Cleft Lip and Cleft Palate By Simeon A Boyadjiev Boyd, MD, University of California, Davis Reviewed / Revised Sep 2022 View Patient Education Diagnosis Treatment Topic Resources Bilateral Cleft Lip Cleft Palate An oral-facial cleft is a birth defect in which the lip, the roof of the mouth, or both do not close in the midline and remain open, creating a cleft lip and / or cleft palate.