This is my 16 year old patient who had braces for 8 years and her orthodontist never managed to create contact between her back teeth. The only contact that existed was between her front teeth, which caused it to be unstable and detrimental for her teeth and jaws. In other words, she never had any bite on any of her back teeth. With accurate measurement and a great dental laboratory, @frontierdentallab, I was able to close her bite with some crowns on her back teeth. As you can see in the bottom pictures we got a very amazingly stable result!