Which treatment would be best to fix my receding chin after braces: Chin implant or jaw surgery? (Photos)

You have a few options to improve the projection and symmetry of your chin. If you’re not sure you’re ready for surgery, but still want to improve and strengthen your chin, I’d suggest augmenting your chin with Sculptra and/or Voluma. If you like your new look, you can make it permanent with a chin implant. I hope that helps.

A Chin implant is only performed for cosmetic purposes to augment the chin foward.  It is performed under local anesthesia as an outpatient procedure which takes approximately 30 minutes.  If the teeth are significantly out  of alignment, then consider a sliding genioplasty performed by an oral surgeon under general anesthesia in the hospital setting with an overnight stay.  For many examples of chin implants, please see the  link below

 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 very weak and there is excess fat and skin 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.   I prefer placement of a  silastic chin implant through a small, curved incision under the chin (submental) instead of through the mouth for the following reasons:
*The submental approach is sterile while the intra-oral approach is not.
*The submental approach requires limited dissection as it is much closer to where the chin implant needs to be placed along the center (front) and lower most sections of the chin on each side (where the wings are placed).  The intra-oral approach by contrast requires dissection all the way down the entire section of the chin in order to reach the same areas for chin implant placement.  This leads to several issues in my humble opinion.  The attachment of the chin muscle to the bone must be cut during the tissue dissection, the sensory nerves (mental) and motor nerves (marginal mandibular nerve) that move the muscles of the lips and mouth) are all in much greater jeopardy of injury because of the added dissection required.
*The added areas of dissection with the intra oral approach allows upward migration of the implant as well as an increased risk of nerve injury.  Damage to a sensory nerve will create numbness and or an ache type discomfort while injuring the motor nerve will result in an inability to "lower" the corner of the mouth and lower lip.Hope this helps.

It is common for orthodontics to be combined with orthognathic/jaw surgery to correct an overbite. Some orthodontists just extract teeth to make the teeth meet; but that ignores the cosmetic viewpoint. If you are only 8 months into ortho, then talk to the orthodontist about jaw surgery and visit a Maxillofacial surgeon for proper analysis. Now is the time to do it.