I was born a Pierre Robin Sequence baby and have a very under developed chin/jawline. I'm not sure which surgery would suit me?

Thank you for your question. I am a surgeon with a cleft lip and palate team and we treat many patients with Pierre Robin Sequence. This medical problem is most often covered by your medical insurance, unless you are under California Children Services and you over age 20. With Pierre Robin Sequence, the chin is very small and I prefer to perform a genioplasty to advance the chin as much as possible. Simultaneous liposuction is also a common procedure performed at the same time. The surgical genioplasty is performed in our office under IV sedation and there is no need for hospitalization. You can expect recovery to take up to a week. 

Dear mlargey3,it is hard to tell without an examination. I would suggest you to consult a board-certified plastic surgeon. Only after a thorough examination you will get more information and recommendations. Daniel Barrett, MD, MHA, MS 
Certified, American Board of Plastic Surgery  
Member, Am. Society of Plastic Surgery

 From the one very limited photograph, it appears that there is weak and recessive chin profile along with fatty deposits in the neck. As  long as you are at your ideal body weight, liposuction can remove the fatty deposits in the neck. Consider a chin implant  to augment the chin  forward for cosmetic purposes. Both procedures are complementary to each other. For many examples of both procedures,  please see the link and the video below

The specific pattern of jaw growth with Pierre Robin does require significant management to obtain a well defined jawline. Firstly, you have to review the bite and determine any treatment you prefer. Secondly, the lack of projection is only one dimension so the 'width' for example is important to the final contours. Typically you could consider only cosmetic improvement with a genioplasty and jawline augmentation as a good approach. Insurance won't assist for esthetic improvements.