It is a commonly held belief that if you cut a V in the middle of your toenail, that will prevent ingrown toenails from occuring. That myth however, is just a myth. The problem with this thought process is toenails grow from a Nail Matrix which is located at the bottom of the nail. Nails grow from the bottom up, not from the outside in. I understand that your grandma’s best friend has done this and never had an ingrown toenail, and has spent the last twenty years walking around with V cut in the middle of her toenails. Your grandma’s friend will tell you she has never had ingrown toenail, and she is telling the truth.
The reason your grandma’s friend has never had an grandma’s friend has never had an ingrown toenail is because ingrown toenails can be caused by tight shoes as well as trauma. If your grandma’s friend never wears the tight shoes that caused her ingrown to begin with, or never drops a soda can on her toe again she will not have an ingrown toenail. So, yes cutting V’s into your toenails, does not, nor has it ever stopped ingrown toenails from forming.