I got into Yangon through Bangkok. I flew Thai from Bangkok. I think they got like 3 times daily, though you might want to check that. I tried to avoid supporting the Gov't so I did not fly Myanma Air, though my Thai flight, using Thai metal was Myanma codeshare. You can also take Silk Air from Singapore, and some other regional carriers from nearby countries. I think Bangkok Air goes there. And Air Mandalay runs twice a week to Chiang Mai from Yangon (and back). Airfare to Myanmar is not cheap.