Fullness under chin after lower neck & face lift 9 months ago, what's needed to correct? (Photos)

You truly need to see a facelift revision expert certified by the American Board of Plastic Surgery. Based on these photos, it appears that the deep neck structures were not properly contoured (if at all). You can see the bulges from the submandibular glands and deep interplatysmal/interdigastric fat. You can also see some recurrent platysmal banding and skin laxity. I would recommend a revision deep plane facelift/necklift.

Hello,
I am sorry to hear about your undesired results. My first question after a face/neck lift when there is sagging skin is to ask if the deeper tissues were addressed properly? Typically a face/neck lift if done correctly should last 10-15 years before needing a revision. If the deeper tissue were not addressed that could be something you talk to your surgeon about. Best of luck!

It appears that the platysma muscle banding was not completely eradicated and that you have prominent digastric muscles which both need to be addressed. There also appears to be residual submental fat and the skin and muscle of the neck can be tightened a bit as well.

You definitely need a revision. It may be possible to do this through an incision under your chin only. However I think it needs a more extensive revision than that

You have multiple issues going on after your previous lower face and neck lift which include residual fat deposits underneath the platysma muscle in your neck, platysma cords, excess neck skin, and most likely prominent sub maxillary salivary glands. Make sure your facelift surgeon is comfortable addressing all of those issues