I heard that excessive trumpet mouthpiece pressure can cause teeth issues when playing, similar to woodwind mouthpieces (ie clarinet/sax).

Umm, not really. But a lot of pressure on your mouth when playing is not good. If it's a ton of pressure, yes it will effect your teeth somehow. But use air, not pressure and you'll be fine. Keep the air flowing, and practice with less pressure on your face for higher notes. Take your trumpet, and point it towards the ground, so you're looking at the tground to so the gravity pulls the trumpet down to realive perssure. Do this, and try not to push the trumpet against your face. A little pressure is ok, and a little pressure is needed, but shoving the trumpet through your head is not good at all.