How can I fix dents on my butt cheeks? (Photo)

Typically the best option in circumstances such as yourself is to have (your own) fat transfered from one part of you body into the individual dents to smooth them out. Several sessions of fat transfer will likely be required to achieve the best result. Glad to help.  

The dents in your butt cheeks that were caused by injections as a child more than likely have scar tissue from deep inside, pulling the skin inward.  If you were my patient, I would initially do a release of these dents using a pickle fork (surgical instrument) followed by fat grafting from some other area of your body.  This improves but does not get rid of these dents.  Again, in my practice, once the majority of the dent has been corrected, I use Sculptra to finish off these depressions and give a smooth appearance to this presently unattractive area.  

If you don’t have fat for a buttock enlargement, then the only option left for you is implants. The other option which you might consider is having a synthetic fillers. However synthetic fillers may need a lot of volume which will be very expensive. Implants can be a good option. Consult a board certified plastic surgeon near you who can guide you further. 

I recommend "subcision" therapy combined with some fat grafting.  Almost like a Brazilian butt lift but with additional release of the dimples and cellulite either with a special cannula during the procedure or with a wire dissector.  Check in with a board certified plastic surgeon familiar with Brazilian Butt Lift surgery.  Best Wishes!!

Many thanks for your question. Fat transfer using your own fat harvested from another area can be used to help improve these indentations you have. They can be due to damage to the underlying fat caused by steroid injections and by certain vaccinations. Be reassured improvement is possible and I would advise seeing a fully accredited plastic surgeon with experience in the area.
All the best,
Jonathan

Hello dear!
Thanks for the pictures and provided information as well.
Based on your photos, you are a good candidate for fat transfer or butt implants to fix your problem, and I think you'll get very good results. 
l recommend you to make an in-person consultation with a board certified plastic surgeon for a proper answer and to talk about your goals and anything you need to know.
Good luck :)

Good day,Thank you for providing photo reference. Fat from different regions of your body can be harvested, reinjected and sculpted into your buttocks to help fill out any indentations you currently have. Please consult with a board certified plastics surgeon who has an extensive expertise on this surgical procedure. Best of Luck to you 

 These are classic vaccination deformities. In some countries, vaccines are mixed with metallic salts as preservatives. When inoculated into small children they create a scar track which causes puckering and depressions. This is seen quite a bit —- it is easily treated with fat grafting. I have attached a website for your review. Best regards,