I would consider consulting with a PHYSICIAN injector of Voluma. See a plastic surgeon or dermatologist physician that do their own Voluma. This is the first step. Our experience with Voluma has been great. Voluma is placed right on the osseous surface and lasts 2 years. Should you not like the effect and want it removed it is very easy to remove with hyaluronidase. My Best, Dr C
Having a large masseter muscle would give a more prominent or squared jawline. This occurs in people who grind their teeth more often, and if not desired can be treated with Botox. If you would like even more definition, I would recommend filler to the jawline and maybe the chin, either Radiesse or Juvederm.
Yes, you can definitely have a more defined jawline. Please see the link below. I use a product called Radiesse. When the correct amount is placed in the appropriate area, the result is wonderful.
It's hard to tell from your photo what is the best treatment. But in some patients fillers can be used to improve the definition of the jawline. If your masseter muscle along the jawline is enlarged, Botox can reduce that effect. Please see a board-certified plastic surgeon or dermatologist to get expert advice on noninvasive treatments.