Dimples can be used for:
The force made by dimples will only be as strong as the aligner’s strength, so it's best to place dimples in a fresh aligner that has not been worn yet or request a remake of the aligner if retention is inadequate.
Overcorrection & Dimpling:
If overcorrection is requested in the treatment setup, it reduces and often negates the need for dimpling. Whenever possible, planned overcorrection in the treatment setup is more advantageous than making dimples (since dimples need to be made for each aligner and are generally limited to one or two teeth).
Dimpling is used as a chairside measure to increase pressure on the tooth for difficult movements. However, the amount of tooth movement is limited as there must be adequate space on the opposing side of the dimple within the aligner to allow the tooth to move. Often this is limited to the size of the air gap between the aligner and the tooth.
There are different approaches to overcorrection and dimpling. Some clinicians prefer to utilize overcorrection as much as possible and dimple only for difficult movements. Others do not plan overcorrection and dimple the aligners as needed, however as described above, dimpling only works for select movements.