Bulge after deep plane neck lift - how can I improve this? (Photos)

That's the platysma muscle that is banding in your neck. You can try botox here to help soften it vs you may need a revision neck to cut the band to release it and resuture it together centrally.

Based off your photos - the muscular bulge you have as you smile can be from scar tissue that formed, vs some muscles that were not completely released (maybe can ask your surgeon to try botox to see if will help - and then if botox works, the answer is muscle that needs to be released to resolve the issue). In the middle of your neck, again hard to tell, but maybe scar formation, or incomplete release and fixation of the muscle (this area might need another revision to properly fix the indentations and possibly fat grafting some if at the first / second surgery, too much was removed.) Try seeking out a few other opinions in your area and seeing what the consensus is vs. going back to your surgeon to see what can be done. Hope this helps (photos are very limited for a more accurate diagnosis)

Based on the two post photos would recommend virtual consultation, but only surgical release of a skin only revision full face neck lift with neck muscle cutting implication most likely fee would be $20,000. Best of virtual consult