Thank you for your question. Invisalign treatment uses removable plastic trays that are custom fitted to effect teeth movement by applying forces on the teeth gradually.Each plastic tray also known as an aligner, has a specific force designed to shift the teeth to the desired position. The maximum amount of tooth movement designed into each aligner is 0.25mm, which may not be very visible with each aligner change, but over time you will notice your teeth starting to shift gradually. You will expect to feel tightness and pain on your teeth for 3-4 days each time you change to a new aligner.Taking aligners in and out of the mouth for meals and brushing teeth may be quite challenging during the first few days of a new aligner due to the pain on the teeth.
Depending on the planned tooth movement, some aligners can be changed weekly, for more challenging tooth movements your dentist/orthodontist may prefer if the intervals were longer. You will start to see visible tooth movements after 3-4 months of wear as the changes to your teeth will be more apparent, however this may not be the case for everyone as some treatment plan effect change on the back teeth first and this may not be so visible.
Hope this helps.
Warm regards,
Dr Priscilla Lu
Orthodontist