Horizontal line between nose and upper lip - What are my treatment options? (photos)

This is cause be muscular contraction of your upper lip elevator muscles, which in turn causes this crease. This is not due to septal surgery, but is just a normal variant seen in some people typically due to a long upper lip vertical length, which seems to be the case for you. If you don't like it, you would benefit from an upper lip lift, which would shorten that distance and eliminate the crease.

Hi, Sandia601! Thank you for your question and photo.
The best way to get rid of this horizontal line is a lip-lift surgery. As I see from your photo, there is not too much distance between your nose and lips, which means that the amount of skin to be removed will be less. The skin and underlying muscle will be seperated and will be prepared to heal seperately, so that we can treat this line effectively.