28 year old, slim with weak jawline and double chin. (Photos)

I would suggest either a chin implant or a volume replacement filler such as Voluma to augment your weak chin.  Kybella is a simple office procedure which can reduce your double chin.

I suggest beginning with an in-person consultation to discuss your options. During your initial examination, your #chin will be evaluated along with the neck and jawline. A weak #chin implies a lack of chin support for the skin along the neck line. In younger individuals a chin implant alone is usually all that is needed to improve the appearance of the neck. Subsequently, it will also improve the overall #balance of the face and can create the illusion of a smaller nose. As a stand-alone procedure, chin augmentation can be performed in the office under local #anesthesia. For individuals with signs of #aging in the neck, a chin implant added to one of the recommended procedures above, will provide optimal results. Also, #liposuction under the chin is also another option your doctor can discuss. If you are not a candidate for chin or neck rejuvenation at the time of your #consultation, your board certified plastic surgeon can recommend alternatives to address your concern. 
However, there may be additional options to improve the appearance of your concern to improve the overall balance of your face. Such can be best evaluated in-person. Consulting with a board-certified plastic surgeon who specializes in #face, #neck and #chin procedures is important to ensure you are receiving the best advice, care, and surgical experience possible.

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 needs to be combined with thermage/ultherapy/exilis or coolsculpting for good results. A chin implant would give more definition. I recommend getting a formal evaluation with a facial sculpting expert. Best, Dr. Emer

Hello dear
Thanks for the question and provided information as well. 

Based on your photo you are a good candidate for chin liposuction,
Chin liposuction can be an option, it makes you look younger and more
attractive with a sharp jawline , and better facial proportions.It is
important evaluate your pictures or a personal evaluation in order to
give you the best option for your case. 
I recommend you to make an appointment with a board certified plastic
surgeon for a good evaluation and to talk about your goals.
Good luck :)

There are some non-surgical means of improving this such as Kybella or Ulthera but I think you'd be best served with maybe a medium chin implant with laser assisted liposuction underneath the chin and jaw (I use SlimLipo).This can be performed under local anesthesia with around 7-14 days of down time.  Best of luck.Chase Lay MD

Good Day.
Thank you for the photographs, including an excellent lateral view. 
Photographic assessment reveals that you have a deficient lower jaw (mandible), some minor excess skin and fat. 
Treatment Recommendations:
Addressing the deficient chin will most likely resolve all of your issues. The placement of an extended anatomical chin implant can be done under oral sedation and local anesthesia with or without intravenous sedation. Alternative anesthesia is general anesthesia where you are completely unconscious.
Proper size chin implant can be assessed by morphing your photograph to show you the appearance with a chin implant in varying the anterior projection of your chin. A lateral face Xray can also help determine the size prior to surgery. In the procedure room, a template of different sizes is also used to finalize the correct size implant for you. 
The chin implant is a permanent cosmetic treatment with a low risk profile and high patient satisfaction.
If the final outcome still reveals some excess skin, skin tightening procedures such as noninvasive skin Radiofrequency (RF) may be used on the neck and lower face area. 
I doubt you have much excess fat, however, fat reduction alone can be attained with an injectable fat absorption chemical know as Kybella (deoxycholate). This does not cause skin tightening. 
combined skin tightening and fat reduction can be accomplished with ultrasound (VASER), which I prefer or Laser liposuction. Both of these techniques provide more skin tightening than standard suction-assisted liposuction.
In summary, I believe a chin implant alone will optimize your cosmetic appearance. If excess skin and/or fat in your neck produces an aesthetic concern after surgery, a variety on both invasive and noninvasive devices can be used to further improve your cosmetic appearance.

 Hi, I have performed many facial shaping procedures, including Chin Augmentation with dermal fillers or silastic chin implants, for over 30 years.  From the photos, your chin is weak as are the back portions of the jaw line and there is some excess fat under the chin.  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".  
 Proper placement of a 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 (requires extensive tissue dissection, bone cuts and placement of metal screws and plates to secure the cut segments of bone).  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.  
 The back portion of your jaw line is a bit weak and can be augmented, without making your face appear masculine, using precise placement of a dermal filler (I prefer using Restylane Lyft).
Hope this helps.