Osteonecrosis of the Jaw
Osteonecrosis of the jaw is a rare disease. It is generally induced by bisphosphonates treatment for patients with cancer or osteoporosis and is mainly caused by
- excess bone turnover suppression,
- impaired vascularization, and
- bone infections.
The majority of cases of osteonecrosis of the jaw are related to the treatment of cancers, including intravenous administration of bisphosphonates. Some rare cases are also related to the treatment of osteoporosis. Osteonecrosis of the jaw occurs mainly after a local trauma and surgery, but sometimes may occur spontaneously without any bisphosphonate medication. In case of osteonecrosis, jaw bone becomes hypovascular and hypodynamic because of the action of the antiresorptive bisphosphonate treatment, and is no longer able to repair correctly after a mechanical stress or an infection.
Osteonecrosis of the jaw is generally represented by following clinical symptoms:
- Exposed necrotic bone, generally in the mandible, but sometimes in the maxilla or palate
- Necrotic lesions that are slow to heal
- Swelling, both with pain or without pain
- Bone infection such as osteomyelitis.
Osteonecrosis of the jaw generally occurs after a long therapy and is associated with a 38.7-month mean duration of bisphosphonate treatment. Radiographic imaging or magnetic resonance imaging confirms the sites of jaw osteonecrosis. The pathogenesis consists of an altered bone remodeling with suppression of the normal cycle of bone resorption and formation due to the bisphosphonate treatment (Raje et al. 2008).
Some jaw osteonecrosis risk factors are as follows:
- Duration of bisphosphonates therapy
- Dental disease or infection
- Corticosteroid use
- Advanced age
- Dental procedure or extraction
- Administration of bisphosphonates intravenously
- Poor oral hygiene
- Alcohol abuse
- Diabetes mellitus
In patients receiving bisphosphonates for postmenopausal osteoporosis treatment, the prevalence of jaw osteonecrosis is low, affecting especially the mandible and then the maxilla. Patients are generally female because of the prevalence of osteoporosis after meno/>