I'm 20 years old and I get a double chin when I smile. What can I do about it? (Photo)

You have a few options. I find that VASER liposuction in combination with ThermiRF are best for contouring the chin in those who are candidates but Kybella can be used as an alternative and gets better results when combined with thermage/ultherapy/exilis or coolsculpting. I recommend getting a formal evaluation with a facial sculpting expert. Best, Dr. Emer

Liposuction of the fatty deposits in the neck can accomplish removal of them and increase the definition in the jawline. The small crease that is present with animation can be released through a small incision underneath the chin. If there is extra fat located underneath the platysma muscle,  a surgical neck lift is required to remove that. No skin removal was required on patient's less than 50 years of age. For more information  and many before-and-after examples, please see the link and the video below

Hi, I have performed many facial shaping procedures, including Chin Augmentation with dermal fillers or silastic chin implants, for over the 30 years.  From the photos, your chin is very weak.  When the chin is weak, this creates an imbalance making the nose appear larger, the mid face top heavy, the lower face looks short, de-emphasizes the lips and allows early formation of a "double chin".  
 The silastic chin implant adds forward projection to the chin thereby creating harmony and balance to the lower face.  Using the same incision, liposuction can be performed to reduce the fat and further shape the neck.  Excess skin, from below the chin, can also be removed through the same incision.  
 I have found that placement of a silastic chin implant, through a small curved incision under the chin (also allows excess skin removal) to be very safe, quick, highly effective and far less invasive than a sliding genioplasty.  I perform chin implant surgery in 30 minutes or less, often using a local anesthetic alone.  In my opinion, you are a good candidate for chin implant surgery.  However if liposuction under the chin was performed alone, this would not add forward projection to your chin to correct the "weak" chin.Hope this helps.