MedGen

The cleft lip is midway between the philtral ridge and the commissure of the mouth. The cleft is lateral to the normally shaped and placed nasal ala and passes onto the cheek. The cleft extends through the lower eyelid lateral to the punctum. The lacrimal system and inner canthus are normal. Microphthalmia may be present. The alveolar cleft passes between the lateral incisor and canine, as in the Number 3 cleft. The cleft passes around the pyriform aperture and continues through the portion of the maxillary sinus medial to the infraorbital foramen. The cleft terminates at the medial end of the inferior orbital rim. There is severe vertical soft tissue deficiency in a Number 4 cleft, with the medial margins of the cleft lip extending directly into the medially placed cleft of the lower eyelid. Within the medial segment of the right-sided cleft lip, muscle elements are apparently absent. Muscle bunching is noted in the ipsilateral lateral lip segment, as is seen in a typical unilateral cleft lip. The anatomically normal nasal ala is superiorly displaced in association with a severe deficiency in the overall nasal length. Marked dystopia of the right globe results in its inferior displacement into the medially deficient orbital floor and inferior rim. Both globes are otherwise normal. The complete palatal cleft passes through the maxilla medial to the infraorbital foramen and extends to the medial portion of the inferior orbital rim without evidence of an intact maxillary sinus. Bony septation persists medially, thereby separating the nasal cavity from the orbit, maxillary sinus, and mouth, which are contiguous. Marked midfacial hypoplasia is present. The cleft is manifest as asymmetry of the body of the sphenoid; it is smaller on the right, with asymmetric placement of the pterygoid plates relative to the midline. The orbital floor cleft has no communication with the inferior orbital fissure. The cleft does not extend to the skull base, but there is marked facial asymmetry associated with plagiocephaly. [from HPO]

Oblique facial clefts are a rare form of orofacial clefting, comprising about 0.25% of all facial clefts. Two major types have been described classically: nasoocular and oroocular, the latter of which can be subdivided into oromedial-canthal and orolateral-canthal (summary by Dasouki et al., 1988). [from OMIM]