Posted on August 06 2015
Clip off the "offending bit" might be the wrong thing to do
Researchers from University of Nottingham in England discovered that ingrown toenails result from an imbalance in the forces acting on them. Normally, nail growth imparts a force on the nail — pushing it outward toward the tip of the finger — that works against the adhesive force holding the nail down to the nail bed
But if a nail grows too quickly, the balance between these forces changes. The additional force from the growth "pulls" on the nail bed, and in response to that pull, the nail edge becomes more curved.
The structure of the nails
Nails are made of the protein keratin, just as hair is, and are attached to the nail bed with structures that are microscopic yet quite strong. It's painful to break this attachment, as anyone who has broken a fingernail knows.
In addition, the shape of the nail plays a role in making it ingrown. Because fingernails are naturally curved, the outer edges are shorter than the center. This means the rates of growth in the different parts of the nail are slightly different — the center grows a bit slower than the edges do.
These forces are also the reason that the big toe seems especially prone to ingrown nails, Rauch said. "This curvature [on the edge of the big toenail] is very flat. By being flattened, these [nails] will generate stress in the transverse direction," he said. In other words, because the edge of this toenail tends to be straighter, the rate of growth in a big toe needed to push the edge of the nail into the skin doesn't need to change as much as it does for other nails.
To snip or not to snip?
So, why is it not always helpful to cut the ingrowing edge of the nail? Because cutting doesn't always rebalance the forces acting on the nail.
- When you cut off the end of the nail, depending on the shape of the cut, you change the nail's shape. But the faster- and slower-growing parts of the nail will keep growing at the same rates, so the change in the shape might get the nail to grow correctly — or it might not.
- The best option seems to be to cut the nail in a parabolic shape, such as an oval, or to cut the edge so that it is slightly curved, rather than straight across at the end of the nail, the researchers said. That method seems to cause the force on one part of the nail and bed to balance the forces from the other parts, they added.
Taken from LiveScience.