Yes, I think this is abuse. This is above and beyond a couple of cavaties. She knew her son was in pain and decided to not take him to the dentist because she thought his baby teeth would just fall out and the problem would be solved. She knew and did nothing, that entails abuse in my book.

Question for you, if you knew your dog or cat was in pain but thought the issue might resolve itself would you still take them to the vet?

If someone knew their pet was in pain, thought the issue might resolve itself, didn't take them to the vet and the issue did turn out to be a major one (exposed nerves counts a major in my book), would that be abuse?

I think it is good idea that this child was taken away.