Marcus Gunn jaw winking synkinesis: report of two cases.

Marcus Gunn jaw winking synkinesis (MGJWS) is caused by congenital miswiring of a branch of the fifth cranial nerve into the branch of the third cranial nerve supplying the levator muscle. It has been observed in 2-13% of patients with congenital ptosis. Although bilateral cases were reported, most were unilateral and occurred more frequently on the left side than the right. We report two cases of children who presented with ptosis and were diagnosed with MGJWS.