My Smile is Crooked, How Can I Get It Fixed? (photo)

If you look at your picture narrow maxilla is evident, especially on your left side that also has dark buccal corridors.   The more active muscles are probably secondary to the developmental issues. While you can inject neurotoxins (Botox) I would suggest looking into the DNA Appliance and Epigenetic orthopedics/orthodontics to address that issue.I uspect this has been the case your whole life.

David,
The "crookedness" of your smile is in your facial muscles that lift your lips and cheeks. You say that it has always been like that. Are there others in your family with the same smile? Since it bothers you I am sure that you have stood in front of the mirror and practiced lifting the right side of your smile. If you are able to force the right side of your smile up to even it out, I would suggest practicing it to strengthen those facial muscles. That procedure is free. If you are unable to lift the right side of your smile no matter how hard you try then you likely have some problems with the nerves that tell those muscle to work fully. I would be very slow to consider facial plastic surgery to "correct" it as it may then make your face look crooked when you weren't smiling.
Lastly, when physical imperfections are not predictably corrected we can change how we see ourselves and smile with every else we can from inside out. Perhaps we can still light up the world around us with our uniqueness. 

It looks like based on your photo that your teeth are even but the lips and musculature on one side of your mouth are asymmetric. This is not uncommon. The best thing to do is to visit a plastic surgeon for options. 

It appears from your photo that the muscles on the left side of your smile have a higher/stronger pull than your right side. One easy fix to this would be to get Botox injections on the left side to keep the muscle from pulling so much an to help even out your smile. The downside to this being that Botox is temporary and will need to be re-done periodically (likely every 3 months). However, the Botox may be able to train your muscle on that side with repeated injections, meaning you may be able to learn how to smile evenly and not need (or not need as much) Botox moving forward. Another option, as others have mentioned, would be to consult an oral surgeon to see if you can surgically reposition those muscles to smile more evenly, but I would try the Botox first to see how you like it since it's much more conservative.

David, thank you for your question. You do have options. Consider Botox injections on the left side of the upper lip. You will need to do those periodicaaly though. Another option is to see plastic surgeon and consider lip muscle reattachment of the left side. Recently also a third option became available. Some periodontists and general dentist, who use lasers and have experience, can help you to even out that smile.