Chin implant, sliding genioplasty or jaw surgery? (Photo)

In the photos you have a very recessive chin which requires a significant forward advancement. Genioplasty surgery is an office procedure whereby your natural chin can be advanced up to 10mm. Silicone chin implants are preferred for smaller advancements of 5-6 mm. With a genioplasty, the chin bone and all the natural chin attachments (muscles, skin, and fascia) are advanced and there is no risk of resorption of bone as there is with a chin implant. Jawline liposuction can be accomplished simultaneously. There is no need for jaw surgery if you are happy with the alignment of your teeth.   

Sliding genioplasty is an extreme surgery that I don’t recommend unless you have functional issues. To fix the cosmetic problem of a weak chin, a chin implant would give you the correction you want. You must find an expert facial plastic surgeon to help you with this. I hope this helps

Based on your photos it appears that you would really benefit from a chin implant and liposuction of the under chin area such as in the example linked below.  Choosing the correct implant can also help make the lower face appear less chubby.

 Placement of a chin implant can augment the mandible forward to help significantly with facial balance  and proportions. Chin implants are manufactured in a large array of thicknesses, sizes, and shapes, which is usually determined at the time of the examination and consultation. In our practice, we place the chin implant through small incision  under the chin under local anesthesia as an outpatient procedure. Liposuction of the fatty deposits in the neck can be accomplished at the same time and is complementary to the chin implant procedure. For many before-and-after examples of both procedures, please see the link and the video below

Your lower jaw is quite underdeveloped genetically and the orthodontist could have combined  braces with a lower jaw advancement surgery. At this point if you have an overbite you still have that option which is better than a genioplasty alone for getting the best result. Alternatively you could have a genioplasty but not an implant in the chin since the pressure from the chin muscle and lips would press the implant back into the bone. Also a genioplasty will better flatten the area under the chin.

 Hi, I have performed many facial shaping procedures, including Chin Augmentation with dermal fillers or silastic chin implants, for over 30 years.  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.  
Hope this helps.