How long Invisalign takes, and who it suits
October 15, 2026
Milder Invisalign cases often finish in around six to eight months, and more complex ones run 18 months or longer. The deciding factor is how far the teeth have to travel. Aligners work for adults and for children, and children can start as early as 8, depending on what is going on in their mouth.
How aligners move teeth
Invisalign is a series of clear plastic trays, each one shaped slightly differently from the last. You wear each set for a week and then move to the next, and the teeth shift a small amount at every stage.
The trays come out to eat and to brush. The rest of the time they stay in, 20 to 22 hours a day, because the teeth only move while there is pressure on them. Leave them out for long stretches and treatment takes longer.
What decides the length of treatment
Distance, mostly. A little crowding at the front is a short trip. Large gaps, a lot of crowding or a bite that needs correcting take longer, and the 18 months or more at the far end is usually where those cases land. How faithfully the trays are worn makes a difference too.
Treatment does not end when the last tray comes out. Teeth tend to drift back toward where they started, and a retainer is what holds them in their new position.
Starting as an adult
There is no upper age for moving teeth. What matters is the health of the gums and the bone holding the teeth. Starting means an examination with radiographs and a scan to check both.
Two adult cases come up again and again. Teeth that have shifted years after braces came off, and crowding at the front that has slowly got worse. Both are often the kind of short trip described above.
Starting as a child
Children can begin orthodontic treatment as early as 8, depending on what is going on in their mouth. Most who need it start once all the baby teeth have fallen out.
Aligners or braces
The practical difference is that aligners come out and braces do not. You take aligners out to eat, so there are no food rules, and cleaning is no harder than usual. They are also close to invisible.
Fixed braces still suit some cases better. For someone who thinks they’ll forget to wear the invisalign trays, braces is likely a better solution.
When the problem looks like a veneer problem
People often ask about veneers when what bothers them is where the teeth sit, not how they look.
What the cost depends on
The cost of Invisalign varies with the same thing as the time it takes: how far the teeth have to move. A short trip costs less than a long one. At our office you get your number in writing at the examination, before you commit to anything.
If you are partway through your Invisalign journey and something is wrong
An attachment comes off, a tray stops fitting, or a tooth moves in a way you did not expect. Email us a photo and tell us what happened. Dr. Fenn will look and tell you what she thinks and what to do next, even if your treatment started somewhere else.
Thinking about straightening your teeth? Book an examination and Dr. Fenn will tell you what is possible, how long it is likely to take, and what it will cost.
FAQ: Addressing Common Concerns
Do I have to wear aligners all day?
Close to it. They come out to eat and to brush and stay in the rest of the time, 20 to 22 hours a day.
Will my teeth move back after Invisalign?
They can. A retainer after treatment holds them in place.
Can children have Invisalign?
Yes. Children can start as early as 8, depending on what is going on in their mouth.
Do I need an examination before starting?
Yes. Tooth movement cannot be planned from a photograph. It needs radiographs and a scan.
