Which hospital should I go to for ingrown toenails? 4-4

My middle school son has ingrown toenails and is doing it himself.

Just keep trimming my nails short whenever they grow even a little longer on my own.

They are cutting or tearing it apart.

Do ingrown toenails require a visit to the dermatologist?

Then where should I go to see it clearly and properly?

I've also heard that they put something under the nail of the mask.

Is that the correct treatment method?

Is it possible to fully recover from ingrown toenails?