Typically, Invisalign treatments are designed with tooth-movement velocities based on wearing each set of aligners 14 days Now, orthodontists can modify this as needed case by case.Assuming that is true in your case, you would finish set 16 on 3/11/14 and then finish set 49 on 6/16/15. Please keep in mind that is assuming you are on the "2 week" schedule. If that seems like a long time, you could always ask your orthodontist about ways to enhance your "tooth movement biology" with technologies such as Acceledent or Propel, which tend to reduce treatment times by 33-50% (depending upon the particulars of your case). Of course there are pros and cons to consider, such as cost or what the procedures entail, that you would need to evaluate for yourself.Also, be aware that some cases are best treated with detailing sequences of aligners after the main set, known as refinements. It is usually the case that indications for refinements are not determined until one sees how the main set of aligners expressed in your mouth (because everyone's bodies react slightly differently).