What can I do to fix my mentolabial sulcus? (photos)

Thank you for your question. Over the years, I have tried to fill this with every product known and failed. More recently, I have performed fat transplantation with complete release of the tethering attachments with huge success. It is a small procedure with a big upside. I don't know any one else who is doing it, but it is a common issue. Best wishes to you.

The Lakeville mental Angola is primarily based on the relationship between the mentalis part of the mandible and the dentition in the mandible. soft tissues have less to do with this and it’s really the relationship between your lower teeth especially your incisors and the amount of projecting bone below them in your chin.
A chin reduction will improve the angle and your sulcus but is a fairly involved procedure.
While your picture shows the circus well it does not give us sufficient information to make a good assessment.
To make an assessment we need to see full facial pictures showing a front view and a profile view of the entire head.
Based on your picture your upper lip has more forward projection than the lower lip. Most likely this is due to having a mandible whose body is insufficient in projection but the mentalis or chin may have excessive projection.
It’s possible to have a mandible that’s both too big and too small at the same time just in different areas.
Advancing the mandible behind your teeth (jaw advancement) while reducing your chin is probably the ideal correction but most likely involves more surgery than most people are willing to undergo.
I suggest having a few consultations with local oral surgeons or plastic surgeons with craniofacial fellowship training.
Adding conservative amounts of filler in the sulcus can help slightly.
Best,
Mats Hagstrom MD

From the limited image it appears you have a reduced bone dimension of the chin/lower jaw. It is often associated with a deeper bite. If orthodontics and jaw surgery are not a focus then a vertically lengthening genioplasty will improve the contours