Can I get sliding genioplasty without having straight teeth?

Thank you for sharing the photos. Yes, certainly. Genioplasty is one of the surgical procedures of the jaw that can be performed completely independent of your occlusion (bite) and will not affect it. It is also one of the procedures that is likely to give you most dramatic results from the aesthetic perspective. The issues highlighted in your photos, namely weak chin, soft tissue ptosis/excess at the chin point and fat deposition under your chin can all be successfully managed irrespective of your bite. And more importantly you are likely to get a much improved results.

Sliding genioplasty moves the bone of the chin forward to change the facial profile.   The shape and position of the teeth do not change.
It is not necessary to align teeth ahead of surgery.   Provided teeth are healthy and there is no gum disease the straightness or otherwise of the teeth is not important.

The condition of your teeth, particularly in regards to their alignment or occlusal relationship, is irrelevant for undergoing a sliding genioplasty procedure. The bone cuts for this procedure are done below the roots of the anterior teeth and do not affect the occlusion in any way. Thus you may move forward with the surgery at any time.

The condition of your teeth should not have an impact on having a sliding genioplasty. It would be really helpful to have better pictures to see if this is a good procedure for you. This needs to include a sideways to view showing I complete profile including your face. At least up to and including your nose. You can block off the eyes  to maintain anonymity.Better yet have a few in person consultations with board-certified plastic surgeon who have experience with this procedure. Alternatively you can talk to oral surgeons who do this on a regular basis.you’re certainly not old but Liposuction should be done with greater caution in people who are beginning to show slight skin laxity in this area.Fat removal tends to not hurt the skin in young people but can ass people get into their 50s. Obviously if the Liposuction is done poorly the results will suffer.Best, Mats Hagstrom MD