How do you treat a low lip line? (Photo)

I have a low upper lip line that covers my teeth when I smile. My teeth are straight thanks to braces that I had as a kid, but my lips seem to cover my entire smile unless I excessively force one out by scrunching my nose up. Are there any treatments for this issue, such as a lip lift or orthodontic procedure, that would solve this problem without drastically changing the appearance of my mouth?