Which condition indicates any deformity of the nails?

The condition that indicates any deformity of the nails is onychosis. This term encompasses a wide range of nail disorders, including changes in the nail's structure, texture, and appearance. Onychosis can manifest in many forms, such as irregular nail growth, discoloration, or deformity—essentially covering any condition that affects the normal structure of the nail.

In contrast, other conditions mentioned are more specific. Nail pterygium refers specifically to an overgrowth of skin from the cuticle area onto the nail plate, resulting in a specific deformity rather than a broader indication of any deformity. Onychorrhexis describes brittle nails that have ridges and split easily, which is a particular type of deformity. Pincer nails indicate a specific abnormal curve of the nails, but again, this is a specific condition rather than a general term for all nail deformities. Thus, onychosis serves as the overarching term for a variety of nail deformities.