Congenital maxillomandibular syngnathia is an extremely rare disorder characterized by craniofacial malformations and inability to open the mouth adequately, which leads to problems with feeding, swallowing, and breathing as well as temporomandibular joint ankylosis. The main goal of the surgery is to release the ankylosis, establish functioning mandible, and prevent re-fusion. However, surgical procedures for this disease are rarely reported.

Here, we report a 7-mo-old girl with bilateral maxillomandibular syngnathia. The patient presented with difficulty in feeding, breathing, sounding, and swallowing and had developmental dysplasia. For treatment, we performed bone isolation by computer-assisted navigation and used silicone to fix the wound surface to prevent refusion of bone. To our knowledge, this is the only syngnathia case in the literature treated using computer-assisted navigation. With the guidance of precise navigation, we were able to minimize operation time by at least one hour, the patient's blood vessels, nerves, and tooth germs were well protected, and excessive bleeding was avoided. After six weeks, the patient showed improvement in mouth opening and no major issues of feeding.

Application of computer-assisted navigation can significantly improve accuracy, effectiveness, and surgical safety in correcting congenital maxillomandibular syngnathia.

• Craniofacial abnormalities
• Mandibular diseases
• Maxilla
• Computer-assisted navigation
• Case report