What would be the best procedure for a defined jaw line like kylie jenner?

Liposuction of the neck is fantastic for contouring and shaping. ThermiRF/VASER Ultrasound can be used for skin tightening with the option of using implant/fillers/fat to shape and contour the chin as needed. See an expert for a consultation. Best, Dr Emer

Thank you for your question. Yes, I think laser-liposuction (Smartlipo) would be a very nice solution to improve the contour of your neck/chin area. It's a fairly short procedure (1.5 - 2 hours, so not exactly just "over the lunch hour"). There is minimal downtime and discomfort with it, but it really takes a solid 3 months before you will see the results. It is very safe and effective. I'd meet with a local plastic surgeon who offers that. Best wishes.

 Neck liposuction or a neck lift takes between 1-2 hours in order to perform correctly.  The procedure can be performed under local or general anesthesia depending upon the patient's desires.  This is not a lunchtime surgery, and  anticipate at least 2 weeks of visible bruising and swelling after the procedure.  This is real surgery.  The neck contains fatty deposits above and below the platysma muscle, so it takes surgery in order to remove both deposits.  When removing the deposits underneath the platysma muscle, the platysma plasty is also required.  For more information many examples, please see the link and the video below

Jawlines consist of an underlying bone structure and the soft tissue draped over the bone. Models/celebrity jawlines most often have a very positive bone structure with youthful natural overlying tissue. The key is the bone support. To that end, lipo is less ideal since it 'thins' the natural cushion soft tissue - focus on small but defined enhancement of the jawline/bone structure with thin implant strips. 

Liposuction under the jaw would take care of the subtle double chin.  However, microlipo of the face and jaw angle would be needed to better define the jaw.  Also, a chin implant would be a consideration.  Seek out a consultation with a board-certified surgeon.  Best wishes.