Why Do I Have an Indent on my Upper Right Butt Cheek?

                 The most common things that would cause such an indentation would be trauma to the area and subsequent fat necrosis, post steroid injection, or post surgery, which is a kind of trauma. 

                  If the area persists and you want treatment, liposuction from another area and fat grafting to the indented area would be a viable option.

I have been very pleased with Sculptra as a way to fill out buttock indentations. I find that the procedure requires little to no downtime and is office based. I have done minor dimples to full buttock augmentations, albeit the latter is for people who want a modest augmentation and with little fat to donate. At times, if the indentation is associated with a scar, then subcision or a scar release may also be warranted.  The cause of these indentations can be trauma, previous surgery, steroid injections, or chronic pressure.

Hello dear!!
Thanks for the question and provided information as well.
Unfortunately, without pictures, it is very difficult to give you a proper answer. l recommend you to make an appointment with a board certified plastic surgeon to talk about your goals and anything you need to know.
Good luck :)

Indentation in the buttock area can be from trauma where you can get a bit of fat loss, or fat from the trauma can shift to an adjacent location, usually above the area of trauma. If that isn’t the case, an old intramuscular injection can create it. But usually there isn’t any other real reason to get a big indentation in the cheek area. But for treatment, options can include some fat transfer with liposuction of the surrounding area if the surround areas are more full, and fat transfer to mild indentation. This can be done with release of any scar tissue you may have in the underneath area. Second option is to have Sculptra injections to the area to gently lift up the depressed tissue.

It is difficult to answer your question accurately without photographs.  There must be something in the recent past that might explain why you have developed an indentation only on one side.  Recent buttock trauma, injection, infection or surgery might explain this new indentation.  I would consult with a board certified plastic surgeon to help determine the cause and the best treatment.  Best of luck!