I am always intrigued by questions that relate to variations in anatomy. The reason most people ask these questions is that we have a perceived notion that perfect symmetry is the norm. Nothing is further from the truth. Anotomical variation is actually perfectly normal. Having said that, Botox will relax the muscles and bring your smile line closer to symmetrical, but you will have to have treatments at regular intervals for as long as you want the symmetrical smile line. If the asymmetry bothers you that much, then it is worth it. I believe in characterization of the smile to achieve a more natural look, however, my patients desire perfection. So, after a frank discussion, I defer to their wishes unless it makes them look crazy, lol! Btw, for what it's worth, you have a beautiful smile imho! Best wishes!