A case of severe infectious arthritis of the temporomandibular joint extending to the mesocranial floor in a child

Infectious arthritis of the temporomandibular joint (TMJ) is rare in pediatric patients.Here, we describe a severe case of infectious arthritis of the TMJ extending to the skull base in a child.A 10-year-old girl was referred to our department with the chief complaint of fever and pain in the right cheek and temporal region.Extraoral findings included swelling and tenderness in the right preauricular area, and intraoral findings included an open bite in the right molar region with trismus.Blood test results showed a high white blood cell count of 10,530/ L and C-reactive protein levels of 9.23 mg/dL.Contrast-enhanced computed tomography showed abscess formation in the right TMJ and extensive bone destruction in the sphenoid pterygoid process.The right TMJ was punctured, and pus was aspirated.Antibiotic treatment was initiated on the first day.Fusobacterium nucleatum was identified in the bacterial cultures.After five weeks of antibiotic treatment, the inflammation improved, and the patient was discharged.The infection was suspected to have spread hematogenously from gingivitis in the right maxillary canine region.Considering the possibility of TMJ ankylosis and developmental sequelae, long-term follow-up of pediatric patients with infectious arthritis of the TMJ is warranted.