Sculptra for buttock indentations
I would recommend that you consider surgical fat grafting or Sculptra to help fill in the indentation. The advantage of Sculptra is that is a quick office-based procedure and the recovery is very easy. I would visit with a plastic surgeon who has experience with Sculptra for off-face regions of the body who can help you with your concern.
Kenalog fat loss
Kenalog injections can cause tissue atrophy, including thinning of the skin and fat loss. Fat can be injected into the area to improve the depression.
Dent in buttock caused by Kenalog?
It is true that kenalog injections can cause some deep natural fatty tissue loss at the site that it was injected at. This is not always predictable. There are other causes however for contour irregularities including a hematoma. Discuss this with your plastic surgeon. Treatment may consist of further fat transfers.
Kenalog can cause the fat to dissolve where the injection is.The dent you have after kenalog injection is due to fat necrosis. Wait a total of six months to make sure all the effects of kenalog is finished. Then can consider fat transfer to the dent. May need more than one session of fat transfer