What is Direct Hair Implant (DHI)?
DHI is a variant of the traditional FUE surgery. Both involve extracting grafts or follicular units (FUs) from the back of the scalp (donor area), but they differ in the implantation phase of the surgery.
Choi pens can simultaneously make incisions in the balding areas of the scalp and place FUs there, allowing for precise placement while eliminating the need for pre-made incisions. However, in regular FUE, slit-making is a separate step of the surgery, which precedes graft placement and is done manually.
Although both FUE and DHI are effective hair transplantation techniques, DHI has certain advantages that make it more appealing to patients.
As an important part of self-expression and identity, hair loss can negatively affect self-esteem, confidence, and body image. But while being bald may not be a choice, modern hair restoration treatments offer you the choice to regain a full head of hair.
With direct hair implantation (DHI) surgery, you can permanently restore your hair without having to shave your entire head and achieve dense and natural-looking results.
In the 1990s, a Korean doctor, Yung Chul Choi, developed the Choi implanter pen, which not only provided more protection to the scalp but also spared the grafts of traumatic injury from forceps. Because these pens can mitigate the risk of damage to the skinny and delicate grafts obtained from follicular unit extraction (FUE) surgery, their usage has become quite popular.
Am I suitable for DHI?
Anyone who is eligible for a traditional follicular unit extraction can also undergo a direct hair implantation procedure. The following might be particularly suitable for DHI, however:
If you’re not looking to shave your entire scalp for a hair transplant, DHI can be ideal since you don’t have to trim your recipient areas. The donor area will still be shaved as grafts need to be extracted, but it may provide more discretion, especially for those with long hair.
If you’ve had a previous hair transplant and want to further increase the density (follicular units per cm2) in an area, DHI can implant newer grafts without causing any damage to the originally transplanted grafts.
If you require 3,000 grafts or fewer, DHI can be recommended since it offers greater precision, better graft survival and a faster recovery time compared to traditional FUE.
How does a Choi Implanter Work?
A Choi implanter is a mechanical pen-like device with a hollowed needle and a bevel – opening at the sloped side of the needle’s tip.
There are two ways to place the grafts into the balding areas of the scalp:
#1
Pre-made incisions, in which the surgeon makes the incisions before grafts are placed into them and
#2
Stick-and-place method where making of the incision and graft placement is immediate and simultaneous.
A Choi pen both pierces the skin to open a channel in the recipient area and places the graft into the said channel using the stick-and-place technique.
However, before the graft can be implanted, trained technicians carefully load each follicular unit into the pen with the help of forceps, making sure that it is directed the right way and placed completely within the needle so it’s not damaged.
Around 6 to 7 Choi pens are used per surgery, with 3 technicians loading the grafts into the pen and the surgeon placing the grafts. Each pen transplants a single graft, and once it has been emptied, it goes back into the circulation to be loaded and used again. In the meantime, the surgeon is handed a new pen to keep the implantation process going.
Choi implanters with different diameters ranging from 0.8 to 1.2 mm are available, and their usage varies according to the type of graft being inserted. Generally, 0.6-0.9 mm can be used for 1-hair follicular units, about 1 mm for follicular units with 2 hairs, and up to 1.2 mm for those that can have 3 to 4 hairs in them.
DHI Procedure
Direct hair implantation surgery begins with extracting hair grafts from the safe donor area at the back and sides of the scalp. It is done under local anaesthesia for a painless experience.
Once the relevant number of grafts have been extracted, sorted (by the number of hairs in each graft) and stored in a special chilled solution to ensure their survival, the “direct hair implantation” part of the surgery begins.
For this, the recipient area is separately anaesthetised and then tumesced (swollen up) with a solution of isotonic water and adrenaline to reduce bleeding while improving the view of the recipient area.
Starting at the hairline, the Choi pen is loaded with a graft, angled at around 15-20 degrees, following which the needle pierces the skin (at the same depth as the length of the graft) to create the slit. Afterwards, the plunger is pushed to take out the needle from the scalp, with the graft now left in its new place.
This process is repeated for each graft, although, of course, the depth of incision, angulation and the type of grafts used can vary according to each region. For instance, where 1-2 hair grafts are used for the hairline, 3-4 hair ones are used for the centre and 4-2 for the crown.
