Biomechanical protocols and strategies for the correction of sagittal malocclusions part 1 and 2 Juan Carlos Rivero Lesmes
Join me for Juan Carlos’ lecture where he explores class 2 and class 3 correction with Invisalign
Part 1 class 2 cases
Distalisation
· Most effective movement with aligners 87% efficacy Simon 2014
Method of correction of class 2
· Sequential distalisation
· Distal molar rotation
· Arch expansion
· IPR / extraction
· Bite jump with elastics
· Orthognathic surgery
Sequential correction
· V sequence
Intrusion in deep bite cases
· Cannot intrude incisors if roots are labial
o Require torqueing 1st, then intrusion
Expansion
· Differential anchorage
o Expansion of 6s and anterior teeth 1st
o Then expansion of 2nd molars
Upper premolar extractions
· Difficult to mesialise upper posterior teeth with aligners
Post herbst
· Closing of lateral openbites
· Cut outs 6s, 5s and box elastics
Class 2 subdivision – asymmetry
· Differential growth in the mandible
· Treatment
o Mesialisation of effected side
o NOT upper molar distalisation
· Mesialise effected side with class 2 elastics
Part 2 – class 3 cases
Posterior crossbite
· Cross elastic posteriorly
o Palatal cut outs upper molars, buccal cut outs lower
o 128g of force
§ Distance for cross elastics 3mm diameter, interarch 4.5mm
Elastics
· Hooks on lower canines
· Cut outs on upper molars with metal buttons
Orthognathic
· Pre surgical preparation
· Post surgery – Miniscrews upper and lower anterior segment for IMF
Class 3 case with 8s
· Lower 8s in situ
· Require 4mm of space
· RCT and hemisects L8s, create 8mm of space
· Use 8 as anchorage unit
Interceptive class 3 case 6 years old
· Previously treated with RME for disjunction and Chincup
· Now treatment with Invisalign
o Attachments each tooth for retention, no secondary teeth
Thank you v.much very nice tips