Should I Expect a Treatment of Invisalign to Last for over 12 Months?

I think 10 to 12 months would be a good estimate if your main focus is to fix the crowding.  From your photos, it is difficult to tell if there is a bite problem (malocclusion) in the back that would add time to treatment if you are interested in fixing that as well. 

Based on what you’re showing us, your Invisalign treatment would indeed be likely to take less than a year to complete although it may be closer to the full year or just over. Of course, pictures don’t tell a full story, so an orthodontist would have the best estimate.

I believe your case can be treated in under 12 months using invisalign.  Braces would be your only other option which would also take about the same time.  Just make sure when your treatment is completed you wear your retainers so that they stay aligned!!!!!  Ask for a permanent retainer on the lower.  It is my retainer of choice.  A small wire is glued behind the lower teeth 6 teeth.  It is comfortable, easy to clean, and can last forever if taken care of properly.

The most optimal tooth movement for Invisalign is 0.1mm per aligner. Therefore, find the most crowded teeth in your mouth. Measure how far off the alignment is. Multiply by ten (the amount of aligners needed). Then divide by 2 (2 aligners per month). That will tell you how many months of treatment is needed. Your case could go over 12 months.

If you finish faster, all the better. There could be unforeseen problems that might prolong the treatment.

Good luck!

Invisalign works great for lower crowding and the length of time required is different for every case. Most cases run about 8-12 months.