Angling can also vary throughout the scalp, reaching up to 40 degrees in the mid-scalp and 45 degrees in the crown but less than 10 degrees in the temporal area. However, the advantage of using a Choi pen is that it’s easier to control the angles, especially when they’re acute.
Angling can also vary throughout the scalp, reaching up to 40 degrees in the mid-scalp and 45 degrees in the crown, but less than 10 degrees in the temporal area.
One thing about DHI is that the number of grafts that can be safely implanted in each session is limited to 3,000 due to the time involved in loading each Choi pen (this surgery can take 6-8 hours, depending on the graft number). Because of this, it is more commonly used for specific areas, such as the hairline or crown or for an improvement in the overall density
Advantages of DHI
In addition to DHI surgery being unshaven, it has several other advantages:
The use of Choi pens avoids the risk of extra pressure and damage to the veins on the scalp. Additionally, the size of the incisions in DHI is smaller, which is no more than the diameter of the graft, making it less traumatic.
Because Choi pens are less traumatic for the scalp, they can also shorten your recovery period.
Implanter pens can protect the grafts from getting bent or crushed, which can then ensure better graft survival and hair growth after the procedure. Moreover, because it combines slit-making with graft placement, grafts don’t have to stay out for too long.
Choi pens can allow for more precision when it comes to making incisions. The surgeon can easily determine the angle, depth and direction of the graft, and an added benefit is that in DHI, both incision-making and graft placement are completely done by the surgeon.
Better angling, graft survival, less trauma, and other benefits of Choi pens can all contribute positively to the final results. With DHI, there is the potential to achieve even more natural-looking results while getting high-density.
Limitations of DHI
The DHI method has a few limitations, one of which is the relatively finite number of grafts that can be implanted.
An unshaven DHI is only possible if you need 3,000 grafts or less because the process of loading the pens, even with three technicians involved, can still be quite time-consuming. For this reason, larger sessions – involving around 4,000 grafts or so – are not possible with it.
In addition, DHI may not be recommended for those who have curled hair roots; instead, traditional FUE is considered preferable. That’s because when putting the graft through the tip of the pen, it can end up getting damaged.
Keep in mind that DHI hair transplants can still be performed on patients with Afro hair, but the surgeon will first need to assess your hair.
Results
You can expect to see the final results of your DHI surgery in 12 to 18 months. Results can vary between patients, depending on factors such as donor area, balding area size, health status, and aftercare.
David's DHI Hair Transplant Journey
In May 2024, David took the next step in restoring his confidence with a Direct Hair Implantation (DHI) procedure. His main concern was his receding hairline, particularly in the corners. After careful consultation, he opted for a 3,000 graft DHI procedure focusing on zone 2, helping to achieve a more youthful and natural-looking hairline.
Watch David’s journey as he experiences the transformation, from the initial stages to the final results.
Patient Journey
The Consultation
1:31The Preperation
1:09How much does DHI Surgery Cost?
Direct hair implantation’s cost can depend on where you decide to have it. In Turkey, the price for DHI can be around £2,000, whereas in the UK, it may cost over £5,000.
Since DHI uses multiple specialised Choi pens and requires advanced skills and knowledge, as well as extra staff for loading the implanter pens, all these factors can add to the cost of this surgery, making it slightly more expensive than regular FUE.
With Longevita, the cost of this hair transplant in Turkey is £1,800 for an all-inclusive treatment plan (whereas regular FUE is £1,500). The price also includes the maximum number of grafts you may need for your surgery.
Frequently asked questions about DHI Implantation
The surgeon will use the Choi pen to insert the grafts in the balding area(s). However, technicians help with the loading of the grafts in the Choi pen to speed up the process.
Yes. It is because of the surgical equipment used. The Choi Pens are disposable, and the surgeon uses over one during the surgery.
DHI hair transplant takes place under local anaesthesia so it’s not painful. However, once it wears off, you can feel some post-operative pain. It is, however, easily managed by painkillers.
The results of a DHI hair transplant are permanent. The transplanted hair follicles are resistant to the effects of the hormone (DHT) that causes hair loss.
We will share the CV and portfolio of the DHI surgeon with you, where you can learn more about their qualifications, training, and experience. You can verify their licensing in the online medical registers of the relevant bodies.
You should start to see your hair grow 3-4 months after the surgery, but you’ll have to wait for 1-1.5 years for all your hair to grow out.
