After Developing a Posterior Open Bite from Invisalign Treatment, the Doctor Recommended Doing Crowns, is This Correct?

This can happen, especially in clenchers due to the thickness of the plastic between the back teeth.  The aligners should be cut behind the canines and allow the back teeth to re-erupt and settle.  Please do this with your dentist's supervision.  Do not have crowns placed to correct this.

The thickness of the plastic that covers the teeth can cause your back teeth to push up (intrude) into the bone because your jaw is on a hinge and the back teeth will come together first when you are wearing Invisalign aligners.  This should not be corrected with crowns in my opinion.  It should be corrected by making an adjustment to the Invisalign first.  If that is not successful then I would recommend treatment with braces as an alternative but not crowns.  

I just saw another posterior open bite from Invisalign last week. Patient is very unhappy with situation and seems to be contacting mainly just on upper left second molar.  Another office did the treatment for a front tooth that was displaced in a softball accident.  The treatment apparently  did not work entirely well, got rather long with more aligners, and now patient has a posterior open bite and can not chew properly.  I took a cone beam CT scan and bite is clearly open in front and back.  The condyles look OK with reduced joint space left.  Don't know how long it has been that way.  I suggested it may be possible posterior intrusion or a possible change of jaw/bite position due to lost neurologic sense of where to bite (engram) ??   I suggested that she stop wearing aligners and try to give teeth time to re-erupt  and/or for the bite to adapt but patient is seeking other opinions also.  I would not recommend crowns as time and adaptive capacity might be able to improve the situation, I would at least try that before other interventions.