Sculptra vs. Voluma for lower face?

Both sculptra and voluma are excellent fillers for volume augmentation.  Sculptra tends to be "more natural" in a sense that it stimulates your own collagen growth over time and it's rare to overfill/ cause lumpiness in my experience. It's great for hollow areas in the face with a relatively large surface area (cheeks, lower face, temples, forehead etc).  So yes, it works very well on the lower face.  Voluma/ hyaluronic acid when injected correctly and conservatively, can also improve the volume deficit in your lower face instantaneously.  However, when it's overdone, it can create heaviness in your lower face which is undesired.  Best to consult with a board certified plastic surgeon/ dermatologist in person.  

Sculpture is used to fill in the sallow and replace lost fat in your face either due to weight loss or the aging process. Sculptra does provide a nice natural result. I like Restylane under the eyes.

Belotero® and Restylane® are indeed best for under hallowing. Sculptra®/ Perlane®/Juvederm® UPXC are best for volumizing the lower face, although Sculptra® can take up to 1-3 months longer to manifest its results.