It depends on how severe the underbite is and the underlying cause.
Underbites can be caused by:
1) Jaw size discrepancy
If your lower jaw is too large in proportion to the upper jaw, or the reverse, then a skeletal underbite is the result.
This results when the developing skeletal issue was not addressed when you were still in your growing years (before puberty). Normally, your dentist or orthodontist can detect this in a growing child, usually around the age of 7-10 years old.
If the discrepancy is mild, you may be able to camouflage it with extractions.
More severe discrepancies may require jaw surgery to correct, especially if you have a large anterior open bite (gap between your upper and lower front teeth).
2) A crossbite in the front teeth
If a single tooth is out of position (due to crowding), it may lock the lower jaw in a forward position causing a crossbite with an underbite in the affected area. Cases like this are simply corrected by aligning the offending tooth and the lower jaw should self correct.
As you can see, the options for treating an underbite vary so a proper assessment is required. Invisalign can correct underbites through camouflage extractions or crossbites.
Here is a case of a mild skeletal discrepancy that I treated with a camouflage extraction using Invisalign.
