Using excessive pressure with a metal pusher may permanently damage which part of the nail?

Using excessive pressure with a metal pusher can indeed cause permanent damage to the matrix of the nail. The matrix is the tissue located at the base of the nail, beneath the cuticle, and is responsible for nail growth. When excessive pressure is applied, it can lead to trauma or injury to the matrix, potentially resulting in changes to the nail's growth pattern, thickness, or even complete nail loss in severe cases.

It's essential for manicurists to use the correct technique and moderate pressure during pushing back the cuticles to avoid damaging the delicate structures involved in nail formation. Maintaining the health of the matrix is vital for ensuring the proper growth and appearance of healthy nails.