2 years post op, unhappy with neck lift results - will a revision correct wrinkles and dip at the top of my neck? (photos)

Based on your photos, I think the most likely explanation for the depression just under your chin is removal of fat in that central area. It is also possible that the platysma muscles may not have been adequately tightened in the front of the neck and are sagging off to the sides. Without knowing the exact technique your surgeon used, I can't say more. Specific recommendations can only be made after reviewing your previous photos, operative report, and a personal consultation to check your anatomy. However, I think there is hope for improvement with a secondary revision to tighten muscles and perhaps even grafting some fat into that central depression (less likely).

Thank you for your question and sharing your photographs. I am sorry that you are disappointed with the result of your neck lift.
To start with, it would help to have a discussion with surgery regarding options for improvement.

The images suggest prominence of the digastric muscles and removal of the fatty tissue between them.

Deep plane neck lift surgery can reduce the size of the digastric muscles and lower part of the submandibular glands and plicate the digastric muscles in the midline to create a smoother contour.

Fatty tissue may also need to be add it in the central part to improve the contours.