Aligner orthodontics. in growing patients. a research based approach. Tommaso Castroflorio
· Expansion ideal prior to lateral incisor eruption: Bjorn Zachrison and Marco Rosa
Cause of maxillary retraction
· Increasing malocclusion in the population Corruccini 1985
· Higher prevalence of reduced intermolar width in recent generations Defraia 2006
Timing of expansion
· Transverse changes of maxilla between 7-11mm Nanda 2012
· Little force required to separate palatal suture in 7-9 year olds Hugo De Clerk and Proffit 2015
Invisalign first
· Attachments on primary and secondary teeth – optimised
· Staging of expansion: 1st molar first
· Simultaneous expansion: anchorage strained.
Research of Invisalign first
1. 43 cases retrospective
2. Average age 8.1
3. Treatment 9.7 months
4. Area increased 19%, volume increase 38%
Mandibular advancement
· Active / optimised wings, similar to twinblock, but laterally placed
· Active plane interact and postures the jaw forwards
· Timing of functional appliances, predictor of timing
o CVM, however validity questioned McNamara and Baccetti
o Females pubertal growth CVM2-3 Oyonarte 2020
o Males pubertal growth CVM3-CVM4 Oyonarte 2020
· New predictor of pubertal growth :
o Stage of 2nd lower molar root development Oyonarte 2020
Case selection for MA
· ANB 5 degrees
· Class 2 molars
· Convex profile
· Average angle
· 2nd molar development
Unpublished research
· 45 treated MA Vs control (no treatment)
o 0.48mm of advancement per month
o Reduction of Witts 2.6mm
o Co-Gn +8mm
o Similar changes to twinblock
super post