[The interesting case -- case no. 65].

Bilateral Osteomyelitis following frontal sinusitis is a rare complication in the antibiotic era. The main risk of a progredient course is mainly the formation of external subperiostal, epidural, subdural abscesses or brain abscesses with potentially life-threatening complications. This is a report on a patient who presented in our department with progredient cephalgia and swelling in the area around the glabella and frontal sinus. Macroscopical examination revealed septum deviation to the right side and nasal polyposis of the right nasal passage. A computed tomography of the paranasal sinuses showed subtotal soft tissue obstruction of all sinuses with the exception of the sphenoidal sinus. Bilateral osteolysis of the ventral osseous borders of the frontal sinus with accompanying osteosclerosis was also observed. The therapy consisted of radical frontal sinus surgery via Unterberger approach. This case demonstrates a rare case of bilateral frontal osteomyelitis together with the necessary diagnostic and therapeutic measures. The management consisted of the removal of all osteomyelitic bone and antibiotic therapy. Differential diagnostic procedures must be carried out in order to exclude orbital and intracranial complications. Regular follow-up examinations and a CT scan of the paranasal sinuses are part of the standard therapy.