Fillers not enough for mid-face sagging? 50 years old (Photo)

Thank you for your question. 
By your photograph, you do have some lines and wrinkles, but you also have volume loss. Combination treatments with laser and filler may obtain the most satisfying results. 
It is important to treat the mid face and cheek area first to give a lift. This will soften the structures of the lower third of the face.  
There are many great products for creating a beautiful result for marionette lines, nasolabial folds, pre jowl sulcus  and cheek volume loss.  Juvederm Voluma or Vollure, Restylane Lyft would all give nice results. 
Active FX laser resurfacing or microneedling would help to tighten and brighten aging skin and improve tone, texture and would be a great choice for under eye wrinkles.  Laser resurfacing requires one treatment whereas, micro needling would require multiple treatments. We use platelet rich plasma with both procedures. 
Please consult a local board certified facial plastic surgeon for more information and a comprehensive consultation 

Your surgeon is correct. The nasolabial folds and the marionette lines under your lips are caused by the loss of fat and bone in your upper face. The most natural and effective way to treat them is to add volume to the cheeks and lift the tissue back up. You can still add filler to the folds directly but it will take less filler and look better if you start in the cheeks! You don't necessarily need Botox, as it doesn't provide much of a lift to the lower face, but it does look nice, and will also make you look younger. I hope you love your filler. They can make you look younger and prettier. Enjoy! -Dr. Jenny