Choi Pen: The Secret to Precision DHI Transplants

A choi pen (also called a choi implanter pen) is a medical tool used to implant hair follicles into the scalp. It has three main parts:

• a hollow needle

• a small chamber where the graft sits

• a plunger that inserts the follicle into the skin

A technician loads one graft at a time into the tip. The surgeon then places the needle on the scalp and presses the plunger. This single motion creates the channel and implants the graft at the correct angle and depth.

The goal is simple: protect the graft, limit handling, and give the surgeon steady control during implantation.

The device was created in the 1990s at Kyungpook National University (KNU) in South Korea. A research group led by Dr. Choi wanted a way to handle straight, thick Asian hair with better accuracy. Traditional forceps sometimes damaged these grafts or made it difficult to achieve the right angle.

Their work produced the implanter pen, which soon spread to clinics across Asia and later Europe, the Middle East, and the US.

During a modern hair transplant procedure, the implantation stage plays a decisive role in the final aesthetic outcome. The implanter pen is often preferred at this stage because it provides greater precision when placing individual grafts into the scalp. Since natural results depend heavily on correct angle, depth, and distribution, controlled implantation becomes one of the most critical parts of the surgery.

DHI (Direct Hair Implantation)

In DHI, the implanter pen is central to the procedure. Grafts are extracted and then directly implanted using the pen without creating channels beforehand. Because channel creation and implantation happen in one step, the device defines this method.

FUE (Follicular Unit Excision)

FUE describes how grafts are harvested from the donor area. It does not dictate how they must be implanted. After extraction, surgeons may either create channels with blades and place grafts using forceps or use implanter pens for insertion.

This means FUE and implanter pens are not opposing techniques. They can work together within the same procedure.

Hybrid or Modified Implanter Approaches

Some clinics combine methods for better control. For example, a surgeon may create channels traditionally in larger areas but use implanter pens in delicate zones such as the frontal hairline.

This selective approach allows flexibility while maintaining precision where angle and density design matter most.

Surgeons prefer the implanter pen because it offers greater precision during the most delicate stage of a hair transplant: graft placement. Since the final appearance depends heavily on angle, depth, and distribution, controlled implantation plays a major role in overall results.

Control Over Angle and Direction

The device allows the surgeon to adjust the exact angle and direction of each graft during insertion. This is especially important when designing natural hairlines, recreating temple points, or blending transplanted hair with existing strands. Small variations in angle can significantly affect how natural the final growth pattern looks.

Reduced Handling of Grafts

With traditional forceps placement, grafts are picked up and inserted after channels are created. The implanter pen reduces direct manipulation by keeping the follicle inside the device from loading to implantation. Less handling may help protect the graft structure and reduce mechanical stress.

Consistent Implantation Depth

The plunger mechanism allows better control over how deep each graft is placed. Consistent depth supports uniform healing and helps minimize issues such as graft popping or uneven growth patterns. Proper depth also contributes to a smoother surface appearance once the hair begins to grow.

Potential for High Density Placement

Because implantation and channel creation happen in one motion, surgeons can work more closely between grafts when needed. This can be beneficial in areas where higher density is desired, such as the frontal hairline or smaller detailed zones.

For clinics that prioritize precision and refined implantation techniques, these advantages make the implanter pen a practical and widely adopted tool.