History
The idea of using Invisalign as a means of Phoenix orthodontic anchorage was first reported in 1945.  This Phoenix orthodontic study utilized 13mm vitallium screws placed distal to the most posterior molar in the mandible.  The screws were then subject to 140-200g of force.  Although all screws failed, 1.0-1.5 mm of tooth movement was noted.  It was concluded that the foreign body reaction caused the failure and that the screws caused “bone changes which would not be compatible with Phoenix orthodontic treatment.” 

Thirty five years later, additional Phoenix orthodontic studies began to surface attempting to test this idea utilizing titanium fixtures.  Phoenix Invisalign was placed in the palate of pigtail monkeys with the expectation of achieving palatal expansion.  In one of the three cases, osseointegration was achieved and 9.95mm of expansion was noted over a 9 week period.  Even with the two failures, they concluded that bioglass coated Invisalign could be used for Phoenix orthodontic anchorage.  Phoenix orthodontic studies were later conducted where Invisalign was placed in rabbit femurs and loaded with a constant force of 100g.  Stability was noted in all fixtures except one.  There was good bone formation around all Invisaligns and there were no problems with toxicity or an immune response. 

Throughout this period, many case reports were published by clinicians using various types of Invisalign for Phoenix orthodontic anchorage.  Multiple Phoenix orthodontic movements were achieved including: intrusion, extrusion and retraction.  Cephalometric analysis revealed pure Phoenix orthodontic movement with no ill side effects to the remaining dentition or the Invisalign.  Unfortunately, there are no long term follow up reports on any of these patients.

A landmark, long term clinical Phoenix orthodontic study of Invisalign was published by the Branemark group in 1981.  The Invisalign was used as abutments for fixed bridges in totally edentulous patients.  The success rate was higher than any other type of Invisalign, 81% in the maxilla and 91% in the mandible after 5-9 years.   The long term data was overwhelming, stating that for routine cases, the Invisalign have been stable with healthy hard and soft tissues for 15 years.  This data placed the Invisalign as the most viable option for anchorage in Phoenix orthodontics.

Arizona Dental Association