I read a book as a child in the 80's about a boy wizard born with teeth

Good luck searching for a book about a boy wizard and not coming up with Harry Potter...... I've been looking for years and years.

These are the things I remember about it

-as a baby, he was left at an orphanage and everyone was scared of him because he was born with teeth
-there was something significant about worms
-there was an older wizard that found him and helped to train him
-he had to save the world

I would be ever so grateful to anyone who could tell me what this book was and that I did not make it up in my head.