How should I go about enhancing my face as an MMA fighter? Can I take hits to the face with facial transfer?

For patients who are involved in contact sports, I recommend something such as a Medpor Chin Implant. This implant is screwed into the bone. It is made of a material called porous polyethylene. Your bone will actually grow into this chin implant, causing it to become extremely durable. I would not suggest a silicone chin implant in your case, even if it is screwed down, because those never incorporate the same way.
Facial fat transfer is also a reasonable option. This fat, once healed, is also quite durable.
The most important thing in both of these procedures would be to allow things to fully heal for several months before subjecting the areas to any kind of trauma.