Direct hair implantation (DHI) is a variation on the popular hair transplant surgery technique known as FUE (follicular unit extraction).
With FUE, the surgeon harvests tiny bundles of donor hair follicles called grafts from a donor area where hair is more plentiful, usually the back of the head. The surgeon then makes a series of tiny incisions in the thinning or bald recipient area and meticulously implants each graft.
The harvesting method for DHI is the same, but then the surgeon uses a sharp hair implanter pen (the Choi pen) to create the recipient incision and implant the hair graft in one step. For this reason, it’s sometimes called the sharp implanter method, or DHI Choi.
There aren’t yet any studies comparing results from the two hair transplant methods, but providers who favor the DHI technique claim that it can lead to more natural-looking results, faster healing, and higher density. Hairs inserted directly into the scalp grip the skin better, they say, which improves graft survival and growth rate.
On the other hand, proponents of the two-step FUE method still consider it the gold standard for graft placement. “Making the recipient sites separately permits me to more densely pack the grafts in and create superior hair density,” says Dr. Jeffrey Epstein, a board-certified hair restoration surgeon in Miami. “It also allows for more acute angulation of the grafts,” giving him more control over which direction each hair graft will go. The result, he says, is a growth pattern that looks more like your natural hair.
One thing all the experts we talked to agree on: the key to great results from any hair transplant procedure is the surgeon's skill. “It’s not something that depends on the pen, but on the person who does the operation,” says Dr. Emrah Cinik, a physician in Istanbul, Turkey, who specializes in hair transplantation procedures. “It’s crucial for individuals considering a hair transplant to consult a skilled surgeon to determine the most suitable technique based on their unique needs and desired outcomes.”