My chin significantly protrudes forward, what can be done to make my chin look more flat and more subtle ? Thank you! (photo)

With a normal chin at rest and then one that sticks out when smiling, that is know as a hyperdynamic chin pad ptosis. You are correct in that it is primarily a soft tissue issue and a dynamic one. Since surgery is a static operation, it is a bit tricky to know how much of the soft tissue chin pad to reduce. But an external submental excision technique is the correct approach.

your chin is slightly large. By doing sliding genioplasty, chin can be pushed back. The operation takes 1 hour under general anesthesia.