In my practice, I find treating scoliosis to need a multi-faceted approach. Opening up the shortened strructures is vital, and they can be on both sides of the spine. Balancing the pelvis is crucial as is teaching self pelvic balancing to the client. Doing work to open up the rib cage (again, both sides) is necessary as well. I have had very good luck with reversing the curve and reducing the overall deformity in many patients. I am currently working with two teenaged equine athletes (the riders...not the horses) who compete at a national level. They are seeing their shoulder and seat become more level and their performance is gaining. Some of the changes occur rather quickly, others are slower, but the myofascial release that I perform has really worked.
There is a research paper on my website's research page that documents the effectiveness of MFR with scoliosis. Take a look.