Is it possible that the doctors used suppressant injections so that the normal signs of the fracture or swelling won't show after the oral surgery?

Yes: You do not mention how extensive the oral surgery was, or for what exactly. If there was significant surgery, it is common for oral surgeons to give a small amount of fast acting steroids (becalomethasone? Or decadron) to reduce post-operative swelling. Not enough information given, so i gave the best general answer i could. Good luck!

Sometimes: In certain situations post operative swelling may complicate healing. Managing post operative conditions may include drugs that reduce swelling. If you think this occurred ask your oral surgeon.

Yes: Dexamethasone or Decadron (dexamethasone) is a steroid commonly administered during surgery to help minimize the swelling associated with oral surgical procedures.

Dexamethasone: This is not used on purpose. Doctors usually give an anti inflammatory called dexamethasone (or some other similar type of corticosteroid) to decrease post operative inflammation and pain. It is not used to mask underlying conditions. If you are having problems post operatively, I would recommend contacting your surgeon. They might want to see you for follow up.

Corticosteroids: often used and appear to be an effective method of reducing pain and edema following oral surgical procedures.