My son is 15 years old. I have sought the opinion of 1 dentist and 4 orthodontist. All 4 have different opinions. His bottom and top teeth align correctly, however they are in an "S" shape rather than the normal "U" shape. He also has some crowding on the bottom. At his age, how much more likely will his teeth continue to change and what are the chances that his teeth continue to turn inward?