So I have what is probably retrognathia, and this is what my orthodontist said it was, or retrogenia (I'm 18 and I'm done with braces). I have an overbite and lip incompetence. In these images, I have kept my upper lip closed in order to avoid mentalis strain, which makes my chin appear smaller.

In regards to mewing, tongue posture has been something that I've always done. When I read about it, I didn't notice but I realized that my tongue had been pushed up against my alveolar ridge and all along the back since as far as I can remember. This is likely what contributed to my having developed jaw bones, along with my affinity for gum and beef jerky. In addition, my palate was wide enough for my orthodontist to decide that my wisdom teeth did not need removal.

But alas, I'm pretty sure it's bad genes that caused this tragic lower facial development. From the front it isn't obvious because my face isn't narrow, but from the side my jawline magically vanishes, and can only be seen from a front angle. And then of course my chin is severely recessed.

I have also heard someone mention that Mike said if your palate is wider than 38mm or something that mewing does nothing? And my palate is 41mm.
When ever I hard mew, the chin muscles contract and form a bulge. Wonderful.

Is it my bad neck posture? Will mewing make a difference or should I just get a chin implant/genioplasty? as much as I want to avoid it. Also it's not a fat issue since I'm skinny.

So in the first pic that's normal side view. The second is when I simulate my mandible being brought forth-seems to be a slight improvement. The third is front view.

Imgur