It is never too late to straighten your teeth. Teeth move very well even at an older age and many esthetic and functional goals can be achieved.
Estheticaly: We can straighten teeth that became crowded as a result of different forces in the mouth. We can change the way the teeth touch, close spaces that have opened and do other things to achieve a beautiful smile.
Functionally:
We can change the position of teeth that moved due to premature lose of other teeth and allow for an optimal position for crowns, implants etc.
In the presence of periodontal disease, teeth can be moved and esthetic goals can be achieves as well. Gentle forces are used.