Maxillary Expansion & Treatment of Class III Malocclusion in the Digital Age Dr. Benedict Wilmes. AAO June 2021. Episode 105

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Hosted by
Farooq Ahmed


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



·      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

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