Invisalign can work for top teeth only in many cases, but sometimes treating only one arch can make the solution worse than the problem. It is important for the top and bottom teeth to fit together in a healthy and stable relationship for the long term success of the teeth. Often times, just treating one arch with Invisalign can improve this relationship, but sometimes it can also make it worse. You should ask your dental provider if Invisalign for the top teeth only would affect your bite in a negative way. If not, and if Invisalign is the right solution for you, it should be OK, but to be honest, in probably 90 percent of my Invisalign cases, I am treating both the top and bottom teeth.