Sharp pain when laughing - upper jaw screws?

[redblondefox]

I had bimax with palate expansion surgery in August 2010. Since then a genio and rhinoplasty. All healed up nicely. But recently I noticed occassionally when I laugh, I get a sharp pain under my nose and and a stiff feeling - as if something has locked. I can't really describe it properly. I'm paranoid I have a loose screw in the top palate but can't feel anything when I poke under my top lip around the gum. I've actually had this sensation before but it went away for a while.

Anyone else who's had upper jaw surgery had this?