A couple weeks ago David had some dental work done. The dentist said to watch him and remind him not bite his lip or his cheek. I guess when your lip is numb, you can bite it hard enough to cause some trauma - and that is exactly what he did! He had a big swollen lip for several days. I don't remember ever being told that before. I guess kids are more curious about the numb feeling and what they can do to their mouth when they can't feel any pain. It was definitely a lesson learned for David. Hopefully he won't need anymore dental work (we've been very good lately about flossing and rinsing with fluoride!) but if he ever does, I'm sure he will leave his lip alone.