is it possible to increase volume with fat grafting to back of the head/neck? (Photos)

Successfully grafting tissues requires there to be post tissue to support the graft.
The answer to your question is highly dependent on where exactly you want the volume.
Scalp on bone is not particularly suitable for successful fat grafting.
If there is a substantial layer of subcutaneous fat in that area can be successfully grafted.
The final outcome of grafted fat is highly dependent on the distribution of host tissue.
It’s a fairly complex procedure and it is very different than working with fillers or bone cement like you had done previously.
The human head, face and body is highly asymmetrical.
Symmetry is not something anybody has or is for that matter not an aesthetic idea.
The human brain is a custom to seeing peoples heads and faces as being asymmetrical since no one has a symmetrical head.
Computer generated purely symmetrical faces are considered less attractive and having odd strange look to them.
There is an expression all plastic surgeons are familiar with that goes“ The enemy of good is perfect“
Sometimes it’s better to leave things as they are.
Would you describe does not sound like a straightforward simple procedure that would give a high patient satisfaction.
You can probably find someone willing to take your money and do the operation but that doesn’t mean it’s a good idea.
You can try having in person consultations and see what providers have to say but you should also be selective and confirm providers have sufficient fat transfer experience to understand when the procedure will work and when it will not.
Best,
Mats Hagstrom MD