Correction of asymmetric chin implant
Correction with soft tissue filler is a good idea. I would suggest to start with hyaluronic acid based one (Juvederm, Restylane, Belotero) because they can be corrected and resolved using enzyme hyaluronidase, if needed. Once your surgeon figures optimal volume and location, a more permanent filler (Artefill) or fat grafts may be used as a long term solution.
You should seek a consultation with a board certified plastic surgeon experienced in facial implants and discuss your options. Good luck.