What is the differences between tardive dyskinesia and dystonia?

Both involuntary: Tardive dyskinesias are slow, repetitive, involuntary movements, most commonly occurring after use of neuroleptic (anti-psychotic) drugs. Dystonias are a kind of abnormal, involuntary movement, which occur when opposing muscle groups contract simultaneously.

Good question!: Tardive dyskinesia is an irreversible side effect of antipsychotics, consisting of usually involuntary mouth and tongue movements. Dystonia is contraction of agonist and antagonist muscles at the same time of the same joint; there are many different types of dystonia(cervical dystonia, blepharospasm, writer's cramp etc). Most are treated with botox. Thanks!