What the fuck is wrong with your Sans?
If this is about the quick animatic "le poof" scene.
I intended to draw a DT fused state of a normal (slight overbite) human skull for sans.
As Sans slowly melt and crumble away, the DT fused with his joints will come apart and the bones themselves will literally collapse under lack of support before poof into dust.
The human skeleton is held up by tendons, muscles and ligaments. DT basically replaced whatever was there before Sans died in "Dust" for the first time.
To answer your other question:
My style is semi-realistic, I like to mix the original cartoonist style with some real life references.
Here's a short post on how I intend to draw my Glitchtale trios.
Quick doodles of the Glitchtale Skele trios and their realistic-ish skull portions. (I had this hidden in my draft bin for so long that now