I have deep mentolabial sulcus, and wanted to find out what I can do to fix it? (Photo)

A deep labiomental sulcus can be improved by the use of fat injection grafting or an actual subcutaneous implant. With chin augmentation the labiomental sulcus will become deeper no matter if it is done with an implant or a sliding genioplasty. The labiomental sulcus will really need to be treated if chin augmentation is done as that concern will become magnified if you do not.

I believe chin augmentation would not resolve the issue. You might want to have an xray (ceph) of your face to determine the cause. Orthodontic and jaw advancement could be the best option.

The reason for the fold relates to factors such as " overbite" and facial height. You can mask this appearance with a  sliding genioplasty that increases the height appropriately and perhaps uses small amount of implant materials to ensure a smooth contour. Quite common in my experience.