Hi, Sorry to hear about your bird.
Is he eating as normal and does he seem comfortable with it?
Obviously you will need to check it daily to make sure that no infection is building up or that food is getting stuck.
The only problem i would be worried about is that the beak may start to grow deformed, and will then need constant trimming.
Personally i would see about taking him to a avian (bird) specialist, he will be able to give you a better prognosis. i know that these can be fixed sometimes with a special filler untill the beak grows. it just depends on how bad and where about the crack is.
if you can - bath the area with some salt water solution this will help keep any infection at bay hopefully, but it could be very painful too.
I hope this is of some help.
Good Luck.
Selena