[en] Congenital bony fusion of the maxilla and mandible is a rare condition. Two classifications were previously proposed dealing exclusively with craniofacial malformations. Most of the reported cases to date represent either aglossia-aclactylia or hemifacial microsomia syndromes. We report a young girl with bony syngnathia associated with multiple defects (severe microcephaly, coloboma, vertebral segmentation defects), growth and mental delay. This patient is very similar to the patient described by Dobrow in 1983 and confirms the existence of this extremely rare disorder. (C) 2004 Lippincott Williams Wilkins.