What are these indents about an inch below tear trough Volbella? (Photos)

So those lines you are talking about are where the Zycomatic-cutaneous ligament attaches to the skin (from the bone).  When there is swelling from trauma in the tear trough region, the fluid is trapped above that ligament.  Ligaments don't stretch so the skin then pouffs out.  I hate cannulas in this region for this reason!  
That ligament defines the lower border of the malar mound or festoon.  There is spongy tissue here which "holds" onto the fluid for quite a while.  If it just from swelling it will eventually resolve, but often, especially with cannulas, the area is injured/pierced and filler gets into the malar mound.  If that is the case it wont go away on its own.
Sometimes it is helpful to put some filler deep on the cheek under that ligament to help support it.  I'd give it at least a month to see if it will resolve on its own.  If not consider 'camouflage' filler to the deep medial cheek fa pad or vitrace to the area to take out any excess filler.
Hope this is helpful.  Best of luck to you,
Dr. Amy

You did not post time frame. Was it