RESUMO
Periostitis ossificans (PO) is a type of chronic osteomyelitis, an inflammation of cortical and cancellous bone. In the maxillo facial region, the mandible is most frequently affected. The cause of inflammatory subperiosteal bone production in PO is spread of infection from a bacterial focus (e.g.: odontogenic disease, pulpal or periodontal infection, and extraction wounds). This pathology is most commonin younger people (mean age of 13 years). Conventional radiographs are one of the most usefultools for diagnosis, but in some cases computed tomography (CT) has a key role in both diagnosis and identification of the tissues involved. This paper reports two cases of PO in which CT help edestablishing the suspicious etiology: a 12-year-old boy with PO of pulpal origin and a 14-year-old boy with PO of periodontal origin.