Human growth hormone, testosterone, testosterone transdermal gel or DHT gel applied directly to the jaw....I know prolonged growth hormone excess thickens the bones of the jaw
Actually DHT can make the entire lower jaw grow, not just the chin. This could give a very aesthetically unpleasing squarish/oldish appearance.
So if somebody is popping DHT suppressors, then his jaw will ... what ?
nothing. let's safely assume your plates are already closed, since somebody is taking 5-ARi's and doing so during puberty is a big no no.
I've red somewhere that that "plates" thing doesn't really apply to face. Actually facial bones may enlarge/decrease/change shape if the stimulus is applied, like the one with an apparatus to relocate your teeth or change the shape of a "ridge" your teeth forms naturally..
Oh, and when you look at some of the professional bb'ers, who are on a high doses of hormones - some of them has quite an interesting changes in head/jaw/overall face size lol...