Curvature Index of Pincer Nail

Pincer nails are a common problem, and various treatments have been reported. However, there is no simple assessment of severity. We designed a curvature index for the nail plate to assess the severity of pincer nail. Measurement of the curvature index was as follows. The apparent width of the nail tip was defined as A, and the traced length of the nail tip was defined as B. The curvature index was defined as B divided by A (B/A). With this curvature index, it is easy to describe the severity of the pincer nail and to compare the improvement before and after treatment.