The Keys of Sagittal Treatment with Aligners. Isavel Flores Allen
Class 2 cases
Options for class 2 correction with aligners
1. Molar derotation
2. IPR
3. Distalisation
4. Simulation class 2 – in young patients, NOT in adults with elastics, rely on growth
5. Extractions
Upper first molar rotation correction
· Why does 1st molar rotate mesially = take space of primary molar.
· Correction via:
o Attachment if 20-30 o
o Buttons and force couple 30o +
IPR
· Maximum 0.5mm in clincheck
· Bolton discrepancy
o Focus tends to be on anterior teeth
o There is a discrepancy posterior – requiring IPR in premolars
Sequential distalisation
· Predicable: 2-4mm in younger patients with elastic use
· How does it work:
o Upper 7s is ½ of the way then the 6 begins to move
· TIP: No more than 2 teeth distalise at the same time
o ‘V’ protocol IN STAGED TOOTH MOVEMENT
o Extraction of 8s required
· Aesthetic start:
o Anterior rotated tooth correct whilst distalising
o Through proclination, intrusion etc
o Retraction when canine ½ way through distalisation
· Elastics from the outset
· At least when 5 begins distalise
· Precision cut / hook Vs button:
o Cut aid retroclination
o Button when no retroclination required
Premolar extraction 1st premolar
o Up to 2mm of mesialisation in maximum anchorage: G6 procotol: 7s are required to be present
o Medium anchorage 2-5mm
o If absolute anchorage = TAD
o No Invisalign protocols for 2nd premolar extractions, use conventional attachments
Typical changes to clincheck for distalisation case
o Precision cuts on upper 2nd premolars for class 2 elastics
o When 1st premolar begins to distalise, change to conventional attachment and cut out (cannot have optomised attachment and cut out on the same tooth, but can have conventional attachment)
o When 3s retract replace optomised attachment to conventional attachment and cut out
o Vertical attachments on upper 6s and 7s
o With class 2 elastics lower molar may mesially tip: use mesial attachment on 6 to upper 5 short elastic to upright
o
Tips
Elastics
Elastics 4.5 ounces 3/16th
