What is the best way to treat deep malar/mid-cheek grooves? (Photos)

For unique cases where a variety of modalities could be used to treat the condition, I would suggest an in person or virtual consultation to develop a custom and effective treatment plan. It is difficult to precisely define the best option without collecting the same information. I suggest reaching out to an expert for a consultation with surgical and non-surgical methods to get a comprehensive option. Best, Dr. Emer.

The pictures you provided show a degree of volume loss in the midface. High density HA fillers would be my first choice for building up deeper volume in this area. The goal would not be to make you cheeks look bigger, but to fill in the areas of existing volume loss. If you have tried HA fillers and are looking for something more permanent you could consider fillers like sculptra or even fat transfer using your own naturally occurring body fat. There is also some degree of cheek descent. So you could also consider radiofrequency tightening like thermage. All the best! 

These midface cheek grooves can be difficult to treat. I find that filler to replace lost cheek volume gives the best result. I do not recommend injecting filler superficially into the groove because it can lead to chronic swelling making things look worse. 

I can answer with confidence that you definitely do not need threading or PRP. You need to be evaluated by a plastic surgeon who can determine if the area where the ale Malar groove is is soft. If soft, fat grafting will work the best. On the other hand if the area is rather firm, then you may need to have some fillers injected in the column like fashion. I hope this helps and good luck from New York City

Thanks for your question.  I have found that those types of grooves are difficult to treat as there some component of edema to them.  I have had the best results using Radiesse in the upper cheeks under the grooves. As a non hyaluronic acid, it does not draw even more fluid to the area.  To further enhance the results, add radio frequency treatment to tighten the skin in the area.  Hope that helps. 

First of all the pictures are amazing very detailed 
Deep injectable fillers like Radiasse would give you nice results.
It also one of the fillers that tends to last over one year, it is thick and smooth.