Now meeth are official, at least in the Urban Dictionary, "Contraction of meth and teeth. The rapid discoloration, deformation and decay of the teeth caused by chronic use of methamphetamine. Research indicates the primary causes for meeth are (i) erosion of the tooth enamel caused by the use of caustic agents in meth, such as battery acid, (ii) dry mouth caused by meth use, which prohibits saliva from secreting, and (iii) the tendency for meth users to crave sugar-rich drinks while high.

"Although similar in appearance, meeth are not to be confused with the acidic erosion of the teeth caused by the habitual vomiting of bulemics.

"'Although the adult actress had perfect hair, professional make up and had a new outfit, those meeth dangling from her gums proved she was still an addicted porn skank.'"

So... too much meth s up your mouth, but it's not the same as ing too much.
http://www.urbandictionary.com