[Primary-chronic osteomyelitis and fibrous dysplasia of the mandible in children. Differential diagnosis and treatment].

Objective: The aim of the study is differential diagnosis of primary chronic osteomyelitis (PCO) and fibrous dysplasia (FD) of the mandible.

Material and methods: A retrospective comparative study of the case histories of 36 patients with PCO (average age 8.9 years) and 12 patients with FD (average age 8.5 years) who were treated at the Department of Maxillofacial surgery of the RCCH in the period from 2015 to 2023 was conducted. The features of clinical manifestations were evaluated: pain, swelling of soft tissues, trismus of the masticatory muscles, bone deformity, numbness of the lips, increased skin temperature in the area of lesions. The condition of the bone structures was assessed according to both panoramic radiographs and computed tomography (CT) scans. The bone structure, involvement of the condyle of the mandible, tooth displacement, displacement and width of the mandibular canal were evaluated.

Results: Both study groups were dominated by girls (PCO 1:2.6; FD 1:1) and unilateral jaw lesion (PCO 1:1.31; PD 1:1.4). Patients with PCO mainly complained of pain (94.4%), soft tissue edema (100.0%) and masticatory muscle trismus (100%), while patients with FD had no pain and an increase in volume of bone (83.3%) without trismus. Computed tomography of patients with PCO showed the formation of the subcortical bone, lysis of the cortical layer, dilation of the mandibular canal on the affected side, whereas in patients with FD, moderate or pronounced bone swelling, a well-defined cortical layer, displacement of teeth and the mandibular canal from the node of FD were mainly observed.

Conclusion: The data obtained emphasize the importance of clinical and radiological signs in various diseases. Pain, edema, formation of the subcostal bone, unilateral expansion of the mandibular canal, the clarity of the boundary of the cortical and medulla and the continuity of the cortical bone are the key points allowing for the differential diagnosis of these conditions.