The MG Manual has a section on dental care for the MG patient:

Consultation with the patient’s neurologist is recommended prior to dental treatment in order to ascertain the extent of neuromuscular weakness, frequency of neuromuscular exacerbations or crises and to discuss the need for medical management to optimize the treatment outcome in the unstable patient.

Myasthenia Gravis: A Manual for the Health Care Provider (PDF) - page 100

Be sure both your neurologist and your dentists understand the issues involved with MG patents and dental care.

-Mark-