Bracing teeth takes time. Altering the position of hard structures (teeth) in soft tissue (gums) requires a good deal of remodeling and change in supportive structures that have become accustomed to the shape of your smile for so long.
Correcting spinal shape takes time as well. Altering the position of vertebrae in soft connective tissue, ligaments and muscles require timely change in the supportive structures that held them there for so long.
When moving teeth for a better cosmetic result, or moving spinal bones for a better structural result, you can't expect to see change overnight. Underneath the final result lay months if not years of foundational change that will ultimately make the shape change stronger and longer lasting. Every worthwhile change in the body requires time.