The honest answer is that it depends on how far your teeth have to move, and on you. Simple crowding can be finished in around six months. Most cases run twelve to eighteen. Complex bite corrections can run longer than that, and occasionally they are better treated with fixed braces.
The twenty-two hour rule
Aligners only move teeth while they are in your mouth. The target is twenty to twenty-two hours a day, which means you take them out to eat and to clean your teeth, and that is it. Patients who treat them as optional at work or at dinner routinely add months to their own treatment and then wonder why the plan slipped.
What else changes the timeline
- The amount of movement required, which determines how many aligners your plan contains
- Whether attachments are needed, since some movements cannot be achieved without them
- Any preparatory work: decay, gum disease and failing restorations are treated before teeth are moved
- Whether a refinement round is needed at the end to finish the detail
Refinements are normal, not a failure
Teeth do not always track exactly to plan. A short refinement series at the end is common and is part of getting the result right rather than a sign something has gone wrong.
Retainers are not optional. Teeth drift for the rest of your life, and the retainer is what holds twelve months of work in place. Budget for them from the start.