A dermal piercing, also known as a microdermal piercing or a single-point piercing, is a piercing that lies on any flat surface of the body and is held in place with a dermal anchor that is installed underneath the skin. Ordinary body piercings have entry and exit points for the jewelry, but, in a dermal piercing, the jewelry sits on the surface and is secured with an anchor that is embedded in the dermal layer (underneath the flesh). This gives the appearance of having small beads or other ornaments on the surface of the skin.
This type of surface piercing is popular because it can be placed on almost any flat surface of the body, which allows you to decorate areas that are difficult to pierce with regular piercings.
You can form patterns using multiple dermals, or you can also attach an ornament by changing the top of the implant, which screws on and off for easy changing.