Braces to Move Just One Tooth?

The small shifting of a single tooth is probably do to some settling of the teeth and the single tooth is getting forced out of alignment.  It should be evaluated by an orthodontist to determine the issue.  The orthodontist would evaluate your bite in general and if everything is functioning normally (including TMJ), then you may have a relatively easy fix.  If it is more complicated, then they will let you know.  The key is a proper evaluation by an expert, your neighborhood orthodontist.

The same thing happened to my brother.  Perfectly straight teeth until his mid-thirties, then a lower front tooth when forward and twisted.  He ended up in braces.  What commonly happens over time, is that the bite deepens due to long term biting pressures.  Since the lower teeth fit within the top teeth, as the bite deepens, all the lower teeth can no longer fit.  Typically some teeth go backwards and some go forward and you might start seeing some wear on the edges of the front teeth.

Common sense tells you that the longer it allows to continue the worse it can get....even to the point of compromising the health of your teeth and function of your bite.

So...the best thing to do is seek an orthodontic consultation to see what options you have to fix it to re-align the teeth, and re-open the bite so it is balanced and looks better.