Different First and Last Name

When I registered first, I typed my first and last name as Mohammad Gad, but my full name is MOHAMMAD ABDELWAHHAB HEMEDA GAD on my passport and medical diploma and transcript, so what's the best should I do? send a letter from the dean affirming that the name on the document "photocopy of my passport" and the name in ECFMG record belong to one and the same person?