One of orthodontist near Osan air base referred an Invisalign patient to me. She had gap between upper and lower molars and premolars. When she bites down, only front teeth and the last molars were touching each other as shown in the picture below.

Side effects of premolar extraction case with Invisalign (Bowing effect)

Crown tipping toward extraction space- mesial crown tipping of 2nd premolars, 1st and 2nd molars
Intrusion of premolars and 1st molars
Extrusion of canines
Posterior open bite, only anterior teeth are occluding

Let’s compare the plan and the actual results. Not good. One bowing effect occurs, it is more difficult to fix. Prevention is the key.

How can we prevent them?

Most important thing is over-correction. If you think molars can be tipped mesially, prescribe distal crown tip on the molars.

How can we over-correct for Invisalign patients? It is by setting up the teeth position considering the amount of tipping or intrusion. from the bowing effect.

This picture shows how to set up teeth to prevent bowing effect.