Superimposed infection in mandibular osteoradionecrosis: diagnosis and outcomes.

Background: Radiation therapy can result in osteoradionecrosis (ORN) and mucosal ulceration predisposing to infection.

Methods: Fourteen patients presenting with infectious sequelae related to mandibular ORN were retrospectively reviewed.

Results: In most patients, infection followed diagnosis of ORN; but in 4 patients, ORN was not diagnosed until after the time of infection and imaging. An early imaging finding of ORN was lingual cortical defects near the last molar. Pain followed by erythema, purulent drainage, and subperiosteal abscess by imaging were the most common signs of infection. In most patients, conservative management eventually failed and segmental mandibulectomies were required.

Conclusions: Soft tissue infection with characteristic bone findings such as subperiosteal abscess and cortical bone erosions helps to distinguish infected ORN from recurrent tumor or sterile ORN. In patients previously treated with radiation who present with infection, pain or an avid PET scan with bone involvement, the mandible should be scrutinized.