Will retainer fit differently if teeth move?

[jmrut22]

I do NOT want my teeth to move,period, after extractions and surgery! I think I am just being paranoid but how would you really know if your teeth had moved. Would the retainer fit differently?

I think mine "settled" just a bit after the braces come off. I mean I look at them constantly

Sometimes I think they have moved just slightly but my retainer goes right back in and fits exactly the same?

So how else would you know?