What is the best size butt implant for a petite girl 4’11 90 lbs?

Other than placing buttock implants within the gluteus maximus muscle (aka “intramuscular”) NOT “subfascial”, the most important factors in creating the perfect derriere and/or hourglass figure with implants is indeed selecting the right size AND shape. I have found the best way to assure this is to simply measure the actual dimensions of the patient’s buttock cheeks and quantity and quality/density of the underlying gluteus muscles. With these anatomical measurements, I can select an implant that not only significantly augments the buttock but also supplies the correct 3-dimensional enhancement to look as real as possible...even in the most petite patients. Note, height and weight are considered but not nearly as relevant as the above measurements. Based purely on your photos, you would most likely be in about the 300 to 330 cc of the Stanton Anatomic oval shape buttock implant  Glad to help  

It is very important that you do not put an oversized implant in your body to start. This significantly increases the complication rate and often results in removal.  Many of these dramatically large implant before and after photos are taken immediately after the procedure and before complications occur. I see complications from other surgeons using the incorrect implant size every day.  please only seek advice from a board certified plastic surgeon who specializes in this procedure and Is well known for it.   

The more coverage you have for the implant the less palpable and less visible they are, in general.  Intramuscular implants can improve volume by 400 cc or so, depending upon the size of the individual. A significant amount above this volume compromises healing by creating more tension on the healing incision.  Measurements during an exam will help determine the size and the shape of implant.Kenneth Hughes, MD, ABPS Board Certified Plastic SurgeonLos Angeles, CA