Sunken area around mouth due to denture wearing. Can fillers help with this?

Thank you for your question. 
Hyaluronic acid fillers or HA fillers can prolong the need to undergo surgery. The results of a liquid face lift are immediate, and with very little to no downtime! You may get some light swelling or bruising, however many of my patients come on their lunch break and resume all normal activities within 24-48 hours. Results vary, but it can last up to 2 years. The cost is relative to surgery, the difference being the instant gratification and little to no down time. 
The LiteLift™ is a modified facelift developed by board-certified plastic surgeons, Dr. Jed Horowitz and myself. We created this facelift technique with the goal of providing a less invasive, natural looking option for women and men wanting to refresh their appearance with less downtime and fewer risks. The LiteLift™ is a “real” facelift, which does address the underlying muscle, tissue, and overlying skin. It is not a superficial skin lift like other mini-lifts performed elsewhere. The LiteLift™ facelift is also not a “Thread-lift” or “String-lift,” and is not to be confused with the mega facelift chain “Lifestyle Lift,” which has closed its doors nationwide.
The LiteLift™ modified facelift technique perfected by us, results in less swelling, bruising, and healing compared to traditional facelift procedures. Most LiteLift™ patients have their procedure performed under local anesthesia, which reduces healing time, because they don’t experience the after effects of general anesthesia. Many patients are able to go back to work within one week.
I hope this helps you, be well!

In general, dermal fillers can help, but you may also have to see a specialist with dentures. Best wishes, Dr. Aldo