What condition describes increased curvature of the nail, commonly known as claw nails?

The condition characterized by increased curvature of the nail, commonly referred to as claw nails, is onychogryposis. This condition typically results in the nails becoming thickened and having an exaggerated curve, resembling a claw. It can be caused by various factors, including trauma, fungal infections, or age-related changes, and is most commonly seen in older adults.

Pterygium, on the other hand, refers to a condition where the skin extends over the nail plate, potentially disrupting normal nail growth and appearance, but does not specifically describe the curvature of the nail. Leuconychia involves the appearance of white spots or discoloration on the nails, not associated with curvature. Onychia refers to inflammation of the nail matrix, which can affect the nail's overall health and growth but does not specifically relate to increases in curvature. Thus, onychogryposis is the term that directly applies to the increased curvature condition known as claw nails.