Expansion
- Planned Vs predicted expansion was statistically less, with weaker accuracy posteriorly Houle et al
- 80% accuracy in intercanine level, and 68% at the first molar region Zhou
Anteroposterior
- Planned Vs predicted overjet was not statistically different = accurate in overjet reduction Kreiger 2011
Sagittal movement planned Vs predicted
- Molar distalisation 87%
- Anterior torque 42%
- Derotation 40%
Experiment: predictability of aligners to correct transverse, anteroposterior and sagittal directions CBCT
What did they do?
- Non extraction cases
- CBCT pre and post
- N = 30
What did they find?
Transverse
- Expansion intercanine 94% and premolar 81%was accurate
- Expansion intermolar – first molar 50%
Angulation
- Proclination: unpredictable
- Retroclination: predictable
Root movement
- Very little root movement
