How to get rid of butt dent? (Photo)

Believe it or not, this is very common. After trauma and a bruise, what can happen is that the fact that was injured in that area loses its blood supply and dies, resulting in a divot and the easiest way to treat this with would be with Fat Grafting similar to that of a tiny BBL,  

Allow me to answer your question as best i can based upon your photos. However, please keep in mind that an in-person, or at least a virtual, consultation with physical exam is first necessary before any legitimate evaluation or final surgical recommendations can be made.

Unfortunately I see this outcome from a hard fall onto the buttock not infrequently. Because, by evidenced by the dent, there is significant scar tissue left behind, fat transfer (aka BBL) does not survive well and fillers (eg Sculptra and hyaluronic acids) are a complete waste of money. So, the only reliable and permanent option is a buttock implant to pop out the dent and provide long term natural buttock convexity.

Please note that an extremely few number of board certified plastic surgeons specialize in buttock or hip implants, so you may need to travel far and away from home to find this particular surgeon. Glad to help.

It is very likely that deep scar developed between the muscle and the skin, as result of the injury, is creating this deformity. A complex procedure which will involve release of the scar and shaping of the area with fat grafts would be the most logical way to approach your problem. In person consultation with a board certified plastic surgeon with experience in fat grafting is recommended. Good luck.