Common symptom of a cocaine-abuser aka coke-head. Inability to stop moving their jaw and not STFU. Grinding their teeth or moving their jaw in a strange manner when talking or standing also applies.
If someone is a coke-head you can tell by their constant sniffing, obnoxiousness , slutiness , paranoia , drama-starting , and coke jaw.
Harvey : Dude, what happened to Vanessa? She used to be so sweet and wholesome before she went to college...I heard she got gangbanged last week by the entire rugby team...
Tony : yea bro....she started hanging out with these sketchballs and lost all her self-respect... She used to be so beautiful then.....she's just a coke jaw noww.....hooo hooo hooo hoo hoo hoo hoo hoo hoo