How do I fix my crooked smile/mouth/laugh?!

Alright, so when I laugh my left part of my mouth sticks out. My mouth doesn't even tilt all the way. Now apparently, when I talk and smile, its the same. When I smile, I'm usually very conscious about it and so I don't do it, IF i notice it. When I mean crooked, (i feel the need to better explain) i mean the left side of mouth tilts left and the right side seems to stay in one side. How can I fix this? Can my dentist/orthodontist do something about it? I'm starting to stress out about it. Please help.