The most important part of the nail unit is its growth center known as the matrix. The nail plate, the unit’s cosmetic structure upon which nail polish is placed, is derived from the matrix. This nail growth center is ¼ - to ½ -inch long and one-inch wide. It starts underneath the proximal nail fold (the skin just next to the cuticle) and ends in the white “half-moon” known as the lunula.

The matrix can be divided into three parts - the third near joint, the third representing the lunula, and a middle third between these two. The third near the joint makes the top of the plate, the lunula makes the bottom of the plate, and the middle third, the section between. Thus, if the third near the joint is injured by pushing the cuticle too vigorously, it shows up as an indentation on the nail plate. If the middle part is injured by overzealous nail filing, white spots may appear. Finally, damage to the lunula will probably cause the nail plate to separate from the nail bed. If the entire matrix is affected as can occur with fungal infections or nail psoriasis, the plate may crumble.

Other factors can affect the matrix. For one, chemotherapy often interferes with matrix nail production, causing a deep dent or grooves across the plate if the third near the plate is affected. A white line from side to side may also develop from use of cancer drugs. Heavy-metal poisoning, such as ingestion of arsenic, may form the same white lines.

All of these changes are a consequence of matrix injury from which the growth center repairs itself. Some injuries to the matrix can cause scar tissue to form, resulting in permanent damage because scar tissue cannot make a nail plate – only matrix is permanently damage, the nail will grow out deformed, if it grows out at all.

One example of permanent damages is attached of the cuticle/proximal nail fold skin to the nail bed. This attachment forms a triangular wedge of skin, called pterygium, and looks like a wing. It can be seen in a skin disorder known as lichen planus, or lack of circulation to the fingers Scleroderma, a internal systemic connective tissue disease, may also cause this condition.

The nail matrix is a delicate structure that deserves protection in order to for it to manufacture a normal, healthy nail plate. This would include avoiding injury and infection around the cuticle. Over-vigorous cutting, pushing back, and trimming of cuticles should not be done. Bacterial and yeast infections near the matrix must be treated quickly and effectively.

You nail plate is a reflection of its producer, the matrix. In orde4r to produce a healthy, attractive nail, the matrix must be treated with care.

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