Partial duplication of the face: case report and review. Complete or partial facial duplication is a rare congenital malformation. A spectrum of structural abnormalities varying in degrees of severity has been described in affected individuals. We present discordance for facial duplication between monozygotic twins in which maxillary and mandibular duplication was present in one. The involved twin showed the following findings: ocular hypertelorism, bifidity of the nose, duplication of the maxilla, macrostomia, cleft of the lower lip, hamartoma of the vomer, supernumerary teeth, duplication of the mandibular teeth, bifidity of the tongue, and hamartoma of the floor of the mouth. Surgical management of the facial anomalies is discussed. A review of the literature and discussion of this rare malformation are presented. 