So, I have metal braces and have had them for a while. This past week, my archwire has come out of the buccal tube on the right side of my lower jaw. I have emailed my orthodontist and am waiting for them to get back to me. Has anyone ever had this happen, and if so, what have you done about it?

If it is projecting out of the rear of the tube, they usually suggest you clip off the excess with nail clippers, although I suspect it damages the nail clippers.  A very small pair of wire cutters might work as well.

If the problem is that it came out of the front of the tube, I had that happen.  It needs to be put put back in the tube.  I was able to spring the wire so the end lined up with the tube and it went in.  I think I did it without a mirror.  It may depend on how far it went in in the first place.  It could be possible also to use a pair of small needle-nosed pliers to grasp the end of the wire and feed it back into the tube.  If all else fails and it is hurting you as bad as mine was hurting me, you might need to cut it as above where it comes out of the nearest bracket and then let the ortho replace the entire arch wire when you can get back to see them.

Same thing happened to me a few weeks ago, while eating some ice cream with brownie bits in it. The cold must have made the niti wire more flexible, and on that side for me it's a large span between the two molars.

I found some needle-nose pliers, swished around the cold water in my mouth, and then reinserted the wire myself. If it had been a less flexible wire, I wouldn't have been able to do it (though maybe it wouldn't have come out). A couple times while eating pretzel bars that also have peanuts in them, I've bent that span of wire so that it's making a U-shape between the two teeth but still in the buccal tube. It takes a bit of force to push it back up and in. Thank goodness it's a niti memory wire, and not permanently bent!