Lillie has an underbite, too. I didn't notice it until all of her adult teeth came in. I thought about showing her but now that's out the window.
Oh, well. There's a reason for everything. I love her anyway. Plus, it 'does' look like she's smiling at me all the time. There is no problem with her eating or anything like that, shes as healthy as they come, just a lil underbite never hurt anyone. =)