Why is my upper center tubercle pushed inward? And how can I fix it? (photos)

This appearance of the upper lip is a genetic trace. Some people have just a small cleft, some people don't have it all, and some people like you have a deeper cleft. In my opinion, after looking at the pictures, dermal fillers are not enough to eliminate that, therefore indeed, surgery would be the only option.

To fix this deformity one can start with filler or even fat grafts. However, very likely it will not completely correct the problem. Surgery in local anesthesia with local flaps and small, mostly hidden scars is, most likely, the best solution. In person consultation with a board certified plastic surgeon, possibly expert in cleft lip surgery, is recommended. Good luck.