Should I get Invisalign for 8mm overjet and previous braces/extractions? (Photos)

The overjet you have appears to be from an imbalance in the length of your jaws. Your teeth appear to be in good position relative to your jaw position. Invisalign can correct the slight irregularity in you alignment but can not fix your overjet. The fact that your dentist suggested that it could is not a good sign. It is possible to correct your overjet but to do that would require a surgical procedure to lengthen your lower jaw. It requires some orthodontic treatment to get the teeth ready and then an oral surgeon performs the surgery. It is a simple surgery and takes less than an hour to perform. See an orthodontist if you would like to look into this treatment.