Would a sliding genioplasty be for me?

Good afternoon! I am writing because I am very self conscious about my small/weak chin and lack of a jaw line. I think it makes me look like I sort of have a double chin no matter how much weight I lose. I have tmj, which I am in the process of getting treated with splints. Should I get the sliding genioplasty before or after my tmj has been resolved? Or should I consider something else such as chin/jaw augmentation? Thanks!!!