Teeth can be aligned by brace at any age. Most adults require alignment of the front upper and lower teeth to improve the smile.
This can be done within weeks to twelve months, using removable (Inman Aligner), Clear Invisible braces or Cosmetic fixed braces.
Most adults require reshaping of worn teeth (Cosmetic treatment) at the end of orthodontic treatment
Internet abounds with sites that claim their brand of braces is the best. Do not get fixated by this. Most practitioners will have tried out different brands and techniques. One has to choose what works best in their hands.