What is the term for the semicircular fold of skin overlapping the nail plate on either side?

The semicircular fold of skin overlapping the nail plate on either side of the nail is called the nail wall. This structure plays a crucial role in protecting the sides of the nail and helping to guide its growth. The nail wall helps to create a natural barrier, keeping dirt and pathogens away from the nail bed, contributing to overall nail health.

In contrast, the free edge refers to the part of the nail that extends beyond the fingertip and is the portion that is often trimmed or shaped. The perionychium encompasses the tissue surrounding the nail, including the skin that is adjacent to both the nail plate and the nail wall. The eponychium, on the other hand, is the tissue at the base of the nail, often confused with the cuticle, which protects the area between the nail and the skin. Understanding these terms is vital for proper nail care and hygiene as they indicate different parts of the nail anatomy.