I believe you can send them after your secondary deadline. I called LLU just to make sure what they want before they can process your application:
-Secondary application online w/ fee paid
-an additional LOR from a religious leader
-a seperate proof of shadowing form from each dentist you shadowed (for me I turned in 3 seperate forms all signed by the dentists I shadowed)
-An LOR from a dentist can replace the "employment LOR"
I think thats it. The only thing that has to be in on time is the fee and the secondary, just be sure to send the other stuff pretty soon after. Good luck to you!