Background and objectives : Bisphosphonates are used for treatment of bone metastases, multiple myeloma, osteoporosis and other bony diseases. Osteonecrosis of the jaw is a well known potential complication of bisphosphonate treatment.

Methods : We report on our experience in the Gregorio Marañón University Hospital with over 30 cases of jaw osteonecrosis in patients treated with bisphosphonates, working diagnosis, clinical presentation, treatment and a literature review.

Results : The majority of ONJ cases occurred in patiens suffering malignant diseases, received nitrogen-containing bisphosphonates intravenously. The most prevalent clinical feature was exposed necrotic bone accompanied with pain. A surgical approach is an effective treatment in the number of cases where other interventions fail or pathological fracture develops.

Conclusions : The findings in our patients, combined with the literature review, suggest that: the most clinical presentation is pain and exposed necrotic bone; conservative treatment is strongly recommended (occasionally radical intervention is necessary); a predilection on mandible; side-effect of long term intravenous nitrogen-containing bisphosphonate; factors that increased risk were female sex, oral surgery and corticosteroids administration; clinical dental examination should be performed before patients begin bisphosphonate therapy.

Key words: osteonecrosis; jaw; risk; bisphosphonate; treatment outcomes