Which procedure would give me a more defined chin and jaw? (photos)

A few small things together would add up to a great result in you. A small chin implant, a very specific filler to help accentuate the mandibular angles and border, and submental liposuction would really sharpen your jawline while still looking proportional and natural.

You have a deep mentolabial fold which indicates that your chin is short in the vertical plane. I would recommend a sliding genioplasty to lengthen your chin with a slight advancement. This is done simultaneously. A chin implant would deepen the fold and does not provide an increase in height.