Marcus gunn jaw winking phenomenon due to relation between which cranial nerves -

Congenital synkinetic ptosis (Marcus Gunn jaw winking ptosis). Jaw-winking ptosis is believed by most to be due to abnormal innervation of the levator muscle and not secondary to myopathic changes, so most histopathologic studies have revealed normal striated muscle. In this condition there occurs retraction of the ptotic lid with jaw movements i.e., with stimulation of ipsilateral pterygoid muscle. So there's mixing of fibres of 5th and 3rd nerve. Ref: AK Khurana 4thE pg356