Malformations of the zygomatic and maxillary regions.

The maxillofacial region develops during 3 to 8 weeks in an embryo. The process involves neural crest cell migration and proliferation as well as facial protrusion jointing and fusion. The maxillofacial region is one of the predilection sites of congenital malformations. We treated a 5-year-old Chinese boy with abnormal development of the left maxillofacial region. We describe in detail the patient's characteristics, diagnosis, and treatment processes and try to explain the possible causes of the disease.