Osteonecrosis of the Jaw Induced by Orally Administered Bisphosphonates

Osteonecrosis of the jaw (ONJ) is a well-known devastating side effect of bisphosphonate therapy for cancer. Several ONJ cases of patients using oral bisphosphonates have been reported in the literature. A study published in Osteoporosis International analysed the clinical features, predisposing factors, and treatment outcome of 11 patients with oral bisphosphonates-related ONJ.

Osteonecrosis of the jaw (ONJ) is a well-known side effect of parenteral bisphosphonates therapy. Although ONJ has been reported in patients using oral bisphosphonates, documentation of this entity is sparse. Researchers hypothesized that the clinical features, predisposing factors, and treatment outcome of this population are different from those of oncologic patients. Reserachers performed a retrospective bi-central study that involved 98 ONJ patients, 13 of whom were treated with oral bisphosphonates. Two patients were excluded because of previous use of intravenous bisphosphonates. The profiles of 11 patients were analysed. The mean duration of alendronate use before developing ONJ was 4.1 years. ONJ was triggered by dental surgery in 9 patients and by ill-fitted dentures in 2. Heavy smokers were the most recalcitrant subjects. Among the nine patients with at least 6 months of follow-up, ONJ healed completely in three, partially in four, and not at all in two. ONJ is a rare devastating side effect of oral bisphosphonates associated with patient morbidity and high financial burden. The study concluded that clinicians must be aware of this entity and inform patients of the risks of dental surgery, and that the synergistic effect of smoking in the pathogenesis of ONJ should be further investigated.(Source: Yarom N, Yahalom R, Shoshani Y et al. Osteonecrosis of the jaw induced by orally administered bisphosphonates: incidence, clinical features, predisposing factors and treatment outcome. Osteoporos Int. 2007 Jun 28 : Jul 2007)