I recently had my wisdom teeth removed. I know shouldn't practice because of the stitches, so is there any way I might keep my lips in decent shape without actually puting the horn up to my face? I don't think it'll matter a whole lot since it's not for very long, but it'd be nice to learn a new trick or two.

Any buzzing or buzzing type thing you do will put pressure on the vacated area. So buzzing is out of the question.

There are other things you can do.
For muscle tone:
What you can do though is gently exercise the lip muscle(s). Be careful when you do this but make an exaggerated 'pucker' with your lips and hold it for 3 counts, then put your lips in an extreme 'smile' for 3 seconds. This will keep activity on your lip and cheek muscles with out putting pressure on the stiched area.

For Breath control:
Breathe in fully letting your whole chest expand like puffer fish, or like someone is blowing up a hot water bottle inside your chest cavity. Then exhale through your lips as though you are playing pianissimo.This will also work the lip muscles and abdominals without putting hardly any pressure in the mouth area.

Air Horn:
Don't actually play your music, but practice just fingering your music. Don't be sloppy and lazy though. Really look at the music and put the fingers down dicisivly only at the last moment you can, without being late. You can also do this with your scales.

Here's one more from The Balanced Enbouchure that should be helpful. Roll both lips in til the red part is not showing, and clamp them tightly together. Hold this position til they begin to feel "crampy." Release. Do this only once a day, but not right before you play. Every day you do this, you'll be able to hold it just a little longer than the day before.

Valerie Wells
http://www.beforhorn.blogspot.com/