I'm about 5 weeks post zygoma and vline surgery and I'm still recovering from a wonky right lip. It's the mandibular nerves that got injured. This nerve control the depressor anguli oris which is resposible for depressing your lip. Most likely it's not permanent unless it's severed. I've been doing mouth exercises like saying "a, e, i, o, u" and making grimaces. I can smile normally now but it's still a little indented (but less obvious now) when I say "O" and "P". But the fact that I can see improvement means it's recovering. Give it about 6 months before freaking out - that's what I told myself. Good luck!