This article covers the following topics:
- The different types of tooth movements in clear aligner treatment; crown tipping, root tipping, torquing, rotation, translation, extrusion, intrusion
- The predictability of tooth movements in clear aligner treatment, including; predictable, moderate and unpredictable/difficult tooth movements
We use these terms to describe the movements of teeth during clear aligner treatment.
Our case parameters describe how much movement we recommend for each of these types of movements.
Crown tipping is the tilting of the crown of a tooth without moving the apex of the root.
Root tipping is tilting the root of the tooth without moving the apex of the crown.
Torquing The definition of torque has evolved from fixed appliances and although there is no wire and bracket, the concept remains the same with clear aligners. In clear aligner therapy, to torque a tooth is to move the tooth buccolingually around the centerpoint, so the crown and root move in opposite directions. It is the twisting force which is traditionally required to adjust the inclination of a crown.
Rotation is turning a tooth about its long axis.
Translation is shifting the tooth along the occlusal plane without changing the orientation of the long axis.
Extrusion is moving a tooth out of the supporting structures.
Intrusion is moving a tooth into the supporting structures.
Predictability of movements
These movements are fairly predictable, and don't usually require engagers.
- All facial/lingual movements
These movements are somewhat less predictable, and often require engagers to complete successfully.
- All distal/mesial movements
- Most rotations
- All torquing movements
How does ClearCorrect torque upper and lower anterior teeth?
These movements are unpredictable and are difficult with clear aligners. They will almost always require engagers, and sometimes require auxiliary treatment.
- Rotations of lower premolars
- Posterior teeth with short clinical crowns
How does ClearCorrect intrude or extrude teeth?