What are my surgical options for an undefined philtrum? (photos)

Since I can see your philtral columns in your photographs, please consider re-asking your question, perhaps with arrows, to explain exactly what you are looking to achieve. You also have a lovely smile. I hope this helps. Sincerely, Dr Joseph

fillers and threads can be used in this area, I suggest you see an expert and start lip pumper products to give your lip more volume and shape (see link).  Best, Dr. Emer.

The first thing to try would be to inject the philtrum with some superficial HA fillers. Easy to do , it can be reversed if you don't like it and it should last 6 m to a year.