How can I fix an uneven smile? (Photo)

From the photos you posted it does appear that your smile is canted and the midline is off.  A full correction may not be possible for you because the underlying bone structure is also asymmetrical.  However, with another round of orthodontics I believe you could get improvement. Minor reshaping of the enamel could also create an improvement.  Good luck with whatever you choose.  You have beautiful teeth and a fantastic smile regardless of whether you decide to undergo further treatment.

When midlines are off by as much as an entire tooth, this usually indicates a missing tooth to one side.  Sometimes braces are used to make things straight, but the missing tooth is not addressed.  The space is filled in by moving the teeth, but the midline is off.  Opening the space back up can be done, but it is a challenge and takes a very long time, often requiring temporary anchor implants to gain the leverage to move the teeth.  After the space is opened back up, an implant or bridge can be used to maintain what was done.Without comprehensive photos and radiographs, I have no idea if you HAVE a missing tooth and if any of this is relevant to you.  I suggest an evaluation with an orthodontist.  Some will suggest simply removing a tooth on the opposite side of the already missing tooth, but this will narrow the arch, decrease space for the tongue and likely lead to breathing disorders while sleeping.

the only way that you can correct this is with braces, and can take up to 1 year, do not try invisalign, this procedure is not for this cases, a complete orthodontic analysis needs to be done, so you can make a more perfect and even smile.