[Watch] Molar Distalization Hack Using Invisalign First for Class II Correction

Class II correction of Phase I patients using Invisalign First can be addressed in several ways. I find the main challenge comes with the short clinical crowns on patients in the early mixed dentition. The short clinical crowns make the use of elastics difficult, so the most common Class II correction techniques we use in teen and adult patients are tough to implement. In some cases, we use the MA appliance to gain improvement. And in most cases, I have found that molar distalization is the most predictable way to achieve a Class I occlusion. In mixed dentition cases, we do not sequentially distalize the posterior teeth as we do in the permanent dentition. The simpler goal is to distalize the molar into a Class I position, using the primary teeth as the anchorage for this single tooth distal movement. This setup does not require the use of intermaxillary elastics and it creates the space needed between the permanent molars and the lateral incisors. This space will allow sufficient arch length for canines and premolars to erupt. Besides addressing arch length discrepancy, it allows for Class II correction and an improved position for the second phase of treatment.

This Smarthack is how to implement molar distalization in an Invisalign First patient to complete Class II correction:

The first step is to complete the desired movements for the treatment plan and leave the molar distalization movement for the last revision. Select the primary second molar and select “lock tooth position” after right-clicking the mouse on the primary molar. Then select the mesial-distal movement tool in 3D controls and move the molar distally into a Class I molar position. This is often one to two millimeters of movement in most cases. Confirm the molar has distal rotation and the modification is complete.