Can Sculptra be used to augment the chin, to enhance the profile from the side?

Absolutely!! I have done it for a good many patients! It is fantastic for shaping faces into desirable ones, and done properly, the results last more than 7 years.  
Another injectable that works well to augment a chin is Radiesse.

Sculptra is not a good choice for chin augmentation, but it works great for butt augmentation - confusing, right?Let me explain why:Your face is a relatively small area, and you want to create very precise changes when balancing out features (which is normally the goal of chin augmentation). Sculptra spreads to the surrounding areas and creates a very diffuse effect - it's not going to augment one area without augmenting the areas around it, which is not what you're looking for.Most injectors use Voluma or Restylane Lyft for chin augmentation. These products are very, very similar. They're both hyaluronic acid gel fillers and last about 2 years. They're precise and placed deep - even as deep as directly on the bone  - that's key in this high-movement area, as it means a natural-looking result even during movement. Sometimes Restylane Defyne or Radiesse may be used instead - depends on the individual patient and preference of physician.Hope this is helpful!