The temporozygomatic Number 7 cleft is found in both Treacher Collins syndrome and hemifacial microsomia. Soft tissue manifestations include macrostomia, malformations of the external and middle ear, temporalis muscle, variable involvement of the seventh cranial nerve (in hemifacial microsomia), and abnormalities of the preauricular hair in Treacher Collins syndrome. The skeletal cleft is through the pterygomaxillary junction, and vertical maxillary hypoplasia is present. In addition, abnormality of the mandibular ramus, coronoid, and condyle and absence of the zygomatic arch are typically present. A soft tissue furrow extends from the macrostomia laterally and superiorly across the cheek toward the preauricular hairline. The lower eyelids are intact. The anatomy of the external ear is normal, and there are no preauricular tags. Bony clefting is through the pterygomaxillary junction with hypoplasia of the alveolar process in the molar region, thereby producing a posterior open bite. The maxilla is hypoplastic, although the maxillary sinuses are symmetrically pneumatized. The hypoplastic zygomatic body arches upward, but then it takes a downward course and is severely malformed and displaced. The zygoma is continuous posteriorly with an apparently normal zygomatic process of the temporal bone. The mandibular condyle and coronoid process are hypoplastic and asymmetric. There is no antegonial notching of the mandible. Marked cranial base asymmetry, with tilting and asymmetric positioning of the temporomandibular articulations, is present. The anatomy of the sphenoid is abnormal, especially on the right where there is no recognizable medial or lateral pterygoid plate. [from
HPO]