Congenital fusion of the maxilla and mandible (syngnathia) is rare and can present in a wide range of severity from single mucosal bands (synechiae) to complete bony fusion (synostosis). Congenital synostosis of the mandible and maxilla is even less common than synechiae, with only 19 cases reported in the literature. Most of them have presented as an incomplete, unilateral fusion. Only three of the reported cases showed more extensive but still incomplete, intermaxillary bony fusion. We present a case of complete bony fusion of the maxilla and mandible associated with a cleft palate, hypoglossia, micrognathia, unilateral choanal atresia, and limb abnormalities as a feature of oromandibular limb hypogenesis syndrome. Details of operative management are presented.