Side effects from conventional RME
· Mesial migration of posterior teeth
· Molar extrusion – bite opening
· Tipping of teeth
TAD and expansion
· More skeletal expansion
· Less mesial migration of molars (for PFM) Nienkemper 2014
· Avoid extrusion of molars Ngan 2015
· Greater airway space compared to tooth bourne Bazargani 2017
Hybrid hyrax Vs MARPE
· MARPE – fitting miniscrew fixture after the appliance
· Hybrid Hyrax – TADs placed in ideal position, followed by appliance insertion : chosing the best bones
TAD insertion
· Ideal bone in the T Zone Wilmes 2016
· Buccal Vs palatal
o Palatal TADs 98.4%, Vs buccal 71% Houfar 2017
Pain
· Reduced pain for 2 palatal TADs Vs other positions, possibly due to loading of dentition as a factor for pain Feldmann 2017
AltRAMEC expansion protocol for class 3 cases
· Alteration of expansion and constriction prior to expansion
o increases AP correction by 2mm Masucci 2014
3D digital planning
1. CAD-CAM insertion guide
2. Digital monitoring
3. CADCAM expander
CAD-CAM Wilmes 2019
· 1 appointment TAD and appliance insertion
· Help less experienced with TADs
· Superimpositon with Cephalogram – Mesh
· Superimpose with CBCT – locate ideal bone for insertion
· Bone borne expander
o Quad-expander = 4 tads anterior and posterior-dentoalveolar
Digital Monitoring
· TeraMon chip – uses heat to monitor compliance for class 3 correction
Poor compliance solutions
· TADs lower arch – however high failure rate
· Bollard plate failure 25% Hevele 2018
o Usually maxilla – bone not well developed
Combination case class 3 case
· Hybrid TAD maxillary expander
o Distalisation as molars have mesialised
· Bollard plates lower anterior – class 3 traction
· Tip
o Leave minscrews in place for skeletal anchorage and secondary orthodontic correction
RME – palatal TADs
· Only TAD borne
· Expansion rate 1 turn / day, not require rapid expansion as no risk of tipping of teeth due to no retention on appliance
· Use pre-formed RPE = RMX
CADCAM manufacturing expansion appliance
· Advantage = very ridged wire
o Precision
o No bands / separators
o Customed
· Placing direct CADCAM appliance
o Fit appliance on molars
o Direct TADs placed = appliance acts as guide, ensure ideal position
o No play between expander and TAD
