Vertical Control with TADs. Etiology and Treatment Modalities of Anterior Open Bite and Relapse Jae Park. Episode 27 October 2020 Part 2

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Farooq Ahmed

Join me for part 2, where Jae Park describes how to plan either extrusion or intrusion movements, the key evidence around AOB closure and TADs, aligners and orthognathic surgery.


  • Resting tongue position is the main soft tissue factor.
  • For increased LAFH, posterior intrusion with tads is indicated.
  • Invisalign for mild AOBs, correction is achieved with incisor extrusion mainly.
  • TADs for intrusion should be placed in the palate should be as distal as possible.
  • If intruding upper molars with TADs, lower molars will erupt unless an appliance is used.
  • 80% of vertical relapse with posterior intrusion occurs in 1st year after debond.

How to plan intrusion posterior teeth  Vs extrusion of anterior teeth

  • Extrusion:
    • No autorotation
    • Increase incisal show
  • Effects of intrusion:
    • Autorotation of mandible
    • Reduction in LAFH
    • Reduced posterior tooth show


  1. If too steep = occlusal interference
  2. If too flat = reverse smile


How to plan extrusion / intrusion:

  • Upper incisor tip positioned 4mm from the upper lip tip



Evidence of AOB closure with TADs

  1. Posterior intrusion of 2mm in the upper and 1mm in the lower 1mm, with 3mm of autorotation. Deguchi 2011
  2. TADs and intrusion less stable, 1mm or 30% relapse Sugawara 2002
  3. If intrude upper posterior teeth, use lower fixed or VFR to prevent lower posterior over eruption.


  • Correct AOBs through 1.5mm incisor extrusion, minimal posterior changes. Khosravi 2017

Orthognathic surgery

Reduced stability due to Stylomandibular and medial pterygoid muscles.


  • Strips muscles in surgery
  • Short split


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