Large indent on left buttock bikini line area

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 :)

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.

Without a photo or the necessary physical exam, my first guess would be autologous fat transfer to fill the dent naturally and evenly.  If the dent is tethered in any way then scar tissue release (a.k.a. subcision) may be required as well.  The procedure may even be done under local anesthesia +/- twilight sedation to avoid the extra recovery of general anesthesia.  Glad to help.