Do Vivera need to be worn on the top and bottom if only the top was treated?

I tell patients that they need to wear retainers as long as they want to keep their teeth straight. You definitely need a retainer for the top and perhaps a permanent retainer as well to ensure that the gap does not open up again. If there was any correction done to the lower teeth then you should have a retainer for them as well.

Generally speaking, you only need to wear the retainer for the arch that was orthodontically treated.  If you had treatment on upper and lower, then you will need to wear both retainers.  As a side note, I would recommend a permanent retainer for your upper front teeth if there was a gap previously.

Vivera retainers are manufactured by Align Tech, the parent company of Invisalign.They are 0.4mm in thickness and are 3D printed to maintain a very accurate fit.As they are printed and not vacuum formed then they will last longer than most retainers.We normally give 3 upper and 3 lower sets.If however you only treated 1 arch then only 1 arch retainer set is provided; although you can have both.Some patients opt for fixed retainer wire, which does seem less hassle, but can be tricky flossing.