In this video he says he started at 19, there is before pictures, and it looks like he had a pretty wide face and good jawline to begin with. 

https://www.youtube.com/watch?v=8NxVFJhN1Gw

I think that having a rather flat side is an Asian phenotype. In addition to looking good he looks healthy as well to me

You can see at the begginning that his swallowing is messed up.

he aint that bad developed wide palate what makes his face wider big skull with a compact face no sagging skin sharp jawline 

only thing is his maxilla and his face is a bit lengthing but overal he is looking good

As mentioned, Asian phenotype is different, plus fwhr is largely testosterone based so lower testosterone can cause a narrower face, and in general Asians tend to have lower testosterone levels

lower t levels won't cause narrow faces

narrow faces get caused by basd nutrition with high calories food and low vitamin food the body can't make enough bone at the critical points in the body like the ribs shoulders and hips they take nutrition from the jaw bone because the body knows that we can survive with a narrow and smaller but not with a weak rib case

also if you swallow with the buccinators they get bigger and those muscles will give more pressure inwards this makes the palate and so they face more narrow

Testosterone levels don't necessarily affect fWHR. However Asians in general seem to have narrow midfaces compared to Africans and Europeans (who have almost identical midface ratios)

The interpupillary distance in Asians looks smaller than Africans and Europeans IMO. They also seem to have a vertically long maxilla.