The Loss of Symmetry in Unilateral Bony Syngnathia: Case Report and Literature Review

Congenital syngnathia is a very rare condition of unknown etiology with multiple clinical manifestations due to different combinations of bony or soft tissue adhesions between the mandible and maxilla. It shares possible association with other congenital anomalies in the head and neck region, or with other syndromes. The aims of the present work were: (1) to perform a literature review on bony syngnathia in order to obtain a general framework on epidemiology and management protocol; (2) to describe a case of a two-year-old boy with a left unilateral bony fusion treated with a distraction protocol of three months. Original articles were searched through PubMed, Cochrane Central database and Embase with a cut-off date of June 2022. In total, 94 articles were identified through database searching. After 39 exclusions, 55 articles were included in the review process. Eighty-seven cases of bony syngnathia have been reported from 1936 to 2022, and different classifications have been suggested in terms of location, extension, functional outcomes and management protocol. Complications may range from feeding difficulty to aspiration pneumonia and respiratory arrest. Early surgery is generally required to release the ankylosis and to establish good mandible function.