facial cleft A congenital abnormality consisting of an opening or gap in the face, which results from incomplete fusion of one or more of the embryonic facial prominences. ICD10:Q18.8 MONDO:0015411 NCIT:C124510 Orphanet:141229 SCTID:92821006 cleft face craniofacial cleft prosoposchisis rare head and neck malformation rare maxillo-facial surgical disease