Clear aligners: why wear time decides your result

Each aligner applies gentle, continuous force to move teeth a fraction of a millimetre. Continuous is the operative word. Removing trays for long stretches lets teeth settle back, so the next aligner no longer fits as designed.

Twenty to twenty-two hours a day sounds demanding until you realise it simply means removing them to eat and to clean your teeth.

Small tooth-coloured bumps bonded to certain teeth give the aligner something to grip so it can rotate or upright a tooth rather than just tip it. They are removed at the end of treatment.

Teeth move throughout life, with or without treatment. Retainers hold the corrected positions. Patients who stop wearing them within the first year are the ones who see relapse — and relapse is far more frustrating than the original crowding.