If i get bimax i need to expand my upper jaw to chew. Expand it before or after?

[.👽.]

I have an overbite and was thinking on getting bimax in a 3rd world Country. But when i jut my lower jaw to the correct Position i cant bite anymore.

Thats why my ortho here told me to expand the arch with braces but after. I dont trust her so what do you Think?

Or should both be done at the same time.
Prob a low iq question

 

[Vidyacoper]

after cause shes the orthodontist and ur not