Swelling is common after liposuction and you can expect to have some for a few weeks after your surgery. Most of it will resolve a in a month or two.Ask your surgeon about massage, as it may help any contour irregularities.
This full area beneath your chin after liposuction is just healing tissue. You should still wear your garment to help control the contour. Within three months this should improve your contour should be readily seen.
Earl Stephenson Junior MD DDS FACS
Recovery after liposuction under chin
It is not unusual to have a firm feeling under the chin 10 days after liposuction to the area. This is normally part of the healing process but it will take several weeks to several months before seeing improvement. I would give it some more time to heal and the issue should improve. If you don't feel that it is improving you should contact your surgeon.