simple formula. The distance between the grafts in millimeters is equal to the a constant, 10.7, divided by the square root of the density in sq. cm. The distance between grafts at 80 per sq. cm is 1.12 mm. The diameter of a single hair is 0.42 mm on average. Two hairs average 0.8 mm and three hairs 1.2 mm. In order to pack 80 per sq. cm, you need to make very tiny incisions and place very small grafts that are aggressively trimmed. In other words, there is a trade off between trauma, size of the graft, the incision size, and the comfort of the fit. Is it acceptable to compress a graft too tightly? Does the yield go down? Is it better or worse to force a graft into an incision size that is too small? No one knows these answers. There are other concerns, as well. When doing body hair transplants, I am always amazed at how many new hairs show up in the same area that I picked clean the year before. There are always hairs that are very hard to see because they are early anagen hairs or exogen hairs that are so microscopic that you cannot see them with the naked eye. This occurs with scalp follicular units, as well. Aggressive trimming risks loosing these hairs and tossing them in the waste. Read Full Post

Posted by: Dr. Cole Be the first one to comment