Cant of upper teeth, asymmetric gum line, little or no deviation of chin. What causes this? What treatments are possible?(Photo)

You have a few different options with this.  You can go a surgical route, which would likely include crowning most of your teeth after re-positioning your mandible.  This would be a major process with a long painful recovery period.  The other option would be to only get veneers and crowns.  A good cosmetic dentist could use veneers and crowns to camouflage the imperfections in your smile.   Good luck and I hope this helps. Follow me if you have more questions.Sarah Thompson, DMDReal Self 100

You need a doctor who can use CB-CT to analyze your skeletal planes and determine the source of canting.