Can i get meth mouth from using vyvanse (lisdexamfetamine)?

No: "meth mouth" is the consequence of many factors associated with high dose amphetamine use. Vyvanse (lisdexamfetamine) at appropriate doses does not do that.

Definitely, no: Vyvanse (lisdexamfetamine) affects chemicals in the brain and nerves that contribute to hyperactivity and impulse control and has no effect on teeth. Meth causing cavities by xerostomia (dry mouth) and releasing toxic chemicals that damage the teeth.