Hello This is involuntary action.for this u have to consult neurophysician

Get full mouth xray or opg to rule out the cause and plan treatment. You can consult through this for prescription of medication based on clinical findings

I would personally like to examine the patient's mouth to identify the exact problem. There could be several reasons why a patient clench and grind her teeth from neurological or muscle related or any local irritation. Until it is completely treated, I would suggest the patient to wear a thick soft splint that protect the teeth from the excessive force exerted by the grinding or clenching which would damage her teeth.