Can I have a sliding genioplasty (I was told my chin was too short)? (Photos)

Hello, I'm writing this because I just had a consultation with a maxilo facial surgeon who told me it was impossible for me to have a genioplasty since my chin is too short, and does not have enough height. To be honest, I've done my research for years and it's not something I've heard about, so is that something that can occur ? Also, the surgeon offered to put a titanium chin implant instead, but it doesn't seem common, has anyone ever go through it ? Thanks