T.F.
When is the last time this. Hold was checked by the dentist?
Call your dentist and get it checked. I used a pediatric dentist until my daughter was 16 but a lot of 10 yr olds are perfectly ok for a regular dentist as well.
I hope your child sees a dentist every 6 months. If not, start now.
We have no idea what to tell you and can't diagnose the problem